1 //===-- ProcessMinidump.cpp -------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // Project includes
11 #include "ProcessMinidump.h"
12 #include "ThreadMinidump.h"
13 
14 // Other libraries and framework includes
15 #include "lldb/Core/Module.h"
16 #include "lldb/Core/ModuleSpec.h"
17 #include "lldb/Core/PluginManager.h"
18 #include "lldb/Core/Section.h"
19 #include "lldb/Target/DynamicLoader.h"
20 #include "lldb/Target/MemoryRegionInfo.h"
21 #include "lldb/Target/SectionLoadList.h"
22 #include "lldb/Target/Target.h"
23 #include "lldb/Target/UnixSignals.h"
24 #include "lldb/Utility/DataBufferLLVM.h"
25 #include "lldb/Utility/LLDBAssert.h"
26 #include "lldb/Utility/Log.h"
27 #include "lldb/Utility/State.h"
28 
29 #include "llvm/Support/MemoryBuffer.h"
30 #include "llvm/Support/Threading.h"
31 
32 #include "Plugins/Process/Utility/StopInfoMachException.h"
33 // C includes
34 // C++ includes
35 
36 using namespace lldb;
37 using namespace lldb_private;
38 using namespace minidump;
39 
40 //------------------------------------------------------------------
41 /// A placeholder module used for minidumps, where the original
42 /// object files may not be available (so we can't parse the object
43 /// files to extract the set of sections/segments)
44 ///
45 /// This placeholder module has a single synthetic section (.module_image)
46 /// which represents the module memory range covering the whole module.
47 //------------------------------------------------------------------
48 class PlaceholderModule : public Module {
49 public:
50   PlaceholderModule(const ModuleSpec &module_spec) :
51     Module(module_spec.GetFileSpec(), module_spec.GetArchitecture()) {
52     if (module_spec.GetUUID().IsValid())
53       SetUUID(module_spec.GetUUID());
54   }
55 
56   // Creates a synthetic module section covering the whole module image (and
57   // sets the section load address as well)
58   void CreateImageSection(const MinidumpModule *module, Target& target) {
59     const ConstString section_name(".module_image");
60     lldb::SectionSP section_sp(new Section(
61         shared_from_this(),     // Module to which this section belongs.
62         nullptr,                // ObjectFile
63         0,                      // Section ID.
64         section_name,           // Section name.
65         eSectionTypeContainer,  // Section type.
66         module->base_of_image,  // VM address.
67         module->size_of_image,  // VM size in bytes of this section.
68         0,                      // Offset of this section in the file.
69         module->size_of_image,  // Size of the section as found in the file.
70         12,                     // Alignment of the section (log2)
71         0,                      // Flags for this section.
72         1));                    // Number of host bytes per target byte
73     section_sp->SetPermissions(ePermissionsExecutable | ePermissionsReadable);
74     GetSectionList()->AddSection(section_sp);
75     target.GetSectionLoadList().SetSectionLoadAddress(
76         section_sp, module->base_of_image);
77   }
78 
79   ObjectFile *GetObjectFile() override { return nullptr; }
80 
81   SectionList *GetSectionList() override {
82     return Module::GetUnifiedSectionList();
83   }
84 };
85 
86 ConstString ProcessMinidump::GetPluginNameStatic() {
87   static ConstString g_name("minidump");
88   return g_name;
89 }
90 
91 const char *ProcessMinidump::GetPluginDescriptionStatic() {
