Bug Summary

File:build/source/lldb/source/Plugins/Process/mach-core/ProcessMachCore.cpp
Warning:line 310, column 7
Value stored to 'found_main_binary_definitively' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name ProcessMachCore.cpp -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/source/build-llvm/tools/clang/stage2-bins -resource-dir /usr/lib/llvm-17/lib/clang/17 -isystem /usr/include/libxml2 -D HAVE_ROUND -D _DEBUG -D _GLIBCXX_ASSERTIONS -D _GNU_SOURCE -D _LIBCPP_ENABLE_ASSERTIONS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I tools/lldb/source/Plugins/Process/mach-core -I /build/source/lldb/source/Plugins/Process/mach-core -I /build/source/lldb/include -I tools/lldb/include -I include -I /build/source/llvm/include -I /usr/include/python3.9 -I /build/source/clang/include -I tools/lldb/../clang/include -I /build/source/lldb/source -I tools/lldb/source -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-17/lib/clang/17/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fmacro-prefix-map=/build/source/= -fcoverage-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fcoverage-prefix-map=/build/source/= -source-date-epoch 1683717183 -O2 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -Wno-misleading-indentation -Wno-deprecated-declarations -Wno-unknown-pragmas -Wno-strict-aliasing -Wno-stringop-truncation -std=c++17 -fdeprecated-macro -fdebug-compilation-dir=/build/source/build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/source/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2023-05-10-133810-16478-1 -x c++ /build/source/lldb/source/Plugins/Process/mach-core/ProcessMachCore.cpp
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/LLDBLog.h"
29#include "lldb/Utility/Log.h"
30#include "lldb/Utility/State.h"
31
32#include "ProcessMachCore.h"
33#include "Plugins/Process/Utility/StopInfoMachException.h"
34#include "ThreadMachCore.h"
35
36// Needed for the plug-in names for the dynamic loaders.
37#include "lldb/Host/SafeMachO.h"
38
39#include "Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.h"
40#include "Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.h"
41#include "Plugins/DynamicLoader/Static/DynamicLoaderStatic.h"
42#include "Plugins/ObjectFile/Mach-O/ObjectFileMachO.h"
43#include "Plugins/Platform/MacOSX/PlatformDarwinKernel.h"
44
45#include <memory>
46#include <mutex>
47
48using namespace lldb;
49using namespace lldb_private;
50
51LLDB_PLUGIN_DEFINE(ProcessMachCore)namespace lldb_private { void lldb_initialize_ProcessMachCore
() { ProcessMachCore::Initialize(); } void lldb_terminate_ProcessMachCore
() { ProcessMachCore::Terminate(); } }
52
53llvm::StringRef ProcessMachCore::GetPluginDescriptionStatic() {
54 return "Mach-O core file debugging plug-in.";
55}
56
57void ProcessMachCore::Terminate() {
58 PluginManager::UnregisterPlugin(ProcessMachCore::CreateInstance);
59}
60
61lldb::ProcessSP ProcessMachCore::CreateInstance(lldb::TargetSP target_sp,
62 ListenerSP listener_sp,
63 const FileSpec *crash_file,
64 bool can_connect) {
65 lldb::ProcessSP process_sp;
66 if (crash_file && !can_connect) {
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
85bool 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
110ProcessMachCore::ProcessMachCore(lldb::TargetSP target_sp,
111 ListenerSP listener_sp,
112 const FileSpec &core_file)
113 : PostMortemProcess(target_sp, listener_sp), m_core_aranges(),
114 m_core_range_infos(), m_core_module_sp(), m_core_file(core_file),
115 m_dyld_addr(LLDB_INVALID_ADDRESS(18446744073709551615UL)),
116 m_mach_kernel_addr(LLDB_INVALID_ADDRESS(18446744073709551615UL)) {}
117
118// Destructor
119ProcessMachCore::~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
128bool ProcessMachCore::CheckAddressForDyldOrKernel(lldb::addr_t addr,
129 addr_t &dyld,
130 addr_t &kernel) {
131 Log *log(GetLog(LLDBLog::DynamicLoader | LLDBLog::Process));
132 llvm::MachO::mach_header header;
133 Status error;
134 dyld = kernel = LLDB_INVALID_ADDRESS(18446744073709551615UL);
135 if (DoReadMemory(addr, &header, sizeof(header), error) != sizeof(header))
136 return false;
137 if (header.magic == llvm::MachO::MH_CIGAM ||
138 header.magic == llvm::MachO::MH_CIGAM_64) {
