1 //===-- ProcessMachCore.cpp -----------------------------------------------===//
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 <errno.h>
10 #include <stdlib.h>
11 
12 #include "llvm/Support/MathExtras.h"
13 #include "llvm/Support/Threading.h"
14 
15 #include "lldb/Core/Debugger.h"
16 #include "lldb/Core/Module.h"
17 #include "lldb/Core/ModuleSpec.h"
18 #include "lldb/Core/PluginManager.h"
19 #include "lldb/Core/Section.h"
20 #include "lldb/Host/Host.h"
21 #include "lldb/Symbol/LocateSymbolFile.h"
22 #include "lldb/Symbol/ObjectFile.h"
23 #include "lldb/Target/MemoryRegionInfo.h"
24 #include "lldb/Target/Target.h"
25 #include "lldb/Target/Thread.h"
26 #include "lldb/Utility/DataBuffer.h"
27 #include "lldb/Utility/Log.h"
28 #include "lldb/Utility/State.h"
29 
30 #include "ProcessMachCore.h"
31 #include "Plugins/Process/Utility/StopInfoMachException.h"
32 #include "ThreadMachCore.h"
33 
34 // Needed for the plug-in names for the dynamic loaders.
35 #include "lldb/Host/SafeMachO.h"
36 
37 #include "Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.h"
38 #include "Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.h"
39 #include "Plugins/ObjectFile/Mach-O/ObjectFileMachO.h"
40 
41 #include <memory>
42 #include <mutex>
43 
44 using namespace lldb;
45 using namespace lldb_private;
46 
47 LLDB_PLUGIN_DEFINE(ProcessMachCore)
48 
49 ConstString ProcessMachCore::GetPluginNameStatic() {
50   static ConstString g_name("mach-o-core");
51   return g_name;
52 }
53 
54 const char *ProcessMachCore::GetPluginDescriptionStatic() {
55   return "Mach-O core file debugging plug-in.";
56 }
57 
58 void ProcessMachCore::Terminate() {
59   PluginManager::UnregisterPlugin(ProcessMachCore::CreateInstance);
60 }
61 
62 lldb::ProcessSP ProcessMachCore::CreateInstance(lldb::TargetSP target_sp,
63                                                 ListenerSP listener_sp,
64                                                 const FileSpec *crash_file) {
65   lldb::ProcessSP process_sp;
66   if (crash_file) {
67     const size_t header_size = sizeof(llvm::MachO::mach_header);
68     auto data_sp = FileSystem::Instance().CreateDataBuffer(
69         crash_file->GetPath(), header_size, 0);
70     if (data_sp && data_sp->GetByteSize() == header_size) {
71       DataExtractor data(data_sp, lldb::eByteOrderLittle, 4);
72 
73       lldb::offset_t data_offset = 0;
74       llvm::MachO::mach_header mach_header;
75       if (ObjectFileMachO::ParseHeader(data, &data_offset, mach_header)) {
76         if (mach_header.filetype == llvm::MachO::MH_CORE)
77           process_sp = std::make_shared<ProcessMachCore>(target_sp, listener_sp,
78                                                          *crash_file);
79       }
80     }
81   }
82   return process_sp;
83 }
84 
85 bool ProcessMachCore::CanDebug(lldb::TargetSP target_sp,
86                                bool plugin_specified_by_name) {
87   if (plugin_specified_by_name)
88     return true;
89 
90   // For now we are just making sure the file exists for a given module
91   if (!m_core_module_sp && FileSystem::Instance().Exists(m_core_file)) {
92     // Don't add the Target's architecture to the ModuleSpec - we may be
93     // working with a core file that doesn't have the correct cpusubtype in the
94     // header but we should still try to use it -
95     // ModuleSpecList::FindMatchingModuleSpec enforces a strict arch mach.
