1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/toolkit/crashreporter/google-breakpad/src/processor/stackwalker_arm.cc Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,311 @@
1.4 +// Copyright (c) 2010 Google Inc.
1.5 +// All rights reserved.
1.6 +//
1.7 +// Redistribution and use in source and binary forms, with or without
1.8 +// modification, are permitted provided that the following conditions are
1.9 +// met:
1.10 +//
1.11 +// * Redistributions of source code must retain the above copyright
1.12 +// notice, this list of conditions and the following disclaimer.
1.13 +// * Redistributions in binary form must reproduce the above
1.14 +// copyright notice, this list of conditions and the following disclaimer
1.15 +// in the documentation and/or other materials provided with the
1.16 +// distribution.
1.17 +// * Neither the name of Google Inc. nor the names of its
1.18 +// contributors may be used to endorse or promote products derived from
1.19 +// this software without specific prior written permission.
1.20 +//
1.21 +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.22 +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.23 +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1.24 +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1.25 +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1.26 +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1.27 +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1.28 +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1.29 +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.30 +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1.31 +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.32 +
1.33 +// stackwalker_arm.cc: arm-specific stackwalker.
1.34 +//
1.35 +// See stackwalker_arm.h for documentation.
1.36 +//
1.37 +// Author: Mark Mentovai, Ted Mielczarek, Jim Blandy
1.38 +
1.39 +#include <vector>
1.40 +
1.41 +#include "common/scoped_ptr.h"
1.42 +#include "google_breakpad/processor/call_stack.h"
1.43 +#include "google_breakpad/processor/memory_region.h"
1.44 +#include "google_breakpad/processor/source_line_resolver_interface.h"
1.45 +#include "google_breakpad/processor/stack_frame_cpu.h"
1.46 +#include "processor/cfi_frame_info.h"
1.47 +#include "common/logging.h"
1.48 +#include "processor/stackwalker_arm.h"
1.49 +
1.50 +namespace google_breakpad {
1.51 +
1.52 +
1.53 +StackwalkerARM::StackwalkerARM(const SystemInfo* system_info,
1.54 + const MDRawContextARM* context,
1.55 + int fp_register,
1.56 + MemoryRegion* memory,
1.57 + const CodeModules* modules,
1.58 + StackFrameSymbolizer* resolver_helper)
1.59 + : Stackwalker(system_info, memory, modules, resolver_helper),
1.60 + context_(context), fp_register_(fp_register),
1.61 + context_frame_validity_(StackFrameARM::CONTEXT_VALID_ALL) { }
1.62 +
1.63 +
1.64 +StackFrame* StackwalkerARM::GetContextFrame() {
1.65 + if (!context_) {
1.66 + BPLOG(ERROR) << "Can't get context frame without context";
1.67 + return NULL;
1.68 + }
1.69 +
1.70 + StackFrameARM* frame = new StackFrameARM();
1.71 +
1.72 + // The instruction pointer is stored directly in a register (r15), so pull it
1.73 + // straight out of the CPU context structure.
1.74 + frame->context = *context_;
1.75 + frame->context_validity = context_frame_validity_;
1.76 + frame->trust = StackFrame::FRAME_TRUST_CONTEXT;
1.77 + frame->instruction = frame->context.iregs[MD_CONTEXT_ARM_REG_PC];
1.78 +
1.79 + return frame;
1.80 +}
1.81 +
1.82 +StackFrameARM* StackwalkerARM::GetCallerByCFIFrameInfo(
1.83 + const vector<StackFrame*> &frames,
1.84 + CFIFrameInfo* cfi_frame_info) {
1.85 + StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());
1.86 +
1.87 + static const UniqueString *register_names[] = {
1.88 + ToUniqueString("r0"), ToUniqueString("r1"),
1.89 + ToUniqueString("r2"), ToUniqueString("r3"),
1.90 + ToUniqueString("r4"), ToUniqueString("r5"),
1.91 + ToUniqueString("r6"), ToUniqueString("r7"),
1.92 + ToUniqueString("r8"), ToUniqueString("r9"),
1.93 + ToUniqueString("r10"), ToUniqueString("r11"),
1.94 + ToUniqueString("r12"), ToUniqueString("sp"),
1.95 + ToUniqueString("lr"), ToUniqueString("pc"),
1.96 + ToUniqueString("f0"), ToUniqueString("f1"),
1.97 + ToUniqueString("f2"), ToUniqueString("f3"),
1.98 + ToUniqueString("f4"), ToUniqueString("f5"),
1.99 + ToUniqueString("f6"), ToUniqueString("f7"),
1.100 + ToUniqueString("fps"), ToUniqueString("cpsr"),
1.101 + NULL
1.102 + };
1.103 +
1.104 + // Populate a dictionary with the valid register values in last_frame.
