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

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

     1 // Copyright (c) 2010 Google Inc.

     2 // All rights reserved.

     3 //

     4 // Redistribution and use in source and binary forms, with or without

     5 // modification, are permitted provided that the following conditions are

     6 // met:

     7 //

     8 //     * Redistributions of source code must retain the above copyright

     9 // notice, this list of conditions and the following disclaimer.

    10 //     * Redistributions in binary form must reproduce the above

    11 // copyright notice, this list of conditions and the following disclaimer

    12 // in the documentation and/or other materials provided with the

    13 // distribution.

    14 //     * Neither the name of Google Inc. nor the names of its

    15 // contributors may be used to endorse or promote products derived from

    16 // this software without specific prior written permission.

    17 //

    18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

    19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

    20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

    21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

    22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

    23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

    24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

    25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

    26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

    27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

    28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    30 // stackwalker_arm.cc: arm-specific stackwalker.

    31 //

    32 // See stackwalker_arm.h for documentation.

    33 //

    34 // Author: Mark Mentovai, Ted Mielczarek, Jim Blandy

    36 #include <vector>

    38 #include "common/scoped_ptr.h"

    39 #include "google_breakpad/processor/call_stack.h"

    40 #include "google_breakpad/processor/memory_region.h"

    41 #include "google_breakpad/processor/source_line_resolver_interface.h"

    42 #include "google_breakpad/processor/stack_frame_cpu.h"

    43 #include "processor/cfi_frame_info.h"

    44 #include "common/logging.h"

    45 #include "processor/stackwalker_arm.h"

    47 namespace google_breakpad {

    50 StackwalkerARM::StackwalkerARM(const SystemInfo* system_info,

    51                                const MDRawContextARM* context,

    52                                int fp_register,

    53                                MemoryRegion* memory,

    54                                const CodeModules* modules,

    55                                StackFrameSymbolizer* resolver_helper)

    56     : Stackwalker(system_info, memory, modules, resolver_helper),

    57       context_(context), fp_register_(fp_register),

    58       context_frame_validity_(StackFrameARM::CONTEXT_VALID_ALL) { }

    61 StackFrame* StackwalkerARM::GetContextFrame() {

    62   if (!context_) {

    63     BPLOG(ERROR) << "Can't get context frame without context";

    64     return NULL;

    65   }

    67   StackFrameARM* frame = new StackFrameARM();

    69   // The instruction pointer is stored directly in a register (r15), so pull it

    70   // straight out of the CPU context structure.

    71   frame->context = *context_;

    72   frame->context_validity = context_frame_validity_;

    73   frame->trust = StackFrame::FRAME_TRUST_CONTEXT;

    74   frame->instruction = frame->context.iregs[MD_CONTEXT_ARM_REG_PC];

    76   return frame;

    77 }

    79 StackFrameARM* StackwalkerARM::GetCallerByCFIFrameInfo(

    80     const vector<StackFrame*> &frames,

    81     CFIFrameInfo* cfi_frame_info) {

    82   StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());

    84   static const UniqueString *register_names[] = {

    85     ToUniqueString("r0"),  ToUniqueString("r1"),

    86     ToUniqueString("r2"),  ToUniqueString("r3"),

    87     ToUniqueString("r4"),  ToUniqueString("r5"),

    88     ToUniqueString("r6"),  ToUniqueString("r7"),

    89     ToUniqueString("r8"),  ToUniqueString("r9"),

    90     ToUniqueString("r10"), ToUniqueString("r11"),

    91     ToUniqueString("r12"), ToUniqueString("sp"),

    92     ToUniqueString("lr"),  ToUniqueString("pc"),

    93     ToUniqueString("f0"),  ToUniqueString("f1"),

    94     ToUniqueString("f2"),  ToUniqueString("f3"),

    95     ToUniqueString("f4"),  ToUniqueString("f5"),

    96     ToUniqueString("f6"),  ToUniqueString("f7"),

    97     ToUniqueString("fps"), ToUniqueString("cpsr"),

    98     NULL

    99   };

   101   // Populate a dictionary with the valid register values in last_frame.

   102   CFIFrameInfo::RegisterValueMap<uint32_t> callee_registers;

   103   for (int i = 0; register_names[i]; i++)

   104     if (last_frame->context_validity & StackFrameARM::RegisterValidFlag(i))

   105       callee_registers.set(register_names[i], last_frame->context.iregs[i]);

   107   // Use the STACK CFI data to recover the caller's register values.

   108   CFIFrameInfo::RegisterValueMap<uint32_t> caller_registers;

   109   if (!cfi_frame_info->FindCallerRegs(callee_registers, *memory_,

   110                                       &caller_registers))

   111     return NULL;

   113   // Construct a new stack frame given the values the CFI recovered.

   114   scoped_ptr<StackFrameARM> frame(new StackFrameARM());

   115   for (int i = 0; register_names[i]; i++) {

   116     bool found = false;

   117     uint32_t v = caller_registers.get(&found, register_names[i]);

   118     if (found) {

   119       // We recovered the value of this register; fill the context with the

   120       // value from caller_registers.

   121       frame->context_validity |= StackFrameARM::RegisterValidFlag(i);

   122       frame->context.iregs[i] = v;

   123     } else if (4 <= i && i <= 11 && (last_frame->context_validity &

   124                                      StackFrameARM::RegisterValidFlag(i))) {

   125       // If the STACK CFI data doesn't mention some callee-saves register, and

   126       // it is valid in the callee, assume the callee has not yet changed it.

