1 // x86_64.cc -- x86_64 target support for gold.
2 
3 // Copyright (C) 2006-2021 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5 
6 // This file is part of gold.
7 
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12 
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 // GNU General Public License for more details.
17 
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22 
23 #include "gold.h"
24 
25 #include <cstring>
26 
27 #include "elfcpp.h"
28 #include "dwarf.h"
29 #include "parameters.h"
30 #include "reloc.h"
31 #include "x86_64.h"
32 #include "object.h"
33 #include "symtab.h"
34 #include "layout.h"
35 #include "output.h"
36 #include "copy-relocs.h"
37 #include "target.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
40 #include "tls.h"
41 #include "freebsd.h"
42 #include "nacl.h"
43 #include "gc.h"
44 #include "icf.h"
45 
46 namespace
47 {
48 
49 using namespace gold;
50 
51 // A class to handle the .got.plt section.
52 
53 class Output_data_got_plt_x86_64 : public Output_section_data_build
54 {
55  public:
Output_data_got_plt_x86_64(Layout * layout)56   Output_data_got_plt_x86_64(Layout* layout)
57     : Output_section_data_build(8),
58       layout_(layout)
59   { }
60 
Output_data_got_plt_x86_64(Layout * layout,off_t data_size)61   Output_data_got_plt_x86_64(Layout* layout, off_t data_size)
62     : Output_section_data_build(data_size, 8),
63       layout_(layout)
64   { }
65 
66  protected:
67   // Write out the PLT data.
68   void
69   do_write(Output_file*);
70 
71   // Write to a map file.
72   void
do_print_to_mapfile(Mapfile * mapfile) const73   do_print_to_mapfile(Mapfile* mapfile) const
74   { mapfile->print_output_data(this, "** GOT PLT"); }
75 
76  private:
77   // A pointer to the Layout class, so that we can find the .dynamic
78   // section when we write out the GOT PLT section.
79   Layout* layout_;
80 };
81 
82 // A class to handle the PLT data.
83 // This is an abstract base class that handles most of the linker details
84 // but does not know the actual contents of PLT entries.  The derived
85 // classes below fill in those details.
86 
87 template<int size>
88 class Output_data_plt_x86_64 : public Output_section_data
89 {
90  public:
91   typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
92 
Output_data_plt_x86_64(Layout * layout,uint64_t addralign,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative)93   Output_data_plt_x86_64(Layout* layout, uint64_t addralign,
94 			 Output_data_got<64, false>* got,
95 			 Output_data_got_plt_x86_64* got_plt,
96 			 Output_data_space* got_irelative)
97     : Output_section_data(addralign), tlsdesc_rel_(NULL),
98       irelative_rel_(NULL), got_(got), got_plt_(got_plt),
99       got_irelative_(got_irelative), count_(0), irelative_count_(0),
100       tlsdesc_got_offset_(-1U), free_list_()
101   { this->init(layout); }
102 
Output_data_plt_x86_64(Layout * layout,uint64_t plt_entry_size,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative,unsigned int plt_count)103   Output_data_plt_x86_64(Layout* layout, uint64_t plt_entry_size,
104 			 Output_data_got<64, false>* got,
105 			 Output_data_got_plt_x86_64* got_plt,
106 			 Output_data_space* got_irelative,
107 			 unsigned int plt_count)
108     : Output_section_data((plt_count + 1) * plt_entry_size,
109 			  plt_entry_size, false),
110       tlsdesc_rel_(NULL), irelative_rel_(NULL), got_(got),
111       got_plt_(got_plt), got_irelative_(got_irelative), count_(plt_count),
112       irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_()
113   {
114     this->init(layout);
115 
116     // Initialize the free list and reserve the first entry.
117     this->free_list_.init((plt_count + 1) * plt_entry_size, false);
118     this->free_list_.remove(0, plt_entry_size);
119   }
120 
121   // Initialize the PLT section.
122   void
123   init(Layout* layout);
124 
125   // Add an entry to the PLT.
126   void
127   add_entry(Symbol_table*, Layout*, Symbol* gsym);
128 
129   // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
130   unsigned int
131   add_local_ifunc_entry(Symbol_table* symtab, Layout*,
132 			Sized_relobj_file<size, false>* relobj,
133 			unsigned int local_sym_index);
134 
135   // Add the relocation for a PLT entry.
136   void
137   add_relocation(Symbol_table*, Layout*, Symbol* gsym,
138 		 unsigned int got_offset);
139 
140   // Add the reserved TLSDESC_PLT entry to the PLT.
141   void
reserve_tlsdesc_entry(unsigned int got_offset)142   reserve_tlsdesc_entry(unsigned int got_offset)
143   { this->tlsdesc_got_offset_ = got_offset; }
144 
145   // Return true if a TLSDESC_PLT entry has been reserved.
146   bool
has_tlsdesc_entry() const147   has_tlsdesc_entry() const
148   { return this->tlsdesc_got_offset_ != -1U; }
149 
150   // Return the GOT offset for the reserved TLSDESC_PLT entry.
151   unsigned int
get_tlsdesc_got_offset() const152   get_tlsdesc_got_offset() const
153   { return this->tlsdesc_got_offset_; }
154 
155   // Return the offset of the reserved TLSDESC_PLT entry.
156   unsigned int
get_tlsdesc_plt_offset() const157   get_tlsdesc_plt_offset() const
158   {
159     return ((this->count_ + this->irelative_count_ + 1)
160 	    * this->get_plt_entry_size());
161   }
162 
163   // Return the .rela.plt section data.
164   Reloc_section*
rela_plt()165   rela_plt()
166   { return this->rel_; }
167 
168   // Return where the TLSDESC relocations should go.
169   Reloc_section*
170   rela_tlsdesc(Layout*);
171 
172   // Return where the IRELATIVE relocations should go in the PLT
173   // relocations.
174   Reloc_section*
175   rela_irelative(Symbol_table*, Layout*);
176 
177   // Return whether we created a section for IRELATIVE relocations.
178   bool
has_irelative_section() const179   has_irelative_section() const
180   { return this->irelative_rel_ != NULL; }
181 
182   // Get count of regular PLT entries.
183   unsigned int
regular_count() const184   regular_count() const
185   { return this->count_; }
186 
187   // Return the total number of PLT entries.
188   unsigned int
entry_count() const189   entry_count() const
190   { return this->count_ + this->irelative_count_; }
191 
192   // Return the offset of the first non-reserved PLT entry.
193   unsigned int
first_plt_entry_offset()194   first_plt_entry_offset()
195   { return this->get_plt_entry_size(); }
196 
197   // Return the size of a PLT entry.
198   unsigned int
get_plt_entry_size() const199   get_plt_entry_size() const
200   { return this->do_get_plt_entry_size(); }
201 
202   // Reserve a slot in the PLT for an existing symbol in an incremental update.
203   void
reserve_slot(unsigned int plt_index)204   reserve_slot(unsigned int plt_index)
205   {
206     this->free_list_.remove((plt_index + 1) * this->get_plt_entry_size(),
207 			    (plt_index + 2) * this->get_plt_entry_size());
208   }
209 
210   // Return the PLT address to use for a global symbol.
211   uint64_t
address_for_global(const Symbol * sym)212   address_for_global(const Symbol* sym)
213   { return do_address_for_global(sym); }
214 
215   // Return the PLT address to use for a local symbol.
216   uint64_t
address_for_local(const Relobj * obj,unsigned int symndx)217   address_for_local(const Relobj* obj, unsigned int symndx)
218   { return do_address_for_local(obj, symndx); }
219 
220   // Add .eh_frame information for the PLT.
221   void
add_eh_frame(Layout * layout)222   add_eh_frame(Layout* layout)
223   { this->do_add_eh_frame(layout); }
224 
225  protected:
226   Output_data_got<64, false>*
got() const227   got() const
228   { return this->got_; }
229 
230   Output_data_got_plt_x86_64*
got_plt() const231   got_plt() const
232   { return this->got_plt_; }
233 
234   Output_data_space*
got_irelative() const235   got_irelative() const
236   { return this->got_irelative_; }
237 
238   // Fill in the first PLT entry.
239   void
fill_first_plt_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address)240   fill_first_plt_entry(unsigned char* pov,
241 		       typename elfcpp::Elf_types<size>::Elf_Addr got_address,
242 		       typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
243   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
244 
245   // Fill in a normal PLT entry.  Returns the offset into the entry that
246   // should be the initial GOT slot value.
247   unsigned int
fill_plt_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address,unsigned int got_offset,unsigned int plt_offset,unsigned int plt_index)248   fill_plt_entry(unsigned char* pov,
249 		 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
250 		 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
251 		 unsigned int got_offset,
252 		 unsigned int plt_offset,
253 		 unsigned int plt_index)
254   {
255     return this->do_fill_plt_entry(pov, got_address, plt_address,
256 				   got_offset, plt_offset, plt_index);
257   }
258 
259   // Fill in the reserved TLSDESC PLT entry.
260   void
fill_tlsdesc_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address,typename elfcpp::Elf_types<size>::Elf_Addr got_base,unsigned int tlsdesc_got_offset,unsigned int plt_offset)261   fill_tlsdesc_entry(unsigned char* pov,
262 		     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
263 		     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
264 		     typename elfcpp::Elf_types<size>::Elf_Addr got_base,
265 		     unsigned int tlsdesc_got_offset,
266 		     unsigned int plt_offset)
267   {
268     this->do_fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
269 				tlsdesc_got_offset, plt_offset);
270   }
271 
272   virtual unsigned int
273   do_get_plt_entry_size() const = 0;
274 
275   virtual void
276   do_fill_first_plt_entry(unsigned char* pov,
277 			  typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
278 			  typename elfcpp::Elf_types<size>::Elf_Addr plt_addr)
279     = 0;
280 
281   virtual unsigned int
282   do_fill_plt_entry(unsigned char* pov,
283 		    typename elfcpp::Elf_types<size>::Elf_Addr got_address,
284 		    typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
285 		    unsigned int got_offset,
286 		    unsigned int plt_offset,
287 		    unsigned int plt_index) = 0;
288 
289   virtual void
290   do_fill_tlsdesc_entry(unsigned char* pov,
291 			typename elfcpp::Elf_types<size>::Elf_Addr got_address,
292 			typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
293 			typename elfcpp::Elf_types<size>::Elf_Addr got_base,
294 			unsigned int tlsdesc_got_offset,
295 			unsigned int plt_offset) = 0;
296 
297   // Return the PLT address to use for a global symbol.
298   virtual uint64_t
299   do_address_for_global(const Symbol* sym);
300 
301   // Return the PLT address to use for a local symbol.
302   virtual uint64_t
303   do_address_for_local(const Relobj* obj, unsigned int symndx);
304 
305   virtual void
306   do_add_eh_frame(Layout* layout) = 0;
307 
308   void
309   do_adjust_output_section(Output_section* os);
310 
311   // Write to a map file.
312   void
do_print_to_mapfile(Mapfile * mapfile) const313   do_print_to_mapfile(Mapfile* mapfile) const
314   { mapfile->print_output_data(this, _("** PLT")); }
315 
316   // The CIE of the .eh_frame unwind information for the PLT.
317   static const int plt_eh_frame_cie_size = 16;
318   static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
319 
320  private:
321   // Set the final size.
322   void
323   set_final_data_size();
324 
325   // Write out the PLT data.
326   void
327   do_write(Output_file*);
328 
329   // The reloc section.
330   Reloc_section* rel_;
331   // The TLSDESC relocs, if necessary.  These must follow the regular
332   // PLT relocs.
333   Reloc_section* tlsdesc_rel_;
334   // The IRELATIVE relocs, if necessary.  These must follow the
335   // regular PLT relocations and the TLSDESC relocations.
336   Reloc_section* irelative_rel_;
337   // The .got section.
338   Output_data_got<64, false>* got_;
339   // The .got.plt section.
340   Output_data_got_plt_x86_64* got_plt_;
341   // The part of the .got.plt section used for IRELATIVE relocs.
342   Output_data_space* got_irelative_;
343   // The number of PLT entries.
344   unsigned int count_;
345   // Number of PLT entries with R_X86_64_IRELATIVE relocs.  These
346   // follow the regular PLT entries.
347   unsigned int irelative_count_;
348   // Offset of the reserved TLSDESC_GOT entry when needed.
349   unsigned int tlsdesc_got_offset_;
350   // List of available regions within the section, for incremental
351   // update links.
352   Free_list free_list_;
353 };
354 
355 template<int size>
356 class Output_data_plt_x86_64_standard : public Output_data_plt_x86_64<size>
357 {
358  public:
Output_data_plt_x86_64_standard(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative)359   Output_data_plt_x86_64_standard(Layout* layout,
360 				  Output_data_got<64, false>* got,
361 				  Output_data_got_plt_x86_64* got_plt,
362 				  Output_data_space* got_irelative)
363     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
364 				   got, got_plt, got_irelative)
365   { }
366 
Output_data_plt_x86_64_standard(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative,unsigned int plt_count)367   Output_data_plt_x86_64_standard(Layout* layout,
368 				  Output_data_got<64, false>* got,
369 				  Output_data_got_plt_x86_64* got_plt,
370 				  Output_data_space* got_irelative,
371 				  unsigned int plt_count)
372     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
373 				   got, got_plt, got_irelative,
374 				   plt_count)
375   { }
376 
377  protected:
378   virtual unsigned int
do_get_plt_entry_size() const379   do_get_plt_entry_size() const
380   { return plt_entry_size; }
381 
382   virtual void
do_add_eh_frame(Layout * layout)383   do_add_eh_frame(Layout* layout)
384   {
385     layout->add_eh_frame_for_plt(this,
386 				 this->plt_eh_frame_cie,
387 				 this->plt_eh_frame_cie_size,
388 				 plt_eh_frame_fde,
389 				 plt_eh_frame_fde_size);
390   }
391 
392   virtual void
393   do_fill_first_plt_entry(unsigned char* pov,
394 			  typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
395 			  typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
396 
397   virtual unsigned int
398   do_fill_plt_entry(unsigned char* pov,
399 		    typename elfcpp::Elf_types<size>::Elf_Addr got_address,
400 		    typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
401 		    unsigned int got_offset,
402 		    unsigned int plt_offset,
403 		    unsigned int plt_index);
404 
405   virtual void
406   do_fill_tlsdesc_entry(unsigned char* pov,
407 			typename elfcpp::Elf_types<size>::Elf_Addr got_address,
408 			typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
409 			typename elfcpp::Elf_types<size>::Elf_Addr got_base,
410 			unsigned int tlsdesc_got_offset,
411 			unsigned int plt_offset);
412 
413  private:
414   // The size of an entry in the PLT.
415   static const int plt_entry_size = 16;
416 
417   // The first entry in the PLT.
418   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
419   // procedure linkage table for both programs and shared objects."
420   static const unsigned char first_plt_entry[plt_entry_size];
421 
422   // Other entries in the PLT for an executable.
423   static const unsigned char plt_entry[plt_entry_size];
424 
425   // The reserved TLSDESC entry in the PLT for an executable.
426   static const unsigned char tlsdesc_plt_entry[plt_entry_size];
427 
428   // The .eh_frame unwind information for the PLT.
429   static const int plt_eh_frame_fde_size = 32;
430   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
431 };
432 
433 class Output_data_plt_x86_64_bnd : public Output_data_plt_x86_64<64>
434 {
435  public:
Output_data_plt_x86_64_bnd(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative)436   Output_data_plt_x86_64_bnd(Layout* layout,
437 			     Output_data_got<64, false>* got,
438 			     Output_data_got_plt_x86_64* got_plt,
439 			     Output_data_space* got_irelative)
440     : Output_data_plt_x86_64<64>(layout, plt_entry_size,
441 				 got, got_plt, got_irelative),
442       aplt_offset_(0)
443   { }
444 
Output_data_plt_x86_64_bnd(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative,unsigned int plt_count)445   Output_data_plt_x86_64_bnd(Layout* layout,
446 			     Output_data_got<64, false>* got,
447 			     Output_data_got_plt_x86_64* got_plt,
448 			     Output_data_space* got_irelative,
449 			     unsigned int plt_count)
450     : Output_data_plt_x86_64<64>(layout, plt_entry_size,
451 				 got, got_plt, got_irelative,
452 				 plt_count),
453       aplt_offset_(0)
454   { }
455 
456  protected:
457   virtual unsigned int
do_get_plt_entry_size() const458   do_get_plt_entry_size() const
459   { return plt_entry_size; }
460 
461   // Return the PLT address to use for a global symbol.
462   uint64_t
463   do_address_for_global(const Symbol*);
464 
465   // Return the PLT address to use for a local symbol.
466   uint64_t
467   do_address_for_local(const Relobj*, unsigned int symndx);
468 
469   virtual void
do_add_eh_frame(Layout * layout)470   do_add_eh_frame(Layout* layout)
471   {
472     layout->add_eh_frame_for_plt(this,
473 				 this->plt_eh_frame_cie,
474 				 this->plt_eh_frame_cie_size,
475 				 plt_eh_frame_fde,
476 				 plt_eh_frame_fde_size);
477   }
478 
479   virtual void
480   do_fill_first_plt_entry(unsigned char* pov,
481 			  elfcpp::Elf_types<64>::Elf_Addr got_addr,
482 			  elfcpp::Elf_types<64>::Elf_Addr plt_addr);
483 
484   virtual unsigned int
485   do_fill_plt_entry(unsigned char* pov,
486 		    elfcpp::Elf_types<64>::Elf_Addr got_address,
487 		    elfcpp::Elf_types<64>::Elf_Addr plt_address,
488 		    unsigned int got_offset,
489 		    unsigned int plt_offset,
490 		    unsigned int plt_index);
491 
492   virtual void
493   do_fill_tlsdesc_entry(unsigned char* pov,
494 			elfcpp::Elf_types<64>::Elf_Addr got_address,
495 			elfcpp::Elf_types<64>::Elf_Addr plt_address,
496 			elfcpp::Elf_types<64>::Elf_Addr got_base,
497 			unsigned int tlsdesc_got_offset,
498 			unsigned int plt_offset);
499 
500   void
501   fill_aplt_entry(unsigned char* pov,
502 		  elfcpp::Elf_types<64>::Elf_Addr got_address,
503 		  elfcpp::Elf_types<64>::Elf_Addr plt_address,
504 		  unsigned int got_offset,
505 		  unsigned int plt_offset,
506 		  unsigned int plt_index);
507 
508  private:
509   // Set the final size.
510   void
511   set_final_data_size();
512 
513   // Write out the BND PLT data.
514   void
515   do_write(Output_file*);
516 
517   // Offset of the Additional PLT (if using -z bndplt).
518   unsigned int aplt_offset_;
519 
520   // The size of an entry in the PLT.
521   static const int plt_entry_size = 16;
522 
523   // The size of an entry in the additional PLT.
524   static const int aplt_entry_size = 8;
525 
526   // The first entry in the PLT.
527   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
528   // procedure linkage table for both programs and shared objects."
529   static const unsigned char first_plt_entry[plt_entry_size];
530 
531   // Other entries in the PLT for an executable.
532   static const unsigned char plt_entry[plt_entry_size];
533 
534   // Entries in the additional PLT.
535   static const unsigned char aplt_entry[aplt_entry_size];
536 
537   // The reserved TLSDESC entry in the PLT for an executable.
538   static const unsigned char tlsdesc_plt_entry[plt_entry_size];
539 
540   // The .eh_frame unwind information for the PLT.
541   static const int plt_eh_frame_fde_size = 32;
542   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
543 };
544 
545 // We use this PLT when Indirect Branch Tracking (IBT) is enabled.
546 
547 template <int size>
548 class Output_data_plt_x86_64_ibt : public Output_data_plt_x86_64<size>
549 {
550  public:
Output_data_plt_x86_64_ibt(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative)551   Output_data_plt_x86_64_ibt(Layout* layout,
552 			     Output_data_got<64, false>* got,
553 			     Output_data_got_plt_x86_64* got_plt,
554 			     Output_data_space* got_irelative)
555     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
556 				   got, got_plt, got_irelative),
557       aplt_offset_(0)
558   { }
559 
Output_data_plt_x86_64_ibt(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative,unsigned int plt_count)560   Output_data_plt_x86_64_ibt(Layout* layout,
561 			     Output_data_got<64, false>* got,
562 			     Output_data_got_plt_x86_64* got_plt,
563 			     Output_data_space* got_irelative,
564 			     unsigned int plt_count)
565     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
566 				   got, got_plt, got_irelative,
567 				   plt_count),
568       aplt_offset_(0)
569   { }
570 
571  protected:
572   virtual unsigned int
do_get_plt_entry_size() const573   do_get_plt_entry_size() const
574   { return plt_entry_size; }
575 
576   // Return the PLT address to use for a global symbol.
577   uint64_t
578   do_address_for_global(const Symbol*);
579 
580   // Return the PLT address to use for a local symbol.
581   uint64_t
582   do_address_for_local(const Relobj*, unsigned int symndx);
583 
584   virtual void
do_add_eh_frame(Layout * layout)585   do_add_eh_frame(Layout* layout)
586   {
587     layout->add_eh_frame_for_plt(this,
588 				 this->plt_eh_frame_cie,
589 				 this->plt_eh_frame_cie_size,
590 				 plt_eh_frame_fde,
591 				 plt_eh_frame_fde_size);
592   }
593 
594   virtual void
595   do_fill_first_plt_entry(unsigned char* pov,
596 			  typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
597 			  typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
598 
599   virtual unsigned int
600   do_fill_plt_entry(unsigned char* pov,
601 		    typename elfcpp::Elf_types<size>::Elf_Addr got_address,
602 		    typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
603 		    unsigned int got_offset,
604 		    unsigned int plt_offset,
605 		    unsigned int plt_index);
606 
607   virtual void
608   do_fill_tlsdesc_entry(unsigned char* pov,
609 			typename elfcpp::Elf_types<size>::Elf_Addr got_address,
610 			typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
611 			typename elfcpp::Elf_types<size>::Elf_Addr got_base,
612 			unsigned int tlsdesc_got_offset,
613 			unsigned int plt_offset);
614 
615   void
616   fill_aplt_entry(unsigned char* pov,
617 		  typename elfcpp::Elf_types<size>::Elf_Addr got_address,
618 		  typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
619 		  unsigned int got_offset,
620 		  unsigned int plt_offset,
621 		  unsigned int plt_index);
622 
623  private:
624   // Set the final size.
625   void
626   set_final_data_size();
627 
628   // Write out the BND PLT data.
629   void
630   do_write(Output_file*);
631 
632   // Offset of the Additional PLT (if using -z bndplt).
633   unsigned int aplt_offset_;
634 
635   // The size of an entry in the PLT.
636   static const int plt_entry_size = 16;
637 
638   // The size of an entry in the additional PLT.
639   static const int aplt_entry_size = 16;
640 
641   // The first entry in the PLT.
642   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
643   // procedure linkage table for both programs and shared objects."
644   static const unsigned char first_plt_entry[plt_entry_size];
645 
646   // Other entries in the PLT for an executable.
647   static const unsigned char plt_entry[plt_entry_size];
648 
649   // Entries in the additional PLT.
650   static const unsigned char aplt_entry[aplt_entry_size];
651 
652   // The reserved TLSDESC entry in the PLT for an executable.
653   static const unsigned char tlsdesc_plt_entry[plt_entry_size];
654 
655   // The .eh_frame unwind information for the PLT.
656   static const int plt_eh_frame_fde_size = 32;
657   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
658 };
659 
660 template<int size>
661 class Lazy_view
662 {
663  public:
Lazy_view(Sized_relobj_file<size,false> * object,unsigned int data_shndx)664   Lazy_view(Sized_relobj_file<size, false>* object, unsigned int data_shndx)
665     : object_(object), data_shndx_(data_shndx), view_(NULL), view_size_(0)
666   { }
667 
668   inline unsigned char
operator [](size_t offset)669   operator[](size_t offset)
670   {
671     if (this->view_ == NULL)
672       this->view_ = this->object_->section_contents(this->data_shndx_,
673                                                     &this->view_size_,
674                                                     true);
675     if (offset >= this->view_size_)
676       return 0;
677     return this->view_[offset];
678   }
679 
680  private:
681   Sized_relobj_file<size, false>* object_;
682   unsigned int data_shndx_;
683   const unsigned char* view_;
684   section_size_type view_size_;
685 };
686 
687 // The x86_64 target class.
688 // See the ABI at
689 //   http://www.x86-64.org/documentation/abi.pdf
690 // TLS info comes from
691 //   http://people.redhat.com/drepper/tls.pdf
692 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
693 
694 template<int size>
695 class Target_x86_64 : public Sized_target<size, false>
696 {
697  public:
698   // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
699   // uses only Elf64_Rela relocation entries with explicit addends."
700   typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
701 
Target_x86_64(const Target::Target_info * info=& x86_64_info)702   Target_x86_64(const Target::Target_info* info = &x86_64_info)
703     : Sized_target<size, false>(info),
704       got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
705       got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
706       rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY),
707       got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
708       tls_base_symbol_defined_(false), isa_1_used_(0), isa_1_needed_(0),
709       feature_1_(0), feature_2_used_(0), feature_2_needed_(0),
710       object_isa_1_used_(0), object_feature_1_(0),
711       object_feature_2_used_(0), seen_first_object_(false)
712   { }
713 
714   // Hook for a new output section.
715   void
716   do_new_output_section(Output_section*) const;
717 
718   // Scan the relocations to look for symbol adjustments.
719   void
720   gc_process_relocs(Symbol_table* symtab,
721 		    Layout* layout,
722 		    Sized_relobj_file<size, false>* object,
723 		    unsigned int data_shndx,
724 		    unsigned int sh_type,
725 		    const unsigned char* prelocs,
726 		    size_t reloc_count,
727 		    Output_section* output_section,
728 		    bool needs_special_offset_handling,
729 		    size_t local_symbol_count,
730 		    const unsigned char* plocal_symbols);
731 
732   // Scan the relocations to look for symbol adjustments.
733   void
734   scan_relocs(Symbol_table* symtab,
735 	      Layout* layout,
736 	      Sized_relobj_file<size, false>* object,
737 	      unsigned int data_shndx,
738 	      unsigned int sh_type,
739 	      const unsigned char* prelocs,
740 	      size_t reloc_count,
741 	      Output_section* output_section,
742 	      bool needs_special_offset_handling,
743 	      size_t local_symbol_count,
744 	      const unsigned char* plocal_symbols);
745 
746   // Finalize the sections.
747   void
748   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
749 
750   // Return the value to use for a dynamic which requires special
751   // treatment.
752   uint64_t
753   do_dynsym_value(const Symbol*) const;
754 
755   // Relocate a section.
756   void
757   relocate_section(const Relocate_info<size, false>*,
758 		   unsigned int sh_type,
759 		   const unsigned char* prelocs,
760 		   size_t reloc_count,
761 		   Output_section* output_section,
762 		   bool needs_special_offset_handling,
763 		   unsigned char* view,
764 		   typename elfcpp::Elf_types<size>::Elf_Addr view_address,
765 		   section_size_type view_size,
766 		   const Reloc_symbol_changes*);
767 
768   // Scan the relocs during a relocatable link.
769   void
770   scan_relocatable_relocs(Symbol_table* symtab,
771 			  Layout* layout,
772 			  Sized_relobj_file<size, false>* object,
773 			  unsigned int data_shndx,
774 			  unsigned int sh_type,
775 			  const unsigned char* prelocs,
776 			  size_t reloc_count,
777 			  Output_section* output_section,
778 			  bool needs_special_offset_handling,
779 			  size_t local_symbol_count,
780 			  const unsigned char* plocal_symbols,
781 			  Relocatable_relocs*);
782 
783   // Scan the relocs for --emit-relocs.
784   void
785   emit_relocs_scan(Symbol_table* symtab,
786 		   Layout* layout,
787 		   Sized_relobj_file<size, false>* object,
788 		   unsigned int data_shndx,
789 		   unsigned int sh_type,
790 		   const unsigned char* prelocs,
791 		   size_t reloc_count,
792 		   Output_section* output_section,
793 		   bool needs_special_offset_handling,
794 		   size_t local_symbol_count,
795 		   const unsigned char* plocal_syms,
796 		   Relocatable_relocs* rr);
797 
798   // Emit relocations for a section.
799   void
800   relocate_relocs(
801       const Relocate_info<size, false>*,
802       unsigned int sh_type,
803       const unsigned char* prelocs,
804       size_t reloc_count,
805       Output_section* output_section,
806       typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
807       unsigned char* view,
808       typename elfcpp::Elf_types<size>::Elf_Addr view_address,
809       section_size_type view_size,
810       unsigned char* reloc_view,
811       section_size_type reloc_view_size);
812 
813   // Return a string used to fill a code section with nops.
814   std::string
815   do_code_fill(section_size_type length) const;
816 
817   // Return whether SYM is defined by the ABI.
818   bool
do_is_defined_by_abi(const Symbol * sym) const819   do_is_defined_by_abi(const Symbol* sym) const
820   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
821 
822   // Return the symbol index to use for a target specific relocation.
823   // The only target specific relocation is R_X86_64_TLSDESC for a
824   // local symbol, which is an absolute reloc.
825   unsigned int
do_reloc_symbol_index(void *,unsigned int r_type) const826   do_reloc_symbol_index(void*, unsigned int r_type) const
827   {
828     gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
829     return 0;
830   }
831 
832   // Return the addend to use for a target specific relocation.
833   uint64_t
834   do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
835 
836   // Return the PLT section.
837   uint64_t
do_plt_address_for_global(const Symbol * gsym) const838   do_plt_address_for_global(const Symbol* gsym) const
839   { return this->plt_section()->address_for_global(gsym); }
840 
841   uint64_t
do_plt_address_for_local(const Relobj * relobj,unsigned int symndx) const842   do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
843   { return this->plt_section()->address_for_local(relobj, symndx); }
844 
845   // This function should be defined in targets that can use relocation
846   // types to determine (implemented in local_reloc_may_be_function_pointer
847   // and global_reloc_may_be_function_pointer)
848   // if a function's pointer is taken.  ICF uses this in safe mode to only
849   // fold those functions whose pointer is defintely not taken.  For x86_64
850   // pie binaries, safe ICF cannot be done by looking at only relocation
851   // types, and for certain cases (e.g. R_X86_64_PC32), the instruction
852   // opcode is checked as well to distinguish a function call from taking
853   // a function's pointer.
854   bool
do_can_check_for_function_pointers() const855   do_can_check_for_function_pointers() const
856   { return true; }
857 
858   // Return the base for a DW_EH_PE_datarel encoding.
859   uint64_t
860   do_ehframe_datarel_base() const;
861 
862   // Adjust -fsplit-stack code which calls non-split-stack code.
863   void
864   do_calls_non_split(Relobj* object, unsigned int shndx,
865 		     section_offset_type fnoffset, section_size_type fnsize,
866 		     const unsigned char* prelocs, size_t reloc_count,
867 		     unsigned char* view, section_size_type view_size,
868 		     std::string* from, std::string* to) const;
869 
870   // Return the size of the GOT section.
871   section_size_type
got_size() const872   got_size() const
873   {
874     gold_assert(this->got_ != NULL);
875     return this->got_->data_size();
876   }
877 
878   // Return the number of entries in the GOT.
879   unsigned int
got_entry_count() const880   got_entry_count() const
881   {
882     if (this->got_ == NULL)
883       return 0;
884     return this->got_size() / 8;
885   }
886 
887   // Return the number of entries in the PLT.
888   unsigned int
889   plt_entry_count() const;
890 
891   // Return the offset of the first non-reserved PLT entry.
892   unsigned int
893   first_plt_entry_offset() const;
894 
895   // Return the size of each PLT entry.
896   unsigned int
897   plt_entry_size() const;
898 
899   // Return the size of each GOT entry.
900   unsigned int
got_entry_size() const901   got_entry_size() const
902   { return 8; };
903 
904   // Create the GOT section for an incremental update.
905   Output_data_got_base*
906   init_got_plt_for_update(Symbol_table* symtab,
907 			  Layout* layout,
908 			  unsigned int got_count,
909 			  unsigned int plt_count);
910 
911   // Reserve a GOT entry for a local symbol, and regenerate any
912   // necessary dynamic relocations.
913   void
914   reserve_local_got_entry(unsigned int got_index,
915 			  Sized_relobj<size, false>* obj,
916 			  unsigned int r_sym,
917 			  unsigned int got_type);
918 
919   // Reserve a GOT entry for a global symbol, and regenerate any
920   // necessary dynamic relocations.
921   void
922   reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
923 			   unsigned int got_type);
924 
925   // Register an existing PLT entry for a global symbol.
