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 <cerrno>
10 #include <cstdlib>
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/SectionLoadList.h"
25 #include "lldb/Target/Target.h"
26 #include "lldb/Target/Thread.h"
27 #include "lldb/Utility/DataBuffer.h"
28 #include "lldb/Utility/Log.h"
29 #include "lldb/Utility/State.h"
30 
31 #include "ProcessMachCore.h"
32 #include "Plugins/Process/Utility/StopInfoMachException.h"
33 #include "ThreadMachCore.h"
34 
35 // Needed for the plug-in names for the dynamic loaders.
36 #include "lldb/Host/SafeMachO.h"
37 
38 #include "Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.h"
39 #include "Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.h"
40 #include "Plugins/DynamicLoader/Static/DynamicLoaderStatic.h"
41 #include "Plugins/ObjectFile/Mach-O/ObjectFileMachO.h"
42 
43 #include <memory>
44 #include <mutex>
45 
46 using namespace lldb;
47 using namespace lldb_private;
48 
49 LLDB_PLUGIN_DEFINE(ProcessMachCore)
50 
51 llvm::StringRef ProcessMachCore::GetPluginDescriptionStatic() {
52   return "Mach-O core file debugging plug-in.";
53 }
54 
55 void ProcessMachCore::Terminate() {
56   PluginManager::UnregisterPlugin(ProcessMachCore::CreateInstance);
57 }
58 
59 lldb::ProcessSP ProcessMachCore::CreateInstance(lldb::TargetSP target_sp,
60                                                 ListenerSP listener_sp,
61                                                 const FileSpec *crash_file,
62                                                 bool can_connect) {
63   lldb::ProcessSP process_sp;
64   if (crash_file && !can_connect) {
65     const size_t header_size = sizeof(llvm::MachO::mach_header);
66     auto data_sp = FileSystem::Instance().CreateDataBuffer(
67         crash_file->GetPath(), header_size, 0);
68     if (data_sp && data_sp->GetByteSize() == header_size) {
69       DataExtractor data(data_sp, lldb::eByteOrderLittle, 4);
70 
71       lldb::offset_t data_offset = 0;
72       llvm::MachO::mach_header mach_header;
73       if (ObjectFileMachO::ParseHeader(data, &data_offset, mach_header)) {
74         if (mach_header.filetype == llvm::MachO::MH_CORE)
75           process_sp = std::make_shared<ProcessMachCore>(target_sp, listener_sp,
76                                                          *crash_file);
77       }
78     }
79   }
80   return process_sp;
81 }
82 
83 bool ProcessMachCore::CanDebug(lldb::TargetSP target_sp,
84                                bool plugin_specified_by_name) {
85   if (plugin_specified_by_name)
86     return true;
87 
88   // For now we are just making sure the file exists for a given module
89   if (!m_core_module_sp && FileSystem::Instance().Exists(m_core_file)) {
90     // Don't add the Target's architecture to the ModuleSpec - we may be
91     // working with a core file that doesn't have the correct cpusubtype in the
92     // header but we should still try to use it -
93     // ModuleSpecList::FindMatchingModuleSpec enforces a strict arch mach.
94     ModuleSpec core_module_spec(m_core_file);
95     Status error(ModuleList::GetSharedModule(core_module_spec, m_core_module_sp,
96                                              nullptr, nullptr, nullptr));
97 
98     if (m_core_module_sp) {
99       ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
100       if (core_objfile && core_objfile->GetType() == ObjectFile::eTypeCoreFile)
101         return true;
102     }
103   }
104   return false;
105 }
106 
107 // ProcessMachCore constructor
108 ProcessMachCore::ProcessMachCore(lldb::TargetSP target_sp,
109                                  ListenerSP listener_sp,
110                                  const FileSpec &core_file)
111     : PostMortemProcess(target_sp, listener_sp), m_core_aranges(),
112       m_core_range_infos(), m_core_module_sp(), m_core_file(core_file),
113       m_dyld_addr(LLDB_INVALID_ADDRESS),
114       m_mach_kernel_addr(LLDB_INVALID_ADDRESS) {}
115 
116 // Destructor
117 ProcessMachCore::~ProcessMachCore() {
118   Clear();
119   // We need to call finalize on the process before destroying ourselves to
120   // make sure all of the broadcaster cleanup goes as planned. If we destruct
121   // this class, then Process::~Process() might have problems trying to fully
122   // destroy the broadcaster.
