1 /* $NetBSD: ppc_reloc.c,v 1.10 2001/09/10 06:09:41 mycroft Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-2-Clause
5 *
6 * Copyright (C) 1998 Tsubai Masanari
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. The name of the author may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/param.h>
33 #include <sys/mman.h>
34
35 #include <errno.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include <machine/cpu.h>
41 #include <machine/atomic.h>
42 #include <machine/md_var.h>
43
44 #include "debug.h"
45 #include "rtld.h"
46
47 #define _ppc_ha(x) ((((u_int32_t)(x) & 0x8000) ? \
48 ((u_int32_t)(x) + 0x10000) : (u_int32_t)(x)) >> 16)
49 #define _ppc_la(x) ((u_int32_t)(x) & 0xffff)
50
51 #define min(a,b) (((a) < (b)) ? (a) : (b))
52 #define max(a,b) (((a) > (b)) ? (a) : (b))
53
54 #define PLT_EXTENDED_BEGIN (1 << 13)
55 #define JMPTAB_BASE(N) (18 + N*2 + ((N > PLT_EXTENDED_BEGIN) ? \
56 (N - PLT_EXTENDED_BEGIN)*2 : 0))
57
58 void _rtld_bind_secureplt_start(void);
59
60 /*
61 * Process the R_PPC_COPY relocations
62 */
63 int
do_copy_relocations(Obj_Entry * dstobj)64 do_copy_relocations(Obj_Entry *dstobj)
65 {
66 const Elf_Rela *relalim;
67 const Elf_Rela *rela;
68
69 /*
70 * COPY relocs are invalid outside of the main program
71 */
72 assert(dstobj->mainprog);
73
74 relalim = (const Elf_Rela *)((const char *) dstobj->rela +
75 dstobj->relasize);
76 for (rela = dstobj->rela; rela < relalim; rela++) {
77 void *dstaddr;
78 const Elf_Sym *dstsym;
79 const char *name;
80 size_t size;
81 const void *srcaddr;
82 const Elf_Sym *srcsym = NULL;
83 const Obj_Entry *srcobj, *defobj;
84 SymLook req;
85 int res;
86
87 if (ELF_R_TYPE(rela->r_info) != R_PPC_COPY) {
88 continue;
89 }
90
91 dstaddr = (void *)(dstobj->relocbase + rela->r_offset);
92 dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info);
93 name = dstobj->strtab + dstsym->st_name;
94 size = dstsym->st_size;
95 symlook_init(&req, name);
96 req.ventry = fetch_ventry(dstobj, ELF_R_SYM(rela->r_info));
97 req.flags = SYMLOOK_EARLY;
98
99 for (srcobj = globallist_next(dstobj); srcobj != NULL;
100 srcobj = globallist_next(srcobj)) {
101 res = symlook_obj(&req, srcobj);
102 if (res == 0) {
103 srcsym = req.sym_out;
104 defobj = req.defobj_out;
105 break;
106 }
107 }
108
109 if (srcobj == NULL) {
110 _rtld_error("Undefined symbol \"%s\" "
111 " referenced from COPY"
112 " relocation in %s", name, dstobj->path);
113 return (-1);
114 }
115
116 srcaddr = (const void *)(defobj->relocbase+srcsym->st_value);
117 memcpy(dstaddr, srcaddr, size);
118 dbg("copy_reloc: src=%p,dst=%p,size=%d\n",srcaddr,dstaddr,size);
119 }
120
121 return (0);
122 }
123
124
125 /*
126 * Perform early relocation of the run-time linker image
127 */
128 void
reloc_non_plt_self(Elf_Dyn * dynp,Elf_Addr relocbase)129 reloc_non_plt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
130 {
131 const Elf_Rela *rela = NULL, *relalim;
132 Elf_Addr relasz = 0;
133 Elf_Addr *where;
134
135 /*
136 * Extract the rela/relasz values from the dynamic section
137 */
138 for (; dynp->d_tag != DT_NULL; dynp++) {
139 switch (dynp->d_tag) {
140 case DT_RELA:
141 rela = (const Elf_Rela *)(relocbase+dynp->d_un.d_ptr);
142 break;
143 case DT_RELASZ:
144 relasz = dynp->d_un.d_val;
145 break;
146 }
147 }
148
149 /*
150 * Relocate these values
151 */
152 relalim = (const Elf_Rela *)((const char *)rela + relasz);
153 for (; rela < relalim; rela++) {
154 where = (Elf_Addr *)(relocbase + rela->r_offset);
155 *where = (Elf_Addr)(relocbase + rela->r_addend);
156 }
157 }
158
159
160 /*
161 * Relocate a non-PLT object with addend.