92   return "Minidump plug-in.";
93 }
94 
95 lldb::ProcessSP ProcessMinidump::CreateInstance(lldb::TargetSP target_sp,
96                                                 lldb::ListenerSP listener_sp,
97                                                 const FileSpec *crash_file) {
98   if (!crash_file)
99     return nullptr;
100 
101   lldb::ProcessSP process_sp;
102   // Read enough data for the Minidump header
103   constexpr size_t header_size = sizeof(MinidumpHeader);
104   auto DataPtr =
105       DataBufferLLVM::CreateSliceFromPath(crash_file->GetPath(), header_size, 0);
106   if (!DataPtr)
107     return nullptr;
108 
109   lldbassert(DataPtr->GetByteSize() == header_size);
110 
111   // first, only try to parse the header, beacuse we need to be fast
112   llvm::ArrayRef<uint8_t> HeaderBytes = DataPtr->GetData();
113   const MinidumpHeader *header = MinidumpHeader::Parse(HeaderBytes);
114   if (header == nullptr)
115     return nullptr;
116 
117   auto AllData = DataBufferLLVM::CreateSliceFromPath(crash_file->GetPath(), -1, 0);
118   if (!AllData)
119     return nullptr;
120 
121   auto minidump_parser = MinidumpParser::Create(AllData);
122   // check if the parser object is valid
123   if (!minidump_parser)
124     return nullptr;
125 
126   return std::make_shared<ProcessMinidump>(target_sp, listener_sp, *crash_file,
127                                            minidump_parser.getValue());
128 }
129 
130 bool ProcessMinidump::CanDebug(lldb::TargetSP target_sp,
131                                bool plugin_specified_by_name) {
132   return true;
133 }
134 
135 ProcessMinidump::ProcessMinidump(lldb::TargetSP target_sp,
136                                  lldb::ListenerSP listener_sp,
137                                  const FileSpec &core_file,
138                                  MinidumpParser minidump_parser)
139     : Process(target_sp, listener_sp), m_minidump_parser(minidump_parser),
140       m_core_file(core_file), m_is_wow64(false) {}
141 
142 ProcessMinidump::~ProcessMinidump() {
143   Clear();
144   // We need to call finalize on the process before destroying ourselves to
145   // make sure all of the broadcaster cleanup goes as planned. If we destruct
146   // this class, then Process::~Process() might have problems trying to fully
147   // destroy the broadcaster.
148   Finalize();
149 }
150 
151 void ProcessMinidump::Initialize() {
152   static llvm::once_flag g_once_flag;
153 
154   llvm::call_once(g_once_flag, []() {
155     PluginManager::RegisterPlugin(GetPluginNameStatic(),
156                                   GetPluginDescriptionStatic(),
157                                   ProcessMinidump::CreateInstance);
158   });
159 }
160 
161 void ProcessMinidump::Terminate() {
162   PluginManager::UnregisterPlugin(ProcessMinidump::CreateInstance);
163 }
164 
165 Status ProcessMinidump::DoLoadCore() {
166   Status error;
167 
168   // Minidump parser initialization & consistency checks
169   error = m_minidump_parser.Initialize();
170   if (error.Fail())
171     return error;
172 
173   // Do we support the minidump's architecture?
174   ArchSpec arch = GetArchitecture();
175   switch (arch.GetMachine()) {
176   case llvm::Triple::x86:
177   case llvm::Triple::x86_64:
178   case llvm::Triple::arm:
179   case llvm::Triple::aarch64:
180     // Any supported architectures must be listed here and also supported in
181     // ThreadMinidump::CreateRegisterContextForFrame().