123   Finalize();
124 }
125 
126 bool ProcessMachCore::GetDynamicLoaderAddress(lldb::addr_t addr) {
127   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER |
128                                                   LIBLLDB_LOG_PROCESS));
129   llvm::MachO::mach_header header;
130   Status error;
131   if (DoReadMemory(addr, &header, sizeof(header), error) != sizeof(header))
132     return false;
133   if (header.magic == llvm::MachO::MH_CIGAM ||
134       header.magic == llvm::MachO::MH_CIGAM_64) {
135     header.magic = llvm::ByteSwap_32(header.magic);
136     header.cputype = llvm::ByteSwap_32(header.cputype);
137     header.cpusubtype = llvm::ByteSwap_32(header.cpusubtype);
138     header.filetype = llvm::ByteSwap_32(header.filetype);
139     header.ncmds = llvm::ByteSwap_32(header.ncmds);
140     header.sizeofcmds = llvm::ByteSwap_32(header.sizeofcmds);
141     header.flags = llvm::ByteSwap_32(header.flags);
142   }
143 
144   // TODO: swap header if needed...
145   // printf("0x%16.16" PRIx64 ": magic = 0x%8.8x, file_type= %u\n", vaddr,
146   // header.magic, header.filetype);
147   if (header.magic == llvm::MachO::MH_MAGIC ||
148       header.magic == llvm::MachO::MH_MAGIC_64) {
149     // Check MH_EXECUTABLE to see if we can find the mach image that contains
150     // the shared library list. The dynamic loader (dyld) is what contains the
151     // list for user applications, and the mach kernel contains a global that
152     // has the list of kexts to load
153     switch (header.filetype) {
154     case llvm::MachO::MH_DYLINKER:
155       // printf("0x%16.16" PRIx64 ": file_type = MH_DYLINKER\n", vaddr);
156       // Address of dyld "struct mach_header" in the core file
157       LLDB_LOGF(log,
158                 "ProcessMachCore::GetDynamicLoaderAddress found a user "
159                 "process dyld binary image at 0x%" PRIx64,
160                 addr);
161       m_dyld_addr = addr;
162       return true;
163 
164     case llvm::MachO::MH_EXECUTE:
165       // printf("0x%16.16" PRIx64 ": file_type = MH_EXECUTE\n", vaddr);
166       // Check MH_EXECUTABLE file types to see if the dynamic link object flag
167       // is NOT set. If it isn't, then we have a mach_kernel.
168       if ((header.flags & llvm::MachO::MH_DYLDLINK) == 0) {
169         LLDB_LOGF(log,
170                   "ProcessMachCore::GetDynamicLoaderAddress found a mach "
171                   "kernel binary image at 0x%" PRIx64,
172                   addr);
173         // Address of the mach kernel "struct mach_header" in the core file.
174         m_mach_kernel_addr = addr;
175         return true;
176       }
177       break;
178     }
179   }
180   return false;
181 }
182 
183 // We have a hint about a binary -- a UUID, possibly a load address.
184 // Try to load a file with that UUID into lldb, and if we have a load
185 // address, set it correctly.  Else assume that the binary was loaded
186 // with no slide.
187 static bool load_standalone_binary(UUID uuid, addr_t value,
188                                    bool value_is_offset, Target &target) {
189   if (uuid.IsValid()) {
190     ModuleSpec module_spec;
191     module_spec.GetUUID() = uuid;
192 
193     // Look up UUID in global module cache before attempting
194     // dsymForUUID-like action.
195     ModuleSP module_sp;
196     Status error = ModuleList::GetSharedModule(module_spec, module_sp, nullptr,
197                                                nullptr, nullptr);
198 
199     if (!module_sp.get()) {
200       // Force a a dsymForUUID lookup, if that tool is available.