162 */
163 static int
reloc_nonplt_object(Obj_Entry * obj_rtld __unused,Obj_Entry * obj,const Elf_Rela * rela,SymCache * cache,int flags,RtldLockState * lockstate)164 reloc_nonplt_object(Obj_Entry *obj_rtld __unused, Obj_Entry *obj,
165 const Elf_Rela *rela, SymCache *cache, int flags, RtldLockState *lockstate)
166 {
167 const Elf_Sym *def = NULL;
168 const Obj_Entry *defobj;
169 Elf_Addr *where, symval = 0;
170
171 /*
172 * First, resolve symbol for relocations which
173 * reference symbols.
174 */
175 switch (ELF_R_TYPE(rela->r_info)) {
176
177 case R_PPC_UADDR32: /* word32 S + A */
178 case R_PPC_ADDR32:
179 case R_PPC_GLOB_DAT: /* word32 S + A */
180 case R_PPC_DTPMOD32:
181 case R_PPC_TPREL32:
182 case R_PPC_DTPREL32:
183 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
184 flags, cache, lockstate);
185 if (def == NULL) {
186 return (-1);
187 }
188
189 /*
190 * If symbol is IFUNC, only perform relocation
191 * when caller allowed it by passing
192 * SYMLOOK_IFUNC flag. Skip the relocations
193 * otherwise.
194 *
195 * Also error out in case IFUNC relocations
196 * are specified for TLS, which cannot be
197 * usefully interpreted.
198 */
199 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
200 switch (ELF_R_TYPE(rela->r_info)) {
201 case R_PPC_UADDR32:
202 case R_PPC_ADDR32:
203 case R_PPC_GLOB_DAT:
204 if ((flags & SYMLOOK_IFUNC) == 0) {
205 dbg("Non-PLT reference to IFUNC found!");
206 obj->non_plt_gnu_ifunc = true;
207 return (0);
208 }
209 symval = (Elf_Addr)rtld_resolve_ifunc(
210 defobj, def);
211 break;
212 default:
213 _rtld_error("%s: IFUNC for TLS reloc",
214 obj->path);
215 return (-1);
216 }
217 } else {
218 if ((flags & SYMLOOK_IFUNC) != 0)
219 return (0);
220 symval = (Elf_Addr)defobj->relocbase +
221 def->st_value;
222 }
223 break;
224 default:
225 if ((flags & SYMLOOK_IFUNC) != 0)
226 return (0);
227 }
228 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
229
230 switch (ELF_R_TYPE(rela->r_info)) {
231 case R_PPC_NONE:
232 break;
233 case R_PPC_UADDR32:
234 case R_PPC_ADDR32:
235 case R_PPC_GLOB_DAT:
236 /* Don't issue write if unnecessary; avoid COW page fault */
237 if (*where != symval + rela->r_addend) {
238 *where = symval + rela->r_addend;
239 }
240 break;
241 case R_PPC_DTPMOD32:
242 *where = (Elf_Addr) defobj->tlsindex;
243 break;
244 case R_PPC_TPREL32:
245 /*
246 * We lazily allocate offsets for static TLS as we
247 * see the first relocation that references the
248 * TLS block. This allows us to support (small
249 * amounts of) static TLS in dynamically loaded
250 * modules. If we run out of space, we generate an
251 * error.
