diff -r 000000000000 -r 6474c204b198 toolkit/crashreporter/google-breakpad/src/processor/stackwalker_amd64.cc --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toolkit/crashreporter/google-breakpad/src/processor/stackwalker_amd64.cc Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,246 @@ +// 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_amd64.cc: amd64-specific stackwalker. +// +// See stackwalker_amd64.h for documentation. +// +// Author: Mark Mentovai, Ted Mielczarek + +#include + +#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 "common/logging.h" +#include "processor/stackwalker_amd64.h" + +namespace google_breakpad { + + +const StackwalkerAMD64::CFIWalker::RegisterSet +StackwalkerAMD64::cfi_register_map_[] = { + // It may seem like $rip and $rsp are callee-saves, because the callee is + // responsible for having them restored upon return. But the callee_saves + // flags here really means that the walker should assume they're + // unchanged if the CFI doesn't mention them --- clearly wrong for $rip + // and $rsp. + { ToUniqueString("$rax"), NULL, false, + StackFrameAMD64::CONTEXT_VALID_RAX, &MDRawContextAMD64::rax }, + { ToUniqueString("$rdx"), NULL, false, + StackFrameAMD64::CONTEXT_VALID_RDX, &MDRawContextAMD64::rdx }, + { ToUniqueString("$rcx"), NULL, false, + StackFrameAMD64::CONTEXT_VALID_RCX, &MDRawContextAMD64::rcx }, + { ToUniqueString("$rbx"), NULL, true, + StackFrameAMD64::CONTEXT_VALID_RBX, &MDRawContextAMD64::rbx }, + { ToUniqueString("$rsi"), NULL, false, + StackFrameAMD64::CONTEXT_VALID_RSI, &MDRawContextAMD64::rsi }, + { ToUniqueString("$rdi"), NULL, false, + StackFrameAMD64::CONTEXT_VALID_RDI, &MDRawContextAMD64::rdi }, + { ToUniqueString("$rbp"), NULL, true, + StackFrameAMD64::CONTEXT_VALID_RBP, &MDRawContextAMD64::rbp }, + { ToUniqueString("$rsp"), ToUniqueString(".cfa"), false, + StackFrameAMD64::CONTEXT_VALID_RSP, &MDRawContextAMD64::rsp }, + { ToUniqueString("$r8"), NULL, false, + StackFrameAMD64::CONTEXT_VALID_R8, &MDRawContextAMD64::r8 }, + { ToUniqueString("$r9"), NULL, false, + StackFrameAMD64::CONTEXT_VALID_R9, &MDRawContextAMD64::r9 }, + { ToUniqueString("$r10"), NULL, false, + StackFrameAMD64::CONTEXT_VALID_R10, &MDRawContextAMD64::r10 }, + { ToUniqueString("$r11"), NULL, false, + StackFrameAMD64::CONTEXT_VALID_R11, &MDRawContextAMD64::r11 }, + { ToUniqueString("$r12"), NULL, true, + StackFrameAMD64::CONTEXT_VALID_R12, &MDRawContextAMD64::r12 }, + { ToUniqueString("$r13"), NULL, true, + StackFrameAMD64::CONTEXT_VALID_R13, &MDRawContextAMD64::r13 }, + { ToUniqueString("$r14"), NULL, true, + StackFrameAMD64::CONTEXT_VALID_R14, &MDRawContextAMD64::r14 }, + { ToUniqueString("$r15"), NULL, true, + StackFrameAMD64::CONTEXT_VALID_R15, &MDRawContextAMD64::r15 }, + { ToUniqueString("$rip"), ToUniqueString(".ra"), false, + StackFrameAMD64::CONTEXT_VALID_RIP, &MDRawContextAMD64::rip }, +}; + +StackwalkerAMD64::StackwalkerAMD64(const SystemInfo* system_info, + const MDRawContextAMD64* context, + MemoryRegion* memory, + const CodeModules* modules, + StackFrameSymbolizer* resolver_helper) + : Stackwalker(system_info, memory, modules, resolver_helper), + context_(context), + cfi_walker_(cfi_register_map_, + (sizeof(cfi_register_map_) / sizeof(cfi_register_map_[0]))) { +} + +uint64_t StackFrameAMD64::ReturnAddress() const +{ + assert(context_validity & StackFrameAMD64::CONTEXT_VALID_RIP); + return context.rip; +} + +StackFrame* StackwalkerAMD64::GetContextFrame() { + if (!context_) { + BPLOG(ERROR) << "Can't get context frame without context"; + return NULL; + } + + StackFrameAMD64* frame = new StackFrameAMD64(); + + // The instruction pointer is stored directly in a register, so pull it + // straight out of the CPU context structure. + frame->context = *context_; + frame->context_validity = StackFrameAMD64::CONTEXT_VALID_ALL; + frame->trust = StackFrame::FRAME_TRUST_CONTEXT; + frame->instruction = frame->context.rip; + + return frame; +} + +StackFrameAMD64* StackwalkerAMD64::GetCallerByCFIFrameInfo( + const