201       if (!module_spec.GetSymbolFileSpec())
202         Symbols::DownloadObjectAndSymbolFile(module_spec, true);
203 
204       if (FileSystem::Instance().Exists(module_spec.GetFileSpec())) {
205         module_sp = std::make_shared<Module>(module_spec);
206       }
207     }
208 
209     // If we couldn't find the binary anywhere else, as a last resort,
210     // read it out of memory in the corefile.
211     if (!module_sp.get() && value != LLDB_INVALID_ADDRESS && !value_is_offset) {
212       char namebuf[80];
213       snprintf(namebuf, sizeof(namebuf), "mem-image-0x%" PRIx64, value);
214       module_sp =
215           target.GetProcessSP()->ReadModuleFromMemory(FileSpec(namebuf), value);
216     }
217 
218     if (module_sp.get()) {
219       target.SetArchitecture(module_sp->GetObjectFile()->GetArchitecture());
220       target.GetImages().AppendIfNeeded(module_sp, false);
221 
222       bool changed = false;
223       if (module_sp->GetObjectFile()) {
224         if (value != LLDB_INVALID_ADDRESS) {
225           module_sp->SetLoadAddress(target, value, value_is_offset, changed);
226         } else {
227           // No address/offset/slide, load the binary at file address,
228           // offset 0.
229           const bool value_is_slide = true;
230           module_sp->SetLoadAddress(target, 0, value_is_slide, changed);
231         }
232       } else {
233         // In-memory image, load at its true address, offset 0.
234         const bool value_is_slide = true;
235         module_sp->SetLoadAddress(target, 0, value_is_slide, changed);
236       }
237 
238       ModuleList added_module;
239       added_module.Append(module_sp, false);
240       target.ModulesDidLoad(added_module);
241 
242       // Flush info in the process (stack frames, etc).
243       ProcessSP process_sp(target.GetProcessSP());
244       if (process_sp)
245         process_sp->Flush();
246 
247       return true;
248     }
249   }
250   return false;
251 }
252 
253 // Process Control
254 Status ProcessMachCore::DoLoadCore() {
255   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER |
256                                                   LIBLLDB_LOG_PROCESS));
257   Status error;
258   if (!m_core_module_sp) {
259     error.SetErrorString("invalid core module");
260     return error;
261   }
262 
263   ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
264   if (core_objfile == nullptr) {
265     error.SetErrorString("invalid core object file");
266     return error;
267   }
268 
269   if (core_objfile->GetNumThreadContexts() == 0) {
270     error.SetErrorString("core file doesn't contain any LC_THREAD load "
271                          "commands, or the LC_THREAD architecture is not "
272                          "supported in this lldb");
273     return error;
274   }
275 
276   SectionList *section_list = core_objfile->GetSectionList();
277   if (section_list == nullptr) {
278     error.SetErrorString("core file has no sections");
279     return error;
280   }
281 
282   const uint32_t num_sections = section_list->GetNumSections(0);
283   if (num_sections == 0) {
284     error.SetErrorString("core file has no sections");
285     return error;
286   }
287 
288   SetCanJIT(false);
289 
290   llvm::MachO::mach_header header;
291   DataExtractor data(&header, sizeof(header),
292                      m_core_module_sp->GetArchitecture().GetByteOrder(),
293                      m_core_module_sp->GetArchitecture().GetAddressByteSize());
294 
295   bool ranges_are_sorted = true;
296   addr_t vm_addr = 0;
297   for (uint32_t i = 0; i < num_sections; ++i) {
298     Section *section = section_list->GetSectionAtIndex(i).get();
299     if (section && section->GetFileSize() > 0) {
300       lldb::addr_t section_vm_addr = section->GetFileAddress();
301       FileRange file_range(section->GetFileOffset(), section->GetFileSize());
302       VMRangeToFileOffset::Entry range_entry(
303           section_vm_addr, section->GetByteSize(), file_range);
304 
305       if (vm_addr > section_vm_addr)
306         ranges_are_sorted = false;
307       vm_addr = section->GetFileAddress();
308       VMRangeToFileOffset::Entry *last_entry = m_core_aranges.Back();
309 
310       if (last_entry &&
311           last_entry->GetRangeEnd() == range_entry.GetRangeBase() &&
312           last_entry->data.GetRangeEnd() == range_entry.data.GetRangeBase()) {
313         last_entry->SetRangeEnd(range_entry.GetRangeEnd());
314         last_entry->data.SetRangeEnd(range_entry.data.GetRangeEnd());
315       } else {
316         m_core_aranges.Append(range_entry);
317       }
318       // Some core files don't fill in the permissions correctly. If that is
319       // the case assume read + execute so clients don't think the memory is
320       // not readable, or executable. The memory isn't writable since this
321       // plug-in doesn't implement DoWriteMemory.