252 */
253 if (!defobj->tls_static) {
254 if (!allocate_tls_offset(
255 __DECONST(Obj_Entry *, defobj))) {
256 _rtld_error("%s: No space available for static "
257 "Thread Local Storage", obj->path);
258 return (-1);
259 }
260 }
261
262 *(Elf_Addr **)where = *where * sizeof(Elf_Addr)
263 + (Elf_Addr *)(def->st_value + rela->r_addend
264 + defobj->tlsoffset - TLS_TP_OFFSET - TLS_TCB_SIZE);
265 break;
266 case R_PPC_DTPREL32:
267 *where += (Elf_Addr)(def->st_value + rela->r_addend
268 - TLS_DTV_OFFSET);
269 break;
270 case R_PPC_RELATIVE: /* word32 B + A */
271 symval = (Elf_Addr)(obj->relocbase + rela->r_addend);
272
273 /* As above, don't issue write unnecessarily */
274 if (*where != symval) {
275 *where = symval;
276 }
277 break;
278 case R_PPC_COPY:
279 /*
280 * These are deferred until all other relocations
281 * have been done. All we do here is make sure
282 * that the COPY relocation is not in a shared
283 * library. They are allowed only in executable
284 * files.
285 */
286 if (!obj->mainprog) {
287 _rtld_error("%s: Unexpected R_COPY "
288 " relocation in shared library",
289 obj->path);
290 return (-1);
291 }
292 break;
293 case R_PPC_IRELATIVE:
294 /*
295 * These will be handled by reloc_iresolve().
296 */
297 obj->irelative = true;
298 break;
299 case R_PPC_JMP_SLOT:
300 /*
301 * These will be handled by the plt/jmpslot routines
302 */
303 break;
304
305 default:
306 _rtld_error("%s: Unsupported relocation type %d"
307 " in non-PLT relocations\n", obj->path,
308 ELF_R_TYPE(rela->r_info));
309 return (-1);
310 }
311 return (0);
312 }
313
314
315 /*
316 * Process non-PLT relocations
317 */
318 int
reloc_non_plt(Obj_Entry * obj,Obj_Entry * obj_rtld,int flags,RtldLockState * lockstate)319 reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
320 RtldLockState *lockstate)
321 {
322 const Elf_Rela *relalim;
323 const Elf_Rela *rela;
324 const Elf_Phdr *phdr;
325 SymCache *cache;
326 int r = -1;
327
328 /*
329 * The dynamic loader may be called from a thread, we have
330 * limited amounts of stack available so we cannot use alloca().
331 */
332 if (obj != obj_rtld) {
333 cache = calloc(obj->dynsymcount, sizeof(SymCache));
334 /* No need to check for NULL here */
335 } else
336 cache = NULL;
337
338 /*
339 * From the SVR4 PPC ABI:
340 * "The PowerPC family uses only the Elf32_Rela relocation
341 * entries with explicit addends."
342 */
343 relalim = (const Elf_Rela *)((const char *)obj->rela + obj->relasize);
344 for (rela = obj->rela; rela < relalim; rela++) {
345 if (reloc_nonplt_object(obj_rtld, obj, rela, cache, flags,
346 lockstate) < 0)
347 goto done;
348 }
349 r = 0;
350 done:
351 if (cache != NULL)
352 free(cache);
353
354 /*
355 * Synchronize icache for executable segments in case we made
356 * any changes.