96     ModuleSpec core_module_spec(m_core_file);
97     Status error(ModuleList::GetSharedModule(core_module_spec, m_core_module_sp,
98                                              nullptr, nullptr, nullptr));
99 
100     if (m_core_module_sp) {
101       ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
102       if (core_objfile && core_objfile->GetType() == ObjectFile::eTypeCoreFile)
103         return true;
104     }
105   }
106   return false;
107 }
108 
109 // ProcessMachCore constructor
110 ProcessMachCore::ProcessMachCore(lldb::TargetSP target_sp,
111                                  ListenerSP listener_sp,
112                                  const FileSpec &core_file)
113     : Process(target_sp, listener_sp), m_core_aranges(), m_core_range_infos(),
114       m_core_module_sp(), m_core_file(core_file),
115       m_dyld_addr(LLDB_INVALID_ADDRESS),
116       m_mach_kernel_addr(LLDB_INVALID_ADDRESS), m_dyld_plugin_name() {}
117 
118 // Destructor
119 ProcessMachCore::~ProcessMachCore() {
120   Clear();
121   // We need to call finalize on the process before destroying ourselves to
122   // make sure all of the broadcaster cleanup goes as planned. If we destruct
123   // this class, then Process::~Process() might have problems trying to fully
124   // destroy the broadcaster.
125   Finalize();
126 }
127 
128 // PluginInterface
129 ConstString ProcessMachCore::GetPluginName() { return GetPluginNameStatic(); }
130 
131 uint32_t ProcessMachCore::GetPluginVersion() { return 1; }
132 
133 bool ProcessMachCore::GetDynamicLoaderAddress(lldb::addr_t addr) {
134   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER |
135                                                   LIBLLDB_LOG_PROCESS));
136   llvm::MachO::mach_header header;
137   Status error;
138   if (DoReadMemory(addr, &header, sizeof(header), error) != sizeof(header))
139     return false;
140   if (header.magic == llvm::MachO::MH_CIGAM ||
141       header.magic == llvm::MachO::MH_CIGAM_64) {
142     header.magic = llvm::ByteSwap_32(header.magic);
143     header.cputype = llvm::ByteSwap_32(header.cputype);
144     header.cpusubtype = llvm::ByteSwap_32(header.cpusubtype);
145     header.filetype = llvm::ByteSwap_32(header.filetype);
146     header.ncmds = llvm::ByteSwap_32(header.ncmds);
147     header.sizeofcmds = llvm::ByteSwap_32(header.sizeofcmds);
148     header.flags = llvm::ByteSwap_32(header.flags);
149   }
150 
151   // TODO: swap header if needed...
152   // printf("0x%16.16" PRIx64 ": magic = 0x%8.8x, file_type= %u\n", vaddr,
153   // header.magic, header.filetype);
154   if (header.magic == llvm::MachO::MH_MAGIC ||
155       header.magic == llvm::MachO::MH_MAGIC_64) {
156     // Check MH_EXECUTABLE to see if we can find the mach image that contains
157     // the shared library list. The dynamic loader (dyld) is what contains the
158     // list for user applications, and the mach kernel contains a global that
159     // has the list of kexts to load
160     switch (header.filetype) {
161     case llvm::MachO::MH_DYLINKER:
162       // printf("0x%16.16" PRIx64 ": file_type = MH_DYLINKER\n", vaddr);
163       // Address of dyld "struct mach_header" in the core file
164       LLDB_LOGF(log,
165                 "ProcessMachCore::GetDynamicLoaderAddress found a user "
166                 "process dyld binary image at 0x%" PRIx64,
167                 addr);
168       m_dyld_addr = addr;
169       return true;
170 
171     case llvm::MachO::MH_EXECUTE:
172       // printf("0x%16.16" PRIx64 ": file_type = MH_EXECUTE\n", vaddr);
173       // Check MH_EXECUTABLE file types to see if the dynamic link object flag
174       // is NOT set. If it isn't, then we have a mach_kernel.
175       if ((header.flags & llvm::MachO::MH_DYLDLINK) == 0) {
176         LLDB_LOGF(log,
177                   "ProcessMachCore::GetDynamicLoaderAddress found a mach "
178                   "kernel binary image at 0x%" PRIx64,
179                   addr);
180         // Address of the mach kernel "struct mach_header" in the core file.
