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