| // 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 |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // 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 |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (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). |
| |
| // Resolve the module information, if a module map was provided. |
| StackFrameSymbolizer::SymbolizerResult symbolizer_result = |
| frame_symbolizer_->FillSourceLineInfo(modules_, unloaded_modules_, |
| system_info_, |
| frame.get()); |
| 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 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); |
| |
| 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 |