139 header.magic = llvm::byteswap<uint32_t>(header.magic);
140 header.cputype = llvm::byteswap<uint32_t>(header.cputype);
141 header.cpusubtype = llvm::byteswap<uint32_t>(header.cpusubtype);
142 header.filetype = llvm::byteswap<uint32_t>(header.filetype);
143 header.ncmds = llvm::byteswap<uint32_t>(header.ncmds);
144 header.sizeofcmds = llvm::byteswap<uint32_t>(header.sizeofcmds);
145 header.flags = llvm::byteswap<uint32_t>(header.flags);
146 }
147
148 if (header.magic == llvm::MachO::MH_MAGIC ||
149 header.magic == llvm::MachO::MH_MAGIC_64) {
150 // Check MH_EXECUTABLE to see if we can find the mach image that contains
151 // the shared library list. The dynamic loader (dyld) is what contains the
152 // list for user applications, and the mach kernel contains a global that
153 // has the list of kexts to load
154 switch (header.filetype) {
155 case llvm::MachO::MH_DYLINKER:
156 LLDB_LOGF(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s found a user " "process dyld binary image at 0x%"
"l" "x", __FUNCTION__, addr); } while (0)
157 "ProcessMachCore::%s found a user "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s found a user " "process dyld binary image at 0x%"
"l" "x", __FUNCTION__, addr); } while (0)
158 "process dyld binary image at 0x%" PRIx64,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s found a user " "process dyld binary image at 0x%"
"l" "x", __FUNCTION__, addr); } while (0)
159 __FUNCTION__, addr)do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s found a user " "process dyld binary image at 0x%"
"l" "x", __FUNCTION__, addr); } while (0);
160 dyld = addr;
161 return true;
162
163 case llvm::MachO::MH_EXECUTE:
164 // Check MH_EXECUTABLE file types to see if the dynamic link object flag
165 // is NOT set. If it isn't, then we have a mach_kernel.
166 if ((header.flags & llvm::MachO::MH_DYLDLINK) == 0) {
167 LLDB_LOGF(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s found a mach " "kernel binary image at 0x%"
"l" "x", __FUNCTION__, addr); } while (0)
168 "ProcessMachCore::%s found a mach "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s found a mach " "kernel binary image at 0x%"
"l" "x", __FUNCTION__, addr); } while (0)
169 "kernel binary image at 0x%" PRIx64,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s found a mach " "kernel binary image at 0x%"
"l" "x", __FUNCTION__, addr); } while (0)
170 __FUNCTION__, addr)do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s found a mach " "kernel binary image at 0x%"
"l" "x", __FUNCTION__, addr); } while (0);
171 // Address of the mach kernel "struct mach_header" in the core file.
172 kernel = addr;
173 return true;
174 }
175 break;
176 }
177 }
178 return false;
179}
180
181void ProcessMachCore::CreateMemoryRegions() {
182 ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
183 SectionList *section_list = core_objfile->GetSectionList();
184 const uint32_t num_sections = section_list->GetNumSections(0);
185
186 bool ranges_are_sorted = true;
187 addr_t vm_addr = 0;
188 for (uint32_t i = 0; i < num_sections; ++i) {
189 Section *section = section_list->GetSectionAtIndex(i).get();
190 if (section && section->GetFileSize() > 0) {
191 lldb::addr_t section_vm_addr = section->GetFileAddress();
192 FileRange file_range(section->GetFileOffset(), section->GetFileSize());
193 VMRangeToFileOffset::Entry range_entry(
194 section_vm_addr, section->GetByteSize(), file_range);
195
196 if (vm_addr > section_vm_addr)
197 ranges_are_sorted = false;
198 vm_addr = section->GetFileAddress();
199 VMRangeToFileOffset::Entry *last_entry = m_core_aranges.Back();
200
201 if (last_entry &&
202 last_entry->GetRangeEnd() == range_entry.GetRangeBase() &&
203 last_entry->data.GetRangeEnd() == range_entry.data.GetRangeBase()) {
204 last_entry->SetRangeEnd(range_entry.GetRangeEnd());
205 last_entry->data.SetRangeEnd(range_entry.data.GetRangeEnd());
206 } else {
207 m_core_aranges.Append(range_entry);
208 }
209 // Some core files don't fill in the permissions correctly. If that is
210 // the case assume read + execute so clients don't think the memory is
211 // not readable, or executable. The memory isn't writable since this
212 // plug-in doesn't implement DoWriteMemory.