322       uint32_t permissions = section->GetPermissions();
323       if (permissions == 0)
324         permissions = lldb::ePermissionsReadable | lldb::ePermissionsExecutable;
325       m_core_range_infos.Append(VMRangeToPermissions::Entry(
326           section_vm_addr, section->GetByteSize(), permissions));
327     }
328   }
329   if (!ranges_are_sorted) {
330     m_core_aranges.Sort();
331     m_core_range_infos.Sort();
332   }
333 
334   bool found_main_binary_definitively = false;
335 
336   addr_t objfile_binary_value;
337   bool objfile_binary_value_is_offset;
338   UUID objfile_binary_uuid;
339   ObjectFile::BinaryType type;
340   if (core_objfile->GetCorefileMainBinaryInfo(objfile_binary_value,
341                                               objfile_binary_value_is_offset,
342                                               objfile_binary_uuid, type)) {
343     if (log) {
344       log->Printf(
345           "ProcessMachCore::DoLoadCore: using binary hint from 'main bin spec' "
346           "LC_NOTE with UUID %s value 0x%" PRIx64
347           " value is offset %d and type %d",
348           objfile_binary_uuid.GetAsString().c_str(), objfile_binary_value,
349           objfile_binary_value_is_offset, type);
350     }
351     if (objfile_binary_value != LLDB_INVALID_ADDRESS &&
352         !objfile_binary_value_is_offset) {
353       if (type == ObjectFile::eBinaryTypeUser) {
354         m_dyld_addr = objfile_binary_value;
355         m_dyld_plugin_name = DynamicLoaderMacOSXDYLD::GetPluginNameStatic();
356         found_main_binary_definitively = true;
357       }
358       if (type == ObjectFile::eBinaryTypeKernel) {
359         m_mach_kernel_addr = objfile_binary_value;
360         m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
361         found_main_binary_definitively = true;
362       }
363     }
364     if (!found_main_binary_definitively) {
365       // ObjectFile::eBinaryTypeStandalone, undeclared types
366       if (load_standalone_binary(objfile_binary_uuid, objfile_binary_value,
367                                  objfile_binary_value_is_offset, GetTarget())) {
368         found_main_binary_definitively = true;
369         m_dyld_plugin_name = DynamicLoaderStatic::GetPluginNameStatic();
370       }
371     }
372   }
373 
374   // This checks for the presence of an LC_IDENT string in a core file;
375   // LC_IDENT is very obsolete and should not be used in new code, but if the
376   // load command is present, let's use the contents.
377   UUID ident_uuid;
378   addr_t ident_binary_addr = LLDB_INVALID_ADDRESS;
379   if (!found_main_binary_definitively) {
380     std::string corefile_identifier = core_objfile->GetIdentifierString();
381 
382     // Search for UUID= and stext= strings in the identifier str.