926   void
927   register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
928 			    Symbol* gsym);
929 
930   // Force a COPY relocation for a given symbol.
931   void
932   emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
933 
934   // Apply an incremental relocation.
935   void
936   apply_relocation(const Relocate_info<size, false>* relinfo,
937 		   typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
938 		   unsigned int r_type,
939 		   typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
940 		   const Symbol* gsym,
941 		   unsigned char* view,
942 		   typename elfcpp::Elf_types<size>::Elf_Addr address,
943 		   section_size_type view_size);
944 
945   // Add a new reloc argument, returning the index in the vector.
946   size_t
add_tlsdesc_info(Sized_relobj_file<size,false> * object,unsigned int r_sym)947   add_tlsdesc_info(Sized_relobj_file<size, false>* object, unsigned int r_sym)
948   {
949     this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
950     return this->tlsdesc_reloc_info_.size() - 1;
951   }
952 
953   Output_data_plt_x86_64<size>*
make_data_plt(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative)954   make_data_plt(Layout* layout,
955 		Output_data_got<64, false>* got,
956 		Output_data_got_plt_x86_64* got_plt,
957 		Output_data_space* got_irelative)
958   {
959     return this->do_make_data_plt(layout, got, got_plt, got_irelative);
960   }
961 
962   Output_data_plt_x86_64<size>*
make_data_plt(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative,unsigned int plt_count)963   make_data_plt(Layout* layout,
964 		Output_data_got<64, false>* got,
965 		Output_data_got_plt_x86_64* got_plt,
966 		Output_data_space* got_irelative,
967 		unsigned int plt_count)
968   {
969     return this->do_make_data_plt(layout, got, got_plt, got_irelative,
970 				  plt_count);
971   }
972 
973   virtual Output_data_plt_x86_64<size>*
974   do_make_data_plt(Layout* layout,
975 		   Output_data_got<64, false>* got,
976 		   Output_data_got_plt_x86_64* got_plt,
977 		   Output_data_space* got_irelative);
978 
979   virtual Output_data_plt_x86_64<size>*
980   do_make_data_plt(Layout* layout,
981 		   Output_data_got<64, false>* got,
982 		   Output_data_got_plt_x86_64* got_plt,
983 		   Output_data_space* got_irelative,
984 		   unsigned int plt_count);
985 
986  private:
987   // The class which scans relocations.
988   class Scan
989   {
990   public:
Scan()991     Scan()
992       : issued_non_pic_error_(false)
993     { }
994 
995     static inline int
996     get_reference_flags(unsigned int r_type);
997 
998     inline void
999     local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
1000 	  Sized_relobj_file<size, false>* object,
1001 	  unsigned int data_shndx,
1002 	  Output_section* output_section,
1003 	  const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
1004 	  const elfcpp::Sym<size, false>& lsym,
1005 	  bool is_discarded);
1006 
1007     inline void
1008     global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
1009 	   Sized_relobj_file<size, false>* object,
1010 	   unsigned int data_shndx,
1011 	   Output_section* output_section,
1012 	   const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
1013 	   Symbol* gsym);
1014 
1015     inline bool
1016     local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
1017 					Target_x86_64* target,
1018 					Sized_relobj_file<size, false>* object,
1019 					unsigned int data_shndx,
1020 					Output_section* output_section,
1021 					const elfcpp::Rela<size, false>& reloc,
1022 					unsigned int r_type,
1023 					const elfcpp::Sym<size, false>& lsym);
1024 
1025     inline bool
1026     global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
1027 					 Target_x86_64* target,
1028 					 Sized_relobj_file<size, false>* object,
1029 					 unsigned int data_shndx,
1030 					 Output_section* output_section,
1031 					 const elfcpp::Rela<size, false>& reloc,
1032 					 unsigned int r_type,
1033 					 Symbol* gsym);
1034 
1035   private:
1036     static void
1037     unsupported_reloc_local(Sized_relobj_file<size, false>*,
1038 			    unsigned int r_type);
1039 
1040     static void
1041     unsupported_reloc_global(Sized_relobj_file<size, false>*,
1042 			     unsigned int r_type, Symbol*);
1043 
1044     void
1045     check_non_pic(Relobj*, unsigned int r_type, Symbol*);
1046 
1047     inline bool
1048     possible_function_pointer_reloc(Sized_relobj_file<size, false>* src_obj,
1049                                     unsigned int src_indx,
1050                                     unsigned int r_offset,
1051                                     unsigned int r_type);
1052 
1053     bool
1054     reloc_needs_plt_for_ifunc(Sized_relobj_file<size, false>*,
1055 			      unsigned int r_type);
1056 
1057     // Whether we have issued an error about a non-PIC compilation.
1058     bool issued_non_pic_error_;
1059   };
1060 
1061   // The class which implements relocation.
1062   class Relocate
1063   {
1064    public:
Relocate()1065     Relocate()
1066       : skip_call_tls_get_addr_(false)
1067     { }
1068 
~Relocate()1069     ~Relocate()
1070     {
1071       if (this->skip_call_tls_get_addr_)
1072 	{
1073 	  // FIXME: This needs to specify the location somehow.
1074 	  gold_error(_("missing expected TLS relocation"));
1075 	}
1076     }
1077 
1078     // Do a relocation.  Return false if the caller should not issue
1079     // any warnings about this relocation.
1080     inline bool
1081     relocate(const Relocate_info<size, false>*, unsigned int,
1082 	     Target_x86_64*, Output_section*, size_t, const unsigned char*,
1083 	     const Sized_symbol<size>*, const Symbol_value<size>*,
1084 	     unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
1085 	     section_size_type);
1086 
1087    private:
1088     // Do a TLS relocation.
1089     inline void
1090     relocate_tls(const Relocate_info<size, false>*, Target_x86_64*,
1091 		 size_t relnum, const elfcpp::Rela<size, false>&,
1092 		 unsigned int r_type, const Sized_symbol<size>*,
1093 		 const Symbol_value<size>*,
1094 		 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
1095 		 section_size_type);
1096 
1097     // Do a TLS General-Dynamic to Initial-Exec transition.
1098     inline void
1099     tls_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
1100 		 const elfcpp::Rela<size, false>&, unsigned int r_type,
1101 		 typename elfcpp::Elf_types<size>::Elf_Addr value,
1102 		 unsigned char* view,
1103 		 typename elfcpp::Elf_types<size>::Elf_Addr,
1104 		 section_size_type view_size);
1105 
1106     // Do a TLS General-Dynamic to Local-Exec transition.
1107     inline void
1108     tls_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
1109 		 Output_segment* tls_segment,
1110 		 const elfcpp::Rela<size, false>&, unsigned int r_type,
1111 		 typename elfcpp::Elf_types<size>::Elf_Addr value,
1112 		 unsigned char* view,
1113 		 section_size_type view_size);
1114 
1115     // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
1116     inline void
1117     tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
1118 		      const elfcpp::Rela<size, false>&, unsigned int r_type,
1119 		      typename elfcpp::Elf_types<size>::Elf_Addr value,
1120 		      unsigned char* view,
1121 		      typename elfcpp::Elf_types<size>::Elf_Addr,
1122 		      section_size_type view_size);
1123 
1124     // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
1125     inline void
1126     tls_desc_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
1127 		      Output_segment* tls_segment,
1128 		      const elfcpp::Rela<size, false>&, unsigned int r_type,
1129 		      typename elfcpp::Elf_types<size>::Elf_Addr value,
1130 		      unsigned char* view,
1131 		      section_size_type view_size);
1132 
1133     // Do a TLS Local-Dynamic to Local-Exec transition.
1134     inline void
1135     tls_ld_to_le(const Relocate_info<size, false>*, size_t relnum,
1136 		 Output_segment* tls_segment,
1137 		 const elfcpp::Rela<size, false>&, unsigned int r_type,
1138 		 typename elfcpp::Elf_types<size>::Elf_Addr value,
1139 		 unsigned char* view,
1140 		 section_size_type view_size);
1141 
1142     // Do a TLS Initial-Exec to Local-Exec transition.
1143     static inline void
1144     tls_ie_to_le(const Relocate_info<size, false>*, size_t relnum,
1145 		 Output_segment* tls_segment,
1146 		 const elfcpp::Rela<size, false>&, unsigned int r_type,
1147 		 typename elfcpp::Elf_types<size>::Elf_Addr value,
1148 		 unsigned char* view,
1149 		 section_size_type view_size);
1150 
1151     // This is set if we should skip the next reloc, which should be a
1152     // PLT32 reloc against ___tls_get_addr.
1153     bool skip_call_tls_get_addr_;
1154   };
1155 
1156   // Check if relocation against this symbol is a candidate for
1157   // conversion from
1158   // mov foo@GOTPCREL(%rip), %reg
1159   // to lea foo(%rip), %reg.
1160   template<class View_type>
1161   static inline bool
can_convert_mov_to_lea(const Symbol * gsym,unsigned int r_type,size_t r_offset,View_type * view)1162   can_convert_mov_to_lea(const Symbol* gsym, unsigned int r_type,
1163                          size_t r_offset, View_type* view)
1164   {
1165     gold_assert(gsym != NULL);
1166     // We cannot do the conversion unless it's one of these relocations.
1167     if (r_type != elfcpp::R_X86_64_GOTPCREL
1168         && r_type != elfcpp::R_X86_64_GOTPCRELX
1169         && r_type != elfcpp::R_X86_64_REX_GOTPCRELX)
1170       return false;
1171     // We cannot convert references to IFUNC symbols, or to symbols that
1172     // are not local to the current module.
1173     // We can't do predefined symbols because they may become undefined
1174     // (e.g., __ehdr_start when the headers aren't mapped to a segment).
1175     if (gsym->type() == elfcpp::STT_GNU_IFUNC
1176         || gsym->is_undefined()
1177         || gsym->is_predefined()
1178         || gsym->is_from_dynobj()
1179         || gsym->is_preemptible())
1180       return false;
1181     // If we are building a shared object and the symbol is protected, we may
1182     // need to go through the GOT.
1183     if (parameters->options().shared()
1184         && gsym->visibility() == elfcpp::STV_PROTECTED)
1185       return false;
1186     // We cannot convert references to the _DYNAMIC symbol.
1187     if (strcmp(gsym->name(), "_DYNAMIC") == 0)
1188       return false;
1189     // Check for a MOV opcode.
1190     return (*view)[r_offset - 2] == 0x8b;
1191   }
1192 
1193   // Convert
1194   // callq *foo@GOTPCRELX(%rip) to
1195   // addr32 callq foo
1196   // and jmpq *foo@GOTPCRELX(%rip) to
1197   // jmpq foo
1198   // nop
1199   template<class View_type>
1200   static inline bool
can_convert_callq_to_direct(const Symbol * gsym,unsigned int r_type,size_t r_offset,View_type * view)1201   can_convert_callq_to_direct(const Symbol* gsym, unsigned int r_type,
1202 			      size_t r_offset, View_type* view)
1203   {
1204     gold_assert(gsym != NULL);
1205     // We cannot do the conversion unless it's a GOTPCRELX relocation.
1206     if (r_type != elfcpp::R_X86_64_GOTPCRELX)
1207       return false;
1208     // We cannot convert references to IFUNC symbols, or to symbols that
1209     // are not local to the current module.
1210     if (gsym->type() == elfcpp::STT_GNU_IFUNC
1211         || gsym->is_undefined ()
1212         || gsym->is_from_dynobj()
1213         || gsym->is_preemptible())
1214       return false;
1215     // Check for a CALLQ or JMPQ opcode.
1216     return ((*view)[r_offset - 2] == 0xff
1217             && ((*view)[r_offset - 1] == 0x15
1218                 || (*view)[r_offset - 1] == 0x25));
1219   }
1220 
1221   // Adjust TLS relocation type based on the options and whether this
1222   // is a local symbol.
1223   static tls::Tls_optimization
1224   optimize_tls_reloc(bool is_final, int r_type);
1225 
1226   // Get the GOT section, creating it if necessary.
1227   Output_data_got<64, false>*
1228   got_section(Symbol_table*, Layout*);
1229 
1230   // Get the GOT PLT section.
1231   Output_data_got_plt_x86_64*
got_plt_section() const1232   got_plt_section() const
1233   {
1234     gold_assert(this->got_plt_ != NULL);
1235     return this->got_plt_;
1236   }
1237 
1238   // Get the GOT section for TLSDESC entries.
1239   Output_data_got<64, false>*
got_tlsdesc_section() const1240   got_tlsdesc_section() const
1241   {
1242     gold_assert(this->got_tlsdesc_ != NULL);
1243     return this->got_tlsdesc_;
1244   }
1245 
1246   // Create the PLT section.
1247   void
1248   make_plt_section(Symbol_table* symtab, Layout* layout);
1249 
1250   // Create a PLT entry for a global symbol.
1251   void
1252   make_plt_entry(Symbol_table*, Layout*, Symbol*);
1253 
1254   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
1255   void
1256   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
1257 			     Sized_relobj_file<size, false>* relobj,
1258 			     unsigned int local_sym_index);
1259 
1260   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1261   void
1262   define_tls_base_symbol(Symbol_table*, Layout*);
1263 
1264   // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1265   void
1266   reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
1267 
1268   // Create a GOT entry for the TLS module index.
1269   unsigned int
1270   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1271 		      Sized_relobj_file<size, false>* object);
1272 
1273   // Get the PLT section.
1274   Output_data_plt_x86_64<size>*
plt_section() const1275   plt_section() const
1276   {
1277     gold_assert(this->plt_ != NULL);
1278     return this->plt_;
1279   }
1280 
1281   // Get the dynamic reloc section, creating it if necessary.
1282   Reloc_section*
1283   rela_dyn_section(Layout*);
1284 
1285   // Get the section to use for TLSDESC relocations.
1286   Reloc_section*
1287   rela_tlsdesc_section(Layout*) const;
1288 
1289   // Get the section to use for IRELATIVE relocations.
1290   Reloc_section*
1291   rela_irelative_section(Layout*);
1292 
1293   // Add a potential copy relocation.
1294   void
copy_reloc(Symbol_table * symtab,Layout * layout,Sized_relobj_file<size,false> * object,unsigned int shndx,Output_section * output_section,Symbol * sym,const elfcpp::Rela<size,false> & reloc)1295   copy_reloc(Symbol_table* symtab, Layout* layout,
1296 	     Sized_relobj_file<size, false>* object,
1297 	     unsigned int shndx, Output_section* output_section,
1298 	     Symbol* sym, const elfcpp::Rela<size, false>& reloc)
1299   {
1300     unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
1301     this->copy_relocs_.copy_reloc(symtab, layout,
1302 				  symtab->get_sized_symbol<size>(sym),
1303 				  object, shndx, output_section,
1304 				  r_type, reloc.get_r_offset(),
1305 				  reloc.get_r_addend(),
1306 				  this->rela_dyn_section(layout));
1307   }
1308 
1309   // Record a target-specific program property in the .note.gnu.property
1310   // section.
1311   void
1312   record_gnu_property(unsigned int, unsigned int, size_t,
1313 		      const unsigned char*, const Object*);
1314 
1315   // Merge the target-specific program properties from the current object.
1316   void
1317   merge_gnu_properties(const Object*);
1318 
1319   // Finalize the target-specific program properties and add them back to
1320   // the layout.
1321   void
1322   do_finalize_gnu_properties(Layout*) const;
1323 
1324   // Information about this specific target which we pass to the
1325   // general Target structure.
1326   static const Target::Target_info x86_64_info;
1327 
1328   // The types of GOT entries needed for this platform.
1329   // These values are exposed to the ABI in an incremental link.
1330   // Do not renumber existing values without changing the version
1331   // number of the .gnu_incremental_inputs section.
1332   enum Got_type
1333   {
1334     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
1335     GOT_TYPE_TLS_OFFSET = 1,    // GOT entry for TLS offset
1336     GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
1337     GOT_TYPE_TLS_DESC = 3       // GOT entry for TLS_DESC pair
1338   };
1339 
1340   // This type is used as the argument to the target specific
1341   // relocation routines.  The only target specific reloc is
1342   // R_X86_64_TLSDESC against a local symbol.
1343   struct Tlsdesc_info
1344   {
Tlsdesc_info__anonb2db37100111::Target_x86_64::Tlsdesc_info1345     Tlsdesc_info(Sized_relobj_file<size, false>* a_object, unsigned int a_r_sym)
1346       : object(a_object), r_sym(a_r_sym)
1347     { }
1348 
1349     // The object in which the local symbol is defined.
1350     Sized_relobj_file<size, false>* object;
1351     // The local symbol index in the object.
1352     unsigned int r_sym;
1353   };
1354 
1355   // The GOT section.
1356   Output_data_got<64, false>* got_;
1357   // The PLT section.
1358   Output_data_plt_x86_64<size>* plt_;
1359   // The GOT PLT section.
1360   Output_data_got_plt_x86_64* got_plt_;
1361   // The GOT section for IRELATIVE relocations.
1362   Output_data_space* got_irelative_;
1363   // The GOT section for TLSDESC relocations.
1364   Output_data_got<64, false>* got_tlsdesc_;
1365   // The _GLOBAL_OFFSET_TABLE_ symbol.
1366   Symbol* global_offset_table_;
1367   // The dynamic reloc section.
1368   Reloc_section* rela_dyn_;
1369   // The section to use for IRELATIVE relocs.
1370   Reloc_section* rela_irelative_;
1371   // Relocs saved to avoid a COPY reloc.
1372   Copy_relocs<elfcpp::SHT_RELA, size, false> copy_relocs_;
1373   // Offset of the GOT entry for the TLS module index.
1374   unsigned int got_mod_index_offset_;
1375   // We handle R_X86_64_TLSDESC against a local symbol as a target
1376   // specific relocation.  Here we store the object and local symbol
1377   // index for the relocation.
1378   std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
1379   // True if the _TLS_MODULE_BASE_ symbol has been defined.
1380   bool tls_base_symbol_defined_;
1381   // Target-specific program properties, from .note.gnu.property section.
1382   // Each bit represents a specific feature.
1383   uint32_t isa_1_used_;
1384   uint32_t isa_1_needed_;
1385   uint32_t feature_1_;
1386   uint32_t feature_2_used_;
1387   uint32_t feature_2_needed_;
1388   // Target-specific properties from the current object.
1389   // These bits get ORed into ISA_1_USED_ after all properties for the object
1390   // have been processed. But if either is all zeroes (as when the property
1391   // is absent from an object), the result should be all zeroes.
1392   // (See PR ld/23486.)
1393   uint32_t object_isa_1_used_;
1394   // These bits get ANDed into FEATURE_1_ after all properties for the object
1395   // have been processed.
1396   uint32_t object_feature_1_;
1397   uint32_t object_feature_2_used_;
1398   // Whether we have seen our first object, for use in initializing FEATURE_1_.
1399   bool seen_first_object_;
1400 };
1401 
1402 template<>
1403 const Target::Target_info Target_x86_64<64>::x86_64_info =
1404 {
1405   64,			// size
1406   false,		// is_big_endian
1407   elfcpp::EM_X86_64,	// machine_code
1408   false,		// has_make_symbol
1409   false,		// has_resolve
1410   true,			// has_code_fill
1411   true,			// is_default_stack_executable
1412   true,			// can_icf_inline_merge_sections
1413   '\0',			// wrap_char
1414   "/lib/ld64.so.1",     // program interpreter
1415   0x400000,		// default_text_segment_address
1416   0x1000,		// abi_pagesize (overridable by -z max-page-size)
1417   0x1000,		// common_pagesize (overridable by -z common-page-size)
1418   false,                // isolate_execinstr
1419   0,                    // rosegment_gap
1420   elfcpp::SHN_UNDEF,	// small_common_shndx
1421   elfcpp::SHN_X86_64_LCOMMON,	// large_common_shndx
1422   0,			// small_common_section_flags
1423   elfcpp::SHF_X86_64_LARGE,	// large_common_section_flags
1424   NULL,			// attributes_section
1425   NULL,			// attributes_vendor
1426   "_start",		// entry_symbol_name
1427   32,			// hash_entry_size
1428   elfcpp::SHT_X86_64_UNWIND,	// unwind_section_type
1429 };
1430 
1431 template<>
1432 const Target::Target_info Target_x86_64<32>::x86_64_info =
1433 {
1434   32,			// size
1435   false,		// is_big_endian
1436   elfcpp::EM_X86_64,	// machine_code
1437   false,		// has_make_symbol
1438   false,		// has_resolve
1439   true,			// has_code_fill
1440   true,			// is_default_stack_executable
1441   true,			// can_icf_inline_merge_sections
1442   '\0',			// wrap_char
1443   "/libx32/ldx32.so.1", // program interpreter
1444   0x400000,		// default_text_segment_address
1445   0x1000,		// abi_pagesize (overridable by -z max-page-size)
1446   0x1000,		// common_pagesize (overridable by -z common-page-size)
1447   false,                // isolate_execinstr
1448   0,                    // rosegment_gap
1449   elfcpp::SHN_UNDEF,	// small_common_shndx
1450   elfcpp::SHN_X86_64_LCOMMON,	// large_common_shndx
1451   0,			// small_common_section_flags
1452   elfcpp::SHF_X86_64_LARGE,	// large_common_section_flags
1453   NULL,			// attributes_section
1454   NULL,			// attributes_vendor
1455   "_start",		// entry_symbol_name
1456   32,			// hash_entry_size
1457   elfcpp::SHT_X86_64_UNWIND,	// unwind_section_type
1458 };
1459 
1460 // This is called when a new output section is created.  This is where
1461 // we handle the SHF_X86_64_LARGE.
1462 
1463 template<int size>
1464 void
do_new_output_section(Output_section * os) const1465 Target_x86_64<size>::do_new_output_section(Output_section* os) const
1466 {
1467   if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
1468     os->set_is_large_section();
1469 }
1470 
1471 // Get the GOT section, creating it if necessary.
1472 
1473 template<int size>
1474 Output_data_got<64, false>*
got_section(Symbol_table * symtab,Layout * layout)1475 Target_x86_64<size>::got_section(Symbol_table* symtab, Layout* layout)
1476 {
1477   if (this->got_ == NULL)
1478     {
1479       gold_assert(symtab != NULL && layout != NULL);
1480 
1481       // When using -z now, we can treat .got.plt as a relro section.
1482       // Without -z now, it is modified after program startup by lazy
1483       // PLT relocations.
1484       bool is_got_plt_relro = parameters->options().now();
1485       Output_section_order got_order = (is_got_plt_relro
1486 					? ORDER_RELRO
1487 					: ORDER_RELRO_LAST);
1488       Output_section_order got_plt_order = (is_got_plt_relro
1489 					    ? ORDER_RELRO
1490 					    : ORDER_NON_RELRO_FIRST);
1491 
1492       this->got_ = new Output_data_got<64, false>();
1493 
1494       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1495 				      (elfcpp::SHF_ALLOC
1496 				       | elfcpp::SHF_WRITE),
1497 				      this->got_, got_order, true);
1498 
1499       this->got_plt_ = new Output_data_got_plt_x86_64(layout);
1500       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1501 				      (elfcpp::SHF_ALLOC
1502 				       | elfcpp::SHF_WRITE),
1503 				      this->got_plt_, got_plt_order,
1504 				      is_got_plt_relro);
1505 
1506       // The first three entries are reserved.
1507       this->got_plt_->set_current_data_size(3 * 8);
1508 
1509       if (!is_got_plt_relro)
1510 	{
1511 	  // Those bytes can go into the relro segment.
1512 	  layout->increase_relro(3 * 8);
1513 	}
1514 
1515       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1516       this->global_offset_table_ =
1517 	symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1518 				      Symbol_table::PREDEFINED,
1519 				      this->got_plt_,
1520 				      0, 0, elfcpp::STT_OBJECT,
1521 				      elfcpp::STB_LOCAL,
1522 				      elfcpp::STV_HIDDEN, 0,
1523 				      false, false);
1524 
1525       // If there are any IRELATIVE relocations, they get GOT entries
1526       // in .got.plt after the jump slot entries.
1527       this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
1528       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1529 				      (elfcpp::SHF_ALLOC
1530 				       | elfcpp::SHF_WRITE),
1531 				      this->got_irelative_,
1532 				      got_plt_order, is_got_plt_relro);
1533 
1534       // If there are any TLSDESC relocations, they get GOT entries in
1535       // .got.plt after the jump slot and IRELATIVE entries.
1536       this->got_tlsdesc_ = new Output_data_got<64, false>();
1537       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1538 				      (elfcpp::SHF_ALLOC
1539 				       | elfcpp::SHF_WRITE),
1540 				      this->got_tlsdesc_,
1541 				      got_plt_order, is_got_plt_relro);
1542     }
1543 
1544   return this->got_;
1545 }
1546 
1547 // Get the dynamic reloc section, creating it if necessary.
1548 
1549 template<int size>
1550 typename Target_x86_64<size>::Reloc_section*
rela_dyn_section(Layout * layout)1551 Target_x86_64<size>::rela_dyn_section(Layout* layout)
1552 {
1553   if (this->rela_dyn_ == NULL)
1554     {
1555       gold_assert(layout != NULL);
1556       this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
1557       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1558 				      elfcpp::SHF_ALLOC, this->rela_dyn_,
1559 				      ORDER_DYNAMIC_RELOCS, false);
1560     }
1561   return this->rela_dyn_;
1562 }
1563 
1564 // Get the section to use for IRELATIVE relocs, creating it if
1565 // necessary.  These go in .rela.dyn, but only after all other dynamic
1566 // relocations.  They need to follow the other dynamic relocations so
1567 // that they can refer to global variables initialized by those
1568 // relocs.
1569 
1570 template<int size>
1571 typename Target_x86_64<size>::Reloc_section*
rela_irelative_section(Layout * layout)1572 Target_x86_64<size>::rela_irelative_section(Layout* layout)
1573 {
1574   if (this->rela_irelative_ == NULL)
1575     {
1576       // Make sure we have already created the dynamic reloc section.
1577       this->rela_dyn_section(layout);
1578       this->rela_irelative_ = new Reloc_section(false);
1579       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1580 				      elfcpp::SHF_ALLOC, this->rela_irelative_,
1581 				      ORDER_DYNAMIC_RELOCS, false);
1582       gold_assert(this->rela_dyn_->output_section()
1583 		  == this->rela_irelative_->output_section());
1584     }
1585   return this->rela_irelative_;
1586 }
1587 
1588 // Record a target-specific program property from the .note.gnu.property
1589 // section.
1590 template<int size>
1591 void
record_gnu_property(unsigned int,unsigned int pr_type,size_t pr_datasz,const unsigned char * pr_data,const Object * object)1592 Target_x86_64<size>::record_gnu_property(
1593     unsigned int, unsigned int pr_type,
1594     size_t pr_datasz, const unsigned char* pr_data,
1595     const Object* object)
1596 {
1597   uint32_t val = 0;
1598 
1599   switch (pr_type)
1600     {
1601     case elfcpp::GNU_PROPERTY_X86_COMPAT_ISA_1_USED:
1602     case elfcpp::GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED:
1603     case elfcpp::GNU_PROPERTY_X86_COMPAT_2_ISA_1_USED:
1604     case elfcpp::GNU_PROPERTY_X86_COMPAT_2_ISA_1_NEEDED:
1605     case elfcpp::GNU_PROPERTY_X86_ISA_1_USED:
1606     case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED:
1607     case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND:
1608     case elfcpp::GNU_PROPERTY_X86_FEATURE_2_USED:
1609     case elfcpp::GNU_PROPERTY_X86_FEATURE_2_NEEDED:
1610       if (pr_datasz != 4)
1611 	{
1612 	  gold_warning(_("%s: corrupt .note.gnu.property section "
1613 			 "(pr_datasz for property %d is not 4)"),
1614 		       object->name().c_str(), pr_type);
1615 	  return;
1616 	}
1617       val = elfcpp::Swap<32, false>::readval(pr_data);
1618       break;
1619     default:
1620       gold_warning(_("%s: unknown program property type 0x%x "
1621 		     "in .note.gnu.property section"),
1622 		   object->name().c_str(), pr_type);
1623       break;
1624     }
1625 
1626   switch (pr_type)
1627     {
1628     case elfcpp::GNU_PROPERTY_X86_ISA_1_USED:
1629       this->object_isa_1_used_ |= val;
1630       break;
1631     case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED:
1632       this->isa_1_needed_ |= val;
1633       break;
1634     case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND:
1635       // If we see multiple feature props in one object, OR them together.
1636       this->object_feature_1_ |= val;
1637       break;
1638     case elfcpp::GNU_PROPERTY_X86_FEATURE_2_USED:
1639       this->object_feature_2_used_ |= val;
1640       break;
1641     case elfcpp::GNU_PROPERTY_X86_FEATURE_2_NEEDED:
1642       this->feature_2_needed_ |= val;
1643       break;
1644     }
1645 }
1646 
1647 // Merge the target-specific program properties from the current object.
1648 template<int size>
1649 void
merge_gnu_properties(const Object *)1650 Target_x86_64<size>::merge_gnu_properties(const Object*)
1651 {
1652   if (this->seen_first_object_)
1653     {
1654       // If any object is missing the ISA_1_USED property, we must omit
1655       // it from the output file.
1656       if (this->object_isa_1_used_ == 0)
1657 	this->isa_1_used_ = 0;
1658       else if (this->isa_1_used_ != 0)
1659 	this->isa_1_used_ |= this->object_isa_1_used_;
1660       this->feature_1_ &= this->object_feature_1_;
1661       // If any object is missing the FEATURE_2_USED property, we must
1662       // omit it from the output file.
1663       if (this->object_feature_2_used_ == 0)
1664 	this->feature_2_used_ = 0;
1665       else if (this->feature_2_used_ != 0)
1666 	this->feature_2_used_ |= this->object_feature_2_used_;
1667     }
1668   else
1669     {
1670       this->isa_1_used_ = this->object_isa_1_used_;
1671       this->feature_1_ = this->object_feature_1_;
1672       this->feature_2_used_ = this->object_feature_2_used_;
1673       this->seen_first_object_ = true;
1674     }
1675   this->object_isa_1_used_ = 0;
1676   this->object_feature_1_ = 0;
1677   this->object_feature_2_used_ = 0;
1678 }
1679 
1680 static inline void
add_property(Layout * layout,unsigned int pr_type,uint32_t val)1681 add_property(Layout* layout, unsigned int pr_type, uint32_t val)
1682 {
1683   unsigned char buf[4];
1684   elfcpp::Swap<32, false>::writeval(buf, val);
1685   layout->add_gnu_property(elfcpp::NT_GNU_PROPERTY_TYPE_0, pr_type, 4, buf);
1686 }
1687 
1688 // Finalize the target-specific program properties and add them back to
1689 // the layout.
1690 template<int size>
1691 void
do_finalize_gnu_properties(Layout * layout) const1692 Target_x86_64<size>::do_finalize_gnu_properties(Layout* layout) const
1693 {
1694   if (this->isa_1_used_ != 0)
1695     add_property(layout, elfcpp::GNU_PROPERTY_X86_ISA_1_USED,
1696 		 this->isa_1_used_);
1697   if (this->isa_1_needed_ != 0)
1698     add_property(layout, elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED,
1699 		 this->isa_1_needed_);
1700   if (this->feature_1_ != 0)
1701     add_property(layout, elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND,
1702 		 this->feature_1_);
1703   if (this->feature_2_used_ != 0)
1704     add_property(layout, elfcpp::GNU_PROPERTY_X86_FEATURE_2_USED,
1705 		 this->feature_2_used_);
1706   if (this->feature_2_needed_ != 0)
1707     add_property(layout, elfcpp::GNU_PROPERTY_X86_FEATURE_2_NEEDED,
1708 		 this->feature_2_needed_);
1709 }
1710 
1711 // Write the first three reserved words of the .got.plt section.
1712 // The remainder of the section is written while writing the PLT
1713 // in Output_data_plt_i386::do_write.
1714 
1715 void
do_write(Output_file * of)1716 Output_data_got_plt_x86_64::do_write(Output_file* of)
1717 {
1718   // The first entry in the GOT is the address of the .dynamic section
1719   // aka the PT_DYNAMIC segment.  The next two entries are reserved.
1720   // We saved space for them when we created the section in
1721   // Target_x86_64::got_section.
1722   const off_t got_file_offset = this->offset();
1723   gold_assert(this->data_size() >= 24);
1724   unsigned char* const got_view = of->get_output_view(got_file_offset, 24);
1725   Output_section* dynamic = this->layout_->dynamic_section();
1726   uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1727   elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr);
1728   memset(got_view + 8, 0, 16);
1729   of->write_output_view(got_file_offset, 24, got_view);
1730 }
1731 
1732 // Initialize the PLT section.