1.105 + CFIFrameInfo::RegisterValueMap<uint32_t> callee_registers;
1.106 + for (int i = 0; register_names[i]; i++)
1.107 + if (last_frame->context_validity & StackFrameARM::RegisterValidFlag(i))
1.108 + callee_registers.set(register_names[i], last_frame->context.iregs[i]);
1.109 +
1.110 + // Use the STACK CFI data to recover the caller's register values.
1.111 + CFIFrameInfo::RegisterValueMap<uint32_t> caller_registers;
1.112 + if (!cfi_frame_info->FindCallerRegs(callee_registers, *memory_,
1.113 + &caller_registers))
1.114 + return NULL;
1.115 +
1.116 + // Construct a new stack frame given the values the CFI recovered.
1.117 + scoped_ptr<StackFrameARM> frame(new StackFrameARM());
1.118 + for (int i = 0; register_names[i]; i++) {
1.119 + bool found = false;
1.120 + uint32_t v = caller_registers.get(&found, register_names[i]);
1.121 + if (found) {
1.122 + // We recovered the value of this register; fill the context with the
1.123 + // value from caller_registers.
1.124 + frame->context_validity |= StackFrameARM::RegisterValidFlag(i);
1.125 + frame->context.iregs[i] = v;
1.126 + } else if (4 <= i && i <= 11 && (last_frame->context_validity &
1.127 + StackFrameARM::RegisterValidFlag(i))) {
1.128 + // If the STACK CFI data doesn't mention some callee-saves register, and
1.129 + // it is valid in the callee, assume the callee has not yet changed it.
1.130 + // Registers r4 through r11 are callee-saves, according to the Procedure
1.131 + // Call Standard for the ARM Architecture, which the Linux ABI follows.
1.132 + frame->context_validity |= StackFrameARM::RegisterValidFlag(i);
1.133 + frame->context.iregs[i] = last_frame->context.iregs[i];
1.134 + }
1.135 + }
1.136 + // If the CFI doesn't recover the PC explicitly, then use .ra.
1.137 + if (!(frame->context_validity & StackFrameARM::CONTEXT_VALID_PC)) {
1.138 + bool found = false;
1.139 + uint32_t v = caller_registers.get(&found, ustr__ZDra());
1.140 + if (found) {
1.141 + if (fp_register_ == -1) {
1.142 + frame->context_validity |= StackFrameARM::CONTEXT_VALID_PC;
1.143 + frame->context.iregs[MD_CONTEXT_ARM_REG_PC] = v;
1.144 + } else {
1.145 + // The CFI updated the link register and not the program counter.
1.146 + // Handle getting the program counter from the link register.
1.147 + frame->context_validity |= StackFrameARM::CONTEXT_VALID_PC;
1.148 + frame->context_validity |= StackFrameARM::CONTEXT_VALID_LR;
1.149 + frame->context.iregs[MD_CONTEXT_ARM_REG_LR] = v;
1.150 + frame->context.iregs[MD_CONTEXT_ARM_REG_PC] =
1.151 + last_frame->context.iregs[MD_CONTEXT_ARM_REG_LR];
1.152 + }
1.153 + }
1.154 + }
1.155 + // If the CFI doesn't recover the SP explicitly, then use .cfa.
