1 //===-- Section.cpp ---------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lldb/Core/Section.h"
10 #include "lldb/Core/Address.h"
11 #include "lldb/Core/Module.h"
12 #include "lldb/Symbol/ObjectFile.h"
13 #include "lldb/Target/SectionLoadList.h"
14 #include "lldb/Target/Target.h"
15 #include "lldb/Utility/FileSpec.h"
16 #include "lldb/Utility/Stream.h"
17 #include "lldb/Utility/VMRange.h"
18 
19 #include <inttypes.h>
20 #include <limits>
21 #include <utility>
22 
23 namespace lldb_private {
24 class DataExtractor;
25 }
26 using namespace lldb;
27 using namespace lldb_private;
28 
29 const char *Section::GetTypeAsCString() const {
30   switch (m_type) {
31   case eSectionTypeInvalid:
32     return "invalid";
33   case eSectionTypeCode:
34     return "code";
35   case eSectionTypeContainer:
36     return "container";
37   case eSectionTypeData:
38     return "data";
39   case eSectionTypeDataCString:
40     return "data-cstr";
41   case eSectionTypeDataCStringPointers:
42     return "data-cstr-ptr";
43   case eSectionTypeDataSymbolAddress:
44     return "data-symbol-addr";
45   case eSectionTypeData4:
46     return "data-4-byte";
47   case eSectionTypeData8:
48     return "data-8-byte";
49   case eSectionTypeData16:
50     return "data-16-byte";
51   case eSectionTypeDataPointers:
52     return "data-ptrs";
53   case eSectionTypeDebug:
54     return "debug";
55   case eSectionTypeZeroFill:
56     return "zero-fill";
57   case eSectionTypeDataObjCMessageRefs:
58     return "objc-message-refs";
59   case eSectionTypeDataObjCCFStrings:
60     return "objc-cfstrings";
61   case eSectionTypeDWARFDebugAbbrev:
62     return "dwarf-abbrev";
63   case eSectionTypeDWARFDebugAbbrevDwo:
64     return "dwarf-abbrev-dwo";
65   case eSectionTypeDWARFDebugAddr:
66     return "dwarf-addr";
67   case eSectionTypeDWARFDebugAranges:
68     return "dwarf-aranges";
69   case eSectionTypeDWARFDebugCuIndex:
70     return "dwarf-cu-index";
71   case eSectionTypeDWARFDebugFrame:
72     return "dwarf-frame";
73   case eSectionTypeDWARFDebugInfo:
74     return "dwarf-info";
75   case eSectionTypeDWARFDebugInfoDwo:
76     return "dwarf-info-dwo";
77   case eSectionTypeDWARFDebugLine:
78     return "dwarf-line";
79   case eSectionTypeDWARFDebugLineStr:
80     return "dwarf-line-str";
81   case eSectionTypeDWARFDebugLoc:
82     return "dwarf-loc";
83   case eSectionTypeDWARFDebugLocDwo:
84     return "dwarf-loc-dwo";
85   case eSectionTypeDWARFDebugLocLists:
86     return "dwarf-loclists";
87   case eSectionTypeDWARFDebugLocListsDwo:
88     return "dwarf-loclists-dwo";
89   case eSectionTypeDWARFDebugMacInfo:
90     return "dwarf-macinfo";
91   case eSectionTypeDWARFDebugMacro:
92     return "dwarf-macro";
93   case eSectionTypeDWARFDebugPubNames:
94     return "dwarf-pubnames";
95   case eSectionTypeDWARFDebugPubTypes:
96     return "dwarf-pubtypes";
97   case eSectionTypeDWARFDebugRanges:
98     return "dwarf-ranges";
99   case eSectionTypeDWARFDebugRngLists:
100     return "dwarf-rnglists";
101   case eSectionTypeDWARFDebugRngListsDwo:
102     return "dwarf-rnglists-dwo";
103   case eSectionTypeDWARFDebugStr:
104     return "dwarf-str";
105   case eSectionTypeDWARFDebugStrDwo:
106     return "dwarf-str-dwo";
107   case eSectionTypeDWARFDebugStrOffsets:
108     return "dwarf-str-offsets";
109   case eSectionTypeDWARFDebugStrOffsetsDwo:
110     return "dwarf-str-offsets-dwo";
111   case eSectionTypeDWARFDebugTypes:
112     return "dwarf-types";
113   case eSectionTypeDWARFDebugTypesDwo:
114     return "dwarf-types-dwo";
115   case eSectionTypeDWARFDebugNames:
116     return "dwarf-names";
117   case eSectionTypeELFSymbolTable:
118     return "elf-symbol-table";
119   case eSectionTypeELFDynamicSymbols:
120     return "elf-dynamic-symbols";
121   case eSectionTypeELFRelocationEntries:
122     return "elf-relocation-entries";
123   case eSectionTypeELFDynamicLinkInfo:
124     return "elf-dynamic-link-info";
125   case eSectionTypeDWARFAppleNames:
126     return "apple-names";
127   case eSectionTypeDWARFAppleTypes:
128     return "apple-types";
129   case eSectionTypeDWARFAppleNamespaces:
130     return "apple-namespaces";
131   case eSectionTypeDWARFAppleObjC:
132     return "apple-objc";
133   case eSectionTypeEHFrame:
134     return "eh-frame";
135   case eSectionTypeARMexidx:
136     return "ARM.exidx";
137   case eSectionTypeARMextab:
138     return "ARM.extab";
139   case eSectionTypeCompactUnwind:
140     return "compact-unwind";
141   case eSectionTypeGoSymtab:
142     return "go-symtab";
143   case eSectionTypeAbsoluteAddress:
144     return "absolute";
145   case eSectionTypeDWARFGNUDebugAltLink:
146     return "dwarf-gnu-debugaltlink";
147   case eSectionTypeOther:
148     return "regular";
149   }
150   return "unknown";
151 }
152 
153 Section::Section(const ModuleSP &module_sp, ObjectFile *obj_file,
154                  user_id_t sect_id, ConstString name,
155                  SectionType sect_type, addr_t file_addr, addr_t byte_size,
156                  lldb::offset_t file_offset, lldb::offset_t file_size,
157                  uint32_t log2align, uint32_t flags,
158                  uint32_t target_byte_size /*=1*/)
159     : ModuleChild(module_sp), UserID(sect_id), Flags(flags),
160       m_obj_file(obj_file), m_type(sect_type), m_parent_wp(), m_name(name),
161       m_file_addr(file_addr), m_byte_size(byte_size),
162       m_file_offset(file_offset), m_file_size(file_size),
163       m_log2align(log2align), m_children(), m_fake(false), m_encrypted(false),
164       m_thread_specific(false), m_readable(false), m_writable(false),
165       m_executable(false), m_relocated(false), m_target_byte_size(target_byte_size) {
166   //    printf ("Section::Section(%p): module=%p, sect_id = 0x%16.16" PRIx64 ",
167   //    addr=[0x%16.16" PRIx64 " - 0x%16.16" PRIx64 "), file [0x%16.16" PRIx64 "
168   //    - 0x%16.16" PRIx64 "), flags = 0x%8.8x, name = %s\n",
169   //            this, module_sp.get(), sect_id, file_addr, file_addr +
170   //            byte_size, file_offset, file_offset + file_size, flags,
171   //            name.GetCString());
172 }
173 
174 Section::Section(const lldb::SectionSP &parent_section_sp,
175                  const ModuleSP &module_sp, ObjectFile *obj_file,
176                  user_id_t sect_id, ConstString name,
177                  SectionType sect_type, addr_t file_addr, addr_t byte_size,
178                  lldb::offset_t file_offset, lldb::offset_t file_size,
179                  uint32_t log2align, uint32_t flags,
180                  uint32_t target_byte_size /*=1*/)
181     : ModuleChild(module_sp), UserID(sect_id), Flags(flags),
182       m_obj_file(obj_file), m_type(sect_type), m_parent_wp(), m_name(name),
183       m_file_addr(file_addr), m_byte_size(byte_size),
184       m_file_offset(file_offset), m_file_size(file_size),
185       m_log2align(log2align), m_children(), m_fake(false), m_encrypted(false),
186       m_thread_specific(false), m_readable(false), m_writable(false),
