| // Copyright (c) 2010 Google Inc. | |
| // All rights reserved. | |
| // | |
| // Redistribution and use in source and binary forms, with or without | |
| // modification, are permitted provided that the following conditions are | |
| // met: | |
| // | |
| // * Redistributions of source code must retain the above copyright | |
| // notice, this list of conditions and the following disclaimer. | |
| // * Redistributions in binary form must reproduce the above | |
| // copyright notice, this list of conditions and the following disclaimer | |
| // in the documentation and/or other materials provided with the | |
| // distribution. | |
| // * Neither the name of Google Inc. nor the names of its | |
| // contributors may be used to endorse or promote products derived from | |
| // this software without specific prior written permission. | |
| // | |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
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| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
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| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| // stackwalker.cc: Generic stackwalker. | |
| // | |
| // See stackwalker.h for documentation. | |
| // | |
| // Author: Mark Mentovai | |
| #include "google_breakpad/processor/stackwalker.h" | |
| #include <assert.h> | |
| #include "common/scoped_ptr.h" | |
| #include "google_breakpad/processor/call_stack.h" | |
| #include "google_breakpad/processor/code_module.h" | |
| #include "google_breakpad/processor/code_modules.h" | |
| #include "google_breakpad/processor/dump_context.h" | |
| #include "google_breakpad/processor/stack_frame.h" | |
| #include "google_breakpad/processor/stack_frame_symbolizer.h" | |
| #include "google_breakpad/processor/system_info.h" | |
| #include "processor/linked_ptr.h" | |
| #include "processor/logging.h" | |
| #include "processor/stackwalker_ppc.h" | |
| #include "processor/stackwalker_ppc64.h" | |
| #include "processor/stackwalker_sparc.h" | |
| #include "processor/stackwalker_x86.h" | |
| #include "processor/stackwalker_amd64.h" | |
| #include "processor/stackwalker_arm.h" | |
| #include "processor/stackwalker_arm64.h" | |
| #include "processor/stackwalker_mips.h" | |
| namespace google_breakpad { | |
| const int Stackwalker::kRASearchWords = 40; | |
| // This default is just a sanity check: a large enough value | |
| // that allow capturing unbounded recursion traces, yet provide a | |
| // guardrail against stack walking bugs. The stack walking invariants | |
| // guarantee that the unwinding process is strictly monotonic and | |
| // practically bounded by the size of the stack memory range. | |
| uint32_t Stackwalker::max_frames_ = 1 << 20; // 1M | |
| bool Stackwalker::max_frames_set_ = false; | |
| uint32_t Stackwalker::max_frames_scanned_ = 1 << 14; // 16k | |
| Stackwalker::Stackwalker(const SystemInfo* system_info, | |
| MemoryRegion* memory, | |
| const CodeModules* modules, | |
| StackFrameSymbolizer* frame_symbolizer) | |
| : system_info_(system_info), | |
| memory_(memory), | |
| modules_(modules), | |
| unloaded_modules_(NULL), | |
| frame_symbolizer_(frame_symbolizer) { | |
| assert(frame_symbolizer_); | |
| } | |
| void InsertSpecialAttentionModule( | |
| StackFrameSymbolizer::SymbolizerResult symbolizer_result, | |
| const CodeModule* module, | |
| vector<const CodeModule*>* modules) { | |
| if (!module) { | |
| return; | |
| } | |
| assert(symbolizer_result == StackFrameSymbolizer::kError || | |
| symbolizer_result == StackFrameSymbolizer::kWarningCorruptSymbols); | |
| bool found = false; | |
| vector<const CodeModule*>::iterator iter; | |
| for (iter = modules->begin(); iter != modules->end(); ++iter) { | |
| if (*iter == module) { | |
| found = true; | |
| break; | |
| } | |
| } | |
| if (!found) { | |
| BPLOG(INFO) << ((symbolizer_result == StackFrameSymbolizer::kError) ? | |
| "Couldn't load symbols for: " : | |