1.156 + if (!(frame->context_validity & StackFrameARM::CONTEXT_VALID_SP)) {
1.157 + bool found = false;
1.158 + uint32_t v = caller_registers.get(&found, ustr__ZDcfa());
1.159 + if (found) {
1.160 + frame->context_validity |= StackFrameARM::CONTEXT_VALID_SP;
1.161 + frame->context.iregs[MD_CONTEXT_ARM_REG_SP] = v;
1.162 + }
1.163 + }
1.164 +
1.165 + // If we didn't recover the PC and the SP, then the frame isn't very useful.
1.166 + static const int essentials = (StackFrameARM::CONTEXT_VALID_SP
1.167 + | StackFrameARM::CONTEXT_VALID_PC);
1.168 + if ((frame->context_validity & essentials) != essentials)
1.169 + return NULL;
1.170 +
1.171 + frame->trust = StackFrame::FRAME_TRUST_CFI;
1.172 + return frame.release();
1.173 +}
1.174 +
1.175 +StackFrameARM* StackwalkerARM::GetCallerByStackScan(
1.176 + const vector<StackFrame*> &frames) {
1.177 + StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());
1.178 + uint32_t last_sp = last_frame->context.iregs[MD_CONTEXT_ARM_REG_SP];
1.179 + uint32_t caller_sp, caller_pc;
1.180 +
1.181 + // When searching for the caller of the context frame,
1.182 + // allow the scanner to look farther down the stack.
1.183 + const int kRASearchWords = frames.size() == 1 ?
1.184 + Stackwalker::kRASearchWords * 4 :
1.185 + Stackwalker::kRASearchWords;
1.186 +
1.187 + if (!ScanForReturnAddress(last_sp, &caller_sp, &caller_pc,
1.188 + kRASearchWords)) {
1.189 + // No plausible return address was found.
1.190 + return NULL;
1.191 + }
1.192 +
1.193 + // ScanForReturnAddress found a reasonable return address. Advance
1.194 + // %sp to the location above the one where the return address was
1.195 + // found.
1.196 + caller_sp += 4;
1.197 +
1.198 + // Create a new stack frame (ownership will be transferred to the caller)
1.199 + // and fill it in.
1.200 + StackFrameARM* frame = new StackFrameARM();
1.201 +
1.202 + frame->trust = StackFrame::FRAME_TRUST_SCAN;
1.203 + frame->context = last_frame->context;
1.204 + frame->context.iregs[MD_CONTEXT_ARM_REG_PC] = caller_pc;
1.205 + frame->context.iregs[MD_CONTEXT_ARM_REG_SP] = caller_sp;
1.206 + frame->context_validity = StackFrameARM::CONTEXT_VALID_PC |
1.207 + StackFrameARM::CONTEXT_VALID_SP;
1.208 +
1.209 + return frame;
1.210 +}
1.211 +
1.212 +StackFrameARM* StackwalkerARM::GetCallerByFramePointer(
1.213 + const vector<StackFrame*> &frames) {
1.214 + StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());
1.215 +
1.216 + if (!(last_frame->context_validity &
1.217 + StackFrameARM::RegisterValidFlag(fp_register_))) {
1.218 + return NULL;
1.219 + }
1.220 +
1.221 + uint32_t last_fp = last_frame->context.iregs[fp_register_];
1.222 +
1.223 + uint32_t caller_fp = 0;
1.224 + if (last_fp && !memory_->GetMemoryAtAddress(last_fp, &caller_fp)) {
1.225 + BPLOG(ERROR) << "Unable to read caller_fp from last_fp: 0x"
1.226 + << std::hex << last_fp;
1.227 + return NULL;
1.228 + }
1.229 +
1.230 + uint32_t caller_lr = 0;
1.231 + if (last_fp && !memory_->GetMemoryAtAddress(last_fp + 4, &caller_lr)) {
1.232 + BPLOG(ERROR) << "Unable to read caller_lr from last_fp + 4: 0x"
1.233 + << std::hex << (last_fp + 4);
1.234 + return NULL;
1.235 + }
1.236 +
1.237 + uint32_t caller_sp = last_fp ? last_fp + 8 :
1.238 + last_frame->context.iregs[MD_CONTEXT_ARM_REG_SP];
1.239 +
1.240 + // Create a new stack frame (ownership will be transferred to the caller)
1.241 + // and fill it in.