187       m_executable(false), m_relocated(false), m_target_byte_size(target_byte_size) {
188   //    printf ("Section::Section(%p): module=%p, sect_id = 0x%16.16" PRIx64 ",
189   //    addr=[0x%16.16" PRIx64 " - 0x%16.16" PRIx64 "), file [0x%16.16" PRIx64 "
190   //    - 0x%16.16" PRIx64 "), flags = 0x%8.8x, name = %s.%s\n",
191   //            this, module_sp.get(), sect_id, file_addr, file_addr +
192   //            byte_size, file_offset, file_offset + file_size, flags,
193   //            parent_section_sp->GetName().GetCString(), name.GetCString());
194   if (parent_section_sp)
195     m_parent_wp = parent_section_sp;
196 }
197 
198 Section::~Section() {
199   //    printf ("Section::~Section(%p)\n", this);
200 }
201 
202 addr_t Section::GetFileAddress() const {
203   SectionSP parent_sp(GetParent());
204   if (parent_sp) {
205     // This section has a parent which means m_file_addr is an offset into the
206     // parent section, so the file address for this section is the file address
207     // of the parent plus the offset
208     return parent_sp->GetFileAddress() + m_file_addr;
209   }
210   // This section has no parent, so m_file_addr is the file base address
211   return m_file_addr;
212 }
213 
214 bool Section::SetFileAddress(lldb::addr_t file_addr) {
215   SectionSP parent_sp(GetParent());
216   if (parent_sp) {
217     if (m_file_addr >= file_addr)
218       return parent_sp->SetFileAddress(m_file_addr - file_addr);
219     return false;
220   } else {
221     // This section has no parent, so m_file_addr is the file base address
222     m_file_addr = file_addr;
223     return true;
224   }
225 }
226 
227 lldb::addr_t Section::GetOffset() const {
228   // This section has a parent which means m_file_addr is an offset.
229   SectionSP parent_sp(GetParent());
230   if (parent_sp)
231     return m_file_addr;
232 
233   // This section has no parent, so there is no offset to be had
234   return 0;
235 }
236 
237 addr_t Section::GetLoadBaseAddress(Target *target) const {
238   addr_t load_base_addr = LLDB_INVALID_ADDRESS;
239   SectionSP parent_sp(GetParent());
240   if (parent_sp) {
241     load_base_addr = parent_sp->GetLoadBaseAddress(target);
242     if (load_base_addr != LLDB_INVALID_ADDRESS)
243       load_base_addr += GetOffset();
244   }
245   if (load_base_addr == LLDB_INVALID_ADDRESS) {
246     load_base_addr = target->GetSectionLoadList().GetSectionLoadAddress(
247         const_cast<Section *>(this)->shared_from_this());
248   }
249   return load_base_addr;
250 }
251 
252 bool Section::ResolveContainedAddress(addr_t offset, Address &so_addr,
253                                       bool allow_section_end) const {
254   const size_t num_children = m_children.GetSize();
255   for (size_t i = 0; i < num_children; i++) {
256     Section *child_section = m_children.GetSectionAtIndex(i).get();
257 
258     addr_t child_offset = child_section->GetOffset();
259     if (child_offset <= offset &&
260         offset - child_offset <
261             child_section->GetByteSize() + (allow_section_end ? 1 : 0))
262       return child_section->ResolveContainedAddress(offset - child_offset,
263                                                     so_addr, allow_section_end);
264   }
265   so_addr.SetOffset(offset);
266   so_addr.SetSection(const_cast<Section *>(this)->shared_from_this());
267 
268 #ifdef LLDB_CONFIGURATION_DEBUG
269   // For debug builds, ensure that there are no orphaned (i.e., moduleless)
270   // sections.