181         m_mach_kernel_addr = addr;
182         return true;
183       }
184       break;
185     }
186   }
187   return false;
188 }
189 
190 // Process Control
191 Status ProcessMachCore::DoLoadCore() {
192   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER |
193                                                   LIBLLDB_LOG_PROCESS));
194   Status error;
195   if (!m_core_module_sp) {
196     error.SetErrorString("invalid core module");
197     return error;
198   }
199 
200   ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
201   if (core_objfile == nullptr) {
202     error.SetErrorString("invalid core object file");
203     return error;
204   }
205 
206   if (core_objfile->GetNumThreadContexts() == 0) {
207     error.SetErrorString("core file doesn't contain any LC_THREAD load "
208                          "commands, or the LC_THREAD architecture is not "
209                          "supported in this lldb");
210     return error;
211   }
212 
213   SectionList *section_list = core_objfile->GetSectionList();
214   if (section_list == nullptr) {
215     error.SetErrorString("core file has no sections");
216     return error;
217   }
218 
219   const uint32_t num_sections = section_list->GetNumSections(0);
220   if (num_sections == 0) {
221     error.SetErrorString("core file has no sections");
222     return error;
223   }
224 
225   SetCanJIT(false);
226 
227   llvm::MachO::mach_header header;
228   DataExtractor data(&header, sizeof(header),
229                      m_core_module_sp->GetArchitecture().GetByteOrder(),
230                      m_core_module_sp->GetArchitecture().GetAddressByteSize());
231 
232   bool ranges_are_sorted = true;
233   addr_t vm_addr = 0;
234   for (uint32_t i = 0; i < num_sections; ++i) {
235     Section *section = section_list->GetSectionAtIndex(i).get();
236     if (section) {
237       lldb::addr_t section_vm_addr = section->GetFileAddress();
238       FileRange file_range(section->GetFileOffset(), section->GetFileSize());
239       VMRangeToFileOffset::Entry range_entry(
240           section_vm_addr, section->GetByteSize(), file_range);
241 
242       if (vm_addr > section_vm_addr)
243         ranges_are_sorted = false;
244       vm_addr = section->GetFileAddress();
245       VMRangeToFileOffset::Entry *last_entry = m_core_aranges.Back();
246       //            printf ("LC_SEGMENT[%u] arange=[0x%16.16" PRIx64 " -
247       //            0x%16.16" PRIx64 "), frange=[0x%8.8x - 0x%8.8x)\n",
248       //                    i,
249       //                    range_entry.GetRangeBase(),
250       //                    range_entry.GetRangeEnd(),
251       //                    range_entry.data.GetRangeBase(),
252       //                    range_entry.data.GetRangeEnd());
253 
254       if (last_entry &&
255           last_entry->GetRangeEnd() == range_entry.GetRangeBase() &&
256           last_entry->data.GetRangeEnd() == range_entry.data.GetRangeBase()) {
257         last_entry->SetRangeEnd(range_entry.GetRangeEnd());
258         last_entry->data.SetRangeEnd(range_entry.data.GetRangeEnd());
259         // puts("combine");
260       } else {
261         m_core_aranges.Append(range_entry);
262       }
263       // Some core files don't fill in the permissions correctly. If that is
264       // the case assume read + execute so clients don't think the memory is
265       // not readable, or executable. The memory isn't writable since this
266       // plug-in doesn't implement DoWriteMemory.