1.242 + StackFrameARM* frame = new StackFrameARM();
1.243 +
1.244 + frame->trust = StackFrame::FRAME_TRUST_FP;
1.245 + frame->context = last_frame->context;
1.246 + frame->context.iregs[fp_register_] = caller_fp;
1.247 + frame->context.iregs[MD_CONTEXT_ARM_REG_SP] = caller_sp;
1.248 + frame->context.iregs[MD_CONTEXT_ARM_REG_PC] =
1.249 + last_frame->context.iregs[MD_CONTEXT_ARM_REG_LR];
1.250 + frame->context.iregs[MD_CONTEXT_ARM_REG_LR] = caller_lr;
1.251 + frame->context_validity = StackFrameARM::CONTEXT_VALID_PC |
1.252 + StackFrameARM::CONTEXT_VALID_LR |
1.253 + StackFrameARM::RegisterValidFlag(fp_register_) |
1.254 + StackFrameARM::CONTEXT_VALID_SP;
1.255 + return frame;
1.256 +}
1.257 +
1.258 +StackFrame* StackwalkerARM::GetCallerFrame(const CallStack* stack,
1.259 + bool stack_scan_allowed) {
1.260 + if (!memory_ || !stack) {
1.261 + BPLOG(ERROR) << "Can't get caller frame without memory or stack";
1.262 + return NULL;
1.263 + }
1.264 +
1.265 + const vector<StackFrame*> &frames = *stack->frames();
1.266 + StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());
1.267 + scoped_ptr<StackFrameARM> frame;
1.268 +
1.269 + // See if there is DWARF call frame information covering this address.
1.270 + scoped_ptr<CFIFrameInfo> cfi_frame_info(
1.271 + frame_symbolizer_->FindCFIFrameInfo(last_frame));
1.272 + if (cfi_frame_info.get())
1.273 + frame.reset(GetCallerByCFIFrameInfo(frames, cfi_frame_info.get()));
1.274 +
1.275 + // If CFI failed, or there wasn't CFI available, fall back
1.276 + // to frame pointer, if this is configured.
1.277 + if (fp_register_ >= 0 && !frame.get())
1.278 + frame.reset(GetCallerByFramePointer(frames));
1.279 +
1.280 + // If everuthing failed, fall back to stack scanning.
1.281 + if (stack_scan_allowed && !frame.get())
1.282 + frame.reset(GetCallerByStackScan(frames));
1.283 +
1.284 + // If nothing worked, tell the caller.
1.285 + if (!frame.get())
1.286 + return NULL;
1.287 +
1.288 +
1.289 + // An instruction address of zero marks the end of the stack.
1.290 + if (frame->context.iregs[MD_CONTEXT_ARM_REG_PC] == 0)
1.291 + return NULL;
1.292 +
1.293 + // If the new stack pointer is at a lower address than the old, then
1.294 + // that's clearly incorrect. Treat this as end-of-stack to enforce
1.295 + // progress and avoid infinite loops.
1.296 + if (frame->context.iregs[MD_CONTEXT_ARM_REG_SP]
1.297 + < last_frame->context.iregs[MD_CONTEXT_ARM_REG_SP])
1.298 + return NULL;
1.299 +
1.300 + // The new frame's context's PC is the return address, which is one
1.301 + // instruction past the instruction that caused us to arrive at the
1.302 + // callee. Set new_frame->instruction to one less than the PC. This won't
1.303 + // reference the beginning of the call instruction, but it's at least
1.304 + // within it, which is sufficient to get the source line information to
1.305 + // match up with the line that contains the function call. Callers that
1.306 + // require the exact return address value may access
1.307 + // frame->context.iregs[MD_CONTEXT_ARM_REG_PC].
1.308 + frame->instruction = frame->context.iregs[MD_CONTEXT_ARM_REG_PC] - 2;
1.309 +
1.310 + return frame.release();
1.311 +}
1.312 +
1.313 +
1.314 +} // namespace google_breakpad