182     break;
183   default:
184     error.SetErrorStringWithFormat("unsupported minidump architecture: %s",
185                                    arch.GetArchitectureName());
186     return error;
187   }
188   GetTarget().SetArchitecture(arch, true /*set_platform*/);
189 
190   m_thread_list = m_minidump_parser.GetThreads();
191   m_active_exception = m_minidump_parser.GetExceptionStream();
192   ReadModuleList();
193 
194   llvm::Optional<lldb::pid_t> pid = m_minidump_parser.GetPid();
195   if (!pid) {
196     error.SetErrorString("failed to parse PID");
197     return error;
198   }
199   SetID(pid.getValue());
200 
201   return error;
202 }
203 
204 DynamicLoader *ProcessMinidump::GetDynamicLoader() {
205   if (m_dyld_ap.get() == nullptr)
206     m_dyld_ap.reset(DynamicLoader::FindPlugin(this, nullptr));
207   return m_dyld_ap.get();
208 }
209 
210 ConstString ProcessMinidump::GetPluginName() { return GetPluginNameStatic(); }
211 
212 uint32_t ProcessMinidump::GetPluginVersion() { return 1; }
213 
214 Status ProcessMinidump::DoDestroy() { return Status(); }
215 
216 void ProcessMinidump::RefreshStateAfterStop() {
217   if (!m_active_exception)
218     return;
219 
220   if (m_active_exception->exception_record.exception_code ==
221       MinidumpException::DumpRequested) {
222     return;
223   }
224 
225   lldb::StopInfoSP stop_info;
226   lldb::ThreadSP stop_thread;
227 
228   Process::m_thread_list.SetSelectedThreadByID(m_active_exception->thread_id);
229   stop_thread = Process::m_thread_list.GetSelectedThread();
230   ArchSpec arch = GetArchitecture();
231 
232   if (arch.GetTriple().getOS() == llvm::Triple::Linux) {
233     stop_info = StopInfo::CreateStopReasonWithSignal(
234         *stop_thread, m_active_exception->exception_record.exception_code);
235   } else if (arch.GetTriple().getVendor() == llvm::Triple::Apple) {
236     stop_info = StopInfoMachException::CreateStopReasonWithMachException(
237         *stop_thread, m_active_exception->exception_record.exception_code, 2,
238         m_active_exception->exception_record.exception_flags,
239         m_active_exception->exception_record.exception_address, 0);
240   } else {
241     std::string desc;
242     llvm::raw_string_ostream desc_stream(desc);
243     desc_stream << "Exception "
244                 << llvm::format_hex(
245                        m_active_exception->exception_record.exception_code, 8)
246                 << " encountered at address "
247                 << llvm::format_hex(
248                        m_active_exception->exception_record.exception_address,
249                        8);
250     stop_info = StopInfo::CreateStopReasonWithException(
251         *stop_thread, desc_stream.str().c_str());
252   }
253 
254   stop_thread->SetStopInfo(stop_info);
255 }
256 
257 bool ProcessMinidump::IsAlive() { return true; }
258 
259 bool ProcessMinidump::WarnBeforeDetach() const { return false; }
260 
261 size_t ProcessMinidump::ReadMemory(lldb::addr_t addr, void *buf, size_t size,
262                                    Status &error) {
263   // Don't allow the caching that lldb_private::Process::ReadMemory does since
264   // we have it all cached in our dump file anyway.
265   return DoReadMemory(addr, buf, size, error);
266 }
267 
268 size_t ProcessMinidump::DoReadMemory(lldb::addr_t addr, void *buf, size_t size,
269                                      Status &error) {
270 
271   llvm::ArrayRef<uint8_t> mem = m_minidump_parser.GetMemory(addr, size);
272   if (mem.empty()) {
273     error.SetErrorString("could not parse memory info");
274     return 0;
275   }
276 
277   std::memcpy(buf, mem.data(), mem.size());
278   return mem.size();
279 }
280 
281 ArchSpec ProcessMinidump::GetArchitecture() {
282   if (!m_is_wow64) {
283     return m_minidump_parser.GetArchitecture();
284   }
285 
286   llvm::Triple triple;
287   triple.setVendor(llvm::Triple::VendorType::UnknownVendor);
288   triple.setArch(llvm::Triple::ArchType::x86);
289   triple.setOS(llvm::Triple::OSType::Win32);
290   return ArchSpec(triple);
291 }
292 
293 Status ProcessMinidump::GetMemoryRegionInfo(lldb::addr_t load_addr,
294                                             MemoryRegionInfo &range_info) {
295   Status error;
296   auto info = m_minidump_parser.GetMemoryRegionInfo(load_addr);