271   assert(GetModule().get());
272 #endif
273   return true;
274 }
275 
276 bool Section::ContainsFileAddress(addr_t vm_addr) const {
277   const addr_t file_addr = GetFileAddress();
278   if (file_addr != LLDB_INVALID_ADDRESS && !IsThreadSpecific()) {
279     if (file_addr <= vm_addr) {
280       const addr_t offset = (vm_addr - file_addr) * m_target_byte_size;
281       return offset < GetByteSize();
282     }
283   }
284   return false;
285 }
286 
287 void Section::Dump(Stream *s, Target *target, uint32_t depth) const {
288   //    s->Printf("%.*p: ", (int)sizeof(void*) * 2, this);
289   s->Indent();
290   s->Printf("0x%8.8" PRIx64 " %-16s ", GetID(), GetTypeAsCString());
291   bool resolved = true;
292   addr_t addr = LLDB_INVALID_ADDRESS;
293 
294   if (GetByteSize() == 0)
295     s->Printf("%39s", "");
296   else {
297     if (target)
298       addr = GetLoadBaseAddress(target);
299 
300     if (addr == LLDB_INVALID_ADDRESS) {
301       if (target)
302         resolved = false;
303       addr = GetFileAddress();
304     }
305 
306     VMRange range(addr, addr + m_byte_size);
307     range.Dump(s->AsRawOstream(), 0);
308   }
309 
310   s->Printf("%c %c%c%c  0x%8.8" PRIx64 " 0x%8.8" PRIx64 " 0x%8.8x ",
311             resolved ? ' ' : '*', m_readable ? 'r' : '-',
312             m_writable ? 'w' : '-', m_executable ? 'x' : '-', m_file_offset,
313             m_file_size, Get());
314 
315   DumpName(s);
316 
317   s->EOL();
318 
319   if (depth > 0)
320     m_children.Dump(s, target, false, depth - 1);
321 }
322 
323 void Section::DumpName(Stream *s) const {
324   SectionSP parent_sp(GetParent());
325   if (parent_sp) {
326     parent_sp->DumpName(s);
327     s->PutChar('.');
328   } else {
329     // The top most section prints the module basename
330     const char *name = nullptr;
331     ModuleSP module_sp(GetModule());
332 
333     if (m_obj_file) {
334       const FileSpec &file_spec = m_obj_file->GetFileSpec();
335       name = file_spec.GetFilename().AsCString();
336     }
337     if ((!name || !name[0]) && module_sp)
338       name = module_sp->GetFileSpec().GetFilename().AsCString();
339     if (name && name[0])
340       s->Printf("%s.", name);
341   }
342   m_name.Dump(s);
343 }
344 
345 bool Section::IsDescendant(const Section *section) {
346   if (this == section)
347     return true;
348   SectionSP parent_sp(GetParent());
349   if (parent_sp)
350     return parent_sp->IsDescendant(section);
351   return false;
352 }
353 
354 bool Section::Slide(addr_t slide_amount, bool slide_children) {
355   if (m_file_addr != LLDB_INVALID_ADDRESS) {
356     if (slide_amount == 0)
357       return true;
358 
359     m_file_addr += slide_amount;
360 
361     if (slide_children)
362       m_children.Slide(slide_amount, slide_children);
363 
364     return true;
365   }
366   return false;
367 }
368 
369 /// Get the permissions as OR'ed bits from lldb::Permissions
370 uint32_t Section::GetPermissions() const {
371   uint32_t permissions = 0;
372   if (m_readable)
373     permissions |= ePermissionsReadable;
374   if (m_writable)
375     permissions |= ePermissionsWritable;
376   if (m_executable)
377     permissions |= ePermissionsExecutable;
378   return permissions;
379 }
380 
381 /// Set the permissions using bits OR'ed from lldb::Permissions
382 void Section::SetPermissions(uint32_t permissions) {
383   m_readable = (permissions & ePermissionsReadable) != 0;
384   m_writable = (permissions & ePermissionsWritable) != 0;
385   m_executable = (permissions & ePermissionsExecutable) != 0;
386 }
387 
388 lldb::offset_t Section::GetSectionData(void *dst, lldb::offset_t dst_len,
389                                        lldb::offset_t offset) {
390   if (m_obj_file)
391     return m_obj_file->ReadSectionData(this, offset, dst, dst_len);
392   return 0;
393 }
394 
395 lldb::offset_t Section::GetSectionData(DataExtractor &section_data) {
396   if (m_obj_file)
397     return m_obj_file->ReadSectionData(this, section_data);
398   return 0;
399 }
400 
401 #pragma mark SectionList
402 
403 SectionList &SectionList::operator=(const SectionList &rhs) {
404   if (this != &rhs)
405     m_sections = rhs.m_sections;
406   return *this;
407 }
408 
409 size_t SectionList::AddSection(const lldb::SectionSP &section_sp) {
410   if (section_sp) {
411     size_t section_index = m_sections.size();
412     m_sections.push_back(section_sp);
413     return section_index;
414   }
415 
416   return std::numeric_limits<size_t>::max();
417 }
418 
419 // Warning, this can be slow as it's removing items from a std::vector.