vector &frames, + CFIFrameInfo* cfi_frame_info) { + StackFrameAMD64* last_frame = static_cast(frames.back()); + + scoped_ptr frame(new StackFrameAMD64()); + if (!cfi_walker_ + .FindCallerRegisters(*memory_, *cfi_frame_info, + last_frame->context, last_frame->context_validity, + &frame->context, &frame->context_validity)) + return NULL; + + // Make sure we recovered all the essentials. + static const int essentials = (StackFrameAMD64::CONTEXT_VALID_RIP + | StackFrameAMD64::CONTEXT_VALID_RSP); + if ((frame->context_validity & essentials) != essentials) + return NULL; + + frame->trust = StackFrame::FRAME_TRUST_CFI; + return frame.release(); +} + +StackFrameAMD64* StackwalkerAMD64::GetCallerByStackScan( + const vector &frames) { + StackFrameAMD64* last_frame = static_cast(frames.back()); + uint64_t last_rsp = last_frame->context.rsp; + uint64_t caller_rip_address, caller_rip; + + if (!ScanForReturnAddress(last_rsp, &caller_rip_address, &caller_rip)) { + // No plausible return address was found. + return NULL; + } + + // Create a new stack frame (ownership will be transferred to the caller) + // and fill it in. + StackFrameAMD64* frame = new StackFrameAMD64(); + + frame->trust = StackFrame::FRAME_TRUST_SCAN; + frame->context = last_frame->context; + frame->context.rip = caller_rip; + // The caller's %rsp is directly underneath the return address pushed by + // the call. + frame->context.rsp = caller_rip_address + 8; + frame->context_validity = StackFrameAMD64::CONTEXT_VALID_RIP | + StackFrameAMD64::CONTEXT_VALID_RSP; + + // Other unwinders give up if they don't have an %rbp value, so see if we + // can pass some plausible value on. + if (last_frame->context_validity & StackFrameAMD64::CONTEXT_VALID_RBP) { + // Functions typically push their caller's %rbp immediately upon entry, + // and then set %rbp to point to that. So if the callee's %rbp is + // pointing to the first word below the alleged return address, presume + // that the caller's %rbp is saved there. + if (caller_rip_address - 8 == last_frame->context.rbp) { + uint64_t caller_rbp = 0; + if (memory_->GetMemoryAtAddress(last_frame->context.rbp, &caller_rbp) && + caller_rbp > caller_rip_address) { + frame->context.rbp = caller_rbp; + frame->context_validity |= StackFrameAMD64::CONTEXT_VALID_RBP; + } + } else if (last_frame->context.rbp >= caller_rip_address + 8) { + // If the callee's %rbp is plausible as a value for the caller's + // %rbp, presume that the callee left it unchanged. + frame->context.rbp = last_frame->context.rbp; + frame->context_validity |= StackFrameAMD64::CONTEXT_VALID_RBP; + } + } + + return frame; +} + +StackFrame* StackwalkerAMD64::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 &frames = *stack->frames(); + StackFrameAMD64* last_frame = static_cast(frames.back()); + scoped_ptr new_frame; + + // If we have DWARF CFI information, use it. + scoped_ptr cfi_frame_info( + frame_symbolizer_->FindCFIFrameInfo(last_frame)); + if (cfi_frame_info.get()) + new_frame.reset(GetCallerByCFIFrameInfo(frames, cfi_frame_info.get())); + + // If CFI failed, or there wasn't CFI available, fall back + // to stack scanning. + if (stack_scan_allowed && !new_frame.get()) { + new_frame.reset(GetCallerByStackScan(frames)); + } + + // If nothing worked, tell the caller. + if (!new_frame.get()) + return NULL; + + // Treat an instruction address of 0 as end-of-stack. + if (new_frame->context.rip == 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 (new_frame->context.rsp <= last_frame->context.rsp) + return NULL; + + // new_frame->context.rip is the return address, which is the instruction + // after the CALL that caused us to arrive at the callee. Set + // new_frame->instruction to one less than that, so it points within the + // CALL instruction. See StackFrame::instruction for details, and + // StackFrameAMD64::ReturnAddress. + new_frame->instruction = new_frame->context.rip - 1; + + return new_frame.release(); +} + +} // namespace google_breakpad