267       uint32_t permissions = section->GetPermissions();
268       if (permissions == 0)
269         permissions = lldb::ePermissionsReadable | lldb::ePermissionsExecutable;
270       m_core_range_infos.Append(VMRangeToPermissions::Entry(
271           section_vm_addr, section->GetByteSize(), permissions));
272     }
273   }
274   if (!ranges_are_sorted) {
275     m_core_aranges.Sort();
276     m_core_range_infos.Sort();
277   }
278 
279 
280   bool found_main_binary_definitively = false;
281 
282   addr_t objfile_binary_addr;
283   UUID objfile_binary_uuid;
284   ObjectFile::BinaryType type;
285   if (core_objfile->GetCorefileMainBinaryInfo(objfile_binary_addr,
286                                               objfile_binary_uuid, type)) {
287     if (objfile_binary_addr != LLDB_INVALID_ADDRESS)
288     {
289         m_mach_kernel_addr = objfile_binary_addr;
290         found_main_binary_definitively = true;
291         LLDB_LOGF(log,
292                   "ProcessMachCore::DoLoadCore: using kernel address 0x%" PRIx64
293                   " from LC_NOTE 'main bin spec' load command.",
294                   m_mach_kernel_addr);
295     }
296   }
297 
298   // This checks for the presence of an LC_IDENT string in a core file;
299   // LC_IDENT is very obsolete and should not be used in new code, but if the
300   // load command is present, let's use the contents.
301   std::string corefile_identifier = core_objfile->GetIdentifierString();
302   if (!found_main_binary_definitively &&
303       corefile_identifier.find("Darwin Kernel") != std::string::npos) {
304     UUID uuid;
305     addr_t addr = LLDB_INVALID_ADDRESS;
306     if (corefile_identifier.find("UUID=") != std::string::npos) {
307       size_t p = corefile_identifier.find("UUID=") + strlen("UUID=");
308       std::string uuid_str = corefile_identifier.substr(p, 36);
309       uuid.SetFromStringRef(uuid_str);
310     }
311     if (corefile_identifier.find("stext=") != std::string::npos) {
312       size_t p = corefile_identifier.find("stext=") + strlen("stext=");
313       if (corefile_identifier[p] == '0' && corefile_identifier[p + 1] == 'x') {
314         errno = 0;
315         addr = ::strtoul(corefile_identifier.c_str() + p, nullptr, 16);
316         if (errno != 0 || addr == 0)
317           addr = LLDB_INVALID_ADDRESS;
318       }
319     }
320     if (uuid.IsValid() && addr != LLDB_INVALID_ADDRESS) {
321       m_mach_kernel_addr = addr;
322       found_main_binary_definitively = true;
323       LLDB_LOGF(
324           log,
325           "ProcessMachCore::DoLoadCore: Using the kernel address 0x%" PRIx64
326           " from LC_IDENT/LC_NOTE 'kern ver str' string: '%s'",
327           addr, corefile_identifier.c_str());
328     }
329   }
330 
331   // In the case where we have an LC_NOTE specifying a standalone
332   // binary with only a UUID (and no load address) (iBoot, EFI, etc),
333   // then let's try to force a load of the binary and set its
334   // load address to 0-offset.
335   //
336   // The two forms this can come in is either a
337   //   'kern ver str' LC_NOTE with "EFI UUID=...."
338   //   'main bin spec' LC_NOTE with UUID and no load address.
339 
340   if (found_main_binary_definitively == false &&
341       (corefile_identifier.find("EFI ") != std::string::npos ||
342        (objfile_binary_uuid.IsValid() &&
343         objfile_binary_addr == LLDB_INVALID_ADDRESS))) {
344     UUID uuid;
345     if (objfile_binary_uuid.IsValid()) {
346       uuid = objfile_binary_uuid;
347       LLDB_LOGF(log,
348                 "ProcessMachCore::DoLoadCore: Using the main bin spec "
349                 "LC_NOTE with UUID %s and no load address",
350                 uuid.GetAsString().c_str());
351     } else {
352       if (corefile_identifier.find("UUID=") != std::string::npos) {
353         size_t p = corefile_identifier.find("UUID=") + strlen("UUID=");
354         std::string uuid_str = corefile_identifier.substr(p, 36);
355         uuid.SetFromStringRef(uuid_str);
356         if (uuid.IsValid()) {
357           LLDB_LOGF(log,
358                     "ProcessMachCore::DoLoadCore: Using the EFI "
359                     "from LC_IDENT/LC_NOTE 'kern ver str' string: '%s'",
360                     corefile_identifier.c_str());
361         }
362       }
363     }
364 
365     if (uuid.IsValid()) {
366       ModuleSpec module_spec;
367       module_spec.GetUUID() = uuid;
368       module_spec.GetArchitecture() = GetTarget().GetArchitecture();
369 
370       // Lookup UUID locally, before attempting dsymForUUID-like action
371       FileSpecList search_paths = Target::GetDefaultDebugFileSearchPaths();
372       module_spec.GetSymbolFileSpec() =
373           Symbols::LocateExecutableSymbolFile(module_spec, search_paths);
374       if (module_spec.GetSymbolFileSpec()) {
375         ModuleSpec executable_module_spec =
376             Symbols::LocateExecutableObjectFile(module_spec);
377         if (FileSystem::Instance().Exists(
378                 executable_module_spec.GetFileSpec())) {
379           module_spec.GetFileSpec() = executable_module_spec.GetFileSpec();
380         }
381       }
382 
383       // Force a a dsymForUUID lookup, if that tool is available.