420 bool SectionList::DeleteSection(size_t idx) {
421   if (idx < m_sections.size()) {
422     m_sections.erase(m_sections.begin() + idx);
423     return true;
424   }
425   return false;
426 }
427 
428 size_t SectionList::FindSectionIndex(const Section *sect) {
429   iterator sect_iter;
430   iterator begin = m_sections.begin();
431   iterator end = m_sections.end();
432   for (sect_iter = begin; sect_iter != end; ++sect_iter) {
433     if (sect_iter->get() == sect) {
434       // The secton was already in this section list
435       return std::distance(begin, sect_iter);
436     }
437   }
438   return UINT32_MAX;
439 }
440 
441 size_t SectionList::AddUniqueSection(const lldb::SectionSP &sect_sp) {
442   size_t sect_idx = FindSectionIndex(sect_sp.get());
443   if (sect_idx == UINT32_MAX) {
444     sect_idx = AddSection(sect_sp);
445   }
446   return sect_idx;
447 }
448 
449 bool SectionList::ReplaceSection(user_id_t sect_id,
450                                  const lldb::SectionSP &sect_sp,
451                                  uint32_t depth) {
452   iterator sect_iter, end = m_sections.end();
453   for (sect_iter = m_sections.begin(); sect_iter != end; ++sect_iter) {
454     if ((*sect_iter)->GetID() == sect_id) {
455       *sect_iter = sect_sp;
456       return true;
457     } else if (depth > 0) {
458       if ((*sect_iter)
459               ->GetChildren()
460               .ReplaceSection(sect_id, sect_sp, depth - 1))
461         return true;
462     }
463   }
464   return false;
465 }
466 
467 size_t SectionList::GetNumSections(uint32_t depth) const {
468   size_t count = m_sections.size();
469   if (depth > 0) {
470     const_iterator sect_iter, end = m_sections.end();
471     for (sect_iter = m_sections.begin(); sect_iter != end; ++sect_iter) {
472       count += (*sect_iter)->GetChildren().GetNumSections(depth - 1);
473     }
474   }
475   return count;
476 }
477 
478 SectionSP SectionList::GetSectionAtIndex(size_t idx) const {
479   SectionSP sect_sp;
480   if (idx < m_sections.size())
481     sect_sp = m_sections[idx];
482   return sect_sp;
483 }
484 
485 SectionSP
486 SectionList::FindSectionByName(ConstString section_dstr) const {
487   SectionSP sect_sp;
488   // Check if we have a valid section string
489   if (section_dstr && !m_sections.empty()) {
490     const_iterator sect_iter;
491     const_iterator end = m_sections.end();
492     for (sect_iter = m_sections.begin();
493          sect_iter != end && sect_sp.get() == nullptr; ++sect_iter) {
494       Section *child_section = sect_iter->get();
495       if (child_section) {
496         if (child_section->GetName() == section_dstr) {
497           sect_sp = *sect_iter;
498         } else {
499           sect_sp =
500               child_section->GetChildren().FindSectionByName(section_dstr);
501         }
502       }
503     }
504   }
505   return sect_sp;
506 }
507 
508 SectionSP SectionList::FindSectionByID(user_id_t sect_id) const {
509   SectionSP sect_sp;
510   if (sect_id) {
511     const_iterator sect_iter;
512     const_iterator end = m_sections.end();
513     for (sect_iter = m_sections.begin();
514          sect_iter != end && sect_sp.get() == nullptr; ++sect_iter) {
515       if ((*sect_iter)->GetID() == sect_id) {
516         sect_sp = *sect_iter;
517         break;
518       } else {
