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

toolkit/crashreporter/google-breakpad/src/processor/stackwalker_arm.cc@6474c204b198 (annotated)

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

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // 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_arm.cc: arm-specific stackwalker.
 //
 // See stackwalker_arm.h for documentation.
 //
 // Author: Mark Mentovai, Ted Mielczarek, Jim Blandy
 #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 "common/logging.h"
 #include "processor/stackwalker_arm.h"
 namespace google_breakpad {
 StackwalkerARM::StackwalkerARM(const SystemInfo* system_info,
                                const MDRawContextARM* context,
                                int fp_register,
                                MemoryRegion* memory,
                                const CodeModules* modules,
                                StackFrameSymbolizer* resolver_helper)
     : Stackwalker(system_info, memory, modules, resolver_helper),
       context_(context), fp_register_(fp_register),
       context_frame_validity_(StackFrameARM::CONTEXT_VALID_ALL) { }
 StackFrame* StackwalkerARM::GetContextFrame() {
   if (!context_) {
     BPLOG(ERROR) << "Can't get context frame without context";
     return NULL;
   }
   StackFrameARM* frame = new StackFrameARM();
   // The instruction pointer is stored directly in a register (r15), 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_ARM_REG_PC];
   return frame;
 }
 StackFrameARM* StackwalkerARM::GetCallerByCFIFrameInfo(
     const vector<StackFrame*> &frames,
     CFIFrameInfo* cfi_frame_info) {
   StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());
   static const UniqueString *register_names[] = {
     ToUniqueString("r0"),  ToUniqueString("r1"),
     ToUniqueString("r2"),  ToUniqueString("r3"),
     ToUniqueString("r4"),  ToUniqueString("r5"),
     ToUniqueString("r6"),  ToUniqueString("r7"),
     ToUniqueString("r8"),  ToUniqueString("r9"),
     ToUniqueString("r10"), ToUniqueString("r11"),
     ToUniqueString("r12"), ToUniqueString("sp"),
     ToUniqueString("lr"),  ToUniqueString("pc"),
     ToUniqueString("f0"),  ToUniqueString("f1"),
     ToUniqueString("f2"),  ToUniqueString("f3"),
     ToUniqueString("f4"),  ToUniqueString("f5"),
     ToUniqueString("f6"),  ToUniqueString("f7"),
     ToUniqueString("fps"), ToUniqueString("cpsr"),
     NULL
   };
   // Populate a dictionary with the valid register values in last_frame.
   CFIFrameInfo::RegisterValueMap<uint32_t> callee_registers;
   for (int i = 0; register_names[i]; i++)
     if (last_frame->context_validity & StackFrameARM::RegisterValidFlag(i))
       callee_registers.set(register_names[i], last_frame->context.iregs[i]);
   // Use the STACK CFI data to recover the caller's register values.
   CFIFrameInfo::RegisterValueMap<uint32_t> caller_registers;
   if (!cfi_frame_info->FindCallerRegs(callee_registers, *memory_,
                                       &caller_registers))
     return NULL;
   // Construct a new stack frame given the values the CFI recovered.
   scoped_ptr<StackFrameARM> frame(new StackFrameARM());
   for (int i = 0; register_names[i]; i++) {
     bool found = false;
     uint32_t v = caller_registers.get(&found, register_names[i]);
     if (found) {
       // We recovered the value of this register; fill the context with the
       // value from caller_registers.
       frame->context_validity |= StackFrameARM::RegisterValidFlag(i);
       frame->context.iregs[i] = v;
     } else if (4 <= i && i <= 11 && (last_frame->context_validity &
                                      StackFrameARM::RegisterValidFlag(i))) {
       // If the STACK CFI data doesn't mention some callee-saves register, and
       // it is valid in the callee, assume the callee has not yet changed it.
       // Registers r4 through r11 are callee-saves, according to the Procedure
       // Call Standard for the ARM Architecture, which the Linux ABI follows.
       frame->context_validity |= StackFrameARM::RegisterValidFlag(i);
       frame->context.iregs[i] = last_frame->context.iregs[i];
     }
   }
   // If the CFI doesn't recover the PC explicitly, then use .ra.
   if (!(frame->context_validity & StackFrameARM::CONTEXT_VALID_PC)) {
     bool found = false;
     uint32_t v = caller_registers.get(&found, ustr__ZDra());
     if (found) {
       if (fp_register_ == -1) {
         frame->context_validity |= StackFrameARM::CONTEXT_VALID_PC;
         frame->context.iregs[MD_CONTEXT_ARM_REG_PC] = v;
       } else {
         // The CFI updated the link register and not the program counter.
         // Handle getting the program counter from the link register.
         frame->context_validity |= StackFrameARM::CONTEXT_VALID_PC;
         frame->context_validity |= StackFrameARM::CONTEXT_VALID_LR;
         frame->context.iregs[MD_CONTEXT_ARM_REG_LR] = v;