1733 
1734 template<int size>
1735 void
init(Layout * layout)1736 Output_data_plt_x86_64<size>::init(Layout* layout)
1737 {
1738   this->rel_ = new Reloc_section(false);
1739   layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1740 				  elfcpp::SHF_ALLOC, this->rel_,
1741 				  ORDER_DYNAMIC_PLT_RELOCS, false);
1742 }
1743 
1744 template<int size>
1745 void
do_adjust_output_section(Output_section * os)1746 Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
1747 {
1748   os->set_entsize(this->get_plt_entry_size());
1749 }
1750 
1751 // Add an entry to the PLT.
1752 
1753 template<int size>
1754 void
add_entry(Symbol_table * symtab,Layout * layout,Symbol * gsym)1755 Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
1756 					Symbol* gsym)
1757 {
1758   gold_assert(!gsym->has_plt_offset());
1759 
1760   unsigned int plt_index;
1761   off_t plt_offset;
1762   section_offset_type got_offset;
1763 
1764   unsigned int* pcount;
1765   unsigned int offset;
1766   unsigned int reserved;
1767   Output_section_data_build* got;
1768   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1769       && gsym->can_use_relative_reloc(false))
1770     {
1771       pcount = &this->irelative_count_;
1772       offset = 0;
1773       reserved = 0;
1774       got = this->got_irelative_;
1775     }
1776   else
1777     {
1778       pcount = &this->count_;
1779       offset = 1;
1780       reserved = 3;
1781       got = this->got_plt_;
1782     }
1783 
1784   if (!this->is_data_size_valid())
1785     {
1786       // Note that when setting the PLT offset for a non-IRELATIVE
1787       // entry we skip the initial reserved PLT entry.
1788       plt_index = *pcount + offset;
1789       plt_offset = plt_index * this->get_plt_entry_size();
1790 
1791       ++*pcount;
1792 
1793       got_offset = (plt_index - offset + reserved) * 8;
1794       gold_assert(got_offset == got->current_data_size());
1795 
1796       // Every PLT entry needs a GOT entry which points back to the PLT
1797       // entry (this will be changed by the dynamic linker, normally
1798       // lazily when the function is called).
1799       got->set_current_data_size(got_offset + 8);
1800     }
1801   else
1802     {
1803       // FIXME: This is probably not correct for IRELATIVE relocs.
1804 
1805       // For incremental updates, find an available slot.
1806       plt_offset = this->free_list_.allocate(this->get_plt_entry_size(),
1807 					     this->get_plt_entry_size(), 0);
1808       if (plt_offset == -1)
1809 	gold_fallback(_("out of patch space (PLT);"
1810 			" relink with --incremental-full"));
1811 
1812       // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1813       // can be calculated from the PLT index, adjusting for the three
1814       // reserved entries at the beginning of the GOT.
1815       plt_index = plt_offset / this->get_plt_entry_size() - 1;
1816       got_offset = (plt_index - offset + reserved) * 8;
1817     }
1818 
1819   gsym->set_plt_offset(plt_offset);
1820 
1821   // Every PLT entry needs a reloc.
1822   this->add_relocation(symtab, layout, gsym, got_offset);
1823 
1824   // Note that we don't need to save the symbol.  The contents of the
1825   // PLT are independent of which symbols are used.  The symbols only
1826   // appear in the relocations.
1827 }
1828 
1829 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
1830 // the PLT offset.
1831 
1832 template<int size>
1833 unsigned int
add_local_ifunc_entry(Symbol_table * symtab,Layout * layout,Sized_relobj_file<size,false> * relobj,unsigned int local_sym_index)1834 Output_data_plt_x86_64<size>::add_local_ifunc_entry(
1835     Symbol_table* symtab,
1836     Layout* layout,
1837     Sized_relobj_file<size, false>* relobj,
1838     unsigned int local_sym_index)
1839 {
1840   unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1841   ++this->irelative_count_;
1842 
1843   section_offset_type got_offset = this->got_irelative_->current_data_size();
1844 
1845   // Every PLT entry needs a GOT entry which points back to the PLT
1846   // entry.
1847   this->got_irelative_->set_current_data_size(got_offset + 8);
1848 
1849   // Every PLT entry needs a reloc.
1850   Reloc_section* rela = this->rela_irelative(symtab, layout);
1851   rela->add_symbolless_local_addend(relobj, local_sym_index,
1852 				    elfcpp::R_X86_64_IRELATIVE,
1853 				    this->got_irelative_, got_offset, 0);
1854 
1855   return plt_offset;
1856 }
1857 
1858 // Add the relocation for a PLT entry.
1859 
1860 template<int size>
1861 void
add_relocation(Symbol_table * symtab,Layout * layout,Symbol * gsym,unsigned int got_offset)1862 Output_data_plt_x86_64<size>::add_relocation(Symbol_table* symtab,
1863 					     Layout* layout,
1864 					     Symbol* gsym,
1865 					     unsigned int got_offset)
1866 {
1867   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1868       && gsym->can_use_relative_reloc(false))
1869     {
1870       Reloc_section* rela = this->rela_irelative(symtab, layout);
1871       rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1872 					 this->got_irelative_, got_offset, 0);
1873     }
1874   else
1875     {
1876       gsym->set_needs_dynsym_entry();
1877       this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1878 			     got_offset, 0);
1879     }
1880 }
1881 
1882 // Return where the TLSDESC relocations should go, creating it if
1883 // necessary.  These follow the JUMP_SLOT relocations.
1884 
1885 template<int size>
1886 typename Output_data_plt_x86_64<size>::Reloc_section*
rela_tlsdesc(Layout * layout)1887 Output_data_plt_x86_64<size>::rela_tlsdesc(Layout* layout)
1888 {
1889   if (this->tlsdesc_rel_ == NULL)
1890     {
1891       this->tlsdesc_rel_ = new Reloc_section(false);
1892       layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1893 				      elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1894 				      ORDER_DYNAMIC_PLT_RELOCS, false);
1895       gold_assert(this->tlsdesc_rel_->output_section()
1896 		  == this->rel_->output_section());
1897     }
1898   return this->tlsdesc_rel_;
1899 }
1900 
1901 // Return where the IRELATIVE relocations should go in the PLT.  These
1902 // follow the JUMP_SLOT and the TLSDESC relocations.
1903 
1904 template<int size>
1905 typename Output_data_plt_x86_64<size>::Reloc_section*
rela_irelative(Symbol_table * symtab,Layout * layout)1906 Output_data_plt_x86_64<size>::rela_irelative(Symbol_table* symtab,
1907 					     Layout* layout)
1908 {
1909   if (this->irelative_rel_ == NULL)
1910     {
1911       // Make sure we have a place for the TLSDESC relocations, in
1912       // case we see any later on.
1913       this->rela_tlsdesc(layout);
1914       this->irelative_rel_ = new Reloc_section(false);
1915       layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1916 				      elfcpp::SHF_ALLOC, this->irelative_rel_,
1917 				      ORDER_DYNAMIC_PLT_RELOCS, false);
1918       gold_assert(this->irelative_rel_->output_section()
1919 		  == this->rel_->output_section());
1920 
1921       if (parameters->doing_static_link())
1922 	{
1923 	  // A statically linked executable will only have a .rela.plt
1924 	  // section to hold R_X86_64_IRELATIVE relocs for
1925 	  // STT_GNU_IFUNC symbols.  The library will use these
1926 	  // symbols to locate the IRELATIVE relocs at program startup
1927 	  // time.
1928 	  symtab->define_in_output_data("__rela_iplt_start", NULL,
1929 					Symbol_table::PREDEFINED,
1930 					this->irelative_rel_, 0, 0,
1931 					elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1932 					elfcpp::STV_HIDDEN, 0, false, true);
1933 	  symtab->define_in_output_data("__rela_iplt_end", NULL,
1934 					Symbol_table::PREDEFINED,
1935 					this->irelative_rel_, 0, 0,
1936 					elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1937 					elfcpp::STV_HIDDEN, 0, true, true);
1938 	}
1939     }
1940   return this->irelative_rel_;
1941 }
1942 
1943 // Return the PLT address to use for a global symbol.
1944 
1945 template<int size>
1946 uint64_t
do_address_for_global(const Symbol * gsym)1947 Output_data_plt_x86_64<size>::do_address_for_global(const Symbol* gsym)
1948 {
1949   uint64_t offset = 0;
1950   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1951       && gsym->can_use_relative_reloc(false))
1952     offset = (this->count_ + 1) * this->get_plt_entry_size();
1953   return this->address() + offset + gsym->plt_offset();
1954 }
1955 
1956 // Return the PLT address to use for a local symbol.  These are always
1957 // IRELATIVE relocs.
1958 
1959 template<int size>
1960 uint64_t
do_address_for_local(const Relobj * object,unsigned int r_sym)1961 Output_data_plt_x86_64<size>::do_address_for_local(const Relobj* object,
1962 						   unsigned int r_sym)
1963 {
1964   return (this->address()
1965 	  + (this->count_ + 1) * this->get_plt_entry_size()
1966 	  + object->local_plt_offset(r_sym));
1967 }
1968 
1969 // Set the final size.
1970 template<int size>
1971 void
set_final_data_size()1972 Output_data_plt_x86_64<size>::set_final_data_size()
1973 {
1974   // Number of regular and IFUNC PLT entries, plus the first entry.
1975   unsigned int count = this->count_ + this->irelative_count_ + 1;
1976   // Count the TLSDESC entry, if present.
1977   if (this->has_tlsdesc_entry())
1978     ++count;
1979   this->set_data_size(count * this->get_plt_entry_size());
1980 }
1981 
1982 // The first entry in the PLT for an executable.
1983 
1984 template<int size>
1985 const unsigned char
1986 Output_data_plt_x86_64_standard<size>::first_plt_entry[plt_entry_size] =
1987 {
1988   // From AMD64 ABI Draft 0.98, page 76
1989   0xff, 0x35,	// pushq contents of memory address
1990   0, 0, 0, 0,	// replaced with address of .got + 8
1991   0xff, 0x25,	// jmp indirect
1992   0, 0, 0, 0,	// replaced with address of .got + 16
1993   0x90, 0x90, 0x90, 0x90   // noop (x4)
1994 };
1995 
1996 template<int size>
1997 void
do_fill_first_plt_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address)1998 Output_data_plt_x86_64_standard<size>::do_fill_first_plt_entry(
1999     unsigned char* pov,
2000     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2001     typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
2002 {
2003   memcpy(pov, first_plt_entry, plt_entry_size);
2004   // We do a jmp relative to the PC at the end of this instruction.
2005   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2006 					      (got_address + 8
2007 					       - (plt_address + 6)));
2008   elfcpp::Swap<32, false>::writeval(pov + 8,
2009 				    (got_address + 16
2010 				     - (plt_address + 12)));
2011 }
2012 
2013 // Subsequent entries in the PLT for an executable.
2014 
2015 template<int size>
2016 const unsigned char
2017 Output_data_plt_x86_64_standard<size>::plt_entry[plt_entry_size] =
2018 {
2019   // From AMD64 ABI Draft 0.98, page 76
2020   0xff, 0x25,	// jmpq indirect
2021   0, 0, 0, 0,	// replaced with address of symbol in .got
2022   0x68,		// pushq immediate
2023   0, 0, 0, 0,	// replaced with offset into relocation table
2024   0xe9,		// jmpq relative
2025   0, 0, 0, 0	// replaced with offset to start of .plt
2026 };
2027 
2028 template<int size>
2029 unsigned int
do_fill_plt_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address,unsigned int got_offset,unsigned int plt_offset,unsigned int plt_index)2030 Output_data_plt_x86_64_standard<size>::do_fill_plt_entry(
2031     unsigned char* pov,
2032     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2033     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2034     unsigned int got_offset,
2035     unsigned int plt_offset,
2036     unsigned int plt_index)
2037 {
2038   // Check PC-relative offset overflow in PLT entry.
2039   uint64_t plt_got_pcrel_offset = (got_address + got_offset
2040 				   - (plt_address + plt_offset + 6));
2041   if (Bits<32>::has_overflow(plt_got_pcrel_offset))
2042     gold_error(_("PC-relative offset overflow in PLT entry %d"),
2043 	       plt_index + 1);
2044 
2045   memcpy(pov, plt_entry, plt_entry_size);
2046   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2047 					      plt_got_pcrel_offset);
2048 
2049   elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
2050   elfcpp::Swap<32, false>::writeval(pov + 12,
2051 				    - (plt_offset + plt_entry_size));
2052 
2053   return 6;
2054 }
2055 
2056 // The reserved TLSDESC entry in the PLT for an executable.
2057 
2058 template<int size>
2059 const unsigned char
2060 Output_data_plt_x86_64_standard<size>::tlsdesc_plt_entry[plt_entry_size] =
2061 {
2062   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2063   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2064   0xff, 0x35,	// pushq x(%rip)
2065   0, 0, 0, 0,	// replaced with address of linkmap GOT entry (at PLTGOT + 8)
2066   0xff,	0x25,	// jmpq *y(%rip)
2067   0, 0, 0, 0,	// replaced with offset of reserved TLSDESC_GOT entry
2068   0x0f,	0x1f,	// nop
2069   0x40, 0
2070 };
2071 
2072 template<int size>
2073 void
do_fill_tlsdesc_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address,typename elfcpp::Elf_types<size>::Elf_Addr got_base,unsigned int tlsdesc_got_offset,unsigned int plt_offset)2074 Output_data_plt_x86_64_standard<size>::do_fill_tlsdesc_entry(
2075     unsigned char* pov,
2076     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2077     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2078     typename elfcpp::Elf_types<size>::Elf_Addr got_base,
2079     unsigned int tlsdesc_got_offset,
2080     unsigned int plt_offset)
2081 {
2082   memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
2083   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2084 					      (got_address + 8
2085 					       - (plt_address + plt_offset
2086 						  + 6)));
2087   elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
2088 					      (got_base
2089 					       + tlsdesc_got_offset
2090 					       - (plt_address + plt_offset
2091 						  + 12)));
2092 }
2093 
2094 // Return the APLT address to use for a global symbol (for -z bndplt).
2095 
2096 uint64_t
do_address_for_global(const Symbol * gsym)2097 Output_data_plt_x86_64_bnd::do_address_for_global(const Symbol* gsym)
2098 {
2099   uint64_t offset = this->aplt_offset_;
2100   // Convert the PLT offset into an APLT offset.
2101   unsigned int plt_offset = gsym->plt_offset();
2102   if (gsym->type() == elfcpp::STT_GNU_IFUNC
2103       && gsym->can_use_relative_reloc(false))
2104     offset += this->regular_count() * aplt_entry_size;
2105   else
2106     plt_offset -= plt_entry_size;
2107   plt_offset = plt_offset / (plt_entry_size / aplt_entry_size);
2108   return this->address() + offset + plt_offset;
2109 }
2110 
2111 // Return the PLT address to use for a local symbol.  These are always
2112 // IRELATIVE relocs.
2113 
2114 uint64_t
do_address_for_local(const Relobj * object,unsigned int r_sym)2115 Output_data_plt_x86_64_bnd::do_address_for_local(const Relobj* object,
2116 						 unsigned int r_sym)
2117 {
2118   // Convert the PLT offset into an APLT offset.
2119   const Sized_relobj_file<64, false>* sized_relobj =
2120     static_cast<const Sized_relobj_file<64, false>*>(object);
2121   const Symbol_value<64>* psymval = sized_relobj->local_symbol(r_sym);
2122   unsigned int plt_offset = ((object->local_plt_offset(r_sym)
2123 			      - (psymval->is_ifunc_symbol()
2124 				 ? 0 : plt_entry_size))
2125 			     / (plt_entry_size / aplt_entry_size));
2126   return (this->address()
2127 	  + this->aplt_offset_
2128 	  + this->regular_count() * aplt_entry_size
2129 	  + plt_offset);
2130 }
2131 
2132 // Set the final size.
2133 void
set_final_data_size()2134 Output_data_plt_x86_64_bnd::set_final_data_size()
2135 {
2136   // Number of regular and IFUNC PLT entries.
2137   unsigned int count = this->entry_count();
2138   // Count the first entry and the TLSDESC entry, if present.
2139   unsigned int extra = this->has_tlsdesc_entry() ? 2 : 1;
2140   unsigned int plt_size = (count + extra) * plt_entry_size;
2141   // Offset of the APLT.
2142   this->aplt_offset_ = plt_size;
2143   // Size of the APLT.
2144   plt_size += count * aplt_entry_size;
2145   this->set_data_size(plt_size);
2146 }
2147 
2148 // The first entry in the BND PLT.
2149 
2150 const unsigned char
2151 Output_data_plt_x86_64_bnd::first_plt_entry[plt_entry_size] =
2152 {
2153   // From AMD64 ABI Draft 0.98, page 76
2154   0xff, 0x35,		// pushq contents of memory address
2155   0, 0, 0, 0,		// replaced with address of .got + 8
2156   0xf2, 0xff, 0x25,	// bnd jmp indirect
2157   0, 0, 0, 0,		// replaced with address of .got + 16
2158   0x0f, 0x1f, 0x00   	// nop
2159 };
2160 
2161 void
do_fill_first_plt_entry(unsigned char * pov,elfcpp::Elf_types<64>::Elf_Addr got_address,elfcpp::Elf_types<64>::Elf_Addr plt_address)2162 Output_data_plt_x86_64_bnd::do_fill_first_plt_entry(
2163     unsigned char* pov,
2164     elfcpp::Elf_types<64>::Elf_Addr got_address,
2165     elfcpp::Elf_types<64>::Elf_Addr plt_address)
2166 {
2167   memcpy(pov, first_plt_entry, plt_entry_size);
2168   // We do a jmp relative to the PC at the end of this instruction.
2169   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2170 					      (got_address + 8
2171 					       - (plt_address + 6)));
2172   elfcpp::Swap<32, false>::writeval(pov + 9,
2173 				    (got_address + 16
2174 				     - (plt_address + 13)));
2175 }
2176 
2177 // Subsequent entries in the BND PLT.
2178 
2179 const unsigned char
2180 Output_data_plt_x86_64_bnd::plt_entry[plt_entry_size] =
2181 {
2182   // From AMD64 ABI Draft 0.99.8, page 139
2183   0x68,				// pushq immediate
2184   0, 0, 0, 0,			// replaced with offset into relocation table
2185   0xf2, 0xe9,			// bnd jmpq relative
2186   0, 0, 0, 0,			// replaced with offset to start of .plt
2187   0x0f, 0x1f, 0x44, 0, 0	// nop
2188 };
2189 
2190 // Entries in the BND Additional PLT.
2191 
2192 const unsigned char
2193 Output_data_plt_x86_64_bnd::aplt_entry[aplt_entry_size] =
2194 {
2195   // From AMD64 ABI Draft 0.99.8, page 139
2196   0xf2, 0xff, 0x25,	// bnd jmpq indirect
2197   0, 0, 0, 0,		// replaced with address of symbol in .got
2198   0x90,			// nop
2199 };
2200 
2201 unsigned int
do_fill_plt_entry(unsigned char * pov,elfcpp::Elf_types<64>::Elf_Addr,elfcpp::Elf_types<64>::Elf_Addr,unsigned int,unsigned int plt_offset,unsigned int plt_index)2202 Output_data_plt_x86_64_bnd::do_fill_plt_entry(
2203     unsigned char* pov,
2204     elfcpp::Elf_types<64>::Elf_Addr,
2205     elfcpp::Elf_types<64>::Elf_Addr,
2206     unsigned int,
2207     unsigned int plt_offset,
2208     unsigned int plt_index)
2209 {
2210   memcpy(pov, plt_entry, plt_entry_size);
2211   elfcpp::Swap_unaligned<32, false>::writeval(pov + 1, plt_index);
2212   elfcpp::Swap<32, false>::writeval(pov + 7, -(plt_offset + 11));
2213   return 0;
2214 }
2215 
2216 void
fill_aplt_entry(unsigned char * pov,elfcpp::Elf_types<64>::Elf_Addr got_address,elfcpp::Elf_types<64>::Elf_Addr plt_address,unsigned int got_offset,unsigned int plt_offset,unsigned int plt_index)2217 Output_data_plt_x86_64_bnd::fill_aplt_entry(
2218     unsigned char* pov,
2219     elfcpp::Elf_types<64>::Elf_Addr got_address,
2220     elfcpp::Elf_types<64>::Elf_Addr plt_address,
2221     unsigned int got_offset,
2222     unsigned int plt_offset,
2223     unsigned int plt_index)
2224 {
2225   // Check PC-relative offset overflow in PLT entry.
2226   uint64_t plt_got_pcrel_offset = (got_address + got_offset
2227 				   - (plt_address + plt_offset + 7));
2228   if (Bits<32>::has_overflow(plt_got_pcrel_offset))
2229     gold_error(_("PC-relative offset overflow in APLT entry %d"),
2230 	       plt_index + 1);
2231 
2232   memcpy(pov, aplt_entry, aplt_entry_size);
2233   elfcpp::Swap_unaligned<32, false>::writeval(pov + 3, plt_got_pcrel_offset);
2234 }
2235 
2236 // The reserved TLSDESC entry in the PLT for an executable.
2237 
2238 const unsigned char
2239 Output_data_plt_x86_64_bnd::tlsdesc_plt_entry[plt_entry_size] =
2240 {
2241   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2242   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2243   0xff, 0x35,		// pushq x(%rip)
2244   0, 0, 0, 0,		// replaced with address of linkmap GOT entry (at PLTGOT + 8)
2245   0xf2, 0xff, 0x25,	// jmpq *y(%rip)
2246   0, 0, 0, 0,		// replaced with offset of reserved TLSDESC_GOT entry
2247   0x0f,	0x1f, 0		// nop
2248 };
2249 
2250 void
do_fill_tlsdesc_entry(unsigned char * pov,elfcpp::Elf_types<64>::Elf_Addr got_address,elfcpp::Elf_types<64>::Elf_Addr plt_address,elfcpp::Elf_types<64>::Elf_Addr got_base,unsigned int tlsdesc_got_offset,unsigned int plt_offset)2251 Output_data_plt_x86_64_bnd::do_fill_tlsdesc_entry(
2252     unsigned char* pov,
2253     elfcpp::Elf_types<64>::Elf_Addr got_address,
2254     elfcpp::Elf_types<64>::Elf_Addr plt_address,
2255     elfcpp::Elf_types<64>::Elf_Addr got_base,
2256     unsigned int tlsdesc_got_offset,
2257     unsigned int plt_offset)
2258 {
2259   memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
2260   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
2261 					      (got_address + 8
2262 					       - (plt_address + plt_offset
2263 						  + 6)));
2264   elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
2265 					      (got_base
2266 					       + tlsdesc_got_offset
2267 					       - (plt_address + plt_offset
2268 						  + 13)));
2269 }
2270 
2271 // Return the APLT address to use for a global symbol (for IBT).
2272 
2273 template<int size>
2274 uint64_t
do_address_for_global(const Symbol * gsym)2275 Output_data_plt_x86_64_ibt<size>::do_address_for_global(const Symbol* gsym)
2276 {
2277   uint64_t offset = this->aplt_offset_;
2278   // Convert the PLT offset into an APLT offset.
2279   unsigned int plt_offset = gsym->plt_offset();
2280   if (gsym->type() == elfcpp::STT_GNU_IFUNC
2281       && gsym->can_use_relative_reloc(false))
2282     offset += this->regular_count() * aplt_entry_size;
2283   else
2284     plt_offset -= plt_entry_size;
2285   plt_offset = plt_offset / (plt_entry_size / aplt_entry_size);
2286   return this->address() + offset + plt_offset;
2287 }
2288 
2289 // Return the PLT address to use for a local symbol.  These are always
2290 // IRELATIVE relocs.
2291 
2292 template<int size>
2293 uint64_t
do_address_for_local(const Relobj * object,unsigned int r_sym)2294 Output_data_plt_x86_64_ibt<size>::do_address_for_local(const Relobj* object,
2295 						 unsigned int r_sym)
2296 {
2297   // Convert the PLT offset into an APLT offset.
2298   const Sized_relobj_file<size, false>* sized_relobj =
2299     static_cast<const Sized_relobj_file<size, false>*>(object);
2300   const Symbol_value<size>* psymval = sized_relobj->local_symbol(r_sym);
2301   unsigned int plt_offset = ((object->local_plt_offset(r_sym)
2302 			      - (psymval->is_ifunc_symbol()
2303 				 ? 0 : plt_entry_size))
2304 			     / (plt_entry_size / aplt_entry_size));
2305   return (this->address()
2306 	  + this->aplt_offset_
2307 	  + this->regular_count() * aplt_entry_size
2308 	  + plt_offset);
2309 }
2310 
2311 // Set the final size.
2312 
2313 template<int size>
2314 void
set_final_data_size()2315 Output_data_plt_x86_64_ibt<size>::set_final_data_size()
2316 {
2317   // Number of regular and IFUNC PLT entries.
2318   unsigned int count = this->entry_count();
2319   // Count the first entry and the TLSDESC entry, if present.
2320   unsigned int extra = this->has_tlsdesc_entry() ? 2 : 1;
2321   unsigned int plt_size = (count + extra) * plt_entry_size;
2322   // Offset of the APLT.
2323   this->aplt_offset_ = plt_size;
2324   // Size of the APLT.
2325   plt_size += count * aplt_entry_size;
2326   this->set_data_size(plt_size);
2327 }
2328 
2329 // The first entry in the IBT PLT.
2330 
2331 template<>
2332 const unsigned char
2333 Output_data_plt_x86_64_ibt<32>::first_plt_entry[plt_entry_size] =
2334 {
2335   // MPX isn't supported for x32, so we don't need the BND prefix.
2336   // From AMD64 ABI Draft 0.98, page 76
2337   0xff, 0x35,		 // pushq contents of memory address
2338   0, 0, 0, 0,		 // replaced with address of .got + 8
2339   0xff, 0x25,		 // jmp indirect
2340   0, 0, 0, 0,		 // replaced with address of .got + 16
2341   0x90, 0x90, 0x90, 0x90 // noop (x4)
2342 };
2343 
2344 template<>
2345 const unsigned char
2346 Output_data_plt_x86_64_ibt<64>::first_plt_entry[plt_entry_size] =
2347 {
2348   // Use the BND prefix so that IBT is compatible with MPX.
2349   0xff, 0x35,		// pushq contents of memory address
2350   0, 0, 0, 0,		// replaced with address of .got + 8
2351   0xf2, 0xff, 0x25,	// bnd jmp indirect
2352   0, 0, 0, 0,		// replaced with address of .got + 16
2353   0x0f, 0x1f, 0x00   	// nop
2354 };
2355 
2356 template<int size>
2357 void
do_fill_first_plt_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address)2358 Output_data_plt_x86_64_ibt<size>::do_fill_first_plt_entry(
2359     unsigned char* pov,
2360     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2361     typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
2362 {
2363   // Offsets to the addresses needing relocation.
2364   const unsigned int roff1 = 2;
2365   const unsigned int roff2 = (size == 32) ? 8 : 9;
2366 
2367   memcpy(pov, first_plt_entry, plt_entry_size);
2368   // We do a jmp relative to the PC at the end of this instruction.
2369   elfcpp::Swap_unaligned<32, false>::writeval(pov + roff1,
2370 					      (got_address + 8
2371 					       - (plt_address + roff1 + 4)));
2372   elfcpp::Swap<32, false>::writeval(pov + roff2,
2373 				    (got_address + 16
2374 				     - (plt_address + roff2 + 4)));
2375 }
2376 
2377 // Subsequent entries in the IBT PLT.
2378 
2379 template<>
2380 const unsigned char
2381 Output_data_plt_x86_64_ibt<32>::plt_entry[plt_entry_size] =
2382 {
2383   // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2384   0xf3, 0x0f, 0x1e, 0xfa,	// endbr64
2385   0x68,				// pushq immediate
2386   0, 0, 0, 0,			// replaced with offset into relocation table
2387   0xe9,				// jmpq relative
2388   0, 0, 0, 0,			// replaced with offset to start of .plt
2389   0x90, 0x90			// nop
2390 };
2391 
2392 template<>
2393 const unsigned char
2394 Output_data_plt_x86_64_ibt<64>::plt_entry[plt_entry_size] =
2395 {
2396   // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2397   0xf3, 0x0f, 0x1e, 0xfa,	// endbr64
2398   0x68,				// pushq immediate
2399   0, 0, 0, 0,			// replaced with offset into relocation table
2400   0xf2, 0xe9,			// bnd jmpq relative
2401   0, 0, 0, 0,			// replaced with offset to start of .plt
2402   0x90				// nop
2403 };
2404 
2405 // Entries in the IBT Additional PLT.
2406 
2407 template<>
2408 const unsigned char
2409 Output_data_plt_x86_64_ibt<32>::aplt_entry[aplt_entry_size] =
2410 {
2411   // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2412   0xf3, 0x0f, 0x1e, 0xfa,	// endbr64
2413   0xff, 0x25,			// jmpq indirect
2414   0, 0, 0, 0,			// replaced with address of symbol in .got
2415   0x0f, 0x1f, 0x04, 0x00,	// nop
2416   0x90, 0x90			// nop
2417 };
2418 
2419 template<>
2420 const unsigned char
2421 Output_data_plt_x86_64_ibt<64>::aplt_entry[aplt_entry_size] =
2422 {
2423   // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
2424   0xf3, 0x0f, 0x1e, 0xfa,	// endbr64
2425   0xf2, 0xff, 0x25,		// bnd jmpq indirect
2426   0, 0, 0, 0,			// replaced with address of symbol in .got
2427   0x0f, 0x1f, 0x04, 0x00,	// nop
2428   0x90,				// nop
2429 };
2430 
2431 template<int size>
2432 unsigned int
do_fill_plt_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr,typename elfcpp::Elf_types<size>::Elf_Addr,unsigned int,unsigned int plt_offset,unsigned int plt_index)2433 Output_data_plt_x86_64_ibt<size>::do_fill_plt_entry(
2434     unsigned char* pov,
2435     typename elfcpp::Elf_types<size>::Elf_Addr,
2436     typename elfcpp::Elf_types<size>::Elf_Addr,
2437     unsigned int,
2438     unsigned int plt_offset,
2439     unsigned int plt_index)
2440 {
2441   // Offsets to the addresses needing relocation.
2442   const unsigned int roff1 = 5;
2443   const unsigned int roff2 = (size == 32) ? 10 : 11;
2444 
2445   memcpy(pov, plt_entry, plt_entry_size);
2446   elfcpp::Swap_unaligned<32, false>::writeval(pov + roff1, plt_index);
2447   elfcpp::Swap<32, false>::writeval(pov + roff2, -(plt_offset + roff2 + 4));
2448   return 0;
2449 }
2450 
2451 template<int size>
2452 void
fill_aplt_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address,unsigned int got_offset,unsigned int plt_offset,unsigned int plt_index)2453 Output_data_plt_x86_64_ibt<size>::fill_aplt_entry(
2454     unsigned char* pov,
2455     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2456     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2457     unsigned int got_offset,
2458     unsigned int plt_offset,
2459     unsigned int plt_index)
2460 {
2461   // Offset to the address needing relocation.
2462   const unsigned int roff = (size == 32) ? 6 : 7;
2463 
2464   // Check PC-relative offset overflow in PLT entry.
2465   uint64_t plt_got_pcrel_offset = (got_address + got_offset
2466 				   - (plt_address + plt_offset + roff + 4));
2467   if (Bits<32>::has_overflow(plt_got_pcrel_offset))
2468     gold_error(_("PC-relative offset overflow in APLT entry %d"),
2469 	       plt_index + 1);
2470 
2471   memcpy(pov, aplt_entry, aplt_entry_size);
2472   elfcpp::Swap_unaligned<32, false>::writeval(pov + roff, plt_got_pcrel_offset);
2473 }
2474 
2475 // The reserved TLSDESC entry in the IBT PLT for an executable.