357 */
358 for (phdr = obj->phdr;
359 (const char *)phdr < (const char *)obj->phdr + obj->phsize;
360 phdr++) {
361 if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X) != 0) {
362 __syncicache(obj->relocbase + phdr->p_vaddr,
363 phdr->p_memsz);
364 }
365 }
366
367 return (r);
368 }
369
370 /*
371 * Initialise a PLT slot to the resolving trampoline
372 */
373 static int
reloc_plt_object(Obj_Entry * obj,const Elf_Rela * rela)374 reloc_plt_object(Obj_Entry *obj, const Elf_Rela *rela)
375 {
376 Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset);
377 Elf_Addr *pltresolve, *pltlongresolve, *jmptab;
378 Elf_Addr distance;
379 int N = obj->pltrelasize / sizeof(Elf_Rela);
380 int reloff;
381
382 reloff = rela - obj->pltrela;
383
384 if (reloff < 0)
385 return (-1);
386
387 if (obj->gotptr != NULL) {
388 *where += (Elf_Addr)obj->relocbase;
389 return (0);
390 }
391
392 pltlongresolve = obj->pltgot + 5;
393 pltresolve = pltlongresolve + 5;
394
395 distance = (Elf_Addr)pltresolve - (Elf_Addr)(where + 1);
396
397 dbg(" reloc_plt_object: where=%p,pltres=%p,reloff=%x,distance=%x",
398 (void *)where, (void *)pltresolve, reloff, distance);
399
400 if (reloff < PLT_EXTENDED_BEGIN) {
401 /* li r11,reloff */
402 /* b pltresolve */
403 where[0] = 0x39600000 | reloff;
404 where[1] = 0x48000000 | (distance & 0x03fffffc);
405 } else {
406 jmptab = obj->pltgot + JMPTAB_BASE(N);
407 jmptab[reloff] = (u_int)pltlongresolve;
408
409 /* lis r11,jmptab[reloff]@ha */
410 /* lwzu r12,jmptab[reloff]@l(r11) */
411 /* mtctr r12 */
412 /* bctr */
413 where[0] = 0x3d600000 | _ppc_ha(&jmptab[reloff]);
414 where[1] = 0x858b0000 | _ppc_la(&jmptab[reloff]);
415 where[2] = 0x7d8903a6;
416 where[3] = 0x4e800420;
417 }
418
419
420 /*
421 * The icache will be sync'd in reloc_plt, which is called
422 * after all the slots have been updated
423 */
424
425 return (0);
426 }
427
428 /*
429 * Process the PLT relocations.
430 */
431 int
reloc_plt(Obj_Entry * obj,int flags __unused,RtldLockState * lockstate __unused)432 reloc_plt(Obj_Entry *obj, int flags __unused, RtldLockState *lockstate __unused)
433 {
434 const Elf_Rela *relalim;
435 const Elf_Rela *rela;
436 int N = obj->pltrelasize / sizeof(Elf_Rela);
437
438 if (obj->pltrelasize != 0) {
439
440 relalim = (const Elf_Rela *)((const char *)obj->pltrela +
441 obj->pltrelasize);
442 for (rela = obj->pltrela; rela < relalim; rela++) {
443 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) {
444 dbg("ABI violation - found IRELATIVE in the PLT.");
445 obj->irelative = true;
446 continue;
447 }
448
449 /*
450 * PowerPC(64) .rela.plt is composed of an array of
451 * R_PPC_JMP_SLOT relocations. Unlike other platforms,
452 * this is the ONLY relocation type that is valid here.
453 */
454 assert(ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT);
455
456 if (reloc_plt_object(obj, rela) < 0) {
457 return (-1);
458 }
459 }
460 }
461
462 /*
463 * Sync the icache for the byte range represented by the
464 * trampoline routines and call slots.
465 */
466 if (obj->pltgot != NULL && obj->gotptr == NULL)
467 __syncicache(obj->pltgot, JMPTAB_BASE(N)*4);
468
469 return (0);
470 }
471
472 /*
473 * LD_BIND_NOW was set - force relocation for all jump slots
474 */
475 int
reloc_jmpslots(Obj_Entry * obj,int flags,RtldLockState * lockstate)476 reloc_jmpslots(Obj_Entry *obj, int flags, RtldLockState *lockstate)
477 {
478 const Obj_Entry *defobj;
479 const Elf_Rela *relalim;
480 const Elf_Rela *rela;
481 const Elf_Sym *def;
482 Elf_Addr *where;
483 Elf_Addr target;
484
485 relalim = (const Elf_Rela *)((const char *)obj->pltrela +
486 obj->pltrelasize);
487 for (rela = obj->pltrela; rela < relalim; rela++) {
488 /* This isn't actually a jump slot, ignore it. */
489 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE)
490 continue;
491 assert(ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT);
492 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
493 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
494 SYMLOOK_IN_PLT | flags, NULL, lockstate);
495 if (def == NULL) {
496 dbg("reloc_jmpslots: sym not found");
497 return (-1);
498 }
499
500 target = (Elf_Addr)(defobj->relocbase + def->st_value);
501
502 if (def == &sym_zero) {
503 /* Zero undefined weak symbols */
504 *where = 0;
505 } else {
506 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
507 /* LD_BIND_NOW, ifunc in shared lib.*/
508 obj->gnu_ifunc = true;
509 continue;
510 }
511 reloc_jmpslot(where, target, defobj, obj,
512 (const Elf_Rel *) rela);
513 }
514 }
515
516 obj->jmpslots_done = true;
517
518 return (0);
519 }
520
521
522 /*
523 * Update the value of a PLT jump slot.
