/thirdparty/breakpad/processor/stackwalker_arm.cc
http://github.com/tomahawk-player/tomahawk · C++ · 293 lines · 175 code · 44 blank · 74 comment · 39 complexity · 644497e8121f84c1a642372549bb5dca MD5 · raw file
- // 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 "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/scoped_ptr.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,
- SymbolSupplier *supplier,
- SourceLineResolverInterface *resolver)
- : Stackwalker(system_info, memory, modules, supplier, resolver),
- context_(context), fp_register_(fp_register),
- context_frame_validity_(StackFrameARM::CONTEXT_VALID_ALL) { }
- StackFrame* StackwalkerARM::GetContextFrame() {
- if (!context_ || !memory_) {
- BPLOG(ERROR) << "Can't get context frame without context or memory";
- 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 char *register_names[] = {
- "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
- "r8", "r9", "r10", "r11", "r12", "sp", "lr", "pc",
- "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
- "fps", "cpsr",
- NULL
- };
- // Populate a dictionary with the valid register values in last_frame.
- CFIFrameInfo::RegisterValueMap<u_int32_t> callee_registers;
- for (int i = 0; register_names[i]; i++)
- if (last_frame->context_validity & StackFrameARM::RegisterValidFlag(i))
- callee_registers[register_names[i]] = last_frame->context.iregs[i];
- // Use the STACK CFI data to recover the caller's register values.
- CFIFrameInfo::RegisterValueMap<u_int32_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++) {
- CFIFrameInfo::RegisterValueMap<u_int32_t>::iterator entry =
- caller_registers.find(register_names[i]);
- if (entry != caller_registers.end()) {
- // 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] = entry->second;
- } 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)) {
- CFIFrameInfo::RegisterValueMap<u_int32_t>::iterator entry =
- caller_registers.find(".ra");
- if (entry != caller_registers.end()) {
- if (fp_register_ == -1) {
- frame->context_validity |= StackFrameARM::CONTEXT_VALID_PC;
- frame->context.iregs[MD_CONTEXT_ARM_REG_PC] = entry->second;
- } 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] = entry->second;
- 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)) {
- CFIFrameInfo::RegisterValueMap<u_int32_t>::iterator entry =
- caller_registers.find(".cfa");
- if (entry != caller_registers.end()) {
- frame->context_validity |= StackFrameARM::CONTEXT_VALID_SP;
- frame->context.iregs[MD_CONTEXT_ARM_REG_SP] = entry->second;
- }
- }
- // 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());
- u_int32_t last_sp = last_frame->context.iregs[MD_CONTEXT_ARM_REG_SP];
- u_int32_t caller_sp, caller_pc;
- if (!ScanForReturnAddress(last_sp, &caller_sp, &caller_pc)) {
- // 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;
- }
- u_int32_t last_fp = last_frame->context.iregs[fp_register_];
- u_int32_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;
- }
- u_int32_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;
- }
- u_int32_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) {
- 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(
- resolver_ ? resolver_->FindCFIFrameInfo(last_frame) : NULL);
- 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 (!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