297   if (!info) {
298     error.SetErrorString("No valid MemoryRegionInfo found!");
299     return error;
300   }
301   range_info = info.getValue();
302   return error;
303 }
304 
305 void ProcessMinidump::Clear() { Process::m_thread_list.Clear(); }
306 
307 bool ProcessMinidump::UpdateThreadList(ThreadList &old_thread_list,
308                                        ThreadList &new_thread_list) {
309   uint32_t num_threads = 0;
310   if (m_thread_list.size() > 0)
311     num_threads = m_thread_list.size();
312 
313   for (lldb::tid_t tid = 0; tid < num_threads; ++tid) {
314     llvm::ArrayRef<uint8_t> context;
315     if (!m_is_wow64)
316       context = m_minidump_parser.GetThreadContext(m_thread_list[tid]);
317     else
318       context = m_minidump_parser.GetThreadContextWow64(m_thread_list[tid]);
319 
320     lldb::ThreadSP thread_sp(
321         new ThreadMinidump(*this, m_thread_list[tid], context));
322     new_thread_list.AddThread(thread_sp);
323   }
324   return new_thread_list.GetSize(false) > 0;
325 }
326 
327 void ProcessMinidump::ReadModuleList() {
328   std::vector<const MinidumpModule *> filtered_modules =
329       m_minidump_parser.GetFilteredModuleList();
330 
331   for (auto module : filtered_modules) {
332     llvm::Optional<std::string> name =
333         m_minidump_parser.GetMinidumpString(module->module_name_rva);
334 
335     if (!name)
336       continue;
337 
338     Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_MODULES));
339     if (log) {
340       log->Printf("ProcessMinidump::%s found module: name: %s %#010" PRIx64
341                   "-%#010" PRIx64 " size: %" PRIu32,
342                   __FUNCTION__, name.getValue().c_str(),
343                   uint64_t(module->base_of_image),
344                   module->base_of_image + module->size_of_image,
345                   uint32_t(module->size_of_image));
346     }
347 
348     // check if the process is wow64 - a 32 bit windows process running on a
349     // 64 bit windows
350     if (llvm::StringRef(name.getValue()).endswith_lower("wow64.dll")) {
351       m_is_wow64 = true;
352     }
353 
354     const auto uuid = m_minidump_parser.GetModuleUUID(module);
355     const auto file_spec =
356         FileSpec(name.getValue(), true, GetArchitecture().GetTriple());
357     ModuleSpec module_spec(file_spec, uuid);
358     Status error;
359     lldb::ModuleSP module_sp = GetTarget().GetSharedModule(module_spec, &error);
360     if (!module_sp || error.Fail()) {
361       // We failed to locate a matching local object file. Fortunately, the
362       // minidump format encodes enough information about each module's memory
363       // range to allow us to create placeholder modules.
364       //
365       // This enables most LLDB functionality involving address-to-module
366       // translations (ex. identifing the module for a stack frame PC) and
367       // modules/sections commands (ex. target modules list, ...)
368       if (log) {
369         log->Printf("Unable to locate the matching object file, creating a "
370                     "placeholder module for: %s",
371                     name.getValue().c_str());
372       }
373 
374       auto placeholder_module =
375           std::make_shared<PlaceholderModule>(module_spec);
376       placeholder_module->CreateImageSection(module, GetTarget());
377       module_sp = placeholder_module;
378       GetTarget().GetImages().Append(module_sp);
379     }
380 
381     if (log) {
382       log->Printf("ProcessMinidump::%s load module: name: %s", __FUNCTION__,
383                   name.getValue().c_str());
384     }
385 
386     bool load_addr_changed = false;
387     module_sp->SetLoadAddress(GetTarget(), module->base_of_image, false,
388                               load_addr_changed);
389   }
390 }
391 
392 bool ProcessMinidump::GetProcessInfo(ProcessInstanceInfo &info) {
393   info.Clear();
394   info.SetProcessID(GetID());
395   info.SetArchitecture(GetArchitecture());
396   lldb::ModuleSP module_sp = GetTarget().GetExecutableModule();
397   if (module_sp) {
398     const bool add_exe_file_as_first_arg = false;
399     info.SetExecutableFile(GetTarget().GetExecutableModule()->GetFileSpec(),
400                            add_exe_file_as_first_arg);
401   }
402   return true;
403 }
404