The Tor Browser: toolkit/crashreporter/google-breakpad/src/processor/stackwalker

toolkit/crashreporter/google-breakpad/src/processor/stackwalker_amd64.cc@b8a032363ba2 (annotated)

toolkit/crashreporter/google-breakpad/src/processor/stackwalker_amd64.cc

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 // 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 <assert.h>
 #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<StackFrame*> &frames,
     CFIFrameInfo* cfi_frame_info) {
   StackFrameAMD64* last_frame = static_cast<StackFrameAMD64*>(frames.back());
   scoped_ptr<StackFrameAMD64> 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<StackFrame*> &frames) {
   StackFrameAMD64* last_frame = static_cast<StackFrameAMD64*>(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<StackFrame*> &frames = *stack->frames();
   StackFrameAMD64* last_frame = static_cast<StackFrameAMD64*>(frames.back());
   scoped_ptr<StackFrameAMD64> new_frame;
   // If we have DWARF CFI information, use it.
   scoped_ptr<CFIFrameInfo> 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

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toolkit/crashreporter/google-breakpad/src/processor/stackwalker_amd64.cc@b8a032363ba2 (annotated)

toolkit/crashreporter/google-breakpad/src/processor/stackwalker_amd64.cc