| "Detected corrupt symbols for: ") | |
| << module->debug_file() << "|" << module->debug_identifier(); | |
| modules->push_back(module); | |
| } | |
| } | |
| bool Stackwalker::Walk( | |
| CallStack* stack, | |
| vector<const CodeModule*>* modules_without_symbols, | |
| vector<const CodeModule*>* modules_with_corrupt_symbols) { | |
| BPLOG_IF(ERROR, !stack) << "Stackwalker::Walk requires |stack|"; | |
| assert(stack); | |
| stack->Clear(); | |
| BPLOG_IF(ERROR, !modules_without_symbols) << "Stackwalker::Walk requires " | |
| << "|modules_without_symbols|"; | |
| BPLOG_IF(ERROR, !modules_without_symbols) << "Stackwalker::Walk requires " | |
| << "|modules_with_corrupt_symbols|"; | |
| assert(modules_without_symbols); | |
| assert(modules_with_corrupt_symbols); | |
| // Begin with the context frame, and keep getting callers until there are | |
| // no more. | |
| // Keep track of the number of scanned or otherwise dubious frames seen | |
| // so far, as the caller may have set a limit. | |
| uint32_t scanned_frames = 0; | |
| // Take ownership of the pointer returned by GetContextFrame. | |
| scoped_ptr<StackFrame> frame(GetContextFrame()); | |
| while (frame.get()) { | |
| // frame already contains a good frame with properly set instruction and | |
| // frame_pointer fields. The frame structure comes from either the | |
| // context frame (above) or a caller frame (below). | |
| vector<std::unique_ptr<StackFrame>> inlined_frames; | |
| // Resolve the module information, if a module map was provided. | |
| StackFrameSymbolizer::SymbolizerResult symbolizer_result = | |
| frame_symbolizer_->FillSourceLineInfo(modules_, unloaded_modules_, | |
| system_info_, | |
| frame.get(), &inlined_frames); | |
| switch (symbolizer_result) { | |
| case StackFrameSymbolizer::kInterrupt: | |
| BPLOG(INFO) << "Stack walk is interrupted."; | |
| return false; | |
| break; | |
| case StackFrameSymbolizer::kError: | |
| InsertSpecialAttentionModule(symbolizer_result, frame->module, | |
| modules_without_symbols); | |
| break; | |
| case StackFrameSymbolizer::kWarningCorruptSymbols: | |
| InsertSpecialAttentionModule(symbolizer_result, frame->module, | |
| modules_with_corrupt_symbols); | |
| break; | |
| case StackFrameSymbolizer::kNoError: | |
| break; | |
| default: | |
| assert(false); | |
| break; | |
| } | |
| // Keep track of the number of dubious frames so far. | |
| switch (frame.get()->trust) { | |
| case StackFrame::FRAME_TRUST_NONE: | |
| case StackFrame::FRAME_TRUST_SCAN: | |
| case StackFrame::FRAME_TRUST_CFI_SCAN: | |
| scanned_frames++; | |
| break; | |
| default: | |
| break; | |
| } | |
| // Add all nested inlined frames belonging to this frame in reverse order. | |
| while (!inlined_frames.empty()) { | |
| stack->frames_.push_back(inlined_frames.back().release()); | |
| inlined_frames.pop_back(); | |
| } | |
| // Add the frame to the call stack. Relinquish the ownership claim | |
| // over the frame, because the stack now owns it. | |
| stack->frames_.push_back(frame.release()); | |
| if (stack->frames_.size() > max_frames_) { | |
| // Only emit an error message in the case where the limit | |
| // reached is the default limit, not set by the user. | |
| if (!max_frames_set_) | |
| BPLOG(ERROR) << "The stack is over " << max_frames_ << " frames."; | |
| break; | |
| } | |
| // Get the next frame and take ownership. | |
| bool stack_scan_allowed = scanned_frames < max_frames_scanned_; | |
| frame.reset(GetCallerFrame(stack, stack_scan_allowed)); | |
| } | |
| return true; | |
| } | |
| // static | |
| Stackwalker* Stackwalker::StackwalkerForCPU( | |
| const SystemInfo* system_info, | |
| DumpContext* context, | |
| MemoryRegion* memory, | |
| const CodeModules* modules, | |
| const CodeModules* unloaded_modules, | |
| StackFrameSymbolizer* frame_symbolizer) { | |
| if (!context) { | |
| BPLOG(ERROR) << "Can't choose a stackwalker implementation without context"; | |