383     if (corefile_identifier.find("UUID=") != std::string::npos) {
384       size_t p = corefile_identifier.find("UUID=") + strlen("UUID=");
385       std::string uuid_str = corefile_identifier.substr(p, 36);
386       ident_uuid.SetFromStringRef(uuid_str);
387       if (log)
388         log->Printf("Got a UUID from LC_IDENT/kern ver str LC_NOTE: %s",
389                     ident_uuid.GetAsString().c_str());
390     }
391     if (corefile_identifier.find("stext=") != std::string::npos) {
392       size_t p = corefile_identifier.find("stext=") + strlen("stext=");
393       if (corefile_identifier[p] == '0' && corefile_identifier[p + 1] == 'x') {
394         ident_binary_addr =
395             ::strtoul(corefile_identifier.c_str() + p, nullptr, 16);
396         if (log)
397           log->Printf("Got a load address from LC_IDENT/kern ver str "
398                       "LC_NOTE: 0x%" PRIx64,
399                       ident_binary_addr);
400       }
401     }
402 
403     // Search for a "Darwin Kernel" str indicating kernel; else treat as
404     // standalone
405     if (corefile_identifier.find("Darwin Kernel") != std::string::npos &&
406         ident_uuid.IsValid() && ident_binary_addr != LLDB_INVALID_ADDRESS) {
407       if (log)
408         log->Printf("ProcessMachCore::DoLoadCore: Found kernel binary via "
409                     "LC_IDENT/kern ver str LC_NOTE");
410       m_mach_kernel_addr = ident_binary_addr;
411       found_main_binary_definitively = true;
412     } else if (ident_uuid.IsValid()) {
413       // We have no address specified, only a UUID.  Load it at the file
414       // address.
415       const bool value_is_offset = false;
416       if (load_standalone_binary(ident_uuid, ident_binary_addr, value_is_offset,
417                                  GetTarget())) {
418         found_main_binary_definitively = true;
419         m_dyld_plugin_name = DynamicLoaderStatic::GetPluginNameStatic();
420       }
421     }
422   }
423 
424   bool did_load_extra_binaries = core_objfile->LoadCoreFileImages(*this);
425   // If we have a "all image infos" LC_NOTE, try to load all of the
426   // binaries listed, and set their Section load addresses in the Target.
427   if (found_main_binary_definitively == false && did_load_extra_binaries) {
428     m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
429     found_main_binary_definitively = true;
430   }
431 
432   if (!found_main_binary_definitively &&
433       (m_dyld_addr == LLDB_INVALID_ADDRESS ||
434        m_mach_kernel_addr == LLDB_INVALID_ADDRESS)) {
435     // We need to locate the main executable in the memory ranges we have in
436     // the core file.  We need to search for both a user-process dyld binary
437     // and a kernel binary in memory; we must look at all the pages in the
438     // binary so we don't miss one or the other.  Step through all memory
439     // segments searching for a kernel binary and for a user process dyld --
440     // we'll decide which to prefer later if both are present.
441 
442     const size_t num_core_aranges = m_core_aranges.GetSize();
443     for (size_t i = 0; i < num_core_aranges; ++i) {
444       const VMRangeToFileOffset::Entry *entry =
445           m_core_aranges.GetEntryAtIndex(i);
446       lldb::addr_t section_vm_addr_start = entry->GetRangeBase();
447       lldb::addr_t section_vm_addr_end = entry->GetRangeEnd();
448       for (lldb::addr_t section_vm_addr = section_vm_addr_start;
449            section_vm_addr < section_vm_addr_end; section_vm_addr += 0x1000) {
450         GetDynamicLoaderAddress(section_vm_addr);
451       }
452     }
453   }
454 
455   if (!found_main_binary_definitively &&
456       m_mach_kernel_addr != LLDB_INVALID_ADDRESS) {
457     // In the case of multiple kernel images found in the core file via
458     // exhaustive search, we may not pick the correct one.  See if the
459     // DynamicLoaderDarwinKernel's search heuristics might identify the correct
460     // one. Most of the time, I expect the address from SearchForDarwinKernel()
461     // will be the same as the address we found via exhaustive search.
462 
463     if (!GetTarget().GetArchitecture().IsValid() && m_core_module_sp.get()) {
464       GetTarget().SetArchitecture(m_core_module_sp->GetArchitecture());
465     }
466 
467     // SearchForDarwinKernel will end up calling back into this this class in
468     // the GetImageInfoAddress method which will give it the
469     // m_mach_kernel_addr/m_dyld_addr it already has.  Save that aside and set
470     // m_mach_kernel_addr/m_dyld_addr to an invalid address temporarily so
471     // DynamicLoaderDarwinKernel does a real search for the kernel using its
472     // own heuristics.