524 */
525 Elf_Addr
reloc_jmpslot(Elf_Addr * wherep,Elf_Addr target,const Obj_Entry * defobj __unused,const Obj_Entry * obj,const Elf_Rel * rel)526 reloc_jmpslot(Elf_Addr *wherep, Elf_Addr target,
527 const Obj_Entry *defobj __unused, const Obj_Entry *obj, const Elf_Rel *rel)
528 {
529 Elf_Addr offset;
530 const Elf_Rela *rela = (const Elf_Rela *) rel;
531
532 dbg(" reloc_jmpslot: where=%p, target=%p",
533 (void *)wherep, (void *)target);
534
535 if (ld_bind_not)
536 goto out;
537
538
539 /*
540 * Process Secure-PLT.
541 */
542 if (obj->gotptr != NULL) {
543 assert(wherep >= (Elf_Word *)obj->pltgot);
544 assert(wherep <
545 (Elf_Word *)obj->pltgot + obj->pltrelasize);
546 if (*wherep != target)
547 *wherep = target;
548 goto out;
549 }
550
551 /*
552 * BSS-PLT optimization:
553 * Branch directly to the target if it is within +/- 32Mb,
554 * otherwise go indirectly via the pltcall trampoline call and
555 * jump table.
556 */
557 offset = target - (Elf_Addr)wherep;
558 if (abs((int)offset) < 32*1024*1024) { /* inside 32MB? */
559 /*
560 * At the PLT entry pointed at by `wherep', construct
561 * a direct transfer to the now fully resolved function
562 * address.
563 */
564 /* b value # branch directly */
565 *wherep = 0x48000000 | (offset & 0x03fffffc);
566 __syncicache(wherep, 4);
567 } else {
568 Elf_Addr *pltcall, *jmptab;
569 int distance;
570 int N = obj->pltrelasize / sizeof(Elf_Rela);
571 int reloff = rela - obj->pltrela;
572
573 if (reloff < 0)
574 return (-1);
575
576 pltcall = obj->pltgot;
577
578 dbg(" reloc_jmpslot: indir, reloff=%x, N=%x\n",
579 reloff, N);
580
581 jmptab = obj->pltgot + JMPTAB_BASE(N);
582 jmptab[reloff] = target;
583 mb(); /* Order jmptab update before next changes */
584
585 if (reloff < PLT_EXTENDED_BEGIN) {
586 /* for extended PLT entries, we keep the old code */
587
588 distance = (Elf_Addr)pltcall - (Elf_Addr)(wherep + 1);
589
590 /* li r11,reloff */
591 /* b pltcall # use indirect pltcall routine */
592
593 /* first instruction same as before */
594 wherep[1] = 0x48000000 | (distance & 0x03fffffc);
595 __syncicache(wherep, 8);
596 }
597 }
598
599 out:
600 return (target);
601 }
602
603 int
reloc_iresolve(Obj_Entry * obj,struct Struct_RtldLockState * lockstate)604 reloc_iresolve(Obj_Entry *obj,
605 struct Struct_RtldLockState *lockstate)
606 {
607 /*
608 * Since PLT slots on PowerPC are always R_PPC_JMP_SLOT,
609 * R_PPC_IRELATIVE is in RELA.
610 */
611 const Elf_Rela *relalim;
612 const Elf_Rela *rela;
613 Elf_Addr *where, target, *ptr;
614
615 if (!obj->irelative)
616 return (0);
617
618 relalim = (const Elf_Rela *)((const char *)obj->rela + obj->relasize);
619 for (rela = obj->rela; rela < relalim; rela++) {
620 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) {
621 ptr = (Elf_Addr *)(obj->relocbase + rela->r_addend);
622 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
623
624 lock_release(rtld_bind_lock, lockstate);
625 target = call_ifunc_resolver(ptr);
626 wlock_acquire(rtld_bind_lock, lockstate);
627
628 *where = target;
629 }
630 }
631 /*
632 * XXX Remove me when lld is fixed!