213 uint32_t permissions = section->GetPermissions();
214 if (permissions == 0)
215 permissions = lldb::ePermissionsReadable | lldb::ePermissionsExecutable;
216 m_core_range_infos.Append(VMRangeToPermissions::Entry(
217 section_vm_addr, section->GetByteSize(), permissions));
218 }
219 }
220 if (!ranges_are_sorted) {
221 m_core_aranges.Sort();
222 m_core_range_infos.Sort();
223 }
224}
225
226void ProcessMachCore::LoadBinariesViaMetadata() {
227 Log *log(GetLog(LLDBLog::DynamicLoader | LLDBLog::Process));
228 ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
229 bool found_main_binary_definitively = false;
230
231 addr_t objfile_binary_value;
232 bool objfile_binary_value_is_offset;
233 UUID objfile_binary_uuid;
234 ObjectFile::BinaryType type;
235
236 if (core_objfile->GetCorefileMainBinaryInfo(objfile_binary_value,
237 objfile_binary_value_is_offset,
238 objfile_binary_uuid, type)) {
239 if (log) {
240 log->Printf("ProcessMachCore::LoadBinariesViaMetadata: using binary hint "
241 "from 'main bin spec' "
242 "LC_NOTE with UUID %s value 0x%" PRIx64"l" "x"
243 " value is offset %d and type %d",
244 objfile_binary_uuid.GetAsString().c_str(),
245 objfile_binary_value, objfile_binary_value_is_offset, type);
246 }
247
248 // If this is the xnu kernel, don't load it now. Note the correct
249 // DynamicLoader plugin to use, and the address of the kernel, and
250 // let the DynamicLoader handle the finding & loading of the binary.
251 if (type == ObjectFile::eBinaryTypeKernel) {
252 m_mach_kernel_addr = objfile_binary_value;
253 m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
254 found_main_binary_definitively = true;
255 } else {
256 const bool force_symbol_search = true;
257 const bool notify = true;
258 if (DynamicLoader::LoadBinaryWithUUIDAndAddress(
259 this, llvm::StringRef(), objfile_binary_uuid,
260 objfile_binary_value, objfile_binary_value_is_offset,
261 force_symbol_search, notify)) {
262 found_main_binary_definitively = true;
263 m_dyld_plugin_name = DynamicLoaderStatic::GetPluginNameStatic();
264 }
265 if (type == ObjectFile::eBinaryTypeUser) {
266 m_dyld_addr = objfile_binary_value;
267 m_dyld_plugin_name = DynamicLoaderMacOSXDYLD::GetPluginNameStatic();
268 }
269 }
270 }
271
272 // This checks for the presence of an LC_IDENT string in a core file;
273 // LC_IDENT is very obsolete and should not be used in new code, but if the
274 // load command is present, let's use the contents.
275 UUID ident_uuid;
276 addr_t ident_binary_addr = LLDB_INVALID_ADDRESS(18446744073709551615UL);
277 if (!found_main_binary_definitively) {
278 std::string corefile_identifier = core_objfile->GetIdentifierString();
279
280 // Search for UUID= and stext= strings in the identifier str.