2476 
2477 template<int size>
2478 const unsigned char
2479 Output_data_plt_x86_64_ibt<size>::tlsdesc_plt_entry[plt_entry_size] =
2480 {
2481   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
2482   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
2483   0xf3, 0x0f, 0x1e, 0xfa, // endbr64
2484   0xff, 0x35,		// pushq x(%rip)
2485   0, 0, 0, 0,		// replaced with address of linkmap GOT entry (at PLTGOT + 8)
2486   0xff, 0x25,		// jmpq *y(%rip)
2487   0, 0, 0, 0,		// replaced with offset of reserved TLSDESC_GOT entry
2488 };
2489 
2490 template<int size>
2491 void
do_fill_tlsdesc_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address,typename elfcpp::Elf_types<size>::Elf_Addr got_base,unsigned int tlsdesc_got_offset,unsigned int plt_offset)2492 Output_data_plt_x86_64_ibt<size>::do_fill_tlsdesc_entry(
2493     unsigned char* pov,
2494     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
2495     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
2496     typename elfcpp::Elf_types<size>::Elf_Addr got_base,
2497     unsigned int tlsdesc_got_offset,
2498     unsigned int plt_offset)
2499 {
2500   memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
2501   elfcpp::Swap_unaligned<32, false>::writeval(pov + 6,
2502 					      (got_address + 8
2503 					       - (plt_address + plt_offset
2504 						  + 10)));
2505   elfcpp::Swap_unaligned<32, false>::writeval(pov + 12,
2506 					      (got_base
2507 					       + tlsdesc_got_offset
2508 					       - (plt_address + plt_offset
2509 						  + 16)));
2510 }
2511 
2512 // The .eh_frame unwind information for the PLT.
2513 
2514 template<int size>
2515 const unsigned char
2516 Output_data_plt_x86_64<size>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
2517 {
2518   1,				// CIE version.
2519   'z',				// Augmentation: augmentation size included.
2520   'R',				// Augmentation: FDE encoding included.
2521   '\0',				// End of augmentation string.
2522   1,				// Code alignment factor.
2523   0x78,				// Data alignment factor.
2524   16,				// Return address column.
2525   1,				// Augmentation size.
2526   (elfcpp::DW_EH_PE_pcrel	// FDE encoding.
2527    | elfcpp::DW_EH_PE_sdata4),
2528   elfcpp::DW_CFA_def_cfa, 7, 8,	// DW_CFA_def_cfa: r7 (rsp) ofs 8.
2529   elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
2530   elfcpp::DW_CFA_nop,		// Align to 16 bytes.
2531   elfcpp::DW_CFA_nop
2532 };
2533 
2534 template<int size>
2535 const unsigned char
2536 Output_data_plt_x86_64_standard<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2537 {
2538   0, 0, 0, 0,				// Replaced with offset to .plt.
2539   0, 0, 0, 0,				// Replaced with size of .plt.
2540   0,					// Augmentation size.
2541   elfcpp::DW_CFA_def_cfa_offset, 16,	// DW_CFA_def_cfa_offset: 16.
2542   elfcpp::DW_CFA_advance_loc + 6,	// Advance 6 to __PLT__ + 6.
2543   elfcpp::DW_CFA_def_cfa_offset, 24,	// DW_CFA_def_cfa_offset: 24.
2544   elfcpp::DW_CFA_advance_loc + 10,	// Advance 10 to __PLT__ + 16.
2545   elfcpp::DW_CFA_def_cfa_expression,	// DW_CFA_def_cfa_expression.
2546   11,					// Block length.
2547   elfcpp::DW_OP_breg7, 8,		// Push %rsp + 8.
2548   elfcpp::DW_OP_breg16, 0,		// Push %rip.
2549   elfcpp::DW_OP_lit15,			// Push 0xf.
2550   elfcpp::DW_OP_and,			// & (%rip & 0xf).
2551   elfcpp::DW_OP_lit11,			// Push 0xb.
2552   elfcpp::DW_OP_ge,			// >= ((%rip & 0xf) >= 0xb)
2553   elfcpp::DW_OP_lit3,			// Push 3.
2554   elfcpp::DW_OP_shl,			// << (((%rip & 0xf) >= 0xb) << 3)
2555   elfcpp::DW_OP_plus,			// + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
2556   elfcpp::DW_CFA_nop,			// Align to 32 bytes.
2557   elfcpp::DW_CFA_nop,
2558   elfcpp::DW_CFA_nop,
2559   elfcpp::DW_CFA_nop
2560 };
2561 
2562 // The .eh_frame unwind information for the BND PLT.
2563 const unsigned char
2564 Output_data_plt_x86_64_bnd::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2565 {
2566   0, 0, 0, 0,				// Replaced with offset to .plt.
2567   0, 0, 0, 0,				// Replaced with size of .plt.
2568   0,					// Augmentation size.
2569   elfcpp::DW_CFA_def_cfa_offset, 16,	// DW_CFA_def_cfa_offset: 16.
2570   elfcpp::DW_CFA_advance_loc + 6,	// Advance 6 to __PLT__ + 6.
2571   elfcpp::DW_CFA_def_cfa_offset, 24,	// DW_CFA_def_cfa_offset: 24.
2572   elfcpp::DW_CFA_advance_loc + 10,	// Advance 10 to __PLT__ + 16.
2573   elfcpp::DW_CFA_def_cfa_expression,	// DW_CFA_def_cfa_expression.
2574   11,					// Block length.
2575   elfcpp::DW_OP_breg7, 8,		// Push %rsp + 8.
2576   elfcpp::DW_OP_breg16, 0,		// Push %rip.
2577   elfcpp::DW_OP_lit15,			// Push 0xf.
2578   elfcpp::DW_OP_and,			// & (%rip & 0xf).
2579   elfcpp::DW_OP_lit5,			// Push 5.
2580   elfcpp::DW_OP_ge,			// >= ((%rip & 0xf) >= 5)
2581   elfcpp::DW_OP_lit3,			// Push 3.
2582   elfcpp::DW_OP_shl,			// << (((%rip & 0xf) >= 5) << 3)
2583   elfcpp::DW_OP_plus,			// + ((((%rip&0xf)>=5)<<3)+%rsp+8
2584   elfcpp::DW_CFA_nop,			// Align to 32 bytes.
2585   elfcpp::DW_CFA_nop,
2586   elfcpp::DW_CFA_nop,
2587   elfcpp::DW_CFA_nop
2588 };
2589 
2590 // The .eh_frame unwind information for the BND PLT.
2591 template<int size>
2592 const unsigned char
2593 Output_data_plt_x86_64_ibt<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2594 {
2595   0, 0, 0, 0,				// Replaced with offset to .plt.
2596   0, 0, 0, 0,				// Replaced with size of .plt.
2597   0,					// Augmentation size.
2598   elfcpp::DW_CFA_def_cfa_offset, 16,	// DW_CFA_def_cfa_offset: 16.
2599   elfcpp::DW_CFA_advance_loc + 6,	// Advance 6 to __PLT__ + 6.
2600   elfcpp::DW_CFA_def_cfa_offset, 24,	// DW_CFA_def_cfa_offset: 24.
2601   elfcpp::DW_CFA_advance_loc + 10,	// Advance 10 to __PLT__ + 16.
2602   elfcpp::DW_CFA_def_cfa_expression,	// DW_CFA_def_cfa_expression.
2603   11,					// Block length.
2604   elfcpp::DW_OP_breg7, 8,		// Push %rsp + 8.
2605   elfcpp::DW_OP_breg16, 0,		// Push %rip.
2606   elfcpp::DW_OP_lit15,			// Push 0xf.
2607   elfcpp::DW_OP_and,			// & (%rip & 0xf).
2608   elfcpp::DW_OP_lit9,			// Push 9.
2609   elfcpp::DW_OP_ge,			// >= ((%rip & 0xf) >= 9)
2610   elfcpp::DW_OP_lit3,			// Push 3.
2611   elfcpp::DW_OP_shl,			// << (((%rip & 0xf) >= 9) << 3)
2612   elfcpp::DW_OP_plus,			// + ((((%rip&0xf)>=9)<<3)+%rsp+8
2613   elfcpp::DW_CFA_nop,			// Align to 32 bytes.
2614   elfcpp::DW_CFA_nop,
2615   elfcpp::DW_CFA_nop,
2616   elfcpp::DW_CFA_nop
2617 };
2618 
2619 // Write out the PLT.  This uses the hand-coded instructions above,
2620 // and adjusts them as needed.  This is specified by the AMD64 ABI.
2621 
2622 template<int size>
2623 void
do_write(Output_file * of)2624 Output_data_plt_x86_64<size>::do_write(Output_file* of)
2625 {
2626   const off_t offset = this->offset();
2627   const section_size_type oview_size =
2628     convert_to_section_size_type(this->data_size());
2629   unsigned char* const oview = of->get_output_view(offset, oview_size);
2630 
2631   const off_t got_file_offset = this->got_plt_->offset();
2632   gold_assert(parameters->incremental_update()
2633 	      || (got_file_offset + this->got_plt_->data_size()
2634 		  == this->got_irelative_->offset()));
2635   const section_size_type got_size =
2636     convert_to_section_size_type(this->got_plt_->data_size()
2637 				 + this->got_irelative_->data_size());
2638   unsigned char* const got_view = of->get_output_view(got_file_offset,
2639 						      got_size);
2640 
2641   unsigned char* pov = oview;
2642 
2643   // The base address of the .plt section.
2644   typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
2645   // The base address of the .got section.
2646   typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address();
2647   // The base address of the PLT portion of the .got section,
2648   // which is where the GOT pointer will point, and where the
2649   // three reserved GOT entries are located.
2650   typename elfcpp::Elf_types<size>::Elf_Addr got_address
2651     = this->got_plt_->address();
2652 
2653   this->fill_first_plt_entry(pov, got_address, plt_address);
2654   pov += this->get_plt_entry_size();
2655 
2656   // The first three entries in the GOT are reserved, and are written
2657   // by Output_data_got_plt_x86_64::do_write.
2658   unsigned char* got_pov = got_view + 24;
2659 
2660   unsigned int plt_offset = this->get_plt_entry_size();
2661   unsigned int got_offset = 24;
2662   const unsigned int count = this->count_ + this->irelative_count_;
2663   for (unsigned int plt_index = 0;
2664        plt_index < count;
2665        ++plt_index,
2666 	 pov += this->get_plt_entry_size(),
2667 	 got_pov += 8,
2668 	 plt_offset += this->get_plt_entry_size(),
2669 	 got_offset += 8)
2670     {
2671       // Set and adjust the PLT entry itself.
2672       unsigned int lazy_offset = this->fill_plt_entry(pov,
2673 						      got_address, plt_address,
2674 						      got_offset, plt_offset,
2675 						      plt_index);
2676 
2677       // Set the entry in the GOT.
2678       elfcpp::Swap<64, false>::writeval(got_pov,
2679 					plt_address + plt_offset + lazy_offset);
2680     }
2681 
2682   if (this->has_tlsdesc_entry())
2683     {
2684       // Set and adjust the reserved TLSDESC PLT entry.
2685       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2686       this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2687 			       tlsdesc_got_offset, plt_offset);
2688       pov += this->get_plt_entry_size();
2689     }
2690 
2691   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2692   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2693 
2694   of->write_output_view(offset, oview_size, oview);
2695   of->write_output_view(got_file_offset, got_size, got_view);
2696 }
2697 
2698 // Write out the BND PLT.
2699 
2700 void
do_write(Output_file * of)2701 Output_data_plt_x86_64_bnd::do_write(Output_file* of)
2702 {
2703   const off_t offset = this->offset();
2704   const section_size_type oview_size =
2705     convert_to_section_size_type(this->data_size());
2706   unsigned char* const oview = of->get_output_view(offset, oview_size);
2707 
2708   Output_data_got<64, false>* got = this->got();
2709   Output_data_got_plt_x86_64* got_plt = this->got_plt();
2710   Output_data_space* got_irelative = this->got_irelative();
2711 
2712   const off_t got_file_offset = got_plt->offset();
2713   gold_assert(parameters->incremental_update()
2714 	      || (got_file_offset + got_plt->data_size()
2715 		  == got_irelative->offset()));
2716   const section_size_type got_size =
2717     convert_to_section_size_type(got_plt->data_size()
2718 				 + got_irelative->data_size());
2719   unsigned char* const got_view = of->get_output_view(got_file_offset,
2720 						      got_size);
2721 
2722   unsigned char* pov = oview;
2723 
2724   // The base address of the .plt section.
2725   elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
2726   // The base address of the .got section.
2727   elfcpp::Elf_types<64>::Elf_Addr got_base = got->address();
2728   // The base address of the PLT portion of the .got section,
2729   // which is where the GOT pointer will point, and where the
2730   // three reserved GOT entries are located.
2731   elfcpp::Elf_types<64>::Elf_Addr got_address = got_plt->address();
2732 
2733   this->fill_first_plt_entry(pov, got_address, plt_address);
2734   pov += plt_entry_size;
2735 
2736   // The first three entries in the GOT are reserved, and are written
2737   // by Output_data_got_plt_x86_64::do_write.
2738   unsigned char* got_pov = got_view + 24;
2739 
2740   unsigned int plt_offset = plt_entry_size;
2741   unsigned int got_offset = 24;
2742   const unsigned int count = this->entry_count();
2743   for (unsigned int plt_index = 0;
2744        plt_index < count;
2745        ++plt_index,
2746 	 pov += plt_entry_size,
2747 	 got_pov += 8,
2748 	 plt_offset += plt_entry_size,
2749 	 got_offset += 8)
2750     {
2751       // Set and adjust the PLT entry itself.
2752       unsigned int lazy_offset = this->fill_plt_entry(pov,
2753 						      got_address, plt_address,
2754 						      got_offset, plt_offset,
2755 						      plt_index);
2756 
2757       // Set the entry in the GOT.
2758       elfcpp::Swap<64, false>::writeval(got_pov,
2759 					plt_address + plt_offset + lazy_offset);
2760     }
2761 
2762   if (this->has_tlsdesc_entry())
2763     {
2764       // Set and adjust the reserved TLSDESC PLT entry.
2765       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2766       this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2767 			       tlsdesc_got_offset, plt_offset);
2768       pov += this->get_plt_entry_size();
2769       plt_offset += plt_entry_size;
2770     }
2771 
2772   // Write the additional PLT.
2773   got_offset = 24;
2774   for (unsigned int plt_index = 0;
2775        plt_index < count;
2776        ++plt_index,
2777 	 pov += aplt_entry_size,
2778 	 plt_offset += aplt_entry_size,
2779 	 got_offset += 8)
2780     {
2781       // Set and adjust the APLT entry.
2782       this->fill_aplt_entry(pov, got_address, plt_address, got_offset,
2783 			    plt_offset, plt_index);
2784     }
2785 
2786   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2787   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2788 
2789   of->write_output_view(offset, oview_size, oview);
2790   of->write_output_view(got_file_offset, got_size, got_view);
2791 }
2792 
2793 // Write out the IBT PLT.
2794 
2795 template<int size>
2796 void
do_write(Output_file * of)2797 Output_data_plt_x86_64_ibt<size>::do_write(Output_file* of)
2798 {
2799   const off_t offset = this->offset();
2800   const section_size_type oview_size =
2801     convert_to_section_size_type(this->data_size());
2802   unsigned char* const oview = of->get_output_view(offset, oview_size);
2803 
2804   Output_data_got<64, false>* got = this->got();
2805   Output_data_got_plt_x86_64* got_plt = this->got_plt();
2806   Output_data_space* got_irelative = this->got_irelative();
2807 
2808   const off_t got_file_offset = got_plt->offset();
2809   gold_assert(parameters->incremental_update()
2810 	      || (got_file_offset + got_plt->data_size()
2811 		  == got_irelative->offset()));
2812   const section_size_type got_size =
2813     convert_to_section_size_type(got_plt->data_size()
2814 				 + got_irelative->data_size());
2815   unsigned char* const got_view = of->get_output_view(got_file_offset,
2816 						      got_size);
2817 
2818   unsigned char* pov = oview;
2819 
2820   // The base address of the .plt section.
2821   elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
2822   // The base address of the .got section.
2823   elfcpp::Elf_types<64>::Elf_Addr got_base = got->address();
2824   // The base address of the PLT portion of the .got section,
2825   // which is where the GOT pointer will point, and where the
2826   // three reserved GOT entries are located.
2827   elfcpp::Elf_types<64>::Elf_Addr got_address = got_plt->address();
2828 
2829   this->fill_first_plt_entry(pov, got_address, plt_address);
2830   pov += plt_entry_size;
2831 
2832   // The first three entries in the GOT are reserved, and are written
2833   // by Output_data_got_plt_x86_64::do_write.
2834   unsigned char* got_pov = got_view + 24;
2835 
2836   unsigned int plt_offset = plt_entry_size;
2837   unsigned int got_offset = 24;
2838   const unsigned int count = this->entry_count();
2839   for (unsigned int plt_index = 0;
2840        plt_index < count;
2841        ++plt_index,
2842 	 pov += plt_entry_size,
2843 	 got_pov += 8,
2844 	 plt_offset += plt_entry_size,
2845 	 got_offset += 8)
2846     {
2847       // Set and adjust the PLT entry itself.
2848       unsigned int lazy_offset = this->fill_plt_entry(pov,
2849 						      got_address, plt_address,
2850 						      got_offset, plt_offset,
2851 						      plt_index);
2852 
2853       // Set the entry in the GOT.
2854       elfcpp::Swap<64, false>::writeval(got_pov,
2855 					plt_address + plt_offset + lazy_offset);
2856     }
2857 
2858   if (this->has_tlsdesc_entry())
2859     {
2860       // Set and adjust the reserved TLSDESC PLT entry.
2861       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2862       this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2863 			       tlsdesc_got_offset, plt_offset);
2864       pov += this->get_plt_entry_size();
2865       plt_offset += plt_entry_size;
2866     }
2867 
2868   // Write the additional PLT.
2869   got_offset = 24;
2870   for (unsigned int plt_index = 0;
2871        plt_index < count;
2872        ++plt_index,
2873 	 pov += aplt_entry_size,
2874 	 plt_offset += aplt_entry_size,
2875 	 got_offset += 8)
2876     {
2877       // Set and adjust the APLT entry.
2878       this->fill_aplt_entry(pov, got_address, plt_address, got_offset,
2879 			    plt_offset, plt_index);
2880     }
2881 
2882   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2883   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2884 
2885   of->write_output_view(offset, oview_size, oview);
2886   of->write_output_view(got_file_offset, got_size, got_view);
2887 }
2888 
2889 // Create the PLT section.
2890 
2891 template<int size>
2892 void
make_plt_section(Symbol_table * symtab,Layout * layout)2893 Target_x86_64<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
2894 {
2895   if (this->plt_ == NULL)
2896     {
2897       // Create the GOT sections first.
2898       this->got_section(symtab, layout);
2899 
2900       this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
2901 				       this->got_irelative_);
2902 
2903       // Add unwind information if requested.
2904       if (parameters->options().ld_generated_unwind_info())
2905 	this->plt_->add_eh_frame(layout);
2906 
2907       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
2908 				      (elfcpp::SHF_ALLOC
2909 				       | elfcpp::SHF_EXECINSTR),
2910 				      this->plt_, ORDER_PLT, false);
2911 
2912       // Make the sh_info field of .rela.plt point to .plt.
2913       Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
2914       rela_plt_os->set_info_section(this->plt_->output_section());
2915     }
2916 }
2917 
2918 template<>
2919 Output_data_plt_x86_64<32>*
do_make_data_plt(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative)2920 Target_x86_64<32>::do_make_data_plt(Layout* layout,
2921 				    Output_data_got<64, false>* got,
2922 				    Output_data_got_plt_x86_64* got_plt,
2923 				    Output_data_space* got_irelative)
2924 {
2925   if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2926     return new Output_data_plt_x86_64_ibt<32>(layout, got, got_plt,
2927 					      got_irelative);
2928   return new Output_data_plt_x86_64_standard<32>(layout, got, got_plt,
2929 						 got_irelative);
2930 }
2931 
2932 template<>
2933 Output_data_plt_x86_64<64>*
do_make_data_plt(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative)2934 Target_x86_64<64>::do_make_data_plt(Layout* layout,
2935 				    Output_data_got<64, false>* got,
2936 				    Output_data_got_plt_x86_64* got_plt,
2937 				    Output_data_space* got_irelative)
2938 {
2939   if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2940     return new Output_data_plt_x86_64_ibt<64>(layout, got, got_plt,
2941 					      got_irelative);
2942   else if (parameters->options().bndplt())
2943     return new Output_data_plt_x86_64_bnd(layout, got, got_plt,
2944 					  got_irelative);
2945   else
2946     return new Output_data_plt_x86_64_standard<64>(layout, got, got_plt,
2947 						   got_irelative);
2948 }
2949 
2950 template<>
2951 Output_data_plt_x86_64<32>*
do_make_data_plt(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative,unsigned int plt_count)2952 Target_x86_64<32>::do_make_data_plt(Layout* layout,
2953 				    Output_data_got<64, false>* got,
2954 				    Output_data_got_plt_x86_64* got_plt,
2955 				    Output_data_space* got_irelative,
2956 				    unsigned int plt_count)
2957 {
2958   if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2959     return new Output_data_plt_x86_64_ibt<32>(layout, got, got_plt,
2960 					      got_irelative, plt_count);
2961   return new Output_data_plt_x86_64_standard<32>(layout, got, got_plt,
2962 						 got_irelative, plt_count);
2963 }
2964 
2965 template<>
2966 Output_data_plt_x86_64<64>*
do_make_data_plt(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative,unsigned int plt_count)2967 Target_x86_64<64>::do_make_data_plt(Layout* layout,
2968 				    Output_data_got<64, false>* got,
2969 				    Output_data_got_plt_x86_64* got_plt,
2970 				    Output_data_space* got_irelative,
2971 				    unsigned int plt_count)
2972 {
2973   if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
2974     return new Output_data_plt_x86_64_ibt<64>(layout, got, got_plt,
2975 					      got_irelative, plt_count);
2976   else if (parameters->options().bndplt())
2977     return new Output_data_plt_x86_64_bnd(layout, got, got_plt,
2978 					  got_irelative, plt_count);
2979   else
2980     return new Output_data_plt_x86_64_standard<64>(layout, got, got_plt,
2981 						   got_irelative,
2982 						   plt_count);
2983 }
2984 
2985 // Return the section for TLSDESC relocations.
2986 
2987 template<int size>
2988 typename Target_x86_64<size>::Reloc_section*
rela_tlsdesc_section(Layout * layout) const2989 Target_x86_64<size>::rela_tlsdesc_section(Layout* layout) const
2990 {
2991   return this->plt_section()->rela_tlsdesc(layout);
2992 }
2993 
2994 // Create a PLT entry for a global symbol.
2995 
2996 template<int size>
2997 void
make_plt_entry(Symbol_table * symtab,Layout * layout,Symbol * gsym)2998 Target_x86_64<size>::make_plt_entry(Symbol_table* symtab, Layout* layout,
2999 				    Symbol* gsym)
3000 {
3001   if (gsym->has_plt_offset())
3002     return;
3003 
3004   if (this->plt_ == NULL)
3005     this->make_plt_section(symtab, layout);
3006 
3007   this->plt_->add_entry(symtab, layout, gsym);
3008 }
3009 
3010 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
3011 
3012 template<int size>
3013 void
make_local_ifunc_plt_entry(Symbol_table * symtab,Layout * layout,Sized_relobj_file<size,false> * relobj,unsigned int local_sym_index)3014 Target_x86_64<size>::make_local_ifunc_plt_entry(
3015     Symbol_table* symtab, Layout* layout,
3016     Sized_relobj_file<size, false>* relobj,
3017     unsigned int local_sym_index)
3018 {
3019   if (relobj->local_has_plt_offset(local_sym_index))
3020     return;
3021   if (this->plt_ == NULL)
3022     this->make_plt_section(symtab, layout);
3023   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
3024 							      relobj,
3025 							      local_sym_index);
3026   relobj->set_local_plt_offset(local_sym_index, plt_offset);
3027 }
3028 
3029 // Return the number of entries in the PLT.
3030 
3031 template<int size>
3032 unsigned int
plt_entry_count() const3033 Target_x86_64<size>::plt_entry_count() const
3034 {
3035   if (this->plt_ == NULL)
3036     return 0;
3037   return this->plt_->entry_count();
3038 }
3039 
3040 // Return the offset of the first non-reserved PLT entry.
3041 
3042 template<int size>
3043 unsigned int
first_plt_entry_offset() const3044 Target_x86_64<size>::first_plt_entry_offset() const
3045 {
3046   if (this->plt_ == NULL)
3047     return 0;
3048   return this->plt_->first_plt_entry_offset();
3049 }
3050 
3051 // Return the size of each PLT entry.
3052 
3053 template<int size>
3054 unsigned int
plt_entry_size() const3055 Target_x86_64<size>::plt_entry_size() const
3056 {
3057   if (this->plt_ == NULL)
3058     return 0;
3059   return this->plt_->get_plt_entry_size();
3060 }
3061 
3062 // Create the GOT and PLT sections for an incremental update.
3063 
3064 template<int size>
3065 Output_data_got_base*
init_got_plt_for_update(Symbol_table * symtab,Layout * layout,unsigned int got_count,unsigned int plt_count)3066 Target_x86_64<size>::init_got_plt_for_update(Symbol_table* symtab,
3067 				       Layout* layout,
3068 				       unsigned int got_count,
3069 				       unsigned int plt_count)
3070 {
3071   gold_assert(this->got_ == NULL);
3072 
3073   this->got_ = new Output_data_got<64, false>(got_count * 8);
3074   layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
3075 				  (elfcpp::SHF_ALLOC
3076 				   | elfcpp::SHF_WRITE),
3077 				  this->got_, ORDER_RELRO_LAST,
3078 				  true);
3079 
3080   // Add the three reserved entries.
3081   this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8);
3082   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
3083 				  (elfcpp::SHF_ALLOC
3084 				   | elfcpp::SHF_WRITE),
3085 				  this->got_plt_, ORDER_NON_RELRO_FIRST,
3086 				  false);
3087 
3088   // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
3089   this->global_offset_table_ =
3090     symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
3091 				  Symbol_table::PREDEFINED,
3092 				  this->got_plt_,
3093 				  0, 0, elfcpp::STT_OBJECT,
3094 				  elfcpp::STB_LOCAL,
3095 				  elfcpp::STV_HIDDEN, 0,
3096 				  false, false);
3097 
3098   // If there are any TLSDESC relocations, they get GOT entries in
3099   // .got.plt after the jump slot entries.
3100   // FIXME: Get the count for TLSDESC entries.
3101   this->got_tlsdesc_ = new Output_data_got<64, false>(0);
3102   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
3103 				  elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
3104 				  this->got_tlsdesc_,
3105 				  ORDER_NON_RELRO_FIRST, false);
3106 
3107   // If there are any IRELATIVE relocations, they get GOT entries in
3108   // .got.plt after the jump slot and TLSDESC entries.
3109   this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
3110   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
3111 				  elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
3112 				  this->got_irelative_,
3113 				  ORDER_NON_RELRO_FIRST, false);
3114 
3115   // Create the PLT section.
3116   this->plt_ = this->make_data_plt(layout, this->got_,
3117 				   this->got_plt_,
3118 				   this->got_irelative_,
3119 				   plt_count);
3120 
3121   // Add unwind information if requested.
3122   if (parameters->options().ld_generated_unwind_info())
3123     this->plt_->add_eh_frame(layout);
3124 
3125   layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
3126 				  elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
3127 				  this->plt_, ORDER_PLT, false);
3128 
3129   // Make the sh_info field of .rela.plt point to .plt.
3130   Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
3131   rela_plt_os->set_info_section(this->plt_->output_section());
3132 
3133   // Create the rela_dyn section.
3134   this->rela_dyn_section(layout);
3135 
3136   return this->got_;
3137 }
3138 
3139 // Reserve a GOT entry for a local symbol, and regenerate any
3140 // necessary dynamic relocations.
3141 
3142 template<int size>
3143 void
reserve_local_got_entry(unsigned int got_index,Sized_relobj<size,false> * obj,unsigned int r_sym,unsigned int got_type)3144 Target_x86_64<size>::reserve_local_got_entry(
3145     unsigned int got_index,
3146     Sized_relobj<size, false>* obj,
3147     unsigned int r_sym,
3148     unsigned int got_type)
3149 {
3150   unsigned int got_offset = got_index * 8;
3151   Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
3152 
3153   this->got_->reserve_local(got_index, obj, r_sym, got_type);
3154   switch (got_type)
3155     {
3156     case GOT_TYPE_STANDARD:
3157       if (parameters->options().output_is_position_independent())
3158 	rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
3159 				     this->got_, got_offset, 0, false);
3160       break;
3161     case GOT_TYPE_TLS_OFFSET:
3162       rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
3163 			  this->got_, got_offset, 0);
3164       break;
3165     case GOT_TYPE_TLS_PAIR:
3166       this->got_->reserve_slot(got_index + 1);
3167       rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
3168 			  this->got_, got_offset, 0);
3169       break;
3170     case GOT_TYPE_TLS_DESC:
3171       gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
3172       // this->got_->reserve_slot(got_index + 1);
3173       // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
3174       //			       this->got_, got_offset, 0);
3175       break;
3176     default:
3177       gold_unreachable();
3178     }
3179 }
3180 
3181 // Reserve a GOT entry for a global symbol, and regenerate any
3182 // necessary dynamic relocations.
3183 
3184 template<int size>
3185 void
reserve_global_got_entry(unsigned int got_index,Symbol * gsym,unsigned int got_type)3186 Target_x86_64<size>::reserve_global_got_entry(unsigned int got_index,
3187 					      Symbol* gsym,
3188 					      unsigned int got_type)
3189 {
3190   unsigned int got_offset = got_index * 8;
3191   Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
3192 
3193   this->got_->reserve_global(got_index, gsym, got_type);
3194   switch (got_type)
3195     {
3196     case GOT_TYPE_STANDARD:
3197       if (!gsym->final_value_is_known())
3198 	{
3199 	  if (gsym->is_from_dynobj()
3200 	      || gsym->is_undefined()
3201 	      || gsym->is_preemptible()
3202 	      || gsym->type() == elfcpp::STT_GNU_IFUNC)
3203 	    rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
3204 				 this->got_, got_offset, 0);
3205 	  else
3206 	    rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
3207 					  this->got_, got_offset, 0, false);
3208 	}
3209       break;
3210     case GOT_TYPE_TLS_OFFSET:
3211       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
3212 				    this->got_, got_offset, 0, false);
3213       break;
3214     case GOT_TYPE_TLS_PAIR:
3215       this->got_->reserve_slot(got_index + 1);
3216       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
3217 				    this->got_, got_offset, 0, false);
3218       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
3219 				    this->got_, got_offset + 8, 0, false);
3220       break;
3221     case GOT_TYPE_TLS_DESC:
3222       this->got_->reserve_slot(got_index + 1);
3223       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
3224 				    this->got_, got_offset, 0, false);
3225       break;
3226     default:
3227       gold_unreachable();
3228     }
3229 }
3230 
3231 // Register an existing PLT entry for a global symbol.
3232 
3233 template<int size>
3234 void
register_global_plt_entry(Symbol_table * symtab,Layout * layout,unsigned int plt_index,Symbol * gsym)3235 Target_x86_64<size>::register_global_plt_entry(Symbol_table* symtab,
3236 					       Layout* layout,
3237 					       unsigned int plt_index,
3238 					       Symbol* gsym)
3239 {
3240   gold_assert(this->plt_ != NULL);
3241   gold_assert(!gsym->has_plt_offset());
3242 
3243   this->plt_->reserve_slot(plt_index);
3244 
3245   gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
3246 
3247   unsigned int got_offset = (plt_index + 3) * 8;
3248   this->plt_->add_relocation(symtab, layout, gsym, got_offset);
3249 }
3250 
3251 // Force a COPY relocation for a given symbol.
3252 
3253 template<int size>
3254 void
emit_copy_reloc(Symbol_table * symtab,Symbol * sym,Output_section * os,off_t offset)3255 Target_x86_64<size>::emit_copy_reloc(
3256     Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
3257 {
3258   this->copy_relocs_.emit_copy_reloc(symtab,
3259 				     symtab->get_sized_symbol<size>(sym),
3260 				     os,
3261 				     offset,
3262 				     this->rela_dyn_section(NULL));
3263 }
3264 
3265 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
3266 
3267 template<int size>
3268 void
define_tls_base_symbol(Symbol_table * symtab,Layout * layout)3269 Target_x86_64<size>::define_tls_base_symbol(Symbol_table* symtab,
3270 					    Layout* layout)
3271 {
3272   if (this->tls_base_symbol_defined_)
3273     return;
3274 
3275   Output_segment* tls_segment = layout->tls_segment();
3276   if (tls_segment != NULL)
3277     {
3278       bool is_exec = parameters->options().output_is_executable();
3279       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
3280 				       Symbol_table::PREDEFINED,
3281 				       tls_segment, 0, 0,
3282 				       elfcpp::STT_TLS,
3283 				       elfcpp::STB_LOCAL,
3284 				       elfcpp::STV_HIDDEN, 0,
3285 				       (is_exec
3286 					? Symbol::SEGMENT_END
3287 					: Symbol::SEGMENT_START),
3288 				       true);
3289     }
3290   this->tls_base_symbol_defined_ = true;
3291 }
3292 
3293 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
3294 
3295 template<int size>
3296 void
reserve_tlsdesc_entries(Symbol_table * symtab,Layout * layout)3297 Target_x86_64<size>::reserve_tlsdesc_entries(Symbol_table* symtab,
3298 					     Layout* layout)
3299 {
3300   if (this->plt_ == NULL)
3301     this->make_plt_section(symtab, layout);
3302 
3303   if (!this->plt_->has_tlsdesc_entry())
3304     {
3305       // Allocate the TLSDESC_GOT entry.
