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Diffstat (limited to 'src/processor/stackwalker_arm64.cc')
| -rw-r--r-- | src/processor/stackwalker_arm64.cc | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/src/processor/stackwalker_arm64.cc b/src/processor/stackwalker_arm64.cc new file mode 100644 index 00000000..f82c9cbf --- /dev/null +++ b/src/processor/stackwalker_arm64.cc @@ -0,0 +1,209 @@ +// Copyright (c) 2013 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_arm64.cc: arm64-specific stackwalker. +// +// See stackwalker_arm64.h for documentation. +// +// Author: Mark Mentovai, Ted Mielczarek, Jim Blandy, Colin Blundell + +#include <vector> + +#include "common/scoped_ptr.h" +#include "google_breakpad/processor/call_stack.h" +#include "google_breakpad/processor/memory_region.h" +#include "google_breakpad/processor/source_line_resolver_interface.h" +#include "google_breakpad/processor/stack_frame_cpu.h" +#include "processor/cfi_frame_info.h" +#include "processor/logging.h" +#include "processor/stackwalker_arm64.h" + +namespace google_breakpad { + + +StackwalkerARM64::StackwalkerARM64(const SystemInfo* system_info, + const MDRawContextARM64* context, + MemoryRegion* memory, + const CodeModules* modules, + StackFrameSymbolizer* resolver_helper) + : Stackwalker(system_info, memory, modules, resolver_helper), + context_(context), + context_frame_validity_(StackFrameARM64::CONTEXT_VALID_ALL) { } + + +StackFrame* StackwalkerARM64::GetContextFrame() { + if (!context_) { + BPLOG(ERROR) << "Can't get context frame without context"; + return NULL; + } + + StackFrameARM64* frame = new StackFrameARM64(); + + // The instruction pointer is stored directly in a register (x32), so pull it + // straight out of the CPU context structure. + frame->context = *context_; + frame->context_validity = context_frame_validity_; + frame->trust = StackFrame::FRAME_TRUST_CONTEXT; + frame->instruction = frame->context.iregs[MD_CONTEXT_ARM64_REG_PC]; + + return frame; +} + +StackFrameARM64* StackwalkerARM64::GetCallerByCFIFrameInfo( + const vector<StackFrame*> &frames, + CFIFrameInfo* cfi_frame_info) { + // Obtaining the stack frame from CFI info is not yet supported for ARM64. + return NULL; +} + +StackFrameARM64* StackwalkerARM64::GetCallerByStackScan( + const vector<StackFrame*> &frames) { + StackFrameARM64* last_frame = static_cast<StackFrameARM64*>(frames.back()); + uint64_t last_sp = last_frame->context.iregs[MD_CONTEXT_ARM64_REG_SP]; + uint64_t caller_sp, caller_pc; + + if (!ScanForReturnAddress(last_sp, &caller_sp, &caller_pc, + frames.size() == 1 /* is_context_frame */)) { + // No plausible return address was found. + return NULL; + } + + // ScanForReturnAddress found a reasonable return address. Advance + // %sp to the location above the one where the return address was + // found. + caller_sp += 8; + + // Create a new stack frame (ownership will be transferred to the caller) + // and fill it in. + StackFrameARM64* frame = new StackFrameARM64(); + + frame->trust = StackFrame::FRAME_TRUST_SCAN; + frame->context = last_frame->context; + frame->context.iregs[MD_CONTEXT_ARM64_REG_PC] = caller_pc; + frame->context.iregs[MD_CONTEXT_ARM64_REG_SP] = caller_sp; + frame->context_validity = StackFrameARM64::CONTEXT_VALID_PC | + StackFrameARM64::CONTEXT_VALID_SP; + + return frame; +} + +StackFrameARM64* StackwalkerARM64::GetCallerByFramePointer( + const vector<StackFrame*> &frames) { + StackFrameARM64* last_frame = static_cast<StackFrameARM64*>(frames.back()); + + uint64_t last_fp = last_frame->context.iregs[MD_CONTEXT_ARM64_REG_FP]; + + uint64_t caller_fp = 0; + if (last_fp && !memory_->GetMemoryAtAddress(last_fp, &caller_fp)) { + BPLOG(ERROR) << "Unable to read caller_fp from last_fp: 0x" + << std::hex << last_fp; + return NULL; + } + + uint64_t caller_lr = 0; + if (last_fp && !memory_->GetMemoryAtAddress(last_fp + 8, &caller_lr)) { + BPLOG(ERROR) << "Unable to read caller_lr from last_fp + 8: 0x" + << std::hex << (last_fp + 8); + return NULL; + } + + uint64_t caller_sp = last_fp ? last_fp + 16 : + last_frame->context.iregs[MD_CONTEXT_ARM64_REG_SP]; + + // Create a new stack frame (ownership will be transferred to the caller) + // and fill it in. + StackFrameARM64* frame = new StackFrameARM64(); + + frame->trust = StackFrame::FRAME_TRUST_FP; + frame->context = last_frame->context; + frame->context.iregs[MD_CONTEXT_ARM64_REG_FP] = caller_fp; + frame->context.iregs[MD_CONTEXT_ARM64_REG_SP] = caller_sp; + frame->context.iregs[MD_CONTEXT_ARM64_REG_PC] = + last_frame->context.iregs[MD_CONTEXT_ARM64_REG_LR]; + frame->context.iregs[MD_CONTEXT_ARM64_REG_LR] = caller_lr; + frame->context_validity = StackFrameARM64::CONTEXT_VALID_PC | + StackFrameARM64::CONTEXT_VALID_LR | + StackFrameARM64::CONTEXT_VALID_FP | + StackFrameARM64::CONTEXT_VALID_SP; + return frame; +} + +StackFrame* StackwalkerARM64::GetCallerFrame(const CallStack* stack, + bool stack_scan_allowed) { + if (!memory_ || !stack) { + BPLOG(ERROR) << "Can't get caller frame without memory or stack"; + return NULL; + } + + const vector<StackFrame*> &frames = *stack->frames(); + StackFrameARM64* last_frame = static_cast<StackFrameARM64*>(frames.back()); + scoped_ptr<StackFrameARM64> frame; + + // See if there is DWARF call frame information covering this address. + scoped_ptr<CFIFrameInfo> cfi_frame_info( + frame_symbolizer_->FindCFIFrameInfo(last_frame)); + if (cfi_frame_info.get()) + frame.reset(GetCallerByCFIFrameInfo(frames, cfi_frame_info.get())); + + // If CFI failed, or there wasn't CFI available, fall back to frame pointer. + if (!frame.get()) + frame.reset(GetCallerByFramePointer(frames)); + + // If everything failed, fall back to stack scanning. + if (stack_scan_allowed && !frame.get()) + frame.reset(GetCallerByStackScan(frames)); + + // If nothing worked, tell the caller. + if (!frame.get()) + return NULL; + + // An instruction address of zero marks the end of the stack. + if (frame->context.iregs[MD_CONTEXT_ARM64_REG_PC] == 0) + return NULL; + + // If the new stack pointer is at a lower address than the old, then + // that's clearly incorrect. Treat this as end-of-stack to enforce + // progress and avoid infinite loops. + if (frame->context.iregs[MD_CONTEXT_ARM64_REG_SP] + < last_frame->context.iregs[MD_CONTEXT_ARM64_REG_SP]) + return NULL; + + // The new frame's context's PC is the return address, which is one + // instruction past the instruction that caused us to arrive at the callee. + // ARM64 instructions have a uniform 4-byte encoding, so subtracting 4 off + // the return address gets back to the beginning of the call instruction. + // Callers that require the exact return address value may access + // frame->context.iregs[MD_CONTEXT_ARM64_REG_PC]. + frame->instruction = frame->context.iregs[MD_CONTEXT_ARM64_REG_PC] - 4; + + return frame.release(); +} + + +} // namespace google_breakpad |