281 if (corefile_identifier.find("UUID=") != std::string::npos) {
282 size_t p = corefile_identifier.find("UUID=") + strlen("UUID=");
283 std::string uuid_str = corefile_identifier.substr(p, 36);
284 ident_uuid.SetFromStringRef(uuid_str);
285 if (log)
286 log->Printf("Got a UUID from LC_IDENT/kern ver str LC_NOTE: %s",
287 ident_uuid.GetAsString().c_str());
288 }
289 if (corefile_identifier.find("stext=") != std::string::npos) {
290 size_t p = corefile_identifier.find("stext=") + strlen("stext=");
291 if (corefile_identifier[p] == '0' && corefile_identifier[p + 1] == 'x') {
292 ident_binary_addr =
293 ::strtoul(corefile_identifier.c_str() + p, nullptr, 16);
294 if (log)
295 log->Printf("Got a load address from LC_IDENT/kern ver str "
296 "LC_NOTE: 0x%" PRIx64"l" "x",
297 ident_binary_addr);
298 }
299 }
300
301 // Search for a "Darwin Kernel" str indicating kernel; else treat as
302 // standalone
303 if (corefile_identifier.find("Darwin Kernel") != std::string::npos &&
304 ident_uuid.IsValid() && ident_binary_addr != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
305 if (log)
306 log->Printf(
307 "ProcessMachCore::LoadBinariesViaMetadata: Found kernel binary via "
308 "LC_IDENT/kern ver str LC_NOTE");
309 m_mach_kernel_addr = ident_binary_addr;
310 found_main_binary_definitively = true;
Value stored to 'found_main_binary_definitively' is never read
311 } else if (ident_uuid.IsValid()) {
312 // We have no address specified, only a UUID. Load it at the file
313 // address.
314 const bool value_is_offset = false;
315 const bool force_symbol_search = true;
316 const bool notify = true;
317 if (DynamicLoader::LoadBinaryWithUUIDAndAddress(
318 this, llvm::StringRef(), ident_uuid, ident_binary_addr,
319 value_is_offset, force_symbol_search, notify)) {
320 found_main_binary_definitively = true;
321 m_dyld_plugin_name = DynamicLoaderStatic::GetPluginNameStatic();
322 }
323 }
324 }
325
326 // Finally, load any binaries noted by "load binary" LC_NOTEs in the
327 // corefile
328 core_objfile->LoadCoreFileImages(*this);
329
330 // LoadCoreFileImges may have set the dynamic loader, e.g. in
331 // PlatformDarwinKernel::LoadPlatformBinaryAndSetup().
332 // If we now have a dynamic loader, save its name so we don't
333 // un-set it later.
334 if (m_dyld_up)
335 m_dyld_plugin_name = GetDynamicLoader()->GetPluginName();
336}
337
338void ProcessMachCore::LoadBinariesViaExhaustiveSearch() {
339 Log *log(GetLog(LLDBLog::DynamicLoader | LLDBLog::Process));
340
341 // Search the pages of the corefile for dyld or mach kernel
342 // binaries. There may be multiple things that look like a kernel
343 // in the corefile; disambiguating to the correct one can be difficult.
344
345 std::vector<addr_t> dylds_found;
346 std::vector<addr_t> kernels_found;
347
348 const size_t num_core_aranges = m_core_aranges.GetSize();
349 for (size_t i = 0; i < num_core_aranges; ++i) {
350 const VMRangeToFileOffset::Entry *entry = m_core_aranges.GetEntryAtIndex(i);
351 lldb::addr_t section_vm_addr_start = entry->GetRangeBase();
352 lldb::addr_t section_vm_addr_end = entry->GetRangeEnd();
353 for (lldb::addr_t section_vm_addr = section_vm_addr_start;
354 section_vm_addr < section_vm_addr_end; section_vm_addr += 0x1000) {
355 addr_t dyld, kernel;
356 if (CheckAddressForDyldOrKernel(section_vm_addr, dyld, kernel)) {
357 if (dyld != LLDB_INVALID_ADDRESS(18446744073709551615UL))
358 dylds_found.push_back(dyld);
359 if (kernel != LLDB_INVALID_ADDRESS(18446744073709551615UL))
360 kernels_found.push_back(kernel);
361 }
362 }
363 }
364
365 // If we found more than one dyld mach-o header in the corefile,
366 // pick the first one.