3306       Output_data_got<64, false>* got = this->got_section(symtab, layout);
3307       unsigned int got_offset = got->add_constant(0);
3308 
3309       // Allocate the TLSDESC_PLT entry.
3310       this->plt_->reserve_tlsdesc_entry(got_offset);
3311     }
3312 }
3313 
3314 // Create a GOT entry for the TLS module index.
3315 
3316 template<int size>
3317 unsigned int
got_mod_index_entry(Symbol_table * symtab,Layout * layout,Sized_relobj_file<size,false> * object)3318 Target_x86_64<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
3319 					 Sized_relobj_file<size, false>* object)
3320 {
3321   if (this->got_mod_index_offset_ == -1U)
3322     {
3323       gold_assert(symtab != NULL && layout != NULL && object != NULL);
3324       Reloc_section* rela_dyn = this->rela_dyn_section(layout);
3325       Output_data_got<64, false>* got = this->got_section(symtab, layout);
3326       unsigned int got_offset = got->add_constant(0);
3327       rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
3328 			  got_offset, 0);
3329       got->add_constant(0);
3330       this->got_mod_index_offset_ = got_offset;
3331     }
3332   return this->got_mod_index_offset_;
3333 }
3334 
3335 // Optimize the TLS relocation type based on what we know about the
3336 // symbol.  IS_FINAL is true if the final address of this symbol is
3337 // known at link time.
3338 
3339 template<int size>
3340 tls::Tls_optimization
optimize_tls_reloc(bool is_final,int r_type)3341 Target_x86_64<size>::optimize_tls_reloc(bool is_final, int r_type)
3342 {
3343   // If we are generating a shared library, then we can't do anything
3344   // in the linker.
3345   if (parameters->options().shared())
3346     return tls::TLSOPT_NONE;
3347 
3348   switch (r_type)
3349     {
3350     case elfcpp::R_X86_64_TLSGD:
3351     case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3352     case elfcpp::R_X86_64_TLSDESC_CALL:
3353       // These are General-Dynamic which permits fully general TLS
3354       // access.  Since we know that we are generating an executable,
3355       // we can convert this to Initial-Exec.  If we also know that
3356       // this is a local symbol, we can further switch to Local-Exec.
3357       if (is_final)
3358 	return tls::TLSOPT_TO_LE;
3359       return tls::TLSOPT_TO_IE;
3360 
3361     case elfcpp::R_X86_64_TLSLD:
3362       // This is Local-Dynamic, which refers to a local symbol in the
3363       // dynamic TLS block.  Since we know that we generating an
3364       // executable, we can switch to Local-Exec.
3365       return tls::TLSOPT_TO_LE;
3366 
3367     case elfcpp::R_X86_64_DTPOFF32:
3368     case elfcpp::R_X86_64_DTPOFF64:
3369       // Another Local-Dynamic reloc.
3370       return tls::TLSOPT_TO_LE;
3371 
3372     case elfcpp::R_X86_64_GOTTPOFF:
3373       // These are Initial-Exec relocs which get the thread offset
3374       // from the GOT.  If we know that we are linking against the
3375       // local symbol, we can switch to Local-Exec, which links the
3376       // thread offset into the instruction.
3377       if (is_final)
3378 	return tls::TLSOPT_TO_LE;
3379       return tls::TLSOPT_NONE;
3380 
3381     case elfcpp::R_X86_64_TPOFF32:
3382       // When we already have Local-Exec, there is nothing further we
3383       // can do.
3384       return tls::TLSOPT_NONE;
3385 
3386     default:
3387       gold_unreachable();
3388     }
3389 }
3390 
3391 // Get the Reference_flags for a particular relocation.
3392 
3393 template<int size>
3394 int
get_reference_flags(unsigned int r_type)3395 Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
3396 {
3397   switch (r_type)
3398     {
3399     case elfcpp::R_X86_64_NONE:
3400     case elfcpp::R_X86_64_GNU_VTINHERIT:
3401     case elfcpp::R_X86_64_GNU_VTENTRY:
3402     case elfcpp::R_X86_64_GOTPC32:
3403     case elfcpp::R_X86_64_GOTPC64:
3404       // No symbol reference.
3405       return 0;
3406 
3407     case elfcpp::R_X86_64_64:
3408     case elfcpp::R_X86_64_32:
3409     case elfcpp::R_X86_64_32S:
3410     case elfcpp::R_X86_64_16:
3411     case elfcpp::R_X86_64_8:
3412       return Symbol::ABSOLUTE_REF;
3413 
3414     case elfcpp::R_X86_64_PC64:
3415     case elfcpp::R_X86_64_PC32:
3416     case elfcpp::R_X86_64_PC32_BND:
3417     case elfcpp::R_X86_64_PC16:
3418     case elfcpp::R_X86_64_PC8:
3419     case elfcpp::R_X86_64_GOTOFF64:
3420       return Symbol::RELATIVE_REF;
3421 
3422     case elfcpp::R_X86_64_PLT32:
3423     case elfcpp::R_X86_64_PLT32_BND:
3424     case elfcpp::R_X86_64_PLTOFF64:
3425       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
3426 
3427     case elfcpp::R_X86_64_GOT64:
3428     case elfcpp::R_X86_64_GOT32:
3429     case elfcpp::R_X86_64_GOTPCREL64:
3430     case elfcpp::R_X86_64_GOTPCREL:
3431     case elfcpp::R_X86_64_GOTPCRELX:
3432     case elfcpp::R_X86_64_REX_GOTPCRELX:
3433     case elfcpp::R_X86_64_GOTPLT64:
3434       // Absolute in GOT.
3435       return Symbol::ABSOLUTE_REF;
3436 
3437     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3438     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3439     case elfcpp::R_X86_64_TLSDESC_CALL:
3440     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3441     case elfcpp::R_X86_64_DTPOFF32:
3442     case elfcpp::R_X86_64_DTPOFF64:
3443     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3444     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3445       return Symbol::TLS_REF;
3446 
3447     case elfcpp::R_X86_64_COPY:
3448     case elfcpp::R_X86_64_GLOB_DAT:
3449     case elfcpp::R_X86_64_JUMP_SLOT:
3450     case elfcpp::R_X86_64_RELATIVE:
3451     case elfcpp::R_X86_64_IRELATIVE:
3452     case elfcpp::R_X86_64_TPOFF64:
3453     case elfcpp::R_X86_64_DTPMOD64:
3454     case elfcpp::R_X86_64_TLSDESC:
3455     case elfcpp::R_X86_64_SIZE32:
3456     case elfcpp::R_X86_64_SIZE64:
3457     default:
3458       // Not expected.  We will give an error later.
3459       return 0;
3460     }
3461 }
3462 
3463 // Report an unsupported relocation against a local symbol.
3464 
3465 template<int size>
3466 void
unsupported_reloc_local(Sized_relobj_file<size,false> * object,unsigned int r_type)3467 Target_x86_64<size>::Scan::unsupported_reloc_local(
3468      Sized_relobj_file<size, false>* object,
3469      unsigned int r_type)
3470 {
3471   gold_error(_("%s: unsupported reloc %u against local symbol"),
3472 	     object->name().c_str(), r_type);
3473 }
3474 
3475 // We are about to emit a dynamic relocation of type R_TYPE.  If the
3476 // dynamic linker does not support it, issue an error.  The GNU linker
3477 // only issues a non-PIC error for an allocated read-only section.
3478 // Here we know the section is allocated, but we don't know that it is
3479 // read-only.  But we check for all the relocation types which the
3480 // glibc dynamic linker supports, so it seems appropriate to issue an
3481 // error even if the section is not read-only.  If GSYM is not NULL,
3482 // it is the symbol the relocation is against; if it is NULL, the
3483 // relocation is against a local symbol.
3484 
3485 template<int size>
3486 void
check_non_pic(Relobj * object,unsigned int r_type,Symbol * gsym)3487 Target_x86_64<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type,
3488 					 Symbol* gsym)
3489 {
3490   switch (r_type)
3491     {
3492       // These are the relocation types supported by glibc for x86_64
3493       // which should always work.
3494     case elfcpp::R_X86_64_RELATIVE:
3495     case elfcpp::R_X86_64_IRELATIVE:
3496     case elfcpp::R_X86_64_GLOB_DAT:
3497     case elfcpp::R_X86_64_JUMP_SLOT:
3498     case elfcpp::R_X86_64_DTPMOD64:
3499     case elfcpp::R_X86_64_DTPOFF64:
3500     case elfcpp::R_X86_64_TPOFF64:
3501     case elfcpp::R_X86_64_64:
3502     case elfcpp::R_X86_64_COPY:
3503       return;
3504 
3505       // glibc supports these reloc types, but they can overflow.
3506     case elfcpp::R_X86_64_PC32:
3507     case elfcpp::R_X86_64_PC32_BND:
3508       // A PC relative reference is OK against a local symbol or if
3509       // the symbol is defined locally.
3510       if (gsym == NULL
3511 	  || (!gsym->is_from_dynobj()
3512 	      && !gsym->is_undefined()
3513 	      && !gsym->is_preemptible()))
3514 	return;
3515       // Fall through.
3516     case elfcpp::R_X86_64_32:
3517       // R_X86_64_32 is OK for x32.
3518       if (size == 32 && r_type == elfcpp::R_X86_64_32)
3519 	return;
3520       if (this->issued_non_pic_error_)
3521 	return;
3522       gold_assert(parameters->options().output_is_position_independent());
3523       if (gsym == NULL)
3524 	object->error(_("requires dynamic R_X86_64_32 reloc which may "
3525 			"overflow at runtime; recompile with -fPIC"));
3526       else
3527 	{
3528 	  const char *r_name;
3529 	  switch (r_type)
3530 	    {
3531 	    case elfcpp::R_X86_64_32:
3532 	      r_name = "R_X86_64_32";
3533 	      break;
3534 	    case elfcpp::R_X86_64_PC32:
3535 	      r_name = "R_X86_64_PC32";
3536 	      break;
3537 	    case elfcpp::R_X86_64_PC32_BND:
3538 	      r_name = "R_X86_64_PC32_BND";
3539 	      break;
3540 	    default:
3541 	      gold_unreachable();
3542 	      break;
3543 	    }
3544 	  object->error(_("requires dynamic %s reloc against '%s' "
3545 			  "which may overflow at runtime; recompile "
3546 			  "with -fPIC"),
3547 			r_name, gsym->name());
3548 	}
3549       this->issued_non_pic_error_ = true;
3550       return;
3551 
3552     default:
3553       // This prevents us from issuing more than one error per reloc
3554       // section.  But we can still wind up issuing more than one
3555       // error per object file.
3556       if (this->issued_non_pic_error_)
3557 	return;
3558       gold_assert(parameters->options().output_is_position_independent());
3559       object->error(_("requires unsupported dynamic reloc %u; "
3560 		      "recompile with -fPIC"),
3561 		    r_type);
3562       this->issued_non_pic_error_ = true;
3563       return;
3564 
3565     case elfcpp::R_X86_64_NONE:
3566       gold_unreachable();
3567     }
3568 }
3569 
3570 // Return whether we need to make a PLT entry for a relocation of the
3571 // given type against a STT_GNU_IFUNC symbol.
3572 
3573 template<int size>
3574 bool
reloc_needs_plt_for_ifunc(Sized_relobj_file<size,false> * object,unsigned int r_type)3575 Target_x86_64<size>::Scan::reloc_needs_plt_for_ifunc(
3576      Sized_relobj_file<size, false>* object,
3577      unsigned int r_type)
3578 {
3579   int flags = Scan::get_reference_flags(r_type);
3580   if (flags & Symbol::TLS_REF)
3581     gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
3582 	       object->name().c_str(), r_type);
3583   return flags != 0;
3584 }
3585 
3586 // Scan a relocation for a local symbol.
3587 
3588 template<int size>
3589 inline void
local(Symbol_table * symtab,Layout * layout,Target_x86_64<size> * target,Sized_relobj_file<size,false> * object,unsigned int data_shndx,Output_section * output_section,const elfcpp::Rela<size,false> & reloc,unsigned int r_type,const elfcpp::Sym<size,false> & lsym,bool is_discarded)3590 Target_x86_64<size>::Scan::local(Symbol_table* symtab,
3591 				 Layout* layout,
3592 				 Target_x86_64<size>* target,
3593 				 Sized_relobj_file<size, false>* object,
3594 				 unsigned int data_shndx,
3595 				 Output_section* output_section,
3596 				 const elfcpp::Rela<size, false>& reloc,
3597 				 unsigned int r_type,
3598 				 const elfcpp::Sym<size, false>& lsym,
3599 				 bool is_discarded)
3600 {
3601   if (is_discarded)
3602     return;
3603 
3604   // A local STT_GNU_IFUNC symbol may require a PLT entry.
3605   bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
3606   if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
3607     {
3608       unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3609       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
3610     }
3611 
3612   switch (r_type)
3613     {
3614     case elfcpp::R_X86_64_NONE:
3615     case elfcpp::R_X86_64_GNU_VTINHERIT:
3616     case elfcpp::R_X86_64_GNU_VTENTRY:
3617       break;
3618 
3619     case elfcpp::R_X86_64_64:
3620       // If building a shared library (or a position-independent
3621       // executable), we need to create a dynamic relocation for this
3622       // location.  The relocation applied at link time will apply the
3623       // link-time value, so we flag the location with an
3624       // R_X86_64_RELATIVE relocation so the dynamic loader can
3625       // relocate it easily.
3626       if (parameters->options().output_is_position_independent())
3627 	{
3628 	  unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3629 	  Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3630 	  rela_dyn->add_local_relative(object, r_sym,
3631 				       (size == 32
3632 					? elfcpp::R_X86_64_RELATIVE64
3633 					: elfcpp::R_X86_64_RELATIVE),
3634 				       output_section, data_shndx,
3635 				       reloc.get_r_offset(),
3636 				       reloc.get_r_addend(), is_ifunc);
3637 	}
3638       break;
3639 
3640     case elfcpp::R_X86_64_32:
3641     case elfcpp::R_X86_64_32S:
3642     case elfcpp::R_X86_64_16:
3643     case elfcpp::R_X86_64_8:
3644       // If building a shared library (or a position-independent
3645       // executable), we need to create a dynamic relocation for this
3646       // location.  We can't use an R_X86_64_RELATIVE relocation
3647       // because that is always a 64-bit relocation.
3648       if (parameters->options().output_is_position_independent())
3649 	{
3650 	  // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
3651 	  if (size == 32 && r_type == elfcpp::R_X86_64_32)
3652 	    {
3653 	      unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3654 	      Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3655 	      rela_dyn->add_local_relative(object, r_sym,
3656 					   elfcpp::R_X86_64_RELATIVE,
3657 					   output_section, data_shndx,
3658 					   reloc.get_r_offset(),
3659 					   reloc.get_r_addend(), is_ifunc);
3660 	      break;
3661 	    }
3662 
3663 	  this->check_non_pic(object, r_type, NULL);
3664 
3665 	  Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3666 	  unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3667 	  if (lsym.get_st_type() != elfcpp::STT_SECTION)
3668 	    rela_dyn->add_local(object, r_sym, r_type, output_section,
3669 				data_shndx, reloc.get_r_offset(),
3670 				reloc.get_r_addend());
3671 	  else
3672 	    {
3673 	      gold_assert(lsym.get_st_value() == 0);
3674 	      unsigned int shndx = lsym.get_st_shndx();
3675 	      bool is_ordinary;
3676 	      shndx = object->adjust_sym_shndx(r_sym, shndx,
3677 					       &is_ordinary);
3678 	      if (!is_ordinary)
3679 		object->error(_("section symbol %u has bad shndx %u"),
3680 			      r_sym, shndx);
3681 	      else
3682 		rela_dyn->add_local_section(object, shndx,
3683 					    r_type, output_section,
3684 					    data_shndx, reloc.get_r_offset(),
3685 					    reloc.get_r_addend());
3686 	    }
3687 	}
3688       break;
3689 
3690     case elfcpp::R_X86_64_PC64:
3691     case elfcpp::R_X86_64_PC32:
3692     case elfcpp::R_X86_64_PC32_BND:
3693     case elfcpp::R_X86_64_PC16:
3694     case elfcpp::R_X86_64_PC8:
3695       break;
3696 
3697     case elfcpp::R_X86_64_PLT32:
3698     case elfcpp::R_X86_64_PLT32_BND:
3699       // Since we know this is a local symbol, we can handle this as a
3700       // PC32 reloc.
3701       break;
3702 
3703     case elfcpp::R_X86_64_GOTPC32:
3704     case elfcpp::R_X86_64_GOTOFF64:
3705     case elfcpp::R_X86_64_GOTPC64:
3706     case elfcpp::R_X86_64_PLTOFF64:
3707       // We need a GOT section.
3708       target->got_section(symtab, layout);
3709       // For PLTOFF64, we'd normally want a PLT section, but since we
3710       // know this is a local symbol, no PLT is needed.
3711       break;
3712 
3713     case elfcpp::R_X86_64_GOT64:
3714     case elfcpp::R_X86_64_GOT32:
3715     case elfcpp::R_X86_64_GOTPCREL64:
3716     case elfcpp::R_X86_64_GOTPCREL:
3717     case elfcpp::R_X86_64_GOTPCRELX:
3718     case elfcpp::R_X86_64_REX_GOTPCRELX:
3719     case elfcpp::R_X86_64_GOTPLT64:
3720       {
3721 	// The symbol requires a GOT section.
3722 	Output_data_got<64, false>* got = target->got_section(symtab, layout);
3723 
3724 	// If the relocation symbol isn't IFUNC,
3725 	// and is local, then we will convert
3726 	// mov foo@GOTPCREL(%rip), %reg
3727 	// to lea foo(%rip), %reg.
3728 	// in Relocate::relocate.
3729 	if (!parameters->incremental()
3730 	    && (r_type == elfcpp::R_X86_64_GOTPCREL
3731 		|| r_type == elfcpp::R_X86_64_GOTPCRELX
3732 		|| r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
3733 	    && reloc.get_r_addend() == -4
3734 	    && reloc.get_r_offset() >= 2
3735 	    && !is_ifunc)
3736 	  {
3737 	    section_size_type stype;
3738 	    const unsigned char* view = object->section_contents(data_shndx,
3739 								 &stype, true);
3740 	    if (view[reloc.get_r_offset() - 2] == 0x8b)
3741 	      break;
3742 	  }
3743 
3744 	// The symbol requires a GOT entry.
3745 	unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3746 
3747 	// For a STT_GNU_IFUNC symbol we want the PLT offset.  That
3748 	// lets function pointers compare correctly with shared
3749 	// libraries.  Otherwise we would need an IRELATIVE reloc.
3750 	bool is_new;
3751 	if (is_ifunc)
3752 	  is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
3753 	else
3754 	  is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
3755 	if (is_new)
3756 	  {
3757 	    // If we are generating a shared object, we need to add a
3758 	    // dynamic relocation for this symbol's GOT entry.
3759 	    if (parameters->options().output_is_position_independent())
3760 	      {
3761 		Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3762 		// R_X86_64_RELATIVE assumes a 64-bit relocation.
3763 		if (r_type != elfcpp::R_X86_64_GOT32)
3764 		  {
3765 		    unsigned int got_offset =
3766 		      object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
3767 		    rela_dyn->add_local_relative(object, r_sym,
3768 						 elfcpp::R_X86_64_RELATIVE,
3769 						 got, got_offset, 0, is_ifunc);
3770 		  }
3771 		else
3772 		  {
3773 		    this->check_non_pic(object, r_type, NULL);
3774 
3775 		    gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
3776 		    rela_dyn->add_local(
3777 			object, r_sym, r_type, got,
3778 			object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
3779 		  }
3780 	      }
3781 	  }
3782 	// For GOTPLT64, we'd normally want a PLT section, but since
3783 	// we know this is a local symbol, no PLT is needed.
3784       }
3785       break;
3786 
3787     case elfcpp::R_X86_64_COPY:
3788     case elfcpp::R_X86_64_GLOB_DAT:
3789     case elfcpp::R_X86_64_JUMP_SLOT:
3790     case elfcpp::R_X86_64_RELATIVE:
3791     case elfcpp::R_X86_64_IRELATIVE:
3792       // These are outstanding tls relocs, which are unexpected when linking
3793     case elfcpp::R_X86_64_TPOFF64:
3794     case elfcpp::R_X86_64_DTPMOD64:
3795     case elfcpp::R_X86_64_TLSDESC:
3796       gold_error(_("%s: unexpected reloc %u in object file"),
3797 		 object->name().c_str(), r_type);
3798       break;
3799 
3800       // These are initial tls relocs, which are expected when linking
3801     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3802     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3803     case elfcpp::R_X86_64_TLSDESC_CALL:
3804     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3805     case elfcpp::R_X86_64_DTPOFF32:
3806     case elfcpp::R_X86_64_DTPOFF64:
3807     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3808     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3809       {
3810 	bool output_is_shared = parameters->options().shared();
3811 	const tls::Tls_optimization optimized_type
3812 	    = Target_x86_64<size>::optimize_tls_reloc(!output_is_shared,
3813 						      r_type);
3814 	switch (r_type)
3815 	  {
3816 	  case elfcpp::R_X86_64_TLSGD:       // General-dynamic
3817 	    if (optimized_type == tls::TLSOPT_NONE)
3818 	      {
3819 		// Create a pair of GOT entries for the module index and
3820 		// dtv-relative offset.
3821 		Output_data_got<64, false>* got
3822 		    = target->got_section(symtab, layout);
3823 		unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3824 		unsigned int shndx = lsym.get_st_shndx();
3825 		bool is_ordinary;
3826 		shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
3827 		if (!is_ordinary)
3828 		  object->error(_("local symbol %u has bad shndx %u"),
3829 			      r_sym, shndx);
3830 		else
3831 		  got->add_local_pair_with_rel(object, r_sym,
3832 					       shndx,
3833 					       GOT_TYPE_TLS_PAIR,
3834 					       target->rela_dyn_section(layout),
3835 					       elfcpp::R_X86_64_DTPMOD64);
3836 	      }
3837 	    else if (optimized_type != tls::TLSOPT_TO_LE)
3838 	      unsupported_reloc_local(object, r_type);
3839 	    break;
3840 
3841 	  case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3842 	    target->define_tls_base_symbol(symtab, layout);
3843 	    if (optimized_type == tls::TLSOPT_NONE)
3844 	      {
3845 		// Create reserved PLT and GOT entries for the resolver.
3846 		target->reserve_tlsdesc_entries(symtab, layout);
3847 
3848 		// Generate a double GOT entry with an
3849 		// R_X86_64_TLSDESC reloc.  The R_X86_64_TLSDESC reloc
3850 		// is resolved lazily, so the GOT entry needs to be in
3851 		// an area in .got.plt, not .got.  Call got_section to
3852 		// make sure the section has been created.
3853 		target->got_section(symtab, layout);
3854 		Output_data_got<64, false>* got = target->got_tlsdesc_section();
3855 		unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3856 		if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
3857 		  {
3858 		    unsigned int got_offset = got->add_constant(0);
3859 		    got->add_constant(0);
3860 		    object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
3861 						 got_offset);
3862 		    Reloc_section* rt = target->rela_tlsdesc_section(layout);
3863 		    // We store the arguments we need in a vector, and
3864 		    // use the index into the vector as the parameter
3865 		    // to pass to the target specific routines.
3866 		    uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
3867 		    void* arg = reinterpret_cast<void*>(intarg);
3868 		    rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
3869 					    got, got_offset, 0);
3870 		  }
3871 	      }
3872 	    else if (optimized_type != tls::TLSOPT_TO_LE)
3873 	      unsupported_reloc_local(object, r_type);
3874 	    break;
3875 
3876 	  case elfcpp::R_X86_64_TLSDESC_CALL:
3877 	    break;
3878 
3879 	  case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
3880 	    if (optimized_type == tls::TLSOPT_NONE)
3881 	      {
3882 		// Create a GOT entry for the module index.
3883 		target->got_mod_index_entry(symtab, layout, object);
3884 	      }
3885 	    else if (optimized_type != tls::TLSOPT_TO_LE)
3886 	      unsupported_reloc_local(object, r_type);
3887 	    break;
3888 
3889 	  case elfcpp::R_X86_64_DTPOFF32:
3890 	  case elfcpp::R_X86_64_DTPOFF64:
3891 	    break;
3892 
3893 	  case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
3894 	    layout->set_has_static_tls();
3895 	    if (optimized_type == tls::TLSOPT_NONE)
3896 	      {
3897 		// Create a GOT entry for the tp-relative offset.
3898 		Output_data_got<64, false>* got
3899 		    = target->got_section(symtab, layout);
3900 		unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3901 		got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
3902 					target->rela_dyn_section(layout),
3903 					elfcpp::R_X86_64_TPOFF64);
3904 	      }
3905 	    else if (optimized_type != tls::TLSOPT_TO_LE)
3906 	      unsupported_reloc_local(object, r_type);
3907 	    break;
3908 
3909 	  case elfcpp::R_X86_64_TPOFF32:     // Local-exec
3910 	    layout->set_has_static_tls();
3911 	    if (output_is_shared)
3912 	      unsupported_reloc_local(object, r_type);
3913 	    break;
3914 
3915 	  default:
3916 	    gold_unreachable();
3917 	  }
3918       }
3919       break;
3920 
3921     case elfcpp::R_X86_64_SIZE32:
3922     case elfcpp::R_X86_64_SIZE64:
3923     default:
3924       gold_error(_("%s: unsupported reloc %u against local symbol"),
3925 		 object->name().c_str(), r_type);
3926       break;
3927     }
3928 }
3929 
3930 
3931 // Report an unsupported relocation against a global symbol.
3932 
3933 template<int size>
3934 void
unsupported_reloc_global(Sized_relobj_file<size,false> * object,unsigned int r_type,Symbol * gsym)3935 Target_x86_64<size>::Scan::unsupported_reloc_global(
3936     Sized_relobj_file<size, false>* object,
3937     unsigned int r_type,
3938     Symbol* gsym)
3939 {
3940   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3941 	     object->name().c_str(), r_type, gsym->demangled_name().c_str());
3942 }
3943 
3944 // Returns true if this relocation type could be that of a function pointer.
3945 template<int size>
3946 inline bool
possible_function_pointer_reloc(Sized_relobj_file<size,false> * src_obj,unsigned int src_indx,unsigned int r_offset,unsigned int r_type)3947 Target_x86_64<size>::Scan::possible_function_pointer_reloc(
3948     Sized_relobj_file<size, false>* src_obj,
3949     unsigned int src_indx,
3950     unsigned int r_offset,
3951     unsigned int r_type)
3952 {
3953   switch (r_type)
3954     {
3955     case elfcpp::R_X86_64_64:
3956     case elfcpp::R_X86_64_32:
3957     case elfcpp::R_X86_64_32S:
3958     case elfcpp::R_X86_64_16:
3959     case elfcpp::R_X86_64_8:
3960     case elfcpp::R_X86_64_GOT64:
3961     case elfcpp::R_X86_64_GOT32:
3962     case elfcpp::R_X86_64_GOTPCREL64:
3963     case elfcpp::R_X86_64_GOTPCREL:
3964     case elfcpp::R_X86_64_GOTPCRELX:
3965     case elfcpp::R_X86_64_REX_GOTPCRELX:
3966     case elfcpp::R_X86_64_GOTPLT64:
3967       {
3968 	return true;
3969       }
3970     case elfcpp::R_X86_64_PC32:
3971       {
3972         // This relocation may be used both for function calls and
3973         // for taking address of a function. We distinguish between
3974         // them by checking the opcodes.
3975         uint64_t sh_flags = src_obj->section_flags(src_indx);
3976         bool is_executable = (sh_flags & elfcpp::SHF_EXECINSTR) != 0;
3977         if (is_executable)
3978           {
3979             section_size_type stype;
3980             const unsigned char* view = src_obj->section_contents(src_indx,
3981                                                                   &stype,
3982                                                                   true);
3983 
3984             // call
3985             if (r_offset >= 1
3986                 && view[r_offset - 1] == 0xe8)
3987               return false;
3988 
3989             // jmp
3990             if (r_offset >= 1
3991                 && view[r_offset - 1] == 0xe9)
3992               return false;
3993 
3994             // jo/jno/jb/jnb/je/jne/jna/ja/js/jns/jp/jnp/jl/jge/jle/jg
3995             if (r_offset >= 2
3996                 && view[r_offset - 2] == 0x0f
3997                 && view[r_offset - 1] >= 0x80
3998                 && view[r_offset - 1] <= 0x8f)
3999               return false;
4000           }
4001 
4002         // Be conservative and treat all others as function pointers.
4003         return true;
4004       }
4005     }
4006   return false;
4007 }
4008 
4009 // For safe ICF, scan a relocation for a local symbol to check if it
4010 // corresponds to a function pointer being taken.  In that case mark
4011 // the function whose pointer was taken as not foldable.
4012 
4013 template<int size>
4014 inline bool
local_reloc_may_be_function_pointer(Symbol_table *,Layout *,Target_x86_64<size> *,Sized_relobj_file<size,false> * src_obj,unsigned int src_indx,Output_section *,const elfcpp::Rela<size,false> & reloc,unsigned int r_type,const elfcpp::Sym<size,false> &)4015 Target_x86_64<size>::Scan::local_reloc_may_be_function_pointer(
4016   Symbol_table* ,
4017   Layout* ,
4018   Target_x86_64<size>* ,
4019   Sized_relobj_file<size, false>* src_obj,
4020   unsigned int src_indx,
4021   Output_section* ,
4022   const elfcpp::Rela<size, false>& reloc,
4023   unsigned int r_type,
4024   const elfcpp::Sym<size, false>&)
4025 {
4026   return possible_function_pointer_reloc(src_obj, src_indx,
4027                                          reloc.get_r_offset(), r_type);
4028 }
4029 
4030 // For safe ICF, scan a relocation for a global symbol to check if it
4031 // corresponds to a function pointer being taken.  In that case mark
4032 // the function whose pointer was taken as not foldable.
4033 
4034 template<int size>
4035 inline bool
global_reloc_may_be_function_pointer(Symbol_table *,Layout *,Target_x86_64<size> *,Sized_relobj_file<size,false> * src_obj,unsigned int src_indx,Output_section *,const elfcpp::Rela<size,false> & reloc,unsigned int r_type,Symbol *)4036 Target_x86_64<size>::Scan::global_reloc_may_be_function_pointer(
4037   Symbol_table*,
4038   Layout* ,
4039   Target_x86_64<size>* ,
4040   Sized_relobj_file<size, false>* src_obj,
4041   unsigned int src_indx,
4042   Output_section* ,
4043   const elfcpp::Rela<size, false>& reloc,
4044   unsigned int r_type,
4045   Symbol*)
4046 {
4047   return possible_function_pointer_reloc(src_obj, src_indx,
4048                                          reloc.get_r_offset(), r_type);
4049 }
4050 
4051 // Scan a relocation for a global symbol.
4052 
4053 template<int size>
4054 inline void
global(Symbol_table * symtab,Layout * layout,Target_x86_64<size> * target,Sized_relobj_file<size,false> * object,unsigned int data_shndx,Output_section * output_section,const elfcpp::Rela<size,false> & reloc,unsigned int r_type,Symbol * gsym)4055 Target_x86_64<size>::Scan::global(Symbol_table* symtab,
4056 			    Layout* layout,
4057 			    Target_x86_64<size>* target,
4058 			    Sized_relobj_file<size, false>* object,
4059 			    unsigned int data_shndx,
4060 			    Output_section* output_section,
4061 			    const elfcpp::Rela<size, false>& reloc,
4062 			    unsigned int r_type,
4063 			    Symbol* gsym)
4064 {
4065   // A STT_GNU_IFUNC symbol may require a PLT entry.