473 
474     addr_t saved_mach_kernel_addr = m_mach_kernel_addr;
475     addr_t saved_user_dyld_addr = m_dyld_addr;
476     m_mach_kernel_addr = LLDB_INVALID_ADDRESS;
477     m_dyld_addr = LLDB_INVALID_ADDRESS;
478 
479     addr_t better_kernel_address =
480         DynamicLoaderDarwinKernel::SearchForDarwinKernel(this);
481 
482     m_mach_kernel_addr = saved_mach_kernel_addr;
483     m_dyld_addr = saved_user_dyld_addr;
484 
485     if (better_kernel_address != LLDB_INVALID_ADDRESS) {
486       LLDB_LOGF(log, "ProcessMachCore::DoLoadCore: Using the kernel address "
487                      "from DynamicLoaderDarwinKernel");
488       m_mach_kernel_addr = better_kernel_address;
489     }
490   }
491 
492   if (m_dyld_plugin_name.empty()) {
493     // If we found both a user-process dyld and a kernel binary, we need to
494     // decide which to prefer.
495     if (GetCorefilePreference() == eKernelCorefile) {
496       if (m_mach_kernel_addr != LLDB_INVALID_ADDRESS) {
497         LLDB_LOGF(log,
498                   "ProcessMachCore::DoLoadCore: Using kernel corefile image "
499                   "at 0x%" PRIx64,
500                   m_mach_kernel_addr);
501         m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
502       } else if (m_dyld_addr != LLDB_INVALID_ADDRESS) {
503         LLDB_LOGF(log,
504                   "ProcessMachCore::DoLoadCore: Using user process dyld "
505                   "image at 0x%" PRIx64,
506                   m_dyld_addr);
507         m_dyld_plugin_name = DynamicLoaderMacOSXDYLD::GetPluginNameStatic();
508       }
509     } else {
510       if (m_dyld_addr != LLDB_INVALID_ADDRESS) {
511         LLDB_LOGF(log,
512                   "ProcessMachCore::DoLoadCore: Using user process dyld "
513                   "image at 0x%" PRIx64,
514                   m_dyld_addr);
515         m_dyld_plugin_name = DynamicLoaderMacOSXDYLD::GetPluginNameStatic();
516       } else if (m_mach_kernel_addr != LLDB_INVALID_ADDRESS) {
517         LLDB_LOGF(log,
518                   "ProcessMachCore::DoLoadCore: Using kernel corefile image "
519                   "at 0x%" PRIx64,
520                   m_mach_kernel_addr);
521         m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
522       }
523     }
524   }
525 
526   if (m_dyld_plugin_name != DynamicLoaderMacOSXDYLD::GetPluginNameStatic()) {
527     // For non-user process core files, the permissions on the core file
528     // segments are usually meaningless, they may be just "read", because we're
529     // dealing with kernel coredumps or early startup coredumps and the dumper
530     // is grabbing pages of memory without knowing what they are.  If they
531     // aren't marked as "executable", that can break the unwinder which will
532     // check a pc value to see if it is in an executable segment and stop the
533     // backtrace early if it is not ("executable" and "unknown" would both be
534     // fine, but "not executable" will break the unwinder).
535     size_t core_range_infos_size = m_core_range_infos.GetSize();
536     for (size_t i = 0; i < core_range_infos_size; i++) {
537       VMRangeToPermissions::Entry *ent =
538           m_core_range_infos.GetMutableEntryAtIndex(i);
539       ent->data = lldb::ePermissionsReadable | lldb::ePermissionsExecutable;
540     }
541   }
542 
543   // Even if the architecture is set in the target, we need to override it to
544   // match the core file which is always single arch.