367 if (dylds_found.size() > 0)
368 m_dyld_addr = dylds_found[0];
369 if (kernels_found.size() > 0)
370 m_mach_kernel_addr = kernels_found[0];
371
372 // Zero or one kernels found, we're done.
373 if (kernels_found.size() < 2)
374 return;
375
376 // In the case of multiple kernel images found in the core file via
377 // exhaustive search, we may not pick the correct one. See if the
378 // DynamicLoaderDarwinKernel's search heuristics might identify the correct
379 // one.
380
381 // SearchForDarwinKernel will call this class' GetImageInfoAddress method
382 // which will give it the addresses we already have.
383 // Save those aside and set
384 // m_mach_kernel_addr/m_dyld_addr to an invalid address temporarily so
385 // DynamicLoaderDarwinKernel does a real search for the kernel using its
386 // own heuristics.
387
388 addr_t saved_mach_kernel_addr = m_mach_kernel_addr;
389 addr_t saved_user_dyld_addr = m_dyld_addr;
390 m_mach_kernel_addr = LLDB_INVALID_ADDRESS(18446744073709551615UL);
391 m_dyld_addr = LLDB_INVALID_ADDRESS(18446744073709551615UL);
392
393 addr_t better_kernel_address =
394 DynamicLoaderDarwinKernel::SearchForDarwinKernel(this);
395
396 m_mach_kernel_addr = saved_mach_kernel_addr;
397 m_dyld_addr = saved_user_dyld_addr;
398
399 if (better_kernel_address != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
400 LLDB_LOGF(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using " "the kernel address "
"from DynamicLoaderDarwinKernel", __FUNCTION__); } while (0)
401 "ProcessMachCore::%s: Using "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using " "the kernel address "
"from DynamicLoaderDarwinKernel", __FUNCTION__); } while (0)
402 "the kernel address "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using " "the kernel address "
"from DynamicLoaderDarwinKernel", __FUNCTION__); } while (0)
403 "from DynamicLoaderDarwinKernel",do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using " "the kernel address "
"from DynamicLoaderDarwinKernel", __FUNCTION__); } while (0)
404 __FUNCTION__)do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using " "the kernel address "
"from DynamicLoaderDarwinKernel", __FUNCTION__); } while (0);
405 m_mach_kernel_addr = better_kernel_address;
406 }
407}
408
409void ProcessMachCore::LoadBinariesAndSetDYLD() {
410 Log *log(GetLog(LLDBLog::DynamicLoader | LLDBLog::Process));
411
412 LoadBinariesViaMetadata();
413 if (m_dyld_plugin_name.empty())
414 LoadBinariesViaExhaustiveSearch();
415
416 if (m_dyld_plugin_name.empty()) {
417 // If we found both a user-process dyld and a kernel binary, we need to
418 // decide which to prefer.
419 if (GetCorefilePreference() == eKernelCorefile) {
420 if (m_mach_kernel_addr != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
421 LLDB_LOGF(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using kernel "
"corefile image " "at 0x%" "l" "x", __FUNCTION__, m_mach_kernel_addr
); } while (0)
422 "ProcessMachCore::%s: Using kernel "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using kernel "
"corefile image " "at 0x%" "l" "x", __FUNCTION__, m_mach_kernel_addr
); } while (0)
423 "corefile image "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using kernel "
"corefile image " "at 0x%" "l" "x", __FUNCTION__, m_mach_kernel_addr
); } while (0)
424 "at 0x%" PRIx64,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using kernel "
"corefile image " "at 0x%" "l" "x", __FUNCTION__, m_mach_kernel_addr
); } while (0)
425 __FUNCTION__, m_mach_kernel_addr)do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using kernel "
"corefile image " "at 0x%" "l" "x", __FUNCTION__, m_mach_kernel_addr
); } while (0);
426 m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
427 } else if (m_dyld_addr != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
428 LLDB_LOGF(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using user process dyld "
"image at 0x%" "l" "x", __FUNCTION__, m_dyld_addr); } while (
0)