         frame->context.iregs[MD_CONTEXT_ARM_REG_PC] =
             last_frame->context.iregs[MD_CONTEXT_ARM_REG_LR];
       }
     }
   }
   // If the CFI doesn't recover the SP explicitly, then use .cfa.
   if (!(frame->context_validity & StackFrameARM::CONTEXT_VALID_SP)) {
     bool found = false;
     uint32_t v = caller_registers.get(&found, ustr__ZDcfa());
     if (found) {
       frame->context_validity |= StackFrameARM::CONTEXT_VALID_SP;
       frame->context.iregs[MD_CONTEXT_ARM_REG_SP] = v;
     }
   }
   // If we didn't recover the PC and the SP, then the frame isn't very useful.
   static const int essentials = (StackFrameARM::CONTEXT_VALID_SP
                                  | StackFrameARM::CONTEXT_VALID_PC);
   if ((frame->context_validity & essentials) != essentials)
     return NULL;
   frame->trust = StackFrame::FRAME_TRUST_CFI;
   return frame.release();
 }
 StackFrameARM* StackwalkerARM::GetCallerByStackScan(
     const vector<StackFrame*> &frames) {
   StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());
   uint32_t last_sp = last_frame->context.iregs[MD_CONTEXT_ARM_REG_SP];
   uint32_t caller_sp, caller_pc;
   // When searching for the caller of the context frame,
   // allow the scanner to look farther down the stack.
   const int kRASearchWords = frames.size() == 1 ?
     Stackwalker::kRASearchWords * 4 :
     Stackwalker::kRASearchWords;
   if (!ScanForReturnAddress(last_sp, &caller_sp, &caller_pc,
                             kRASearchWords)) {
     // 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 += 4;
   // Create a new stack frame (ownership will be transferred to the caller)
   // and fill it in.
   StackFrameARM* frame = new StackFrameARM();
   frame->trust = StackFrame::FRAME_TRUST_SCAN;
   frame->context = last_frame->context;
   frame->context.iregs[MD_CONTEXT_ARM_REG_PC] = caller_pc;
   frame->context.iregs[MD_CONTEXT_ARM_REG_SP] = caller_sp;
   frame->context_validity = StackFrameARM::CONTEXT_VALID_PC |
                             StackFrameARM::CONTEXT_VALID_SP;
   return frame;
 }
 StackFrameARM* StackwalkerARM::GetCallerByFramePointer(
     const vector<StackFrame*> &frames) {
   StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());
   if (!(last_frame->context_validity &
         StackFrameARM::RegisterValidFlag(fp_register_))) {
     return NULL;
   }
   uint32_t last_fp = last_frame->context.iregs[fp_register_];
   uint32_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;
   }
   uint32_t caller_lr = 0;
   if (last_fp && !memory_->GetMemoryAtAddress(last_fp + 4, &caller_lr)) {
     BPLOG(ERROR) << "Unable to read caller_lr from last_fp + 4: 0x"
                  << std::hex << (last_fp + 4);
     return NULL;
   }
   uint32_t caller_sp = last_fp ? last_fp + 8 :
       last_frame->context.iregs[MD_CONTEXT_ARM_REG_SP];
   // Create a new stack frame (ownership will be transferred to the caller)
   // and fill it in.
   StackFrameARM* frame = new StackFrameARM();
   frame->trust = StackFrame::FRAME_TRUST_FP;
   frame->context = last_frame->context;
   frame->context.iregs[fp_register_] = caller_fp;
   frame->context.iregs[MD_CONTEXT_ARM_REG_SP] = caller_sp;
   frame->context.iregs[MD_CONTEXT_ARM_REG_PC] =
       last_frame->context.iregs[MD_CONTEXT_ARM_REG_LR];
   frame->context.iregs[MD_CONTEXT_ARM_REG_LR] = caller_lr;
   frame->context_validity = StackFrameARM::CONTEXT_VALID_PC |
                             StackFrameARM::CONTEXT_VALID_LR |
                             StackFrameARM::RegisterValidFlag(fp_register_) |
                             StackFrameARM::CONTEXT_VALID_SP;
   return frame;
 }
 StackFrame* StackwalkerARM::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();
   StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());
   scoped_ptr<StackFrameARM> 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 this is configured.
   if (fp_register_ >= 0 && !frame.get())
     frame.reset(GetCallerByFramePointer(frames));
   // If everuthing 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_ARM_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_ARM_REG_SP]
       < last_frame->context.iregs[MD_CONTEXT_ARM_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. Set new_frame->instruction to one less than the PC. This won't
   // reference the beginning of the call instruction, but it's at least
   // within it, which is sufficient to get the source line information to
   // match up with the line that contains the function call. Callers that
   // require the exact return address value may access
   // frame->context.iregs[MD_CONTEXT_ARM_REG_PC].
   frame->instruction = frame->context.iregs[MD_CONTEXT_ARM_REG_PC] - 2;
   return frame.release();
 }
 }  // namespace google_breakpad

The Tor Browser / annotate

toolkit/crashreporter/google-breakpad/src/processor/stackwalker_arm.cc@6474c204b198 (annotated)

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