384       if (!module_spec.GetSymbolFileSpec())
385         Symbols::DownloadObjectAndSymbolFile(module_spec, true);
386 
387       // If we found a binary, load it at offset 0 and set our
388       // dyld_plugin to be the static plugin.
389       if (FileSystem::Instance().Exists(module_spec.GetFileSpec())) {
390         ModuleSP module_sp(new Module(module_spec));
391         if (module_sp.get() && module_sp->GetObjectFile()) {
392           GetTarget().GetImages().AppendIfNeeded(module_sp, true);
393           GetTarget().SetExecutableModule(module_sp, eLoadDependentsNo);
394           found_main_binary_definitively = true;
395           bool changed = true;
396           module_sp->SetLoadAddress(GetTarget(), 0, true, changed);
397           ModuleList added_module;
398           added_module.Append(module_sp, false);
399           GetTarget().ModulesDidLoad(added_module);
400           m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
401         }
402       }
403     }
404   }
405 
406   if (!found_main_binary_definitively &&
407       (m_dyld_addr == LLDB_INVALID_ADDRESS ||
408        m_mach_kernel_addr == LLDB_INVALID_ADDRESS)) {
409     // We need to locate the main executable in the memory ranges we have in
410     // the core file.  We need to search for both a user-process dyld binary
411     // and a kernel binary in memory; we must look at all the pages in the
412     // binary so we don't miss one or the other.  Step through all memory
413     // segments searching for a kernel binary and for a user process dyld --
414     // we'll decide which to prefer later if both are present.
415 
416     const size_t num_core_aranges = m_core_aranges.GetSize();
417     for (size_t i = 0; i < num_core_aranges; ++i) {
418       const VMRangeToFileOffset::Entry *entry =
419           m_core_aranges.GetEntryAtIndex(i);
420       lldb::addr_t section_vm_addr_start = entry->GetRangeBase();
421       lldb::addr_t section_vm_addr_end = entry->GetRangeEnd();
422       for (lldb::addr_t section_vm_addr = section_vm_addr_start;
423            section_vm_addr < section_vm_addr_end; section_vm_addr += 0x1000) {
424         GetDynamicLoaderAddress(section_vm_addr);
425       }
426     }
427   }
428 
429   if (!found_main_binary_definitively &&
430       m_mach_kernel_addr != LLDB_INVALID_ADDRESS) {
431     // In the case of multiple kernel images found in the core file via
432     // exhaustive search, we may not pick the correct one.  See if the
433     // DynamicLoaderDarwinKernel's search heuristics might identify the correct
434     // one. Most of the time, I expect the address from SearchForDarwinKernel()
435     // will be the same as the address we found via exhaustive search.
436 
437     if (!GetTarget().GetArchitecture().IsValid() && m_core_module_sp.get()) {
438       GetTarget().SetArchitecture(m_core_module_sp->GetArchitecture());
439     }
440 
441     // SearchForDarwinKernel will end up calling back into this this class in
442     // the GetImageInfoAddress method which will give it the
443     // m_mach_kernel_addr/m_dyld_addr it already has.  Save that aside and set
444     // m_mach_kernel_addr/m_dyld_addr to an invalid address temporarily so
445     // DynamicLoaderDarwinKernel does a real search for the kernel using its
446     // own heuristics.