| return NULL; | |
| } | |
| Stackwalker* cpu_stackwalker = NULL; | |
| uint32_t cpu = context->GetContextCPU(); | |
| switch (cpu) { | |
| case MD_CONTEXT_X86: | |
| cpu_stackwalker = new StackwalkerX86(system_info, | |
| context->GetContextX86(), | |
| memory, modules, frame_symbolizer); | |
| break; | |
| case MD_CONTEXT_PPC: | |
| cpu_stackwalker = new StackwalkerPPC(system_info, | |
| context->GetContextPPC(), | |
| memory, modules, frame_symbolizer); | |
| break; | |
| case MD_CONTEXT_PPC64: | |
| cpu_stackwalker = new StackwalkerPPC64(system_info, | |
| context->GetContextPPC64(), | |
| memory, modules, frame_symbolizer); | |
| break; | |
| case MD_CONTEXT_AMD64: | |
| cpu_stackwalker = new StackwalkerAMD64(system_info, | |
| context->GetContextAMD64(), | |
| memory, modules, frame_symbolizer); | |
| break; | |
| case MD_CONTEXT_SPARC: | |
| cpu_stackwalker = new StackwalkerSPARC(system_info, | |
| context->GetContextSPARC(), | |
| memory, modules, frame_symbolizer); | |
| break; | |
| case MD_CONTEXT_MIPS: | |
| case MD_CONTEXT_MIPS64: | |
| cpu_stackwalker = new StackwalkerMIPS(system_info, | |
| context->GetContextMIPS(), | |
| memory, modules, frame_symbolizer); | |
| break; | |
| case MD_CONTEXT_ARM: | |
| { | |
| int fp_register = -1; | |
| if (system_info->os_short == "ios") | |
| fp_register = MD_CONTEXT_ARM_REG_IOS_FP; | |
| cpu_stackwalker = new StackwalkerARM(system_info, | |
| context->GetContextARM(), | |
| fp_register, memory, modules, | |
| frame_symbolizer); | |
| break; | |
| } | |
| case MD_CONTEXT_ARM64: | |
| cpu_stackwalker = new StackwalkerARM64(system_info, | |
| context->GetContextARM64(), | |
| memory, modules, | |
| frame_symbolizer); | |
| break; | |
| } | |
| BPLOG_IF(ERROR, !cpu_stackwalker) << "Unknown CPU type " << HexString(cpu) << | |
| ", can't choose a stackwalker " | |
| "implementation"; | |
| if (cpu_stackwalker) { | |
| cpu_stackwalker->unloaded_modules_ = unloaded_modules; | |
| } | |
| return cpu_stackwalker; | |
| } | |
| // CONSIDER: check stack alignment? | |
| bool Stackwalker::TerminateWalk(uint64_t caller_ip, | |
| uint64_t caller_sp, | |
| uint64_t callee_sp, | |
| bool first_unwind) const { | |
| // Treat an instruction address less than 4k as end-of-stack. | |
| // (using InstructionAddressSeemsValid() here is very tempting, | |
| // but we need to handle JITted code) | |
| if (caller_ip < (1 << 12)) { | |
| return true; | |
| } | |
| // NOTE: The stack address range is implicitly checked | |
| // when the stack memory is accessed. | |
| // The stack pointer should monotonically increase. For first unwind | |
| // we allow caller_sp == callee_sp to account for architectures where | |
| // the return address is stored in a register (so it's possible to have | |
| // leaf functions which don't move the stack pointer) | |
| if (first_unwind ? (caller_sp < callee_sp) : (caller_sp <= callee_sp)) { | |
| return true; | |
| } | |
| return false; | |
| } | |
| bool Stackwalker::InstructionAddressSeemsValid(uint64_t address) const { | |
| StackFrame frame; | |
| frame.instruction = address; | |
| StackFrameSymbolizer::SymbolizerResult symbolizer_result = | |
| frame_symbolizer_->FillSourceLineInfo(modules_, unloaded_modules_, | |
| system_info_, &frame, nullptr); | |
| if (!frame.module) { | |
| // not inside any loaded module | |
| return false; | |
| } | |
| if (!frame_symbolizer_->HasImplementation()) { | |
| // No valid implementation to symbolize stack frame, but the address is | |
| // within a known module. | |
| return true; | |
| } | |
| if (symbolizer_result != StackFrameSymbolizer::kNoError && | |
| symbolizer_result != StackFrameSymbolizer::kWarningCorruptSymbols) { | |
| // Some error occurred during symbolization, but the address is within a | |
| // known module | |
| return true; | |
| } | |
| return !frame.function_name.empty(); | |
| } | |
| } // namespace google_breakpad |