   127       // Registers r4 through r11 are callee-saves, according to the Procedure

   128       // Call Standard for the ARM Architecture, which the Linux ABI follows.

   129       frame->context_validity |= StackFrameARM::RegisterValidFlag(i);

   130       frame->context.iregs[i] = last_frame->context.iregs[i];

   131     }

   132   }

   133   // If the CFI doesn't recover the PC explicitly, then use .ra.

   134   if (!(frame->context_validity & StackFrameARM::CONTEXT_VALID_PC)) {

   135     bool found = false;

   136     uint32_t v = caller_registers.get(&found, ustr__ZDra());

   137     if (found) {

   138       if (fp_register_ == -1) {

   139         frame->context_validity |= StackFrameARM::CONTEXT_VALID_PC;

   140         frame->context.iregs[MD_CONTEXT_ARM_REG_PC] = v;

   141       } else {

   142         // The CFI updated the link register and not the program counter.

   143         // Handle getting the program counter from the link register.

   144         frame->context_validity |= StackFrameARM::CONTEXT_VALID_PC;

   145         frame->context_validity |= StackFrameARM::CONTEXT_VALID_LR;

   146         frame->context.iregs[MD_CONTEXT_ARM_REG_LR] = v;

   147         frame->context.iregs[MD_CONTEXT_ARM_REG_PC] =

   148             last_frame->context.iregs[MD_CONTEXT_ARM_REG_LR];

   149       }

   150     }

   151   }

   152   // If the CFI doesn't recover the SP explicitly, then use .cfa.

   153   if (!(frame->context_validity & StackFrameARM::CONTEXT_VALID_SP)) {

   154     bool found = false;

   155     uint32_t v = caller_registers.get(&found, ustr__ZDcfa());

   156     if (found) {

   157       frame->context_validity |= StackFrameARM::CONTEXT_VALID_SP;

   158       frame->context.iregs[MD_CONTEXT_ARM_REG_SP] = v;

   159     }

   160   }

   162   // If we didn't recover the PC and the SP, then the frame isn't very useful.

   163   static const int essentials = (StackFrameARM::CONTEXT_VALID_SP

   164                                  | StackFrameARM::CONTEXT_VALID_PC);

   165   if ((frame->context_validity & essentials) != essentials)

   166     return NULL;

   168   frame->trust = StackFrame::FRAME_TRUST_CFI;

   169   return frame.release();

   170 }

   172 StackFrameARM* StackwalkerARM::GetCallerByStackScan(

   173     const vector<StackFrame*> &frames) {

   174   StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());

   175   uint32_t last_sp = last_frame->context.iregs[MD_CONTEXT_ARM_REG_SP];

   176   uint32_t caller_sp, caller_pc;

   178   // When searching for the caller of the context frame,

   179   // allow the scanner to look farther down the stack.

   180   const int kRASearchWords = frames.size() == 1 ?

   181     Stackwalker::kRASearchWords * 4 :

   182     Stackwalker::kRASearchWords;

   184   if (!ScanForReturnAddress(last_sp, &caller_sp, &caller_pc,

   185                             kRASearchWords)) {

   186     // No plausible return address was found.

   187     return NULL;

   188   }

   190   // ScanForReturnAddress found a reasonable return address. Advance

   191   // %sp to the location above the one where the return address was

   192   // found.

   193   caller_sp += 4;

   195   // Create a new stack frame (ownership will be transferred to the caller)

   196   // and fill it in.

   197   StackFrameARM* frame = new StackFrameARM();

   199   frame->trust = StackFrame::FRAME_TRUST_SCAN;

   200   frame->context = last_frame->context;

   201   frame->context.iregs[MD_CONTEXT_ARM_REG_PC] = caller_pc;

   202   frame->context.iregs[MD_CONTEXT_ARM_REG_SP] = caller_sp;

   203   frame->context_validity = StackFrameARM::CONTEXT_VALID_PC |

   204                             StackFrameARM::CONTEXT_VALID_SP;

   206   return frame;

   207 }

   209 StackFrameARM* StackwalkerARM::GetCallerByFramePointer(

   210     const vector<StackFrame*> &frames) {

   211   StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());

   213   if (!(last_frame->context_validity &

   214         StackFrameARM::RegisterValidFlag(fp_register_))) {

   215     return NULL;

   216   }

   218   uint32_t last_fp = last_frame->context.iregs[fp_register_];

   220   uint32_t caller_fp = 0;

   221   if (last_fp && !memory_->GetMemoryAtAddress(last_fp, &caller_fp)) {

   222     BPLOG(ERROR) << "Unable to read caller_fp from last_fp: 0x"

   223                  << std::hex << last_fp;

   224     return NULL;

   225   }

   227   uint32_t caller_lr = 0;

   228   if (last_fp && !memory_->GetMemoryAtAddress(last_fp + 4, &caller_lr)) {

   229     BPLOG(ERROR) << "Unable to read caller_lr from last_fp + 4: 0x"

   230                  << std::hex << (last_fp + 4);

   231     return NULL;

   232   }

   234   uint32_t caller_sp = last_fp ? last_fp + 8 :

   235       last_frame->context.iregs[MD_CONTEXT_ARM_REG_SP];

   237   // Create a new stack frame (ownership will be transferred to the caller)

   238   // and fill it in.

   239   StackFrameARM* frame = new StackFrameARM();

   241   frame->trust = StackFrame::FRAME_TRUST_FP;