447 
448     addr_t saved_mach_kernel_addr = m_mach_kernel_addr;
449     addr_t saved_user_dyld_addr = m_dyld_addr;
450     m_mach_kernel_addr = LLDB_INVALID_ADDRESS;
451     m_dyld_addr = LLDB_INVALID_ADDRESS;
452 
453     addr_t better_kernel_address =
454         DynamicLoaderDarwinKernel::SearchForDarwinKernel(this);
455 
456     m_mach_kernel_addr = saved_mach_kernel_addr;
457     m_dyld_addr = saved_user_dyld_addr;
458 
459     if (better_kernel_address != LLDB_INVALID_ADDRESS) {
460       LLDB_LOGF(log, "ProcessMachCore::DoLoadCore: Using the kernel address "
461                      "from DynamicLoaderDarwinKernel");
462       m_mach_kernel_addr = better_kernel_address;
463     }
464   }
465 
466   if (m_dyld_plugin_name.IsEmpty()) {
467     // If we found both a user-process dyld and a kernel binary, we need to
468     // decide which to prefer.
469     if (GetCorefilePreference() == eKernelCorefile) {
470       if (m_mach_kernel_addr != LLDB_INVALID_ADDRESS) {
471         LLDB_LOGF(log,
472                   "ProcessMachCore::DoLoadCore: Using kernel corefile image "
473                   "at 0x%" PRIx64,
474                   m_mach_kernel_addr);
475         m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
476       } else if (m_dyld_addr != LLDB_INVALID_ADDRESS) {
477         LLDB_LOGF(log,
478                   "ProcessMachCore::DoLoadCore: Using user process dyld "
479                   "image at 0x%" PRIx64,
480                   m_dyld_addr);
481         m_dyld_plugin_name = DynamicLoaderMacOSXDYLD::GetPluginNameStatic();
482       }
483     } else {
484       if (m_dyld_addr != LLDB_INVALID_ADDRESS) {
485         LLDB_LOGF(log,
486                   "ProcessMachCore::DoLoadCore: Using user process dyld "
487                   "image at 0x%" PRIx64,
488                   m_dyld_addr);
489         m_dyld_plugin_name = DynamicLoaderMacOSXDYLD::GetPluginNameStatic();
490       } else if (m_mach_kernel_addr != LLDB_INVALID_ADDRESS) {
491         LLDB_LOGF(log,
492                   "ProcessMachCore::DoLoadCore: Using kernel corefile image "
493                   "at 0x%" PRIx64,
494                   m_mach_kernel_addr);
495         m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
496       }
497     }
498   }
499 
500   if (m_dyld_plugin_name != DynamicLoaderMacOSXDYLD::GetPluginNameStatic()) {
501     // For non-user process core files, the permissions on the core file
502     // segments are usually meaningless, they may be just "read", because we're
503     // dealing with kernel coredumps or early startup coredumps and the dumper
504     // is grabbing pages of memory without knowing what they are.  If they
505     // aren't marked as "executable", that can break the unwinder which will
506     // check a pc value to see if it is in an executable segment and stop the
507     // backtrace early if it is not ("executable" and "unknown" would both be
508     // fine, but "not executable" will break the unwinder).
509     size_t core_range_infos_size = m_core_range_infos.GetSize();
510     for (size_t i = 0; i < core_range_infos_size; i++) {
511       VMRangeToPermissions::Entry *ent =
512           m_core_range_infos.GetMutableEntryAtIndex(i);
513       ent->data = lldb::ePermissionsReadable | lldb::ePermissionsExecutable;
514     }
515   }
516 
517   // Even if the architecture is set in the target, we need to override it to
518   // match the core file which is always single arch.
519   ArchSpec arch(m_core_module_sp->GetArchitecture());
520   if (arch.GetCore() == ArchSpec::eCore_x86_32_i486) {
521     arch = Platform::GetAugmentedArchSpec(GetTarget().GetPlatform().get(), "i386");
522   }
523   if (arch.IsValid())
524     GetTarget().SetArchitecture(arch);
525 
526   return error;
527 }
528 
529 lldb_private::DynamicLoader *ProcessMachCore::GetDynamicLoader() {
530   if (m_dyld_up.get() == nullptr)
531     m_dyld_up.reset(DynamicLoader::FindPlugin(
532         this, m_dyld_plugin_name.IsEmpty() ? nullptr
533                                            : m_dyld_plugin_name.GetCString()));
534   return m_dyld_up.get();
535 }
536 
537 bool ProcessMachCore::UpdateThreadList(ThreadList &old_thread_list,
538                                        ThreadList &new_thread_list) {
539   if (old_thread_list.GetSize(false) == 0) {
540     // Make up the thread the first time this is called so we can setup our one
541     // and only core thread state.
542     ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
543 
544     if (core_objfile) {
545       const uint32_t num_threads = core_objfile->GetNumThreadContexts();
546       for (lldb::tid_t tid = 0; tid < num_threads; ++tid) {
547         ThreadSP thread_sp(new ThreadMachCore(*this, tid));
548         new_thread_list.AddThread(thread_sp);
549       }
550     }
551   } else {
552     const uint32_t num_threads = old_thread_list.GetSize(false);
553     for (uint32_t i = 0; i < num_threads; ++i)
554       new_thread_list.AddThread(old_thread_list.GetThreadAtIndex(i, false));
555   }
556   return new_thread_list.GetSize(false) > 0;
557 }
558 
559 void ProcessMachCore::RefreshStateAfterStop() {
560   // Let all threads recover from stopping and do any clean up based on the
561   // previous thread state (if any).
562   m_thread_list.RefreshStateAfterStop();
563   // SetThreadStopInfo (m_last_stop_packet);
564 }
565 
566 Status ProcessMachCore::DoDestroy() { return Status(); }
567 
568 // Process Queries
569 
570 bool ProcessMachCore::IsAlive() { return true; }
571 
572 bool ProcessMachCore::WarnBeforeDetach() const { return false; }
573 
574 // Process Memory
575 size_t ProcessMachCore::ReadMemory(addr_t addr, void *buf, size_t size,
576                                    Status &error) {
577   // Don't allow the caching that lldb_private::Process::ReadMemory does since
578   // in core files we have it all cached our our core file anyway.
579   return DoReadMemory(addr, buf, size, error);
580 }
581 
582 size_t ProcessMachCore::DoReadMemory(addr_t addr, void *buf, size_t size,
583                                      Status &error) {
584   ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
585   size_t bytes_read = 0;
586 
587   if (core_objfile) {
588     // Segments are not always contiguous in mach-o core files. We have core
589     // files that have segments like:
590     //            Address    Size       File off   File size
591     //            ---------- ---------- ---------- ----------
592     // LC_SEGMENT 0x000f6000 0x00001000 0x1d509ee8 0x00001000 --- ---   0
593     // 0x00000000 __TEXT LC_SEGMENT 0x0f600000 0x00100000 0x1d50aee8 0x00100000
594     // --- ---   0 0x00000000 __TEXT LC_SEGMENT 0x000f7000 0x00001000
595     // 0x1d60aee8 0x00001000 --- ---   0 0x00000000 __TEXT
596     //
597     // Any if the user executes the following command:
598     //
599     // (lldb) mem read 0xf6ff0
600     //
601     // We would attempt to read 32 bytes from 0xf6ff0 but would only get 16
602     // unless we loop through consecutive memory ranges that are contiguous in
603     // the address space, but not in the file data.
604     while (bytes_read < size) {
605       const addr_t curr_addr = addr + bytes_read;
606       const VMRangeToFileOffset::Entry *core_memory_entry =
607           m_core_aranges.FindEntryThatContains(curr_addr);
608 
609       if (core_memory_entry) {
610         const addr_t offset = curr_addr - core_memory_entry->GetRangeBase();
611         const addr_t bytes_left = core_memory_entry->GetRangeEnd() - curr_addr;
612         const size_t bytes_to_read =
613             std::min(size - bytes_read, (size_t)bytes_left);
614         const size_t curr_bytes_read = core_objfile->CopyData(
615             core_memory_entry->data.GetRangeBase() + offset, bytes_to_read,
616             (char *)buf + bytes_read);
617         if (curr_bytes_read == 0)
618           break;
619         bytes_read += curr_bytes_read;
620       } else {
621         // Only set the error if we didn't read any bytes
622         if (bytes_read == 0)
623           error.SetErrorStringWithFormat(
624               "core file does not contain 0x%" PRIx64, curr_addr);
625         break;
626       }
627     }
628   }
629 
630   return bytes_read;
631 }
632 
633 Status ProcessMachCore::GetMemoryRegionInfo(addr_t load_addr,
634                                             MemoryRegionInfo &region_info) {
635   region_info.Clear();
636   const VMRangeToPermissions::Entry *permission_entry =
637       m_core_range_infos.FindEntryThatContainsOrFollows(load_addr);
638   if (permission_entry) {
639     if (permission_entry->Contains(load_addr)) {
640       region_info.GetRange().SetRangeBase(permission_entry->GetRangeBase());
641       region_info.GetRange().SetRangeEnd(permission_entry->GetRangeEnd());
642       const Flags permissions(permission_entry->data);
643       region_info.SetReadable(permissions.Test(ePermissionsReadable)
644                                   ? MemoryRegionInfo::eYes
645                                   : MemoryRegionInfo::eNo);
646       region_info.SetWritable(permissions.Test(ePermissionsWritable)
647                                   ? MemoryRegionInfo::eYes
648                                   : MemoryRegionInfo::eNo);
649       region_info.SetExecutable(permissions.Test(ePermissionsExecutable)
650                                     ? MemoryRegionInfo::eYes
651                                     : MemoryRegionInfo::eNo);
652       region_info.SetMapped(MemoryRegionInfo::eYes);
653     } else if (load_addr < permission_entry->GetRangeBase()) {
654       region_info.GetRange().SetRangeBase(load_addr);
655       region_info.GetRange().SetRangeEnd(permission_entry->GetRangeBase());
656       region_info.SetReadable(MemoryRegionInfo::eNo);
657       region_info.SetWritable(MemoryRegionInfo::eNo);
658       region_info.SetExecutable(MemoryRegionInfo::eNo);
659       region_info.SetMapped(MemoryRegionInfo::eNo);
660     }
661     return Status();
662   }
663 
664   region_info.GetRange().SetRangeBase(load_addr);
665   region_info.GetRange().SetRangeEnd(LLDB_INVALID_ADDRESS);
666   region_info.SetReadable(MemoryRegionInfo::eNo);
667   region_info.SetWritable(MemoryRegionInfo::eNo);
668   region_info.SetExecutable(MemoryRegionInfo::eNo);
669   region_info.SetMapped(MemoryRegionInfo::eNo);
670   return Status();
671 }
672 
673 void ProcessMachCore::Clear() { m_thread_list.Clear(); }
674 
675 void ProcessMachCore::Initialize() {
676   static llvm::once_flag g_once_flag;
677 
678   llvm::call_once(g_once_flag, []() {
679     PluginManager::RegisterPlugin(GetPluginNameStatic(),
680                                   GetPluginDescriptionStatic(), CreateInstance);
681   });
682 }
683 
684 addr_t ProcessMachCore::GetImageInfoAddress() {
685   // If we found both a user-process dyld and a kernel binary, we need to
686   // decide which to prefer.
687   if (GetCorefilePreference() == eKernelCorefile) {
688     if (m_mach_kernel_addr != LLDB_INVALID_ADDRESS) {
689       return m_mach_kernel_addr;
690     }
691     return m_dyld_addr;
692   } else {
693     if (m_dyld_addr != LLDB_INVALID_ADDRESS) {
694       return m_dyld_addr;
695     }
696     return m_mach_kernel_addr;
697   }
698 }
699 
700 lldb_private::ObjectFile *ProcessMachCore::GetCoreObjectFile() {
701   return m_core_module_sp->GetObjectFile();
702 }
703