429 "ProcessMachCore::%s: Using user process dyld "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using user process dyld "
"image at 0x%" "l" "x", __FUNCTION__, m_dyld_addr); } while (
0)
430 "image at 0x%" PRIx64,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using user process dyld "
"image at 0x%" "l" "x", __FUNCTION__, m_dyld_addr); } while (
0)
431 __FUNCTION__, m_dyld_addr)do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using user process dyld "
"image at 0x%" "l" "x", __FUNCTION__, m_dyld_addr); } while (
0);
432 m_dyld_plugin_name = DynamicLoaderMacOSXDYLD::GetPluginNameStatic();
433 }
434 } else {
435 if (m_dyld_addr != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
436 LLDB_LOGF(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using user process dyld "
"image at 0x%" "l" "x", __FUNCTION__, m_dyld_addr); } while (
0)
437 "ProcessMachCore::%s: Using user process dyld "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using user process dyld "
"image at 0x%" "l" "x", __FUNCTION__, m_dyld_addr); } while (
0)
438 "image at 0x%" PRIx64,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using user process dyld "
"image at 0x%" "l" "x", __FUNCTION__, m_dyld_addr); } while (
0)
439 __FUNCTION__, m_dyld_addr)do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using user process dyld "
"image at 0x%" "l" "x", __FUNCTION__, m_dyld_addr); } while (
0);
440 m_dyld_plugin_name = DynamicLoaderMacOSXDYLD::GetPluginNameStatic();
441 } else if (m_mach_kernel_addr != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
442 LLDB_LOGF(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using kernel "
"corefile image " "at 0x%" "l" "x", __FUNCTION__, m_mach_kernel_addr
); } while (0)
443 "ProcessMachCore::%s: Using kernel "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using kernel "
"corefile image " "at 0x%" "l" "x", __FUNCTION__, m_mach_kernel_addr
); } while (0)
444 "corefile image "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using kernel "
"corefile image " "at 0x%" "l" "x", __FUNCTION__, m_mach_kernel_addr
); } while (0)
445 "at 0x%" PRIx64,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using kernel "
"corefile image " "at 0x%" "l" "x", __FUNCTION__, m_mach_kernel_addr
); } while (0)
446 __FUNCTION__, m_mach_kernel_addr)do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("ProcessMachCore::%s: Using kernel "
"corefile image " "at 0x%" "l" "x", __FUNCTION__, m_mach_kernel_addr
); } while (0);
447 m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
448 }
449 }
450 }
451}
452
453void ProcessMachCore::CleanupMemoryRegionPermissions() {
454 if (m_dyld_plugin_name != DynamicLoaderMacOSXDYLD::GetPluginNameStatic()) {
455 // For non-user process core files, the permissions on the core file
456 // segments are usually meaningless, they may be just "read", because we're
457 // dealing with kernel coredumps or early startup coredumps and the dumper
458 // is grabbing pages of memory without knowing what they are. If they
459 // aren't marked as "executable", that can break the unwinder which will
460 // check a pc value to see if it is in an executable segment and stop the
461 // backtrace early if it is not ("executable" and "unknown" would both be
462 // fine, but "not executable" will break the unwinder).
463 size_t core_range_infos_size = m_core_range_infos.GetSize();
464 for (size_t i = 0; i < core_range_infos_size; i++) {
465 VMRangeToPermissions::Entry *ent =
466 m_core_range_infos.GetMutableEntryAtIndex(i);
467 ent->data = lldb::ePermissionsReadable | lldb::ePermissionsExecutable;
468 }
469 }
470}
471
472// Process Control
473Status ProcessMachCore::DoLoadCore() {
474 Status error;
475 if (!m_core_module_sp) {
476 error.SetErrorString("invalid core module");
477 return error;
478 }
479
480 ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
481 if (core_objfile == nullptr) {
482 error.SetErrorString("invalid core object file");
483 return error;
484 }
485
486 SetCanJIT(false);
487
488 // The corefile's architecture is our best starting point.