545   ArchSpec arch(m_core_module_sp->GetArchitecture());
546   if (arch.GetCore() == ArchSpec::eCore_x86_32_i486) {
547     arch = Platform::GetAugmentedArchSpec(GetTarget().GetPlatform().get(), "i386");
548   }
549   if (arch.IsValid())
550     GetTarget().SetArchitecture(arch);
551 
552   addr_t address_mask = core_objfile->GetAddressMask();
553   if (address_mask != 0) {
554     SetCodeAddressMask(address_mask);
555     SetDataAddressMask(address_mask);
556   }
557   return error;
558 }
559 
560 lldb_private::DynamicLoader *ProcessMachCore::GetDynamicLoader() {
561   if (m_dyld_up.get() == nullptr)
562     m_dyld_up.reset(DynamicLoader::FindPlugin(this, m_dyld_plugin_name));
563   return m_dyld_up.get();
564 }
565 
566 bool ProcessMachCore::DoUpdateThreadList(ThreadList &old_thread_list,
567                                          ThreadList &new_thread_list) {
568   if (old_thread_list.GetSize(false) == 0) {
569     // Make up the thread the first time this is called so we can setup our one
570     // and only core thread state.
571     ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
572 
573     if (core_objfile) {
574       const uint32_t num_threads = core_objfile->GetNumThreadContexts();
575       for (lldb::tid_t tid = 0; tid < num_threads; ++tid) {
576         ThreadSP thread_sp(new ThreadMachCore(*this, tid));
577         new_thread_list.AddThread(thread_sp);
578       }
579     }
580   } else {
581     const uint32_t num_threads = old_thread_list.GetSize(false);
582     for (uint32_t i = 0; i < num_threads; ++i)
583       new_thread_list.AddThread(old_thread_list.GetThreadAtIndex(i, false));
584   }
585   return new_thread_list.GetSize(false) > 0;
586 }
587 
588 void ProcessMachCore::RefreshStateAfterStop() {
589   // Let all threads recover from stopping and do any clean up based on the
590   // previous thread state (if any).
591   m_thread_list.RefreshStateAfterStop();
592   // SetThreadStopInfo (m_last_stop_packet);
593 }
594 
595 Status ProcessMachCore::DoDestroy() { return Status(); }
596 
597 // Process Queries
598 
599 bool ProcessMachCore::IsAlive() { return true; }
600 
601 bool ProcessMachCore::WarnBeforeDetach() const { return false; }
602 
603 // Process Memory
604 size_t ProcessMachCore::ReadMemory(addr_t addr, void *buf, size_t size,
605                                    Status &error) {
606   // Don't allow the caching that lldb_private::Process::ReadMemory does since
607   // in core files we have it all cached our our core file anyway.
608   return DoReadMemory(addr, buf, size, error);
609 }
610 
611 size_t ProcessMachCore::DoReadMemory(addr_t addr, void *buf, size_t size,
612                                      Status &error) {
613   ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
614   size_t bytes_read = 0;
615 
616   if (core_objfile) {
617     // Segments are not always contiguous in mach-o core files. We have core
618     // files that have segments like:
619     //            Address    Size       File off   File size
620     //            ---------- ---------- ---------- ----------
621     // LC_SEGMENT 0x000f6000 0x00001000 0x1d509ee8 0x00001000 --- ---   0
622     // 0x00000000 __TEXT LC_SEGMENT 0x0f600000 0x00100000 0x1d50aee8 0x00100000
623     // --- ---   0 0x00000000 __TEXT LC_SEGMENT 0x000f7000 0x00001000
624     // 0x1d60aee8 0x00001000 --- ---   0 0x00000000 __TEXT
625     //
626     // Any if the user executes the following command:
627     //
628     // (lldb) mem read 0xf6ff0
629     //
630     // We would attempt to read 32 bytes from 0xf6ff0 but would only get 16
631     // unless we loop through consecutive memory ranges that are contiguous in
632     // the address space, but not in the file data.
633     while (bytes_read < size) {
634       const addr_t curr_addr = addr + bytes_read;
635       const VMRangeToFileOffset::Entry *core_memory_entry =
636           m_core_aranges.FindEntryThatContains(curr_addr);
637 
638       if (core_memory_entry) {
639         const addr_t offset = curr_addr - core_memory_entry->GetRangeBase();
640         const addr_t bytes_left = core_memory_entry->GetRangeEnd() - curr_addr;
641         const size_t bytes_to_read =
642             std::min(size - bytes_read, (size_t)bytes_left);
643         const size_t curr_bytes_read = core_objfile->CopyData(
644             core_memory_entry->data.GetRangeBase() + offset, bytes_to_read,
645             (char *)buf + bytes_read);
646         if (curr_bytes_read == 0)
647           break;
648         bytes_read += curr_bytes_read;
649       } else {
650         // Only set the error if we didn't read any bytes
651         if (bytes_read == 0)
652           error.SetErrorStringWithFormat(
653               "core file does not contain 0x%" PRIx64, curr_addr);
654         break;
655       }
656     }
657   }
658 
659   return bytes_read;
660 }
661 
662 Status ProcessMachCore::GetMemoryRegionInfo(addr_t load_addr,
663                                             MemoryRegionInfo &region_info) {
664   region_info.Clear();
665   const VMRangeToPermissions::Entry *permission_entry =
666       m_core_range_infos.FindEntryThatContainsOrFollows(load_addr);
667   if (permission_entry) {
668     if (permission_entry->Contains(load_addr)) {
669       region_info.GetRange().SetRangeBase(permission_entry->GetRangeBase());
670       region_info.GetRange().SetRangeEnd(permission_entry->GetRangeEnd());
671       const Flags permissions(permission_entry->data);
672       region_info.SetReadable(permissions.Test(ePermissionsReadable)
673                                   ? MemoryRegionInfo::eYes
674                                   : MemoryRegionInfo::eNo);
675       region_info.SetWritable(permissions.Test(ePermissionsWritable)
676                                   ? MemoryRegionInfo::eYes
677                                   : MemoryRegionInfo::eNo);
678       region_info.SetExecutable(permissions.Test(ePermissionsExecutable)
679                                     ? MemoryRegionInfo::eYes
680                                     : MemoryRegionInfo::eNo);
681       region_info.SetMapped(MemoryRegionInfo::eYes);
682     } else if (load_addr < permission_entry->GetRangeBase()) {
683       region_info.GetRange().SetRangeBase(load_addr);
684       region_info.GetRange().SetRangeEnd(permission_entry->GetRangeBase());
685       region_info.SetReadable(MemoryRegionInfo::eNo);
686       region_info.SetWritable(MemoryRegionInfo::eNo);
687       region_info.SetExecutable(MemoryRegionInfo::eNo);
688       region_info.SetMapped(MemoryRegionInfo::eNo);
689     }
690     return Status();
691   }
692 
693   region_info.GetRange().SetRangeBase(load_addr);
694   region_info.GetRange().SetRangeEnd(LLDB_INVALID_ADDRESS);
695   region_info.SetReadable(MemoryRegionInfo::eNo);
696   region_info.SetWritable(MemoryRegionInfo::eNo);
697   region_info.SetExecutable(MemoryRegionInfo::eNo);
698   region_info.SetMapped(MemoryRegionInfo::eNo);
699   return Status();
700 }
701 
702 void ProcessMachCore::Clear() { m_thread_list.Clear(); }
703 
704 void ProcessMachCore::Initialize() {
705   static llvm::once_flag g_once_flag;
706 
707   llvm::call_once(g_once_flag, []() {
708     PluginManager::RegisterPlugin(GetPluginNameStatic(),
709                                   GetPluginDescriptionStatic(), CreateInstance);
710   });
711 }
712 
713 addr_t ProcessMachCore::GetImageInfoAddress() {
714   // If we found both a user-process dyld and a kernel binary, we need to
715   // decide which to prefer.
716   if (GetCorefilePreference() == eKernelCorefile) {
717     if (m_mach_kernel_addr != LLDB_INVALID_ADDRESS) {
718       return m_mach_kernel_addr;
719     }
720     return m_dyld_addr;
721   } else {
722     if (m_dyld_addr != LLDB_INVALID_ADDRESS) {
723       return m_dyld_addr;
724     }
725     return m_mach_kernel_addr;
726   }
727 }
728 
729 lldb_private::ObjectFile *ProcessMachCore::GetCoreObjectFile() {
730   return m_core_module_sp->GetObjectFile();
731 }
732