633 * LLD currently makes illegal relocations in the PLT.
634 */
635 relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize);
636 for (rela = obj->pltrela; rela < relalim; rela++) {
637 if (ELF_R_TYPE(rela->r_info) == R_PPC_IRELATIVE) {
638 ptr = (Elf_Addr *)(obj->relocbase + rela->r_addend);
639 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
640
641 lock_release(rtld_bind_lock, lockstate);
642 target = call_ifunc_resolver(ptr);
643 wlock_acquire(rtld_bind_lock, lockstate);
644
645 *where = target;
646 }
647 }
648
649 obj->irelative = false;
650 return (0);
651 }
652
653 int
reloc_iresolve_nonplt(Obj_Entry * obj __unused,struct Struct_RtldLockState * lockstate __unused)654 reloc_iresolve_nonplt(Obj_Entry *obj __unused,
655 struct Struct_RtldLockState *lockstate __unused)
656 {
657 return (0);
658 }
659
660 int
reloc_gnu_ifunc(Obj_Entry * obj __unused,int flags __unused,struct Struct_RtldLockState * lockstate __unused)661 reloc_gnu_ifunc(Obj_Entry *obj __unused, int flags __unused,
662 struct Struct_RtldLockState *lockstate __unused)
663 {
664 const Elf_Rela *relalim;
665 const Elf_Rela *rela;
666 Elf_Addr *where, target;
667 const Elf_Sym *def;
668 const Obj_Entry *defobj;
669
670 if (!obj->gnu_ifunc)
671 return (0);
672 relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize);
673 for (rela = obj->pltrela; rela < relalim; rela++) {
674 if (ELF_R_TYPE(rela->r_info) == R_PPC_JMP_SLOT) {
675 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
676 def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
677 SYMLOOK_IN_PLT | flags, NULL, lockstate);
678 if (def == NULL)
679 return (-1);
680 if (ELF_ST_TYPE(def->st_info) != STT_GNU_IFUNC)
681 continue;
682 lock_release(rtld_bind_lock, lockstate);
683 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
684 wlock_acquire(rtld_bind_lock, lockstate);
685 reloc_jmpslot(where, target, defobj, obj,
686 (const Elf_Rel *)rela);
687 }
688 }
689 obj->gnu_ifunc = false;
690 return (0);
691 }
692
693 /*
694 * Setup the plt glue routines.
695 */
696 #define PLTCALL_SIZE 20
697 #define PLTLONGRESOLVE_SIZE 20
698 #define PLTRESOLVE_SIZE 24
699
700 void
init_pltgot(Obj_Entry * obj)701 init_pltgot(Obj_Entry *obj)
702 {
703 Elf_Word *pltcall, *pltresolve, *pltlongresolve;
704 Elf_Word *jmptab;
705 int N = obj->pltrelasize / sizeof(Elf_Rela);
706
707 pltcall = obj->pltgot;
708
709 if (pltcall == NULL) {
710 return;
711 }
712
713 /* Handle Secure-PLT first, if applicable. */
714 if (obj->gotptr != NULL) {
715 obj->gotptr[1] = (Elf_Addr)_rtld_bind_secureplt_start;
716 obj->gotptr[2] = (Elf_Addr)obj;
717 dbg("obj %s secure-plt gotptr=%p start=%p obj=%p",
718 obj->path, obj->gotptr,
719 (void *)obj->gotptr[1], (void *)obj->gotptr[2]);
720 return;
721 }
722
723 /*
724 * From the SVR4 PPC ABI:
725 *
726 * 'The first 18 words (72 bytes) of the PLT are reserved for
727 * use by the dynamic linker.
728 * ...
729 * 'If the executable or shared object requires N procedure
730 * linkage table entries, the link editor shall reserve 3*N
731 * words (12*N bytes) following the 18 reserved words. The
732 * first 2*N of these words are the procedure linkage table
733 * entries themselves. The static linker directs calls to bytes
734 * (72 + (i-1)*8), for i between 1 and N inclusive. The remaining
735 * N words (4*N bytes) are reserved for use by the dynamic linker.'