4066   if (gsym->type() == elfcpp::STT_GNU_IFUNC
4067       && this->reloc_needs_plt_for_ifunc(object, r_type))
4068     target->make_plt_entry(symtab, layout, gsym);
4069 
4070   switch (r_type)
4071     {
4072     case elfcpp::R_X86_64_NONE:
4073     case elfcpp::R_X86_64_GNU_VTINHERIT:
4074     case elfcpp::R_X86_64_GNU_VTENTRY:
4075       break;
4076 
4077     case elfcpp::R_X86_64_64:
4078     case elfcpp::R_X86_64_32:
4079     case elfcpp::R_X86_64_32S:
4080     case elfcpp::R_X86_64_16:
4081     case elfcpp::R_X86_64_8:
4082       {
4083 	// Make a PLT entry if necessary.
4084 	if (gsym->needs_plt_entry())
4085 	  {
4086 	    target->make_plt_entry(symtab, layout, gsym);
4087 	    // Since this is not a PC-relative relocation, we may be
4088 	    // taking the address of a function. In that case we need to
4089 	    // set the entry in the dynamic symbol table to the address of
4090 	    // the PLT entry.
4091 	    if (gsym->is_from_dynobj() && !parameters->options().shared())
4092 	      gsym->set_needs_dynsym_value();
4093 	  }
4094 	// Make a dynamic relocation if necessary.
4095 	if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
4096 	  {
4097 	    if (!parameters->options().output_is_position_independent()
4098 		&& gsym->may_need_copy_reloc())
4099 	      {
4100 		target->copy_reloc(symtab, layout, object,
4101 				   data_shndx, output_section, gsym, reloc);
4102 	      }
4103 	    else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
4104 		      || (size == 32 && r_type == elfcpp::R_X86_64_32))
4105 		     && gsym->type() == elfcpp::STT_GNU_IFUNC
4106 		     && gsym->can_use_relative_reloc(false)
4107 		     && !gsym->is_from_dynobj()
4108 		     && !gsym->is_undefined()
4109 		     && !gsym->is_preemptible())
4110 	      {
4111 		// Use an IRELATIVE reloc for a locally defined
4112 		// STT_GNU_IFUNC symbol.  This makes a function
4113 		// address in a PIE executable match the address in a
4114 		// shared library that it links against.
4115 		Reloc_section* rela_dyn =
4116 		  target->rela_irelative_section(layout);
4117 		unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
4118 		rela_dyn->add_symbolless_global_addend(gsym, r_type,
4119 						       output_section, object,
4120 						       data_shndx,
4121 						       reloc.get_r_offset(),
4122 						       reloc.get_r_addend());
4123 	      }
4124 	    else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
4125 		      || (size == 32 && r_type == elfcpp::R_X86_64_32))
4126 		     && gsym->can_use_relative_reloc(false))
4127 	      {
4128 		Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4129 		rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
4130 					      output_section, object,
4131 					      data_shndx,
4132 					      reloc.get_r_offset(),
4133 					      reloc.get_r_addend(), false);
4134 	      }
4135 	    else
4136 	      {
4137 		this->check_non_pic(object, r_type, gsym);
4138 		Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4139 		rela_dyn->add_global(gsym, r_type, output_section, object,
4140 				     data_shndx, reloc.get_r_offset(),
4141 				     reloc.get_r_addend());
4142 	      }
4143 	  }
4144       }
4145       break;
4146 
4147     case elfcpp::R_X86_64_PC64:
4148     case elfcpp::R_X86_64_PC32:
4149     case elfcpp::R_X86_64_PC32_BND:
4150     case elfcpp::R_X86_64_PC16:
4151     case elfcpp::R_X86_64_PC8:
4152       {
4153 	// Make a PLT entry if necessary.
4154 	if (gsym->needs_plt_entry())
4155 	  target->make_plt_entry(symtab, layout, gsym);
4156 	// Make a dynamic relocation if necessary.
4157 	if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
4158 	  {
4159 	    if (parameters->options().output_is_executable()
4160 		&& gsym->may_need_copy_reloc())
4161 	      {
4162 		target->copy_reloc(symtab, layout, object,
4163 				   data_shndx, output_section, gsym, reloc);
4164 	      }
4165 	    else
4166 	      {
4167 		this->check_non_pic(object, r_type, gsym);
4168 		Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4169 		rela_dyn->add_global(gsym, r_type, output_section, object,
4170 				     data_shndx, reloc.get_r_offset(),
4171 				     reloc.get_r_addend());
4172 	      }
4173 	  }
4174       }
4175       break;
4176 
4177     case elfcpp::R_X86_64_GOT64:
4178     case elfcpp::R_X86_64_GOT32:
4179     case elfcpp::R_X86_64_GOTPCREL64:
4180     case elfcpp::R_X86_64_GOTPCREL:
4181     case elfcpp::R_X86_64_GOTPCRELX:
4182     case elfcpp::R_X86_64_REX_GOTPCRELX:
4183     case elfcpp::R_X86_64_GOTPLT64:
4184       {
4185 	// The symbol requires a GOT entry.
4186 	Output_data_got<64, false>* got = target->got_section(symtab, layout);
4187 
4188 	// If we convert this from
4189 	// mov foo@GOTPCREL(%rip), %reg
4190 	// to lea foo(%rip), %reg.
4191 	// OR
4192 	// if we convert
4193 	// (callq|jmpq) *foo@GOTPCRELX(%rip) to
4194 	// (callq|jmpq) foo
4195 	// in Relocate::relocate, then there is nothing to do here.
4196 	// We cannot make these optimizations in incremental linking mode,
4197 	// because we look at the opcode to decide whether or not to make
4198 	// change, and during an incremental update, the change may have
4199 	// already been applied.
4200 
4201         Lazy_view<size> view(object, data_shndx);
4202         size_t r_offset = reloc.get_r_offset();
4203         if (!parameters->incremental()
4204 	    && reloc.get_r_addend() == -4
4205 	    && r_offset >= 2
4206             && Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
4207                                                            r_offset, &view))
4208           break;
4209 
4210 	if (!parameters->incremental()
4211 	    && r_offset >= 2
4212 	    && Target_x86_64<size>::can_convert_callq_to_direct(gsym, r_type,
4213 								r_offset,
4214 								&view))
4215           break;
4216 
4217 	if (gsym->final_value_is_known())
4218 	  {
4219 	    // For a STT_GNU_IFUNC symbol we want the PLT address.
4220 	    if (gsym->type() == elfcpp::STT_GNU_IFUNC)
4221 	      got->add_global_plt(gsym, GOT_TYPE_STANDARD);
4222 	    else
4223 	      got->add_global(gsym, GOT_TYPE_STANDARD);
4224 	  }
4225 	else
4226 	  {
4227 	    // If this symbol is not fully resolved, we need to add a
4228 	    // dynamic relocation for it.
4229 	    Reloc_section* rela_dyn = target->rela_dyn_section(layout);
4230 
4231 	    // Use a GLOB_DAT rather than a RELATIVE reloc if:
4232 	    //
4233 	    // 1) The symbol may be defined in some other module.
4234 	    //
4235 	    // 2) We are building a shared library and this is a
4236 	    // protected symbol; using GLOB_DAT means that the dynamic
4237 	    // linker can use the address of the PLT in the main
4238 	    // executable when appropriate so that function address
4239 	    // comparisons work.
4240 	    //
4241 	    // 3) This is a STT_GNU_IFUNC symbol in position dependent
4242 	    // code, again so that function address comparisons work.
4243 	    if (gsym->is_from_dynobj()
4244 		|| gsym->is_undefined()
4245 		|| gsym->is_preemptible()
4246 		|| (gsym->visibility() == elfcpp::STV_PROTECTED
4247 		    && parameters->options().shared())
4248 		|| (gsym->type() == elfcpp::STT_GNU_IFUNC
4249 		    && parameters->options().output_is_position_independent()))
4250 	      got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
4251 				       elfcpp::R_X86_64_GLOB_DAT);
4252 	    else
4253 	      {
4254 		// For a STT_GNU_IFUNC symbol we want to write the PLT
4255 		// offset into the GOT, so that function pointer
4256 		// comparisons work correctly.
4257 		bool is_new;
4258 		if (gsym->type() != elfcpp::STT_GNU_IFUNC)
4259 		  is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
4260 		else
4261 		  {
4262 		    is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
4263 		    // Tell the dynamic linker to use the PLT address
4264 		    // when resolving relocations.
4265 		    if (gsym->is_from_dynobj()
4266 			&& !parameters->options().shared())
4267 		      gsym->set_needs_dynsym_value();
4268 		  }
4269 		if (is_new)
4270 		  {
4271 		    unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
4272 		    rela_dyn->add_global_relative(gsym,
4273 						  elfcpp::R_X86_64_RELATIVE,
4274 						  got, got_off, 0, false);
4275 		  }
4276 	      }
4277 	  }
4278       }
4279       break;
4280 
4281     case elfcpp::R_X86_64_PLT32:
4282     case elfcpp::R_X86_64_PLT32_BND:
4283       // If the symbol is fully resolved, this is just a PC32 reloc.
4284       // Otherwise we need a PLT entry.
4285       if (gsym->final_value_is_known())
4286 	break;
4287       // If building a shared library, we can also skip the PLT entry
4288       // if the symbol is defined in the output file and is protected
4289       // or hidden.
4290       if (gsym->is_defined()
4291 	  && !gsym->is_from_dynobj()
4292 	  && !gsym->is_preemptible())
4293 	break;
4294       target->make_plt_entry(symtab, layout, gsym);
4295       break;
4296 
4297     case elfcpp::R_X86_64_GOTPC32:
4298     case elfcpp::R_X86_64_GOTOFF64:
4299     case elfcpp::R_X86_64_GOTPC64:
4300     case elfcpp::R_X86_64_PLTOFF64:
4301       // We need a GOT section.
4302       target->got_section(symtab, layout);
4303       // For PLTOFF64, we also need a PLT entry (but only if the
4304       // symbol is not fully resolved).
4305       if (r_type == elfcpp::R_X86_64_PLTOFF64
4306 	  && !gsym->final_value_is_known())
4307 	target->make_plt_entry(symtab, layout, gsym);
4308       break;
4309 
4310     case elfcpp::R_X86_64_COPY:
4311     case elfcpp::R_X86_64_GLOB_DAT:
4312     case elfcpp::R_X86_64_JUMP_SLOT:
4313     case elfcpp::R_X86_64_RELATIVE:
4314     case elfcpp::R_X86_64_IRELATIVE:
4315       // These are outstanding tls relocs, which are unexpected when linking
4316     case elfcpp::R_X86_64_TPOFF64:
4317     case elfcpp::R_X86_64_DTPMOD64:
4318     case elfcpp::R_X86_64_TLSDESC:
4319       gold_error(_("%s: unexpected reloc %u in object file"),
4320 		 object->name().c_str(), r_type);
4321       break;
4322 
4323       // These are initial tls relocs, which are expected for global()
4324     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
4325     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
4326     case elfcpp::R_X86_64_TLSDESC_CALL:
4327     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
4328     case elfcpp::R_X86_64_DTPOFF32:
4329     case elfcpp::R_X86_64_DTPOFF64:
4330     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
4331     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
4332       {
4333 	// For the Initial-Exec model, we can treat undef symbols as final
4334 	// when building an executable.
4335 	const bool is_final = (gsym->final_value_is_known() ||
4336 			       (r_type == elfcpp::R_X86_64_GOTTPOFF &&
4337 			        gsym->is_undefined() &&
4338 				parameters->options().output_is_executable()));
4339 	const tls::Tls_optimization optimized_type
4340 	    = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
4341 	switch (r_type)
4342 	  {
4343 	  case elfcpp::R_X86_64_TLSGD:       // General-dynamic
4344 	    if (optimized_type == tls::TLSOPT_NONE)
4345 	      {
4346 		// Create a pair of GOT entries for the module index and
4347 		// dtv-relative offset.
4348 		Output_data_got<64, false>* got
4349 		    = target->got_section(symtab, layout);
4350 		got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
4351 					      target->rela_dyn_section(layout),
4352 					      elfcpp::R_X86_64_DTPMOD64,
4353 					      elfcpp::R_X86_64_DTPOFF64);
4354 	      }
4355 	    else if (optimized_type == tls::TLSOPT_TO_IE)
4356 	      {
4357 		// Create a GOT entry for the tp-relative offset.
4358 		Output_data_got<64, false>* got
4359 		    = target->got_section(symtab, layout);
4360 		got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
4361 					 target->rela_dyn_section(layout),
4362 					 elfcpp::R_X86_64_TPOFF64);
4363 	      }
4364 	    else if (optimized_type != tls::TLSOPT_TO_LE)
4365 	      unsupported_reloc_global(object, r_type, gsym);
4366 	    break;
4367 
4368 	  case elfcpp::R_X86_64_GOTPC32_TLSDESC:
4369 	    target->define_tls_base_symbol(symtab, layout);
4370 	    if (optimized_type == tls::TLSOPT_NONE)
4371 	      {
4372 		// Create reserved PLT and GOT entries for the resolver.
4373 		target->reserve_tlsdesc_entries(symtab, layout);
4374 
4375 		// Create a double GOT entry with an R_X86_64_TLSDESC
4376 		// reloc.  The R_X86_64_TLSDESC reloc is resolved
4377 		// lazily, so the GOT entry needs to be in an area in
4378 		// .got.plt, not .got.  Call got_section to make sure
4379 		// the section has been created.
4380 		target->got_section(symtab, layout);
4381 		Output_data_got<64, false>* got = target->got_tlsdesc_section();
4382 		Reloc_section* rt = target->rela_tlsdesc_section(layout);
4383 		got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
4384 					      elfcpp::R_X86_64_TLSDESC, 0);
4385 	      }
4386 	    else if (optimized_type == tls::TLSOPT_TO_IE)
4387 	      {
4388 		// Create a GOT entry for the tp-relative offset.
4389 		Output_data_got<64, false>* got
4390 		    = target->got_section(symtab, layout);
4391 		got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
4392 					 target->rela_dyn_section(layout),
4393 					 elfcpp::R_X86_64_TPOFF64);
4394 	      }
4395 	    else if (optimized_type != tls::TLSOPT_TO_LE)
4396 	      unsupported_reloc_global(object, r_type, gsym);
4397 	    break;
4398 
4399 	  case elfcpp::R_X86_64_TLSDESC_CALL:
4400 	    break;
4401 
4402 	  case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
4403 	    if (optimized_type == tls::TLSOPT_NONE)
4404 	      {
4405 		// Create a GOT entry for the module index.
4406 		target->got_mod_index_entry(symtab, layout, object);
4407 	      }
4408 	    else if (optimized_type != tls::TLSOPT_TO_LE)
4409 	      unsupported_reloc_global(object, r_type, gsym);
4410 	    break;
4411 
4412 	  case elfcpp::R_X86_64_DTPOFF32:
4413 	  case elfcpp::R_X86_64_DTPOFF64:
4414 	    break;
4415 
4416 	  case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
4417 	    layout->set_has_static_tls();
4418 	    if (optimized_type == tls::TLSOPT_NONE)
4419 	      {
4420 		// Create a GOT entry for the tp-relative offset.
4421 		Output_data_got<64, false>* got
4422 		    = target->got_section(symtab, layout);
4423 		got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
4424 					 target->rela_dyn_section(layout),
4425 					 elfcpp::R_X86_64_TPOFF64);
4426 	      }
4427 	    else if (optimized_type != tls::TLSOPT_TO_LE)
4428 	      unsupported_reloc_global(object, r_type, gsym);
4429 	    break;
4430 
4431 	  case elfcpp::R_X86_64_TPOFF32:     // Local-exec
4432 	    layout->set_has_static_tls();
4433 	    if (parameters->options().shared())
4434 	      unsupported_reloc_global(object, r_type, gsym);
4435 	    break;
4436 
4437 	  default:
4438 	    gold_unreachable();
4439 	  }
4440       }
4441       break;
4442 
4443     case elfcpp::R_X86_64_SIZE32:
4444     case elfcpp::R_X86_64_SIZE64:
4445     default:
4446       gold_error(_("%s: unsupported reloc %u against global symbol %s"),
4447 		 object->name().c_str(), r_type,
4448 		 gsym->demangled_name().c_str());
4449       break;
4450     }
4451 }
4452 
4453 template<int size>
4454 void
gc_process_relocs(Symbol_table * symtab,Layout * layout,Sized_relobj_file<size,false> * object,unsigned int data_shndx,unsigned int sh_type,const unsigned char * prelocs,size_t reloc_count,Output_section * output_section,bool needs_special_offset_handling,size_t local_symbol_count,const unsigned char * plocal_symbols)4455 Target_x86_64<size>::gc_process_relocs(Symbol_table* symtab,
4456 				       Layout* layout,
4457 				       Sized_relobj_file<size, false>* object,
4458 				       unsigned int data_shndx,
4459 				       unsigned int sh_type,
4460 				       const unsigned char* prelocs,
4461 				       size_t reloc_count,
4462 				       Output_section* output_section,
4463 				       bool needs_special_offset_handling,
4464 				       size_t local_symbol_count,
4465 				       const unsigned char* plocal_symbols)
4466 {
4467   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4468       Classify_reloc;
4469 
4470   if (sh_type == elfcpp::SHT_REL)
4471     {
4472       return;
4473     }
4474 
4475    gold::gc_process_relocs<size, false, Target_x86_64<size>, Scan,
4476 			   Classify_reloc>(
4477     symtab,
4478     layout,
4479     this,
4480     object,
4481     data_shndx,
4482     prelocs,
4483     reloc_count,
4484     output_section,
4485     needs_special_offset_handling,
4486     local_symbol_count,
4487     plocal_symbols);
4488 
4489 }
4490 // Scan relocations for a section.
4491 
4492 template<int size>
4493 void
scan_relocs(Symbol_table * symtab,Layout * layout,Sized_relobj_file<size,false> * object,unsigned int data_shndx,unsigned int sh_type,const unsigned char * prelocs,size_t reloc_count,Output_section * output_section,bool needs_special_offset_handling,size_t local_symbol_count,const unsigned char * plocal_symbols)4494 Target_x86_64<size>::scan_relocs(Symbol_table* symtab,
4495 				 Layout* layout,
4496 				 Sized_relobj_file<size, false>* object,
4497 				 unsigned int data_shndx,
4498 				 unsigned int sh_type,
4499 				 const unsigned char* prelocs,
4500 				 size_t reloc_count,
4501 				 Output_section* output_section,
4502 				 bool needs_special_offset_handling,
4503 				 size_t local_symbol_count,
4504 				 const unsigned char* plocal_symbols)
4505 {
4506   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4507       Classify_reloc;
4508 
4509   if (sh_type == elfcpp::SHT_REL)
4510     {
4511       gold_error(_("%s: unsupported REL reloc section"),
4512 		 object->name().c_str());
4513       return;
4514     }
4515 
4516   gold::scan_relocs<size, false, Target_x86_64<size>, Scan, Classify_reloc>(
4517     symtab,
4518     layout,
4519     this,
4520     object,
4521     data_shndx,
4522     prelocs,
4523     reloc_count,
4524     output_section,
4525     needs_special_offset_handling,
4526     local_symbol_count,
4527     plocal_symbols);
4528 }
4529 
4530 // Finalize the sections.
4531 
4532 template<int size>
4533 void
do_finalize_sections(Layout * layout,const Input_objects *,Symbol_table * symtab)4534 Target_x86_64<size>::do_finalize_sections(
4535     Layout* layout,
4536     const Input_objects*,
4537     Symbol_table* symtab)
4538 {
4539   const Reloc_section* rel_plt = (this->plt_ == NULL
4540 				  ? NULL
4541 				  : this->plt_->rela_plt());
4542   layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
4543 				  this->rela_dyn_, true, false);
4544 
4545   // Fill in some more dynamic tags.
4546   Output_data_dynamic* const odyn = layout->dynamic_data();
4547   if (odyn != NULL)
4548     {
4549       if (this->plt_ != NULL
4550 	  && this->plt_->output_section() != NULL
4551 	  && this->plt_->has_tlsdesc_entry())
4552 	{
4553 	  unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
4554 	  unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
4555 	  this->got_->finalize_data_size();
4556 	  odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
4557 					this->plt_, plt_offset);
4558 	  odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
4559 					this->got_, got_offset);
4560 	}
4561     }
4562 
4563   // Emit any relocs we saved in an attempt to avoid generating COPY
4564   // relocs.
4565   if (this->copy_relocs_.any_saved_relocs())
4566     this->copy_relocs_.emit(this->rela_dyn_section(layout));
4567 
4568   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
4569   // the .got.plt section.
4570   Symbol* sym = this->global_offset_table_;
4571   if (sym != NULL)
4572     {
4573       uint64_t data_size = this->got_plt_->current_data_size();
4574       symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
4575     }
4576 
4577   if (parameters->doing_static_link()
4578       && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
4579     {
4580       // If linking statically, make sure that the __rela_iplt symbols
4581       // were defined if necessary, even if we didn't create a PLT.
4582       static const Define_symbol_in_segment syms[] =
4583 	{
4584 	  {
4585 	    "__rela_iplt_start",	// name
4586 	    elfcpp::PT_LOAD,		// segment_type
4587 	    elfcpp::PF_W,		// segment_flags_set
4588 	    elfcpp::PF(0),		// segment_flags_clear
4589 	    0,				// value
4590 	    0,				// size
4591 	    elfcpp::STT_NOTYPE,		// type
4592 	    elfcpp::STB_GLOBAL,		// binding
4593 	    elfcpp::STV_HIDDEN,		// visibility
4594 	    0,				// nonvis
4595 	    Symbol::SEGMENT_START,	// offset_from_base
4596 	    true			// only_if_ref
4597 	  },
4598 	  {
4599 	    "__rela_iplt_end",		// name
4600 	    elfcpp::PT_LOAD,		// segment_type
4601 	    elfcpp::PF_W,		// segment_flags_set
4602 	    elfcpp::PF(0),		// segment_flags_clear
4603 	    0,				// value
4604 	    0,				// size
4605 	    elfcpp::STT_NOTYPE,		// type
4606 	    elfcpp::STB_GLOBAL,		// binding
4607 	    elfcpp::STV_HIDDEN,		// visibility
4608 	    0,				// nonvis
4609 	    Symbol::SEGMENT_START,	// offset_from_base
4610 	    true			// only_if_ref
4611 	  }
4612 	};
4613 
4614       symtab->define_symbols(layout, 2, syms,
4615 			     layout->script_options()->saw_sections_clause());
4616     }
4617 }
4618 
4619 // For x32, we need to handle PC-relative relocations using full 64-bit
4620 // arithmetic, so that we can detect relocation overflows properly.
4621 // This class overrides the pcrela32_check methods from the defaults in
4622 // Relocate_functions in reloc.h.
4623 
4624 template<int size>
4625 class X86_64_relocate_functions : public Relocate_functions<size, false>
4626 {
4627  public:
4628   typedef Relocate_functions<size, false> Base;
4629 
4630   // Do a simple PC relative relocation with the addend in the
4631   // relocation.
4632   static inline typename Base::Reloc_status
pcrela32_check(unsigned char * view,typename elfcpp::Elf_types<64>::Elf_Addr value,typename elfcpp::Elf_types<64>::Elf_Swxword addend,typename elfcpp::Elf_types<64>::Elf_Addr address)4633   pcrela32_check(unsigned char* view,
4634 		 typename elfcpp::Elf_types<64>::Elf_Addr value,
4635 		 typename elfcpp::Elf_types<64>::Elf_Swxword addend,
4636 		 typename elfcpp::Elf_types<64>::Elf_Addr address)
4637   {
4638     typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
4639     Valtype* wv = reinterpret_cast<Valtype*>(view);
4640     value = value + addend - address;
4641     elfcpp::Swap<32, false>::writeval(wv, value);
4642     return (Bits<32>::has_overflow(value)
4643 	    ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
4644   }
4645 
4646   // Do a simple PC relative relocation with a Symbol_value with the
4647   // addend in the relocation.
4648   static inline typename Base::Reloc_status
pcrela32_check(unsigned char * view,const Sized_relobj_file<size,false> * object,const Symbol_value<size> * psymval,typename elfcpp::Elf_types<64>::Elf_Swxword addend,typename elfcpp::Elf_types<64>::Elf_Addr address)4649   pcrela32_check(unsigned char* view,
4650 		 const Sized_relobj_file<size, false>* object,
4651 		 const Symbol_value<size>* psymval,
4652 		 typename elfcpp::Elf_types<64>::Elf_Swxword addend,
4653 		 typename elfcpp::Elf_types<64>::Elf_Addr address)
4654   {
4655     typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
4656     Valtype* wv = reinterpret_cast<Valtype*>(view);
4657     typename elfcpp::Elf_types<64>::Elf_Addr value;
4658     if (addend >= 0)
4659       value = psymval->value(object, addend);
4660     else
4661       {
4662 	// For negative addends, get the symbol value without
4663 	// the addend, then add the addend using 64-bit arithmetic.
4664 	value = psymval->value(object, 0);
4665 	value += addend;
4666       }
4667     value -= address;
4668     elfcpp::Swap<32, false>::writeval(wv, value);
4669     return (Bits<32>::has_overflow(value)
4670 	    ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
4671   }
4672 };
4673 
4674 // Perform a relocation.
4675 
4676 template<int size>
4677 inline bool
relocate(const Relocate_info<size,false> * relinfo,unsigned int,Target_x86_64<size> * target,Output_section *,size_t relnum,const unsigned char * preloc,const Sized_symbol<size> * gsym,const Symbol_value<size> * psymval,unsigned char * view,typename elfcpp::Elf_types<size>::Elf_Addr address,section_size_type view_size)4678 Target_x86_64<size>::Relocate::relocate(
4679     const Relocate_info<size, false>* relinfo,
4680     unsigned int,
4681     Target_x86_64<size>* target,
4682     Output_section*,
4683     size_t relnum,
4684     const unsigned char* preloc,
4685     const Sized_symbol<size>* gsym,
4686     const Symbol_value<size>* psymval,
4687     unsigned char* view,
4688     typename elfcpp::Elf_types<size>::Elf_Addr address,
4689     section_size_type view_size)
4690 {
4691   typedef X86_64_relocate_functions<size> Reloc_funcs;
4692   const elfcpp::Rela<size, false> rela(preloc);
4693   unsigned int r_type = elfcpp::elf_r_type<size>(rela.get_r_info());
4694 
4695   if (this->skip_call_tls_get_addr_)
4696     {
4697       if ((r_type != elfcpp::R_X86_64_PLT32
4698 	   && r_type != elfcpp::R_X86_64_GOTPCREL
4699 	   && r_type != elfcpp::R_X86_64_GOTPCRELX
4700 	   && r_type != elfcpp::R_X86_64_PLT32_BND
4701 	   && r_type != elfcpp::R_X86_64_PC32_BND
4702 	   && r_type != elfcpp::R_X86_64_PC32)
4703 	  || gsym == NULL
4704 	  || strcmp(gsym->name(), "__tls_get_addr") != 0)
4705 	{
4706 	  gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4707 				 _("missing expected TLS relocation"));
4708 	  this->skip_call_tls_get_addr_ = false;
4709 	}
4710       else
4711 	{
4712 	  this->skip_call_tls_get_addr_ = false;
4713 	  return false;
4714 	}
4715     }
4716 
4717   if (view == NULL)
4718     return true;
4719 
4720   const Sized_relobj_file<size, false>* object = relinfo->object;
4721 
4722   // Pick the value to use for symbols defined in the PLT.
4723   Symbol_value<size> symval;
4724   if (gsym != NULL
4725       && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
4726     {
4727       symval.set_output_value(target->plt_address_for_global(gsym));
4728       psymval = &symval;
4729     }
4730   else if (gsym == NULL && psymval->is_ifunc_symbol())
4731     {
4732       unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4733       if (object->local_has_plt_offset(r_sym))
4734 	{
4735 	  symval.set_output_value(target->plt_address_for_local(object, r_sym));
4736 	  psymval = &symval;
4737 	}
4738     }
4739 
4740   const elfcpp::Elf_Xword addend = rela.get_r_addend();
4741 
4742   // Get the GOT offset if needed.
4743   // The GOT pointer points to the end of the GOT section.
4744   // We need to subtract the size of the GOT section to get
4745   // the actual offset to use in the relocation.
4746   bool have_got_offset = false;
4747   // Since the actual offset is always negative, we use signed int to
4748   // support 64-bit GOT relocations.
4749   int got_offset = 0;
4750   switch (r_type)
4751     {
4752     case elfcpp::R_X86_64_GOT32:
4753     case elfcpp::R_X86_64_GOT64:
4754     case elfcpp::R_X86_64_GOTPLT64:
4755     case elfcpp::R_X86_64_GOTPCREL64:
4756       if (gsym != NULL)
4757 	{
4758 	  gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
4759 	  got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
4760 	}
4761       else
4762 	{
4763 	  unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4764 	  gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
4765 	  got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
4766 			- target->got_size());
4767 	}
4768       have_got_offset = true;
4769       break;
4770 
4771     default:
4772       break;
4773     }
4774 
4775   typename Reloc_funcs::Reloc_status rstatus = Reloc_funcs::RELOC_OK;
4776 
4777   switch (r_type)
4778     {
4779     case elfcpp::R_X86_64_NONE:
4780     case elfcpp::R_X86_64_GNU_VTINHERIT:
4781     case elfcpp::R_X86_64_GNU_VTENTRY:
4782       break;
4783 
4784     case elfcpp::R_X86_64_64:
4785       Reloc_funcs::rela64(view, object, psymval, addend);
4786       break;
4787 
4788     case elfcpp::R_X86_64_PC64:
4789       Reloc_funcs::pcrela64(view, object, psymval, addend,
4790 					      address);
4791       break;
4792 
4793     case elfcpp::R_X86_64_32:
4794       rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
4795 					  Reloc_funcs::CHECK_UNSIGNED);
4796       break;
4797 
4798     case elfcpp::R_X86_64_32S:
4799       rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
4800 					  Reloc_funcs::CHECK_SIGNED);
4801       break;
4802 
4803     case elfcpp::R_X86_64_PC32:
4804     case elfcpp::R_X86_64_PC32_BND:
4805       rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
4806 					    address);
4807       break;
4808 
4809     case elfcpp::R_X86_64_16:
4810       Reloc_funcs::rela16(view, object, psymval, addend);
4811       break;
4812 
4813     case elfcpp::R_X86_64_PC16:
4814       Reloc_funcs::pcrela16(view, object, psymval, addend, address);
4815       break;
4816 
4817     case elfcpp::R_X86_64_8:
4818       Reloc_funcs::rela8(view, object, psymval, addend);
4819       break;
4820 
4821     case elfcpp::R_X86_64_PC8:
4822       Reloc_funcs::pcrela8(view, object, psymval, addend, address);
4823       break;
4824 
4825     case elfcpp::R_X86_64_PLT32:
4826     case elfcpp::R_X86_64_PLT32_BND:
4827       gold_assert(gsym == NULL
4828 		  || gsym->has_plt_offset()
4829 		  || gsym->final_value_is_known()
4830 		  || (gsym->is_defined()
4831 		      && !gsym->is_from_dynobj()
4832 		      && !gsym->is_preemptible()));
4833       // Note: while this code looks the same as for R_X86_64_PC32, it
4834       // behaves differently because psymval was set to point to
4835       // the PLT entry, rather than the symbol, in Scan::global().
4836       rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
4837 					    address);
4838       break;
4839 
4840     case elfcpp::R_X86_64_PLTOFF64:
4841       {
4842 	gold_assert(gsym);
4843 	gold_assert(gsym->has_plt_offset()
4844 		    || gsym->final_value_is_known());
4845 	typename elfcpp::Elf_types<size>::Elf_Addr got_address;
4846 	// This is the address of GLOBAL_OFFSET_TABLE.
4847 	got_address = target->got_plt_section()->address();
4848 	Reloc_funcs::rela64(view, object, psymval, addend - got_address);
4849       }
4850       break;
4851 
4852     case elfcpp::R_X86_64_GOT32:
4853       gold_assert(have_got_offset);
4854       Reloc_funcs::rela32(view, got_offset, addend);
4855       break;
4856 
4857     case elfcpp::R_X86_64_GOTPC32:
4858       {
4859 	gold_assert(gsym);
4860 	typename elfcpp::Elf_types<size>::Elf_Addr value;
4861 	value = target->got_plt_section()->address();
4862 	Reloc_funcs::pcrela32_check(view, value, addend, address);
4863       }
4864       break;
4865 
4866     case elfcpp::R_X86_64_GOT64:
4867     case elfcpp::R_X86_64_GOTPLT64:
4868       // R_X86_64_GOTPLT64 is obsolete and treated the same as
4869       // GOT64.