519         sect_sp = (*sect_iter)->GetChildren().FindSectionByID(sect_id);
520       }
521     }
522   }
523   return sect_sp;
524 }
525 
526 SectionSP SectionList::FindSectionByType(SectionType sect_type,
527                                          bool check_children,
528                                          size_t start_idx) const {
529   SectionSP sect_sp;
530   size_t num_sections = m_sections.size();
531   for (size_t idx = start_idx; idx < num_sections; ++idx) {
532     if (m_sections[idx]->GetType() == sect_type) {
533       sect_sp = m_sections[idx];
534       break;
535     } else if (check_children) {
536       sect_sp = m_sections[idx]->GetChildren().FindSectionByType(
537           sect_type, check_children, 0);
538       if (sect_sp)
539         break;
540     }
541   }
542   return sect_sp;
543 }
544 
545 SectionSP SectionList::FindSectionContainingFileAddress(addr_t vm_addr,
546                                                         uint32_t depth) const {
547   SectionSP sect_sp;
548   const_iterator sect_iter;
549   const_iterator end = m_sections.end();
550   for (sect_iter = m_sections.begin();
551        sect_iter != end && sect_sp.get() == nullptr; ++sect_iter) {
552     Section *sect = sect_iter->get();
553     if (sect->ContainsFileAddress(vm_addr)) {
554       // The file address is in this section. We need to make sure one of our
555       // child sections doesn't contain this address as well as obeying the
556       // depth limit that was passed in.
557       if (depth > 0)
558         sect_sp = sect->GetChildren().FindSectionContainingFileAddress(
559             vm_addr, depth - 1);
560 
561       if (sect_sp.get() == nullptr && !sect->IsFake())
562         sect_sp = *sect_iter;
563     }
564   }
565   return sect_sp;
566 }
567 
568 bool SectionList::ContainsSection(user_id_t sect_id) const {
569   return FindSectionByID(sect_id).get() != nullptr;
570 }
571 
572 void SectionList::Dump(Stream *s, Target *target, bool show_header,
573                        uint32_t depth) const {
574   bool target_has_loaded_sections =
575       target && !target->GetSectionLoadList().IsEmpty();
576   if (show_header && !m_sections.empty()) {
577     s->Indent();
578     s->Printf("SectID     Type             %s Address                          "
579               "   Perm File Off.  File Size  Flags "
580               "     Section Name\n",
581               target_has_loaded_sections ? "Load" : "File");
582     s->Indent();
583     s->PutCString("---------- ---------------- "
584                   "---------------------------------------  ---- ---------- "
585                   "---------- "
586                   "---------- ----------------------------\n");
587   }
588 
589   const_iterator sect_iter;
590   const_iterator end = m_sections.end();
591   for (sect_iter = m_sections.begin(); sect_iter != end; ++sect_iter) {
592     (*sect_iter)->Dump(s, target_has_loaded_sections ? target : nullptr, depth);
593   }
594 
595   if (show_header && !m_sections.empty())
596     s->IndentLess();
597 }
598 
599 size_t SectionList::Slide(addr_t slide_amount, bool slide_children) {
600   size_t count = 0;
601   const_iterator pos, end = m_sections.end();
602   for (pos = m_sections.begin(); pos != end; ++pos) {
603     if ((*pos)->Slide(slide_amount, slide_children))
604       ++count;
605   }
606   return count;
607 }
608