736 */
737
738 /*
739 * Copy the absolute-call assembler stub into the first part of
740 * the reserved PLT area.
741 */
742 memcpy(pltcall, _rtld_powerpc_pltcall, PLTCALL_SIZE);
743
744 /*
745 * Determine the address of the jumptable, which is the dyn-linker
746 * reserved area after the call cells. Write the absolute address
747 * of the jumptable into the absolute-call assembler code so it
748 * can determine this address.
749 */
750 jmptab = obj->pltgot + JMPTAB_BASE(N);
751 pltcall[1] |= _ppc_ha(jmptab); /* addis 11,11,jmptab@ha */
752 pltcall[2] |= _ppc_la(jmptab); /* lwz 11,jmptab@l(11) */
753
754 /*
755 * Skip down 20 bytes into the initial reserved area and copy
756 * in the standard resolving assembler call. Into this assembler,
757 * insert the absolute address of the _rtld_bind_start routine
758 * and the address of the relocation object.
759 *
760 * We place pltlongresolve first, so it can fix up its arguments
761 * and then fall through to the regular PLT resolver.
762 */
763 pltlongresolve = obj->pltgot + 5;
764
765 memcpy(pltlongresolve, _rtld_powerpc_pltlongresolve,
766 PLTLONGRESOLVE_SIZE);
767 pltlongresolve[0] |= _ppc_ha(jmptab); /* lis 12,jmptab@ha */
768 pltlongresolve[1] |= _ppc_la(jmptab); /* addi 12,12,jmptab@l */
769
770 pltresolve = pltlongresolve + PLTLONGRESOLVE_SIZE/sizeof(uint32_t);
771 memcpy(pltresolve, _rtld_powerpc_pltresolve, PLTRESOLVE_SIZE);
772 pltresolve[0] |= _ppc_ha(_rtld_bind_start);
773 pltresolve[1] |= _ppc_la(_rtld_bind_start);
774 pltresolve[3] |= _ppc_ha(obj);
775 pltresolve[4] |= _ppc_la(obj);
776
777 /*
778 * The icache will be sync'd in reloc_plt, which is called
779 * after all the slots have been updated
780 */
781 }
782
783 /*
784 * 32 bit cpu feature flag fields.
785 */
786 u_long cpu_features;
787 u_long cpu_features2;
788
789 void
powerpc_abi_variant_hook(Elf_Auxinfo ** aux_info)790 powerpc_abi_variant_hook(Elf_Auxinfo** aux_info)
791 {
792 /*
793 * Since aux_info[] is easier to work with than aux, go ahead and
794 * initialize cpu_features / cpu_features2.
795 */
796 cpu_features = -1UL;
797 cpu_features2 = -1UL;
798 if (aux_info[AT_HWCAP] != NULL)
799 cpu_features = aux_info[AT_HWCAP]->a_un.a_val;
800 if (aux_info[AT_HWCAP2] != NULL)
801 cpu_features2 = aux_info[AT_HWCAP2]->a_un.a_val;
802 }
803
804 void
ifunc_init(Elf_Auxinfo aux_info[__min_size (AT_COUNT)]__unused)805 ifunc_init(Elf_Auxinfo aux_info[__min_size(AT_COUNT)] __unused)
806 {
807
808 }
809
810 void
allocate_initial_tls(Obj_Entry * list)811 allocate_initial_tls(Obj_Entry *list)
812 {
813
814 /*
815 * Fix the size of the static TLS block by using the maximum
816 * offset allocated so far and adding a bit for dynamic modules to
817 * use.
818 */
819
820 tls_static_space = tls_last_offset + tls_last_size +
821 ld_static_tls_extra;
822
823 _tcb_set(allocate_tls(list, NULL, TLS_TCB_SIZE, TLS_TCB_ALIGN));
824 }
825
826 void*
__tls_get_addr(tls_index * ti)827 __tls_get_addr(tls_index* ti)
828 {
829 uintptr_t **dtvp;
830 char *p;
831
832 dtvp = &_tcb_get()->tcb_dtv;
833 p = tls_get_addr_common(dtvp, ti->ti_module, ti->ti_offset);
834
835 return (p + TLS_DTV_OFFSET);
836 }
837