4870       gold_assert(have_got_offset);
4871       Reloc_funcs::rela64(view, got_offset, addend);
4872       break;
4873 
4874     case elfcpp::R_X86_64_GOTPC64:
4875       {
4876 	gold_assert(gsym);
4877 	typename elfcpp::Elf_types<size>::Elf_Addr value;
4878 	value = target->got_plt_section()->address();
4879 	Reloc_funcs::pcrela64(view, value, addend, address);
4880       }
4881       break;
4882 
4883     case elfcpp::R_X86_64_GOTOFF64:
4884       {
4885 	typename elfcpp::Elf_types<size>::Elf_Addr reladdr;
4886 	reladdr = target->got_plt_section()->address();
4887 	Reloc_funcs::pcrela64(view, object, psymval, addend, reladdr);
4888       }
4889       break;
4890 
4891     case elfcpp::R_X86_64_GOTPCREL:
4892     case elfcpp::R_X86_64_GOTPCRELX:
4893     case elfcpp::R_X86_64_REX_GOTPCRELX:
4894       {
4895       bool converted_p = false;
4896 
4897       if (rela.get_r_addend() == -4)
4898 	{
4899 	  // Convert
4900 	  // mov foo@GOTPCREL(%rip), %reg
4901 	  // to lea foo(%rip), %reg.
4902 	  // if possible.
4903 	  if (!parameters->incremental()
4904 	      && ((gsym == NULL
4905 		   && rela.get_r_offset() >= 2
4906 		   && view[-2] == 0x8b
4907 		   && !psymval->is_ifunc_symbol())
4908 		  || (gsym != NULL
4909 		      && rela.get_r_offset() >= 2
4910 		      && Target_x86_64<size>::can_convert_mov_to_lea(gsym,
4911 								     r_type,
4912 								     0,
4913 								     &view))))
4914 	    {
4915 	      view[-2] = 0x8d;
4916 	      Reloc_funcs::pcrela32(view, object, psymval, addend, address);
4917 	      converted_p = true;
4918 	    }
4919 	  // Convert
4920 	  // callq *foo@GOTPCRELX(%rip) to
4921 	  // addr32 callq foo
4922 	  // and jmpq *foo@GOTPCRELX(%rip) to
4923 	  // jmpq foo
4924 	  // nop
4925 	  else if (!parameters->incremental()
4926 		   && gsym != NULL
4927 		   && rela.get_r_offset() >= 2
4928 		   && Target_x86_64<size>::can_convert_callq_to_direct(gsym,
4929 								       r_type,
4930 								       0,
4931 								       &view))
4932 	    {
4933 	      if (view[-1] == 0x15)
4934 		{
4935 		  // Convert callq *foo@GOTPCRELX(%rip) to addr32 callq.
4936 		  // Opcode of addr32 is 0x67 and opcode of direct callq
4937 		  // is 0xe8.
4938 		  view[-2] = 0x67;
4939 		  view[-1] = 0xe8;
4940 		  // Convert GOTPCRELX to 32-bit pc relative reloc.
4941 		  Reloc_funcs::pcrela32(view, object, psymval, addend,
4942 					address);
4943 		  converted_p = true;
4944 		}
4945 	      else
4946 		{
4947 		  // Convert jmpq *foo@GOTPCRELX(%rip) to
4948 		  // jmpq foo
4949 		  // nop
4950 		  // The opcode of direct jmpq is 0xe9.
4951 		  view[-2] = 0xe9;
4952 		  // The opcode of nop is 0x90.
4953 		  view[3] = 0x90;
4954 		  // Convert GOTPCRELX to 32-bit pc relative reloc.  jmpq
4955 		  // is rip relative and since the instruction following
4956 		  // the jmpq is now the nop, offset the address by 1
4957 		  // byte.  The start of the relocation also moves ahead
4958 		  // by 1 byte.
4959 		  Reloc_funcs::pcrela32(&view[-1], object, psymval, addend,
4960 					address - 1);
4961 		  converted_p = true;
4962 		}
4963 	    }
4964 	}
4965 
4966       if (!converted_p)
4967 	{
4968 	  if (gsym != NULL)
4969 	    {
4970 	      gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
4971 	      got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
4972 			    - target->got_size());
4973 	    }
4974 	  else
4975 	    {
4976 	      unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4977 	      gold_assert(object->local_has_got_offset(r_sym,
4978 						       GOT_TYPE_STANDARD));
4979 	      got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
4980 			    - target->got_size());
4981 	    }
4982 	  typename elfcpp::Elf_types<size>::Elf_Addr value;
4983 	  value = target->got_plt_section()->address() + got_offset;
4984 	  Reloc_funcs::pcrela32_check(view, value, addend, address);
4985 	}
4986       }
4987       break;
4988 
4989     case elfcpp::R_X86_64_GOTPCREL64:
4990       {
4991 	gold_assert(have_got_offset);
4992 	typename elfcpp::Elf_types<size>::Elf_Addr value;
4993 	value = target->got_plt_section()->address() + got_offset;
4994 	Reloc_funcs::pcrela64(view, value, addend, address);
4995       }
4996       break;
4997 
4998     case elfcpp::R_X86_64_COPY:
4999     case elfcpp::R_X86_64_GLOB_DAT:
5000     case elfcpp::R_X86_64_JUMP_SLOT:
5001     case elfcpp::R_X86_64_RELATIVE:
5002     case elfcpp::R_X86_64_IRELATIVE:
5003       // These are outstanding tls relocs, which are unexpected when linking
5004     case elfcpp::R_X86_64_TPOFF64:
5005     case elfcpp::R_X86_64_DTPMOD64:
5006     case elfcpp::R_X86_64_TLSDESC:
5007       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5008 			     _("unexpected reloc %u in object file"),
5009 			     r_type);
5010       break;
5011 
5012       // These are initial tls relocs, which are expected when linking
5013     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
5014     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
5015     case elfcpp::R_X86_64_TLSDESC_CALL:
5016     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
5017     case elfcpp::R_X86_64_DTPOFF32:
5018     case elfcpp::R_X86_64_DTPOFF64:
5019     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
5020     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
5021       this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
5022 			 view, address, view_size);
5023       break;
5024 
5025     case elfcpp::R_X86_64_SIZE32:
5026     case elfcpp::R_X86_64_SIZE64:
5027     default:
5028       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5029 			     _("unsupported reloc %u"),
5030 			     r_type);
5031       break;
5032     }
5033 
5034   if (rstatus == Reloc_funcs::RELOC_OVERFLOW)
5035     {
5036       if (gsym == NULL)
5037         {
5038 	  unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
5039 	  gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5040 				 _("relocation overflow: "
5041 				   "reference to local symbol %u in %s"),
5042 				 r_sym, object->name().c_str());
5043         }
5044       else if (gsym->is_defined() && gsym->source() == Symbol::FROM_OBJECT)
5045         {
5046 	  gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5047 				 _("relocation overflow: "
5048 				   "reference to '%s' defined in %s"),
5049 				 gsym->name(),
5050 				 gsym->object()->name().c_str());
5051         }
5052       else
5053         {
5054 	  gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5055 				 _("relocation overflow: reference to '%s'"),
5056 				 gsym->name());
5057         }
5058     }
5059 
5060   return true;
5061 }
5062 
5063 // Perform a TLS relocation.
5064 
5065 template<int size>
5066 inline void
relocate_tls(const Relocate_info<size,false> * relinfo,Target_x86_64<size> * target,size_t relnum,const elfcpp::Rela<size,false> & rela,unsigned int r_type,const Sized_symbol<size> * gsym,const Symbol_value<size> * psymval,unsigned char * view,typename elfcpp::Elf_types<size>::Elf_Addr address,section_size_type view_size)5067 Target_x86_64<size>::Relocate::relocate_tls(
5068     const Relocate_info<size, false>* relinfo,
5069     Target_x86_64<size>* target,
5070     size_t relnum,
5071     const elfcpp::Rela<size, false>& rela,
5072     unsigned int r_type,
5073     const Sized_symbol<size>* gsym,
5074     const Symbol_value<size>* psymval,
5075     unsigned char* view,
5076     typename elfcpp::Elf_types<size>::Elf_Addr address,
5077     section_size_type view_size)
5078 {
5079   Output_segment* tls_segment = relinfo->layout->tls_segment();
5080 
5081   const Sized_relobj_file<size, false>* object = relinfo->object;
5082   const elfcpp::Elf_Xword addend = rela.get_r_addend();
5083   elfcpp::Shdr<size, false> data_shdr(relinfo->data_shdr);
5084   bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
5085 
5086   typename elfcpp::Elf_types<size>::Elf_Addr value = psymval->value(relinfo->object, 0);
5087 
5088   const bool is_final = (gsym == NULL
5089 			 ? !parameters->options().shared()
5090 			 : gsym->final_value_is_known());
5091   tls::Tls_optimization optimized_type
5092       = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
5093   switch (r_type)
5094     {
5095     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
5096       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
5097 	{
5098 	  // If this code sequence is used in a non-executable section,
5099 	  // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
5100 	  // on the assumption that it's being used by itself in a debug
5101 	  // section.  Therefore, in the unlikely event that the code
5102 	  // sequence appears in a non-executable section, we simply
5103 	  // leave it unoptimized.
5104 	  optimized_type = tls::TLSOPT_NONE;
5105 	}
5106       if (optimized_type == tls::TLSOPT_TO_LE)
5107 	{
5108 	  if (tls_segment == NULL)
5109 	    {
5110 	      gold_assert(parameters->errors()->error_count() > 0
5111 			  || issue_undefined_symbol_error(gsym));
5112 	      return;
5113 	    }
5114 	  this->tls_gd_to_le(relinfo, relnum, tls_segment,
5115 			     rela, r_type, value, view,
5116 			     view_size);
5117 	  break;
5118 	}
5119       else
5120 	{
5121 	  unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
5122 				   ? GOT_TYPE_TLS_OFFSET
5123 				   : GOT_TYPE_TLS_PAIR);
5124 	  unsigned int got_offset;
5125 	  if (gsym != NULL)
5126 	    {
5127 	      gold_assert(gsym->has_got_offset(got_type));
5128 	      got_offset = gsym->got_offset(got_type) - target->got_size();
5129 	    }
5130 	  else
5131 	    {
5132 	      unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
5133 	      gold_assert(object->local_has_got_offset(r_sym, got_type));
5134 	      got_offset = (object->local_got_offset(r_sym, got_type)
5135 			    - target->got_size());
5136 	    }
5137 	  if (optimized_type == tls::TLSOPT_TO_IE)
5138 	    {
5139 	      value = target->got_plt_section()->address() + got_offset;
5140 	      this->tls_gd_to_ie(relinfo, relnum, rela, r_type,
5141 				 value, view, address, view_size);
5142 	      break;
5143 	    }
5144 	  else if (optimized_type == tls::TLSOPT_NONE)
5145 	    {
5146 	      // Relocate the field with the offset of the pair of GOT
5147 	      // entries.
5148 	      value = target->got_plt_section()->address() + got_offset;
5149 	      Relocate_functions<size, false>::pcrela32(view, value, addend,
5150 							address);
5151 	      break;
5152 	    }
5153 	}
5154       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5155 			     _("unsupported reloc %u"), r_type);
5156       break;
5157 
5158     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
5159     case elfcpp::R_X86_64_TLSDESC_CALL:
5160       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
5161 	{
5162 	  // See above comment for R_X86_64_TLSGD.
5163 	  optimized_type = tls::TLSOPT_NONE;
5164 	}
5165       if (optimized_type == tls::TLSOPT_TO_LE)
5166 	{
5167 	  if (tls_segment == NULL)
5168 	    {
5169 	      gold_assert(parameters->errors()->error_count() > 0
5170 			  || issue_undefined_symbol_error(gsym));
5171 	      return;
5172 	    }
5173 	  this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
5174 				  rela, r_type, value, view,
5175 				  view_size);
5176 	  break;
5177 	}
5178       else
5179 	{
5180 	  unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
5181 				   ? GOT_TYPE_TLS_OFFSET
5182 				   : GOT_TYPE_TLS_DESC);
5183 	  unsigned int got_offset = 0;
5184 	  if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
5185 	      && optimized_type == tls::TLSOPT_NONE)
5186 	    {
5187 	      // We created GOT entries in the .got.tlsdesc portion of
5188 	      // the .got.plt section, but the offset stored in the
5189 	      // symbol is the offset within .got.tlsdesc.
5190 	      got_offset = (target->got_size()
5191 			    + target->got_plt_section()->data_size());
5192 	    }
5193 	  if (gsym != NULL)
5194 	    {
5195 	      gold_assert(gsym->has_got_offset(got_type));
5196 	      got_offset += gsym->got_offset(got_type) - target->got_size();
5197 	    }
5198 	  else
5199 	    {
5200 	      unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
5201 	      gold_assert(object->local_has_got_offset(r_sym, got_type));
5202 	      got_offset += (object->local_got_offset(r_sym, got_type)
5203 			     - target->got_size());
5204 	    }
5205 	  if (optimized_type == tls::TLSOPT_TO_IE)
5206 	    {
5207 	      value = target->got_plt_section()->address() + got_offset;
5208 	      this->tls_desc_gd_to_ie(relinfo, relnum,
5209 				      rela, r_type, value, view, address,
5210 				      view_size);
5211 	      break;
5212 	    }
5213 	  else if (optimized_type == tls::TLSOPT_NONE)
5214 	    {
5215 	      if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
5216 		{
5217 		  // Relocate the field with the offset of the pair of GOT
5218 		  // entries.
5219 		  value = target->got_plt_section()->address() + got_offset;
5220 		  Relocate_functions<size, false>::pcrela32(view, value, addend,
5221 							    address);
5222 		}
5223 	      break;
5224 	    }
5225 	}
5226       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5227 			     _("unsupported reloc %u"), r_type);
5228       break;
5229 
5230     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
5231       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
5232 	{
5233 	  // See above comment for R_X86_64_TLSGD.
5234 	  optimized_type = tls::TLSOPT_NONE;
5235 	}
5236       if (optimized_type == tls::TLSOPT_TO_LE)
5237 	{
5238 	  if (tls_segment == NULL)
5239 	    {
5240 	      gold_assert(parameters->errors()->error_count() > 0
5241 			  || issue_undefined_symbol_error(gsym));
5242 	      return;
5243 	    }
5244 	  this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
5245 			     value, view, view_size);
5246 	  break;
5247 	}
5248       else if (optimized_type == tls::TLSOPT_NONE)
5249 	{
5250 	  // Relocate the field with the offset of the GOT entry for
5251 	  // the module index.
5252 	  unsigned int got_offset;
5253 	  got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
5254 			- target->got_size());
5255 	  value = target->got_plt_section()->address() + got_offset;
5256 	  Relocate_functions<size, false>::pcrela32(view, value, addend,
5257 						    address);
5258 	  break;
5259 	}
5260       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5261 			     _("unsupported reloc %u"), r_type);
5262       break;
5263 
5264     case elfcpp::R_X86_64_DTPOFF32:
5265       // This relocation type is used in debugging information.
5266       // In that case we need to not optimize the value.  If the
5267       // section is not executable, then we assume we should not
5268       // optimize this reloc.  See comments above for R_X86_64_TLSGD,
5269       // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
5270       // R_X86_64_TLSLD.
5271       if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
5272 	{
5273 	  if (tls_segment == NULL)
5274 	    {
5275 	      gold_assert(parameters->errors()->error_count() > 0
5276 			  || issue_undefined_symbol_error(gsym));
5277 	      return;
5278 	    }
5279 	  value -= tls_segment->memsz();
5280 	}
5281       Relocate_functions<size, false>::rela32(view, value, addend);
5282       break;
5283 
5284     case elfcpp::R_X86_64_DTPOFF64:
5285       // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
5286       if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
5287 	{
5288 	  if (tls_segment == NULL)
5289 	    {
5290 	      gold_assert(parameters->errors()->error_count() > 0
5291 			  || issue_undefined_symbol_error(gsym));
5292 	      return;
5293 	    }
5294 	  value -= tls_segment->memsz();
5295 	}
5296       Relocate_functions<size, false>::rela64(view, value, addend);
5297       break;
5298 
5299     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
5300       if (gsym != NULL
5301 	  && gsym->is_undefined()
5302 	  && parameters->options().output_is_executable())
5303 	{
5304 	  Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
5305 						      NULL, rela,
5306 						      r_type, value, view,
5307 						      view_size);
5308 	  break;
5309 	}
5310       else if (optimized_type == tls::TLSOPT_TO_LE)
5311 	{
5312 	  if (tls_segment == NULL)
5313 	    {
5314 	      gold_assert(parameters->errors()->error_count() > 0
5315 			  || issue_undefined_symbol_error(gsym));
5316 	      return;
5317 	    }
5318 	  Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
5319 						      tls_segment, rela,
5320 						      r_type, value, view,
5321 						      view_size);
5322 	  break;
5323 	}
5324       else if (optimized_type == tls::TLSOPT_NONE)
5325 	{
5326 	  // Relocate the field with the offset of the GOT entry for
5327 	  // the tp-relative offset of the symbol.
5328 	  unsigned int got_offset;
5329 	  if (gsym != NULL)
5330 	    {
5331 	      gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
5332 	      got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
5333 			    - target->got_size());
5334 	    }
5335 	  else
5336 	    {
5337 	      unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
5338 	      gold_assert(object->local_has_got_offset(r_sym,
5339 						       GOT_TYPE_TLS_OFFSET));
5340 	      got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
5341 			    - target->got_size());
5342 	    }
5343 	  value = target->got_plt_section()->address() + got_offset;
5344 	  Relocate_functions<size, false>::pcrela32(view, value, addend,
5345 						    address);
5346 	  break;
5347 	}
5348       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
5349 			     _("unsupported reloc type %u"),
5350 			     r_type);
5351       break;
5352 
5353     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
5354       if (tls_segment == NULL)
5355 	{
5356 	  gold_assert(parameters->errors()->error_count() > 0
5357 		      || issue_undefined_symbol_error(gsym));
5358 	  return;
5359 	}
5360       value -= tls_segment->memsz();
5361       Relocate_functions<size, false>::rela32(view, value, addend);
5362       break;
5363     }
5364 }
5365 
5366 // Do a relocation in which we convert a TLS General-Dynamic to an
5367 // Initial-Exec.
5368 
5369 template<int size>
5370 inline void
tls_gd_to_ie(const Relocate_info<size,false> * relinfo,size_t relnum,const elfcpp::Rela<size,false> & rela,unsigned int,typename elfcpp::Elf_types<size>::Elf_Addr value,unsigned char * view,typename elfcpp::Elf_types<size>::Elf_Addr address,section_size_type view_size)5371 Target_x86_64<size>::Relocate::tls_gd_to_ie(
5372     const Relocate_info<size, false>* relinfo,
5373     size_t relnum,
5374     const elfcpp::Rela<size, false>& rela,
5375     unsigned int,
5376     typename elfcpp::Elf_types<size>::Elf_Addr value,
5377     unsigned char* view,
5378     typename elfcpp::Elf_types<size>::Elf_Addr address,
5379     section_size_type view_size)
5380 {
5381   // For SIZE == 64:
5382   //	.byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5383   //	.word 0x6666; rex64; call __tls_get_addr@PLT
5384   //	==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
5385   //	.byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5386   //	.word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5387   //	==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
5388   // For SIZE == 32:
5389   //	leaq foo@tlsgd(%rip),%rdi;
5390   //	.word 0x6666; rex64; call __tls_get_addr@PLT
5391   //	==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
5392   //	leaq foo@tlsgd(%rip),%rdi;
5393   //	.word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5394   //	==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
5395 
5396   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
5397   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5398 		 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0
5399 		  || memcmp(view + 4, "\x66\x48\xff", 3) == 0));
5400 
5401   if (size == 64)
5402     {
5403       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5404 		       -4);
5405       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5406 		     (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
5407       memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
5408 	     16);
5409     }
5410   else
5411     {
5412       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5413 		       -3);
5414       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5415 		     (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
5416       memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
5417 	     15);
5418     }
5419 
5420   const elfcpp::Elf_Xword addend = rela.get_r_addend();
5421   Relocate_functions<size, false>::pcrela32(view + 8, value, addend - 8,
5422 					    address);
5423 
5424   // The next reloc should be a PLT32 reloc against __tls_get_addr.
5425   // We can skip it.
5426   this->skip_call_tls_get_addr_ = true;
5427 }
5428 
5429 // Do a relocation in which we convert a TLS General-Dynamic to a
5430 // Local-Exec.
5431 
5432 template<int size>
5433 inline void
tls_gd_to_le(const Relocate_info<size,false> * relinfo,size_t relnum,Output_segment * tls_segment,const elfcpp::Rela<size,false> & rela,unsigned int,typename elfcpp::Elf_types<size>::Elf_Addr value,unsigned char * view,section_size_type view_size)5434 Target_x86_64<size>::Relocate::tls_gd_to_le(
5435     const Relocate_info<size, false>* relinfo,
5436     size_t relnum,
5437     Output_segment* tls_segment,
5438     const elfcpp::Rela<size, false>& rela,
5439     unsigned int,
5440     typename elfcpp::Elf_types<size>::Elf_Addr value,
5441     unsigned char* view,
5442     section_size_type view_size)
5443 {
5444   // For SIZE == 64:
5445   //	.byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5446   //	.word 0x6666; rex64; call __tls_get_addr@PLT
5447   //	==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
5448   //	.byte 0x66; leaq foo@tlsgd(%rip),%rdi;
5449   //	.word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5450   //	==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
5451   // For SIZE == 32:
5452   //	leaq foo@tlsgd(%rip),%rdi;
5453   //	.word 0x6666; rex64; call __tls_get_addr@PLT
5454   //	==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
5455   //	leaq foo@tlsgd(%rip),%rdi;
5456   //	.word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
5457   //	==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
5458 
5459   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
5460   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5461 		 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0
5462 		  || memcmp(view + 4, "\x66\x48\xff", 3) == 0));
5463 
5464   if (size == 64)
5465     {
5466       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5467 		       -4);
5468       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5469 		     (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
5470       memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
5471 	     16);
5472     }
5473   else
5474     {
5475       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
5476 		       -3);
5477       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5478 		     (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
5479 
5480       memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
5481 	     15);
5482     }
5483 
5484   value -= tls_segment->memsz();
5485   Relocate_functions<size, false>::rela32(view + 8, value, 0);
5486 
5487   // The next reloc should be a PLT32 reloc against __tls_get_addr.
5488   // We can skip it.
5489   this->skip_call_tls_get_addr_ = true;
5490 }
5491 
5492 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
5493 
5494 template<int size>
5495 inline void
tls_desc_gd_to_ie(const Relocate_info<size,false> * relinfo,size_t relnum,const elfcpp::Rela<size,false> & rela,unsigned int r_type,typename elfcpp::Elf_types<size>::Elf_Addr value,unsigned char * view,typename elfcpp::Elf_types<size>::Elf_Addr address,section_size_type view_size)5496 Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
5497     const Relocate_info<size, false>* relinfo,
5498     size_t relnum,
5499     const elfcpp::Rela<size, false>& rela,
5500     unsigned int r_type,
5501     typename elfcpp::Elf_types<size>::Elf_Addr value,
5502     unsigned char* view,
5503     typename elfcpp::Elf_types<size>::Elf_Addr address,
5504     section_size_type view_size)
5505 {
5506   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
5507     {
5508       // LP64: leaq foo@tlsdesc(%rip), %rax
5509       //       ==> movq foo@gottpoff(%rip), %rax
5510       // X32:  rex leal foo@tlsdesc(%rip), %eax
5511       //       ==> rex movl foo@gottpoff(%rip), %eax
5512       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5513       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
5514       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5515 		     (((view[-3] & 0xfb) == 0x48
5516 		       || (size == 32 && (view[-3] & 0xfb) == 0x40))
5517 		      && view[-2] == 0x8d
5518 		      && (view[-1] & 0xc7) == 0x05));
5519       view[-2] = 0x8b;
5520       const elfcpp::Elf_Xword addend = rela.get_r_addend();
5521       Relocate_functions<size, false>::pcrela32(view, value, addend, address);
5522     }
5523   else
5524     {
5525       // LP64: call *foo@tlscall(%rax)
5526       //       ==> xchg %ax, %ax
5527       // X32:  call *foo@tlscall(%eax)
5528       //       ==> nopl (%rax)
5529       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
5530       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
5531       int prefix = 0;
5532       if (size == 32 && view[0] == 0x67)
5533 	{
5534 	  tls::check_range(relinfo, relnum, rela.get_r_offset(),
5535 			   view_size, 3);
5536 	  prefix = 1;
5537 	}
5538       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5539 		     view[prefix] == 0xff && view[prefix + 1] == 0x10);
5540       if (prefix)
5541 	{
5542 	  view[0] = 0x0f;
5543 	  view[1] = 0x1f;
5544 	  view[2] = 0x00;
5545 	}
5546       else
5547 	{
5548 	  view[0] = 0x66;
5549 	  view[1] = 0x90;
5550 	}
5551     }
5552 }
5553 
5554 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
5555 
5556 template<int size>
5557 inline void
tls_desc_gd_to_le(const Relocate_info<size,false> * relinfo,size_t relnum,Output_segment * tls_segment,const elfcpp::Rela<size,false> & rela,unsigned int r_type,typename elfcpp::Elf_types<size>::Elf_Addr value,unsigned char * view,section_size_type view_size)5558 Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
5559     const Relocate_info<size, false>* relinfo,
5560     size_t relnum,
5561     Output_segment* tls_segment,
5562     const elfcpp::Rela<size, false>& rela,
5563     unsigned int r_type,
5564     typename elfcpp::Elf_types<size>::Elf_Addr value,
5565     unsigned char* view,
5566     section_size_type view_size)
5567 {
5568   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
5569     {
5570       // LP64: leaq foo@tlsdesc(%rip), %rax
5571       //       ==> movq foo@tpoff, %rax
5572       // X32:  rex leal foo@tlsdesc(%rip), %eax
5573       //       ==> rex movl foo@tpoff, %eax
5574       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5575       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
5576       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5577 		     (((view[-3] & 0xfb) == 0x48
5578 		       || (size == 32 && (view[-3] & 0xfb) == 0x40))
5579 		      && view[-2] == 0x8d
5580 		      && (view[-1] & 0xc7) == 0x05));
5581       view[-3] = (view[-3] & 0x48) | ((view[-3] >> 2) & 1);
5582       view[-2] = 0xc7;
5583       view[-1] = 0xc0 | ((view[-1] >> 3) & 7);
5584       value -= tls_segment->memsz();
5585       Relocate_functions<size, false>::rela32(view, value, 0);
5586     }
5587   else
5588     {
5589       // LP64: call *foo@tlscall(%rax)
5590       //       ==> xchg %ax, %ax
5591       // X32:  call *foo@tlscall(%eax)
5592       //       ==> nopl (%rax)
5593       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
5594       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
5595       int prefix = 0;
5596       if (size == 32 && view[0] == 0x67)
5597 	{
5598 	  tls::check_range(relinfo, relnum, rela.get_r_offset(),
5599 			   view_size, 3);
5600 	  prefix = 1;
5601 	}
5602       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5603 		     view[prefix] == 0xff && view[prefix + 1] == 0x10);
5604       if (prefix)
5605 	{
5606 	  view[0] = 0x0f;
5607 	  view[1] = 0x1f;
5608 	  view[2] = 0x00;
5609 	}
5610       else
5611 	{
5612 	  view[0] = 0x66;
5613 	  view[1] = 0x90;
5614 	}
5615     }
5616 }
5617 
5618 template<int size>
5619 inline void
tls_ld_to_le(const Relocate_info<size,false> * relinfo,size_t relnum,Output_segment *,const elfcpp::Rela<size,false> & rela,unsigned int,typename elfcpp::Elf_types<size>::Elf_Addr,unsigned char * view,section_size_type view_size)5620 Target_x86_64<size>::Relocate::tls_ld_to_le(
5621     const Relocate_info<size, false>* relinfo,
5622     size_t relnum,
5623     Output_segment*,
5624     const elfcpp::Rela<size, false>& rela,
5625     unsigned int,
5626     typename elfcpp::Elf_types<size>::Elf_Addr,
5627     unsigned char* view,
5628     section_size_type view_size)
5629 {
5630   // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
5631   // For SIZE == 64:
5632   // ... leq foo@dtpoff(%rax),%reg
5633   // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
5634   // For SIZE == 32:
5635   // ... leq foo@dtpoff(%rax),%reg
5636   // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
5637   // leaq foo@tlsld(%rip),%rdi; call *__tls_get_addr@GOTPCREL(%rip)
5638   // For SIZE == 64:
5639   // ... leq foo@dtpoff(%rax),%reg
5640   // ==> .word 0x6666; .byte 0x6666; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
5641   // For SIZE == 32:
5642   // ... leq foo@dtpoff(%rax),%reg
5643   // ==> nopw 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
5644 
5645   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5646   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
5647 
5648   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5649 		 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
5650 
5651   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
5652 		 view[4] == 0xe8 || view[4] == 0xff);
5653 
5654   if (view[4] == 0xe8)
5655     {
5656       if (size == 64)
5657 	memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
5658       else
5659 	memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
5660     }
5661   else
5662     {
5663       if (size == 64)
5664 	memcpy(view - 3, "\x66\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0",
5665 	       13);
5666       else
5667 	memcpy(view - 3, "\x66\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0",
5668 	       13);
5669     }
5670 
5671   // The next reloc should be a PLT32 reloc against __tls_get_addr.
5672   // We can skip it.
5673   this->skip_call_tls_get_addr_ = true;
5674 }
5675 
5676 // Do a relocation in which we convert a TLS Initial-Exec to a
5677 // Local-Exec.
5678 
5679 template<int size>
5680 inline void
tls_ie_to_le(const Relocate_info<size,false> * relinfo,size_t relnum,Output_segment * tls_segment,const elfcpp::Rela<size,false> & rela,unsigned int,typename elfcpp::Elf_types<size>::Elf_Addr value,unsigned char * view,section_size_type view_size)5681 Target_x86_64<size>::Relocate::tls_ie_to_le(
5682     const Relocate_info<size, false>* relinfo,
5683     size_t relnum,
5684     Output_segment* tls_segment,
5685     const elfcpp::Rela<size, false>& rela,
5686     unsigned int,
5687     typename elfcpp::Elf_types<size>::Elf_Addr value,
5688     unsigned char* view,
5689     section_size_type view_size)
5690 {
5691   // We need to examine the opcodes to figure out which instruction we
5692   // are looking at.
5693 
5694   // movq foo@gottpoff(%rip),%reg  ==>  movq $YY,%reg
5695   // addq foo@gottpoff(%rip),%reg  ==>  addq $YY,%reg
5696 
5697   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
5698   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
5699 
5700   unsigned char op1 = view[-3];
5701   unsigned char op2 = view[-2];
5702   unsigned char op3 = view[-1];
5703   unsigned char reg = op3 >> 3;
5704 
5705   if (op2 == 0x8b)
5706     {
5707       // movq
5708       if (op1 == 0x4c)
5709 	view[-3] = 0x49;
5710       else if (size == 32 && op1 == 0x44)
5711 	view[-3] = 0x41;
5712       view[-2] = 0xc7;
5713       view[-1] = 0xc0 | reg;
5714     }
5715   else if (reg == 4)
5716     {
5717       // Special handling for %rsp.
5718       if (op1 == 0x4c)
5719 	view[-3] = 0x49;
5720       else if (size == 32 && op1 == 0x44)
5721 	view[-3] = 0x41;
5722       view[-2] = 0x81;
5723       view[-1] = 0xc0 | reg;
5724     }
5725   else
5726     {
5727       // addq
5728       if (op1 == 0x4c)
5729 	view[-3] = 0x4d;
5730       else if (size == 32 && op1 == 0x44)
5731 	view[-3] = 0x45;
5732       view[-2] = 0x8d;
5733       view[-1] = 0x80 | reg | (reg << 3);
5734     }
5735 
5736   if (tls_segment != NULL)
5737     value -= tls_segment->memsz();
5738   Relocate_functions<size, false>::rela32(view, value, 0);
5739 }
5740 
5741 // Relocate section data.
5742 
5743 template<int size>
5744 void
relocate_section(const Relocate_info<size,false> * relinfo,unsigned int sh_type,const unsigned char * prelocs,size_t reloc_count,Output_section * output_section,bool needs_special_offset_handling,unsigned char * view,typename elfcpp::Elf_types<size>::Elf_Addr address,section_size_type view_size,const Reloc_symbol_changes * reloc_symbol_changes)5745 Target_x86_64<size>::relocate_section(
5746     const Relocate_info<size, false>* relinfo,
5747     unsigned int sh_type,
5748     const unsigned char* prelocs,
5749     size_t reloc_count,
5750     Output_section* output_section,
5751     bool needs_special_offset_handling,
5752     unsigned char* view,
5753     typename elfcpp::Elf_types<size>::Elf_Addr address,
5754     section_size_type view_size,
5755     const Reloc_symbol_changes* reloc_symbol_changes)
5756 {
5757   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5758       Classify_reloc;
5759 
5760   gold_assert(sh_type == elfcpp::SHT_RELA);
5761 
5762   gold::relocate_section<size, false, Target_x86_64<size>, Relocate,
5763 			 gold::Default_comdat_behavior, Classify_reloc>(
5764     relinfo,
5765     this,
5766     prelocs,
5767     reloc_count,
5768     output_section,
5769     needs_special_offset_handling,
5770     view,
5771     address,
5772     view_size,
5773     reloc_symbol_changes);
5774 }
5775 
5776 // Apply an incremental relocation.  Incremental relocations always refer
5777 // to global symbols.
5778 
5779 template<int size>
5780 void
apply_relocation(const Relocate_info<size,false> * relinfo,typename elfcpp::Elf_types<size>::Elf_Addr r_offset,unsigned int r_type,typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,const Symbol * gsym,unsigned char * view,typename elfcpp::Elf_types<size>::Elf_Addr address,section_size_type view_size)5781 Target_x86_64<size>::apply_relocation(
5782     const Relocate_info<size, false>* relinfo,
5783     typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
5784     unsigned int r_type,
5785     typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
5786     const Symbol* gsym,
5787     unsigned char* view,
5788     typename elfcpp::Elf_types<size>::Elf_Addr address,
5789     section_size_type view_size)
5790 {
5791   gold::apply_relocation<size, false, Target_x86_64<size>,
5792 			 typename Target_x86_64<size>::Relocate>(
5793     relinfo,
5794     this,
5795     r_offset,
5796     r_type,
5797     r_addend,
5798     gsym,
5799     view,
5800     address,
5801     view_size);
5802 }
5803 
5804 // Scan the relocs during a relocatable link.
5805 
5806 template<int size>
5807 void
scan_relocatable_relocs(Symbol_table * symtab,Layout * layout,Sized_relobj_file<size,false> * object,unsigned int data_shndx,unsigned int sh_type,const unsigned char * prelocs,size_t reloc_count,Output_section * output_section,bool needs_special_offset_handling,size_t local_symbol_count,const unsigned char * plocal_symbols,Relocatable_relocs * rr)5808 Target_x86_64<size>::scan_relocatable_relocs(
5809     Symbol_table* symtab,
5810     Layout* layout,
5811     Sized_relobj_file<size, false>* object,
5812     unsigned int data_shndx,
5813     unsigned int sh_type,
5814     const unsigned char* prelocs,
5815     size_t reloc_count,
5816     Output_section* output_section,
5817     bool needs_special_offset_handling,
5818     size_t local_symbol_count,
5819     const unsigned char* plocal_symbols,
5820     Relocatable_relocs* rr)
5821 {
5822   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5823       Classify_reloc;
5824   typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
5825       Scan_relocatable_relocs;
5826 
5827   gold_assert(sh_type == elfcpp::SHT_RELA);
5828 
5829   gold::scan_relocatable_relocs<size, false, Scan_relocatable_relocs>(
5830     symtab,
5831     layout,
5832     object,
5833     data_shndx,
5834     prelocs,
5835     reloc_count,
5836     output_section,
5837     needs_special_offset_handling,
5838     local_symbol_count,
5839     plocal_symbols,
5840     rr);
5841 }
5842 
5843 // Scan the relocs for --emit-relocs.
5844 
5845 template<int size>
5846 void
emit_relocs_scan(Symbol_table * symtab,Layout * layout,Sized_relobj_file<size,false> * object,unsigned int data_shndx,unsigned int sh_type,const unsigned char * prelocs,size_t reloc_count,Output_section * output_section,bool needs_special_offset_handling,size_t local_symbol_count,const unsigned char * plocal_syms,Relocatable_relocs * rr)5847 Target_x86_64<size>::emit_relocs_scan(
5848     Symbol_table* symtab,
5849     Layout* layout,
5850     Sized_relobj_file<size, false>* object,
5851     unsigned int data_shndx,
5852     unsigned int sh_type,
5853     const unsigned char* prelocs,
5854     size_t reloc_count,
5855     Output_section* output_section,
5856     bool needs_special_offset_handling,
5857     size_t local_symbol_count,
5858     const unsigned char* plocal_syms,
5859     Relocatable_relocs* rr)
5860 {
5861   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5862       Classify_reloc;
5863   typedef gold::Default_emit_relocs_strategy<Classify_reloc>
5864       Emit_relocs_strategy;
5865 
5866   gold_assert(sh_type == elfcpp::SHT_RELA);
5867 
5868   gold::scan_relocatable_relocs<size, false, Emit_relocs_strategy>(
5869     symtab,
5870     layout,
5871     object,
5872     data_shndx,
5873     prelocs,
5874     reloc_count,
5875     output_section,
5876     needs_special_offset_handling,
5877     local_symbol_count,
5878     plocal_syms,
5879     rr);
5880 }
5881 
5882 // Relocate a section during a relocatable link.
5883 
5884 template<int size>
5885 void
relocate_relocs(const Relocate_info<size,false> * relinfo,unsigned int sh_type,const unsigned char * prelocs,size_t reloc_count,Output_section * output_section,typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,unsigned char * view,typename elfcpp::Elf_types<size>::Elf_Addr view_address,section_size_type view_size,unsigned char * reloc_view,section_size_type reloc_view_size)5886 Target_x86_64<size>::relocate_relocs(
5887     const Relocate_info<size, false>* relinfo,
5888     unsigned int sh_type,
5889     const unsigned char* prelocs,
5890     size_t reloc_count,
5891     Output_section* output_section,
5892     typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
5893     unsigned char* view,
5894     typename elfcpp::Elf_types<size>::Elf_Addr view_address,
5895     section_size_type view_size,
5896     unsigned char* reloc_view,
5897     section_size_type reloc_view_size)
5898 {
5899   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5900       Classify_reloc;
5901 
5902   gold_assert(sh_type == elfcpp::SHT_RELA);
5903 
5904   gold::relocate_relocs<size, false, Classify_reloc>(
5905     relinfo,
5906     prelocs,
5907     reloc_count,
5908     output_section,
5909     offset_in_output_section,
5910     view,
5911     view_address,
5912     view_size,
5913     reloc_view,
5914     reloc_view_size);
5915 }
5916 
5917 // Return the value to use for a dynamic which requires special
5918 // treatment.  This is how we support equality comparisons of function
5919 // pointers across shared library boundaries, as described in the
5920 // processor specific ABI supplement.
5921 
5922 template<int size>
5923 uint64_t
do_dynsym_value(const Symbol * gsym) const5924 Target_x86_64<size>::do_dynsym_value(const Symbol* gsym) const
5925 {
5926   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
5927   return this->plt_address_for_global(gsym);
5928 }
5929 
5930 // Return a string used to fill a code section with nops to take up
5931 // the specified length.
5932 
5933 template<int size>
5934 std::string
do_code_fill(section_size_type length) const5935 Target_x86_64<size>::do_code_fill(section_size_type length) const
5936 {
5937   if (length >= 16)
5938     {
5939       // Build a jmpq instruction to skip over the bytes.
5940       unsigned char jmp[5];
5941       jmp[0] = 0xe9;
5942       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
5943       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
5944 	      + std::string(length - 5, static_cast<char>(0x90)));
5945     }
5946 
5947   // Nop sequences of various lengths.
5948   const char nop1[1] = { '\x90' };                 // nop
5949   const char nop2[2] = { '\x66', '\x90' };         // xchg %ax %ax
5950   const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
5951   const char nop4[4] = { '\x0f', '\x1f', '\x40',   // nop 0(%rax)
5952 			 '\x00'};
5953   const char nop5[5] = { '\x0f', '\x1f', '\x44',   // nop 0(%rax,%rax,1)
5954 			 '\x00', '\x00' };
5955   const char nop6[6] = { '\x66', '\x0f', '\x1f',   // nopw 0(%rax,%rax,1)
5956 			 '\x44', '\x00', '\x00' };
5957   const char nop7[7] = { '\x0f', '\x1f', '\x80',   // nopl 0L(%rax)
5958 			 '\x00', '\x00', '\x00',
5959 			 '\x00' };
5960   const char nop8[8] = { '\x0f', '\x1f', '\x84',   // nopl 0L(%rax,%rax,1)
5961 			 '\x00', '\x00', '\x00',
5962 			 '\x00', '\x00' };
5963   const char nop9[9] = { '\x66', '\x0f', '\x1f',   // nopw 0L(%rax,%rax,1)
5964 			 '\x84', '\x00', '\x00',
5965 			 '\x00', '\x00', '\x00' };
5966   const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5967 			   '\x1f', '\x84', '\x00',
5968 			   '\x00', '\x00', '\x00',
5969 			   '\x00' };
5970   const char nop11[11] = { '\x66', '\x66', '\x2e', // data16
5971 			   '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5972 			   '\x00', '\x00', '\x00',
5973 			   '\x00', '\x00' };
5974   const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16
5975 			   '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5976 			   '\x84', '\x00', '\x00',
5977 			   '\x00', '\x00', '\x00' };
5978   const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
5979 			   '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5980 			   '\x1f', '\x84', '\x00',
5981 			   '\x00', '\x00', '\x00',
5982 			   '\x00' };
5983   const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
5984 			   '\x66', '\x66', '\x2e', // data16
5985 			   '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5986 			   '\x00', '\x00', '\x00',
5987 			   '\x00', '\x00' };
5988   const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
5989 			   '\x66', '\x66', '\x66', // data16; data16
5990 			   '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5991 			   '\x84', '\x00', '\x00',
5992 			   '\x00', '\x00', '\x00' };
5993 
5994   const char* nops[16] = {
5995     NULL,
5996     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
5997     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
5998   };
5999 
6000   return std::string(nops[length], length);
6001 }
6002 
6003 // Return the addend to use for a target specific relocation.  The
6004 // only target specific relocation is R_X86_64_TLSDESC for a local
6005 // symbol.  We want to set the addend is the offset of the local
6006 // symbol in the TLS segment.
6007 
6008 template<int size>
6009 uint64_t
do_reloc_addend(void * arg,unsigned int r_type,uint64_t) const6010 Target_x86_64<size>::do_reloc_addend(void* arg, unsigned int r_type,
6011 				     uint64_t) const
6012 {
6013   gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
6014   uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
6015   gold_assert(intarg < this->tlsdesc_reloc_info_.size());
6016   const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
6017   const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
6018   gold_assert(psymval->is_tls_symbol());
6019   // The value of a TLS symbol is the offset in the TLS segment.
6020   return psymval->value(ti.object, 0);
6021 }
6022 
6023 // Return the value to use for the base of a DW_EH_PE_datarel offset
6024 // in an FDE.  Solaris and SVR4 use DW_EH_PE_datarel because their
6025 // assembler can not write out the difference between two labels in
6026 // different sections, so instead of using a pc-relative value they
6027 // use an offset from the GOT.
6028 
6029 template<int size>
6030 uint64_t
do_ehframe_datarel_base() const6031 Target_x86_64<size>::do_ehframe_datarel_base() const
6032 {
6033   gold_assert(this->global_offset_table_ != NULL);
6034   Symbol* sym = this->global_offset_table_;
6035   Sized_symbol<size>* ssym = static_cast<Sized_symbol<size>*>(sym);
6036   return ssym->value();
6037 }
6038 
6039 // FNOFFSET in section SHNDX in OBJECT is the start of a function
6040 // compiled with -fsplit-stack.  The function calls non-split-stack
6041 // code.  We have to change the function so that it always ensures
6042 // that it has enough stack space to run some random function.
6043 
6044 static const unsigned char cmp_insn_32[] = { 0x64, 0x3b, 0x24, 0x25 };
6045 static const unsigned char lea_r10_insn_32[] = { 0x44, 0x8d, 0x94, 0x24 };
6046 static const unsigned char lea_r11_insn_32[] = { 0x44, 0x8d, 0x9c, 0x24 };
6047 
6048 static const unsigned char cmp_insn_64[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
6049 static const unsigned char lea_r10_insn_64[] = { 0x4c, 0x8d, 0x94, 0x24 };
6050 static const unsigned char lea_r11_insn_64[] = { 0x4c, 0x8d, 0x9c, 0x24 };
6051 
6052 template<int size>
6053 void
do_calls_non_split(Relobj * object,unsigned int shndx,section_offset_type fnoffset,section_size_type fnsize,const unsigned char *,size_t,unsigned char * view,section_size_type view_size,std::string * from,std::string * to) const6054 Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
6055 					section_offset_type fnoffset,
6056 					section_size_type fnsize,
6057 					const unsigned char*,
6058 					size_t,
6059 					unsigned char* view,
6060 					section_size_type view_size,
6061 					std::string* from,
6062 					std::string* to) const
6063 {
6064   const char* const cmp_insn = reinterpret_cast<const char*>
6065       (size == 32 ? cmp_insn_32 : cmp_insn_64);
6066   const char* const lea_r10_insn = reinterpret_cast<const char*>
6067       (size == 32 ? lea_r10_insn_32 : lea_r10_insn_64);
6068   const char* const lea_r11_insn = reinterpret_cast<const char*>
6069       (size == 32 ? lea_r11_insn_32 : lea_r11_insn_64);
6070 
6071   const size_t cmp_insn_len =
6072       (size == 32 ? sizeof(cmp_insn_32) : sizeof(cmp_insn_64));
6073   const size_t lea_r10_insn_len =
6074       (size == 32 ? sizeof(lea_r10_insn_32) : sizeof(lea_r10_insn_64));
6075   const size_t lea_r11_insn_len =
6076       (size == 32 ? sizeof(lea_r11_insn_32) : sizeof(lea_r11_insn_64));
6077   const size_t nop_len = (size == 32 ? 7 : 8);
6078 
6079   // The function starts with a comparison of the stack pointer and a
6080   // field in the TCB.  This is followed by a jump.
6081 
6082   // cmp %fs:NN,%rsp
6083   if (this->match_view(view, view_size, fnoffset, cmp_insn, cmp_insn_len)
6084       && fnsize > nop_len + 1)
6085     {
6086       // We will call __morestack if the carry flag is set after this
6087       // comparison.  We turn the comparison into an stc instruction
6088       // and some nops.
6089       view[fnoffset] = '\xf9';
6090       this->set_view_to_nop(view, view_size, fnoffset + 1, nop_len);
6091     }
6092   // lea NN(%rsp),%r10
6093   // lea NN(%rsp),%r11
6094   else if ((this->match_view(view, view_size, fnoffset,
6095 			     lea_r10_insn, lea_r10_insn_len)
6096 	    || this->match_view(view, view_size, fnoffset,
6097 				lea_r11_insn, lea_r11_insn_len))
6098 	   && fnsize > 8)
6099     {
6100       // This is loading an offset from the stack pointer for a
6101       // comparison.  The offset is negative, so we decrease the
6102       // offset by the amount of space we need for the stack.  This
6103       // means we will avoid calling __morestack if there happens to
6104       // be plenty of space on the stack already.
6105       unsigned char* pval = view + fnoffset + 4;
6106       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
6107       val -= parameters->options().split_stack_adjust_size();
6108       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
6109     }
6110   else
6111     {
6112       if (!object->has_no_split_stack())
6113 	object->error(_("failed to match split-stack sequence at "
6114 			"section %u offset %0zx"),
6115 		      shndx, static_cast<size_t>(fnoffset));
6116       return;
6117     }
6118 
6119   // We have to change the function so that it calls
6120   // __morestack_non_split instead of __morestack.  The former will
6121   // allocate additional stack space.
6122   *from = "__morestack";
6123   *to = "__morestack_non_split";
6124 }
6125 
6126 // The selector for x86_64 object files.  Note this is never instantiated
6127 // directly.  It's only used in Target_selector_x86_64_nacl, below.
6128 
6129 template<int size>
6130 class Target_selector_x86_64 : public Target_selector_freebsd
6131 {
6132 public:
Target_selector_x86_64()6133   Target_selector_x86_64()
6134     : Target_selector_freebsd(elfcpp::EM_X86_64, size, false,
6135 			      (size == 64
6136 			       ? "elf64-x86-64" : "elf32-x86-64"),
6137 			      (size == 64
6138 			       ? "elf64-x86-64-freebsd"
6139 			       : "elf32-x86-64-freebsd"),
6140 			      (size == 64 ? "elf_x86_64" : "elf32_x86_64"))
6141   { }
6142 
6143   Target*
do_instantiate_target()6144   do_instantiate_target()
6145   { return new Target_x86_64<size>(); }
6146 
6147 };
6148 
6149 // NaCl variant.  It uses different PLT contents.
6150 
6151 template<int size>
6152 class Output_data_plt_x86_64_nacl : public Output_data_plt_x86_64<size>
6153 {
6154  public:
Output_data_plt_x86_64_nacl(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative)6155   Output_data_plt_x86_64_nacl(Layout* layout,
6156 			      Output_data_got<64, false>* got,
6157 			      Output_data_got_plt_x86_64* got_plt,
6158 			      Output_data_space* got_irelative)
6159     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
6160 				   got, got_plt, got_irelative)
6161   { }
6162 
Output_data_plt_x86_64_nacl(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative,unsigned int plt_count)6163   Output_data_plt_x86_64_nacl(Layout* layout,
6164 			      Output_data_got<64, false>* got,
6165 			      Output_data_got_plt_x86_64* got_plt,
6166 			      Output_data_space* got_irelative,
6167 			      unsigned int plt_count)
6168     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
6169 				   got, got_plt, got_irelative,
6170 				   plt_count)
6171   { }
6172 
6173  protected:
6174   virtual unsigned int
do_get_plt_entry_size() const6175   do_get_plt_entry_size() const
6176   { return plt_entry_size; }
6177 
6178   virtual void
do_add_eh_frame(Layout * layout)6179   do_add_eh_frame(Layout* layout)
6180   {
6181     layout->add_eh_frame_for_plt(this,
6182 				 this->plt_eh_frame_cie,
6183 				 this->plt_eh_frame_cie_size,
6184 				 plt_eh_frame_fde,
6185 				 plt_eh_frame_fde_size);
6186   }
6187 
6188   virtual void
6189   do_fill_first_plt_entry(unsigned char* pov,
6190 			  typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
6191 			  typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
6192 
6193   virtual unsigned int
6194   do_fill_plt_entry(unsigned char* pov,
6195 		    typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6196 		    typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6197 		    unsigned int got_offset,
6198 		    unsigned int plt_offset,
6199 		    unsigned int plt_index);
6200 
6201   virtual void
6202   do_fill_tlsdesc_entry(unsigned char* pov,
6203 			typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6204 			typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6205 			typename elfcpp::Elf_types<size>::Elf_Addr got_base,
6206 			unsigned int tlsdesc_got_offset,
6207 			unsigned int plt_offset);
6208 
6209  private:
6210   // The size of an entry in the PLT.
6211   static const int plt_entry_size = 64;
6212 
6213   // The first entry in the PLT.
6214   static const unsigned char first_plt_entry[plt_entry_size];
6215 
6216   // Other entries in the PLT for an executable.
6217   static const unsigned char plt_entry[plt_entry_size];
6218 
6219   // The reserved TLSDESC entry in the PLT for an executable.
6220   static const unsigned char tlsdesc_plt_entry[plt_entry_size];
6221 
6222   // The .eh_frame unwind information for the PLT.
6223   static const int plt_eh_frame_fde_size = 32;
6224   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
6225 };
6226 
6227 template<int size>
6228 class Target_x86_64_nacl : public Target_x86_64<size>
6229 {
6230  public:
Target_x86_64_nacl()6231   Target_x86_64_nacl()
6232     : Target_x86_64<size>(&x86_64_nacl_info)
6233   { }
6234 
6235   virtual Output_data_plt_x86_64<size>*
do_make_data_plt(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative)6236   do_make_data_plt(Layout* layout,
6237 		   Output_data_got<64, false>* got,
6238 		   Output_data_got_plt_x86_64* got_plt,
6239 		   Output_data_space* got_irelative)
6240   {
6241     return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
6242 						 got_irelative);
6243   }
6244 
6245   virtual Output_data_plt_x86_64<size>*
do_make_data_plt(Layout * layout,Output_data_got<64,false> * got,Output_data_got_plt_x86_64 * got_plt,Output_data_space * got_irelative,unsigned int plt_count)6246   do_make_data_plt(Layout* layout,
6247 		   Output_data_got<64, false>* got,
6248 		   Output_data_got_plt_x86_64* got_plt,
6249 		   Output_data_space* got_irelative,
6250 		   unsigned int plt_count)
6251   {
6252     return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
6253 						 got_irelative,
6254 						 plt_count);
6255   }
6256 
6257   virtual std::string
6258   do_code_fill(section_size_type length) const;
6259 
6260  private:
6261   static const Target::Target_info x86_64_nacl_info;
6262 };
6263 
6264 template<>
6265 const Target::Target_info Target_x86_64_nacl<64>::x86_64_nacl_info =
6266 {
6267   64,			// size
6268   false,		// is_big_endian
6269   elfcpp::EM_X86_64,	// machine_code
6270   false,		// has_make_symbol
6271   false,		// has_resolve
6272   true,			// has_code_fill
6273   true,			// is_default_stack_executable
6274   true,			// can_icf_inline_merge_sections
6275   '\0',			// wrap_char
6276   "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
6277   0x20000,		// default_text_segment_address
6278   0x10000,		// abi_pagesize (overridable by -z max-page-size)
6279   0x10000,		// common_pagesize (overridable by -z common-page-size)
6280   true,                 // isolate_execinstr
6281   0x10000000,           // rosegment_gap
6282   elfcpp::SHN_UNDEF,	// small_common_shndx
6283   elfcpp::SHN_X86_64_LCOMMON,	// large_common_shndx
6284   0,			// small_common_section_flags
6285   elfcpp::SHF_X86_64_LARGE,	// large_common_section_flags
6286   NULL,			// attributes_section
6287   NULL,			// attributes_vendor
6288   "_start",		// entry_symbol_name
6289   32,			// hash_entry_size
6290   elfcpp::SHT_X86_64_UNWIND,	// unwind_section_type
6291 };
6292 
6293 template<>
6294 const Target::Target_info Target_x86_64_nacl<32>::x86_64_nacl_info =
6295 {
6296   32,			// size
6297   false,		// is_big_endian
6298   elfcpp::EM_X86_64,	// machine_code
6299   false,		// has_make_symbol
6300   false,		// has_resolve
6301   true,			// has_code_fill
6302   true,			// is_default_stack_executable
6303   true,			// can_icf_inline_merge_sections
6304   '\0',			// wrap_char
6305   "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
6306   0x20000,		// default_text_segment_address
6307   0x10000,		// abi_pagesize (overridable by -z max-page-size)
6308   0x10000,		// common_pagesize (overridable by -z common-page-size)
6309   true,                 // isolate_execinstr
6310   0x10000000,           // rosegment_gap
6311   elfcpp::SHN_UNDEF,	// small_common_shndx
6312   elfcpp::SHN_X86_64_LCOMMON,	// large_common_shndx
6313   0,			// small_common_section_flags
6314   elfcpp::SHF_X86_64_LARGE,	// large_common_section_flags
6315   NULL,			// attributes_section
6316   NULL,			// attributes_vendor
6317   "_start",		// entry_symbol_name
6318   32,			// hash_entry_size
6319   elfcpp::SHT_X86_64_UNWIND,	// unwind_section_type
6320 };
6321 
6322 #define	NACLMASK	0xe0            // 32-byte alignment mask.
6323 
6324 // The first entry in the PLT.
6325 
6326 template<int size>
6327 const unsigned char
6328 Output_data_plt_x86_64_nacl<size>::first_plt_entry[plt_entry_size] =
6329 {
6330   0xff, 0x35,                         // pushq contents of memory address
6331   0, 0, 0, 0,                         // replaced with address of .got + 8
6332   0x4c, 0x8b, 0x1d,                   // mov GOT+16(%rip), %r11
6333   0, 0, 0, 0,                         // replaced with address of .got + 16
6334   0x41, 0x83, 0xe3, NACLMASK,         // and $-32, %r11d
6335   0x4d, 0x01, 0xfb,                   // add %r15, %r11
6336   0x41, 0xff, 0xe3,                   // jmpq *%r11
6337 
6338   // 9-byte nop sequence to pad out to the next 32-byte boundary.
6339   0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
6340 
6341   // 32 bytes of nop to pad out to the standard size
6342   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
6343   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6344   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
6345   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6346   0x66,                                  // excess data32 prefix
6347   0x90                                   // nop
6348 };
6349 
6350 template<int size>
6351 void
do_fill_first_plt_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address)6352 Output_data_plt_x86_64_nacl<size>::do_fill_first_plt_entry(
6353     unsigned char* pov,
6354     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6355     typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
6356 {
6357   memcpy(pov, first_plt_entry, plt_entry_size);
6358   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
6359 					      (got_address + 8
6360 					       - (plt_address + 2 + 4)));
6361   elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
6362 					      (got_address + 16
6363 					       - (plt_address + 9 + 4)));
6364 }
6365 
6366 // Subsequent entries in the PLT.
6367 
6368 template<int size>
6369 const unsigned char
6370 Output_data_plt_x86_64_nacl<size>::plt_entry[plt_entry_size] =
6371 {
6372   0x4c, 0x8b, 0x1d,              // mov name@GOTPCREL(%rip),%r11
6373   0, 0, 0, 0,                    // replaced with address of symbol in .got
6374   0x41, 0x83, 0xe3, NACLMASK,    // and $-32, %r11d
6375   0x4d, 0x01, 0xfb,              // add %r15, %r11
6376   0x41, 0xff, 0xe3,              // jmpq *%r11
6377 
6378   // 15-byte nop sequence to pad out to the next 32-byte boundary.
6379   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
6380   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6381 
6382   // Lazy GOT entries point here (32-byte aligned).
6383   0x68,                       // pushq immediate
6384   0, 0, 0, 0,                 // replaced with index into relocation table
6385   0xe9,                       // jmp relative
6386   0, 0, 0, 0,                 // replaced with offset to start of .plt0
6387 
6388   // 22 bytes of nop to pad out to the standard size.
6389   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
6390   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6391   0x0f, 0x1f, 0x80, 0, 0, 0, 0,          // nopl 0x0(%rax)
6392 };
6393 
6394 template<int size>
6395 unsigned int
do_fill_plt_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address,unsigned int got_offset,unsigned int plt_offset,unsigned int plt_index)6396 Output_data_plt_x86_64_nacl<size>::do_fill_plt_entry(
6397     unsigned char* pov,
6398     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6399     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6400     unsigned int got_offset,
6401     unsigned int plt_offset,
6402     unsigned int plt_index)
6403 {
6404   memcpy(pov, plt_entry, plt_entry_size);
6405   elfcpp::Swap_unaligned<32, false>::writeval(pov + 3,
6406 					      (got_address + got_offset
6407 					       - (plt_address + plt_offset
6408 						  + 3 + 4)));
6409 
6410   elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_index);
6411   elfcpp::Swap_unaligned<32, false>::writeval(pov + 38,
6412 					      - (plt_offset + 38 + 4));
6413 
6414   return 32;
6415 }
6416 
6417 // The reserved TLSDESC entry in the PLT.
6418 
6419 template<int size>
6420 const unsigned char
6421 Output_data_plt_x86_64_nacl<size>::tlsdesc_plt_entry[plt_entry_size] =
6422 {
6423   0xff, 0x35,			// pushq x(%rip)
6424   0, 0, 0, 0,	// replaced with address of linkmap GOT entry (at PLTGOT + 8)
6425   0x4c, 0x8b, 0x1d,		// mov y(%rip),%r11
6426   0, 0, 0, 0,	// replaced with offset of reserved TLSDESC_GOT entry
6427   0x41, 0x83, 0xe3, NACLMASK,	// and $-32, %r11d
6428   0x4d, 0x01, 0xfb,             // add %r15, %r11
6429   0x41, 0xff, 0xe3,             // jmpq *%r11
6430 
6431   // 41 bytes of nop to pad out to the standard size.
6432   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
6433   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6434   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
6435   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6436   0x66, 0x66,                            // excess data32 prefixes
6437   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
6438 };
6439 
6440 template<int size>
6441 void
do_fill_tlsdesc_entry(unsigned char * pov,typename elfcpp::Elf_types<size>::Elf_Addr got_address,typename elfcpp::Elf_types<size>::Elf_Addr plt_address,typename elfcpp::Elf_types<size>::Elf_Addr got_base,unsigned int tlsdesc_got_offset,unsigned int plt_offset)6442 Output_data_plt_x86_64_nacl<size>::do_fill_tlsdesc_entry(
6443     unsigned char* pov,
6444     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
6445     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
6446     typename elfcpp::Elf_types<size>::Elf_Addr got_base,
6447     unsigned int tlsdesc_got_offset,
6448     unsigned int plt_offset)
6449 {
6450   memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
6451   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
6452 					      (got_address + 8
6453 					       - (plt_address + plt_offset
6454 						  + 2 + 4)));
6455   elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
6456 					      (got_base
6457 					       + tlsdesc_got_offset
6458 					       - (plt_address + plt_offset
6459 						  + 9 + 4)));
6460 }
6461 
6462 // The .eh_frame unwind information for the PLT.
6463 
6464 template<int size>
6465 const unsigned char
6466 Output_data_plt_x86_64_nacl<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
6467 {
6468   0, 0, 0, 0,				// Replaced with offset to .plt.
6469   0, 0, 0, 0,				// Replaced with size of .plt.
6470   0,					// Augmentation size.
6471   elfcpp::DW_CFA_def_cfa_offset, 16,	// DW_CFA_def_cfa_offset: 16.
6472   elfcpp::DW_CFA_advance_loc + 6,	// Advance 6 to __PLT__ + 6.
6473   elfcpp::DW_CFA_def_cfa_offset, 24,	// DW_CFA_def_cfa_offset: 24.
6474   elfcpp::DW_CFA_advance_loc + 58,	// Advance 58 to __PLT__ + 64.
6475   elfcpp::DW_CFA_def_cfa_expression,	// DW_CFA_def_cfa_expression.
6476   13,					// Block length.
6477   elfcpp::DW_OP_breg7, 8,		// Push %rsp + 8.
6478   elfcpp::DW_OP_breg16, 0,		// Push %rip.
6479   elfcpp::DW_OP_const1u, 63,		// Push 0x3f.
6480   elfcpp::DW_OP_and,			// & (%rip & 0x3f).
6481   elfcpp::DW_OP_const1u, 37,            // Push 0x25.
6482   elfcpp::DW_OP_ge,			// >= ((%rip & 0x3f) >= 0x25)
6483   elfcpp::DW_OP_lit3,			// Push 3.
6484   elfcpp::DW_OP_shl,			// << (((%rip & 0x3f) >= 0x25) << 3)
6485   elfcpp::DW_OP_plus,			// + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
6486   elfcpp::DW_CFA_nop,			// Align to 32 bytes.
6487   elfcpp::DW_CFA_nop
6488 };
6489 
6490 // Return a string used to fill a code section with nops.
6491 // For NaCl, long NOPs are only valid if they do not cross
6492 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
6493 template<int size>
6494 std::string
do_code_fill(section_size_type length) const6495 Target_x86_64_nacl<size>::do_code_fill(section_size_type length) const
6496 {
6497   return std::string(length, static_cast<char>(0x90));
6498 }
6499 
6500 // The selector for x86_64-nacl object files.
6501 
6502 template<int size>
6503 class Target_selector_x86_64_nacl
6504   : public Target_selector_nacl<Target_selector_x86_64<size>,
6505 				Target_x86_64_nacl<size> >
6506 {
6507  public:
Target_selector_x86_64_nacl()6508   Target_selector_x86_64_nacl()
6509     : Target_selector_nacl<Target_selector_x86_64<size>,
6510 			   Target_x86_64_nacl<size> >("x86-64",
6511 						      size == 64
6512 						      ? "elf64-x86-64-nacl"
6513 						      : "elf32-x86-64-nacl",
6514 						      size == 64
6515 						      ? "elf_x86_64_nacl"
6516 						      : "elf32_x86_64_nacl")
6517   { }
6518 };
6519 
6520 Target_selector_x86_64_nacl<64> target_selector_x86_64;
6521 Target_selector_x86_64_nacl<32> target_selector_x32;
6522 
6523 } // End anonymous namespace.
6524