489 ArchSpec arch(m_core_module_sp->GetArchitecture());
490 if (arch.IsValid())
491 GetTarget().SetArchitecture(arch);
492
493 CreateMemoryRegions();
494
495 LoadBinariesAndSetDYLD();
496
497 CleanupMemoryRegionPermissions();
498
499 addr_t address_mask = core_objfile->GetAddressMask();
500 if (address_mask != 0) {
501 SetCodeAddressMask(address_mask);
502 SetDataAddressMask(address_mask);
503 }
504 return error;
505}
506
507lldb_private::DynamicLoader *ProcessMachCore::GetDynamicLoader() {
508 if (m_dyld_up.get() == nullptr)
509 m_dyld_up.reset(DynamicLoader::FindPlugin(this, m_dyld_plugin_name));
510 return m_dyld_up.get();
511}
512
513bool ProcessMachCore::DoUpdateThreadList(ThreadList &old_thread_list,
514 ThreadList &new_thread_list) {
515 if (old_thread_list.GetSize(false) == 0) {
516 // Make up the thread the first time this is called so we can setup our one
517 // and only core thread state.
518 ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
519
520 if (core_objfile) {
521 const uint32_t num_threads = core_objfile->GetNumThreadContexts();
522 for (lldb::tid_t tid = 0; tid < num_threads; ++tid) {
523 ThreadSP thread_sp(new ThreadMachCore(*this, tid));
524 new_thread_list.AddThread(thread_sp);
525 }
526 }
527 } else {
528 const uint32_t num_threads = old_thread_list.GetSize(false);
529 for (uint32_t i = 0; i < num_threads; ++i)
530 new_thread_list.AddThread(old_thread_list.GetThreadAtIndex(i, false));
531 }
532 return new_thread_list.GetSize(false) > 0;
533}
534
535void ProcessMachCore::RefreshStateAfterStop() {
536 // Let all threads recover from stopping and do any clean up based on the
537 // previous thread state (if any).
538 m_thread_list.RefreshStateAfterStop();
539 // SetThreadStopInfo (m_last_stop_packet);
540}
541
542Status ProcessMachCore::DoDestroy() { return Status(); }
543
544// Process Queries
545
546bool ProcessMachCore::IsAlive() { return true; }
547
548bool ProcessMachCore::WarnBeforeDetach() const { return false; }
549
550// Process Memory
551size_t ProcessMachCore::ReadMemory(addr_t addr, void *buf, size_t size,
552 Status &error) {
553 // Don't allow the caching that lldb_private::Process::ReadMemory does since
554 // in core files we have it all cached our our core file anyway.
555 return DoReadMemory(addr, buf, size, error);
556}
557
558size_t ProcessMachCore::DoReadMemory(addr_t addr, void *buf, size_t size,
559 Status &error) {
560 ObjectFile *core_objfile = m_core_module_sp->GetObjectFile();
561 size_t bytes_read = 0;
562
563 if (core_objfile) {
564 // Segments are not always contiguous in mach-o core files. We have core
565 // files that have segments like:
566 // Address Size File off File size
567 // ---------- ---------- ---------- ----------
568 // LC_SEGMENT 0x000f6000 0x00001000 0x1d509ee8 0x00001000 --- --- 0
569 // 0x00000000 __TEXT LC_SEGMENT 0x0f600000 0x00100000 0x1d50aee8 0x00100000
570 // --- --- 0 0x00000000 __TEXT LC_SEGMENT 0x000f7000 0x00001000
571 // 0x1d60aee8 0x00001000 --- --- 0 0x00000000 __TEXT
572 //
573 // Any if the user executes the following command:
574 //
575 // (lldb) mem read 0xf6ff0
576 //
577 // We would attempt to read 32 bytes from 0xf6ff0 but would only get 16
578 // unless we loop through consecutive memory ranges that are contiguous in
579 // the address space, but not in the file data.
580 while (bytes_read < size) {
581 const addr_t curr_addr = addr + bytes_read;
582 const VMRangeToFileOffset::Entry *core_memory_entry =
583 m_core_aranges.FindEntryThatContains(curr_addr);
584
585 if (core_memory_entry) {
586 const addr_t offset = curr_addr - core_memory_entry->GetRangeBase();
587 const addr_t bytes_left = core_memory_entry->GetRangeEnd() - curr_addr;
588 const size_t bytes_to_read =
589 std::min(size - bytes_read, (size_t)bytes_left);
590 const size_t curr_bytes_read = core_objfile->CopyData(
591 core_memory_entry->data.GetRangeBase() + offset, bytes_to_read,
592 (char *)buf + bytes_read);
593 if (curr_bytes_read == 0)
594 break;
595 bytes_read += curr_bytes_read;
596 } else {
597 // Only set the error if we didn't read any bytes
598 if (bytes_read == 0)
599 error.SetErrorStringWithFormat(
600 "core file does not contain 0x%" PRIx64"l" "x", curr_addr);
601 break;
602 }
603 }
604 }
605
606 return bytes_read;
607}
608
609Status ProcessMachCore::DoGetMemoryRegionInfo(addr_t load_addr,
610 MemoryRegionInfo &region_info) {
611 region_info.Clear();
612 const VMRangeToPermissions::Entry *permission_entry =
613 m_core_range_infos.FindEntryThatContainsOrFollows(load_addr);
614 if (permission_entry) {
615 if (permission_entry->Contains(load_addr)) {
616 region_info.GetRange().SetRangeBase(permission_entry->GetRangeBase());
617 region_info.GetRange().SetRangeEnd(permission_entry->GetRangeEnd());
618 const Flags permissions(permission_entry->data);
619 region_info.SetReadable(permissions.Test(ePermissionsReadable)
620 ? MemoryRegionInfo::eYes
621 : MemoryRegionInfo::eNo);
622 region_info.SetWritable(permissions.Test(ePermissionsWritable)
623 ? MemoryRegionInfo::eYes
624 : MemoryRegionInfo::eNo);
625 region_info.SetExecutable(permissions.Test(ePermissionsExecutable)
626 ? MemoryRegionInfo::eYes
627 : MemoryRegionInfo::eNo);
628 region_info.SetMapped(MemoryRegionInfo::eYes);
629 } else if (load_addr < permission_entry->GetRangeBase()) {
630 region_info.GetRange().SetRangeBase(load_addr);
631 region_info.GetRange().SetRangeEnd(permission_entry->GetRangeBase());
632 region_info.SetReadable(MemoryRegionInfo::eNo);
633 region_info.SetWritable(MemoryRegionInfo::eNo);
634 region_info.SetExecutable(MemoryRegionInfo::eNo);
635 region_info.SetMapped(MemoryRegionInfo::eNo);
636 }
637 return Status();
638 }
639
640 region_info.GetRange().SetRangeBase(load_addr);
641 region_info.GetRange().SetRangeEnd(LLDB_INVALID_ADDRESS(18446744073709551615UL));
642 region_info.SetReadable(MemoryRegionInfo::eNo);
643 region_info.SetWritable(MemoryRegionInfo::eNo);
644 region_info.SetExecutable(MemoryRegionInfo::eNo);
645 region_info.SetMapped(MemoryRegionInfo::eNo);
646 return Status();
647}
648
649void ProcessMachCore::Clear() { m_thread_list.Clear(); }
650
651void ProcessMachCore::Initialize() {
652 static llvm::once_flag g_once_flag;
653
654 llvm::call_once(g_once_flag, []() {
655 PluginManager::RegisterPlugin(GetPluginNameStatic(),
656 GetPluginDescriptionStatic(), CreateInstance);
657 });
658}
659
660addr_t ProcessMachCore::GetImageInfoAddress() {
661 // If we found both a user-process dyld and a kernel binary, we need to
662 // decide which to prefer.
663 if (GetCorefilePreference() == eKernelCorefile) {
664 if (m_mach_kernel_addr != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
665 return m_mach_kernel_addr;
666 }
667 return m_dyld_addr;
668 } else {
669 if (m_dyld_addr != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
670 return m_dyld_addr;
671 }
672 return m_mach_kernel_addr;
673 }
674}
675
676lldb_private::ObjectFile *ProcessMachCore::GetCoreObjectFile() {
677 return m_core_module_sp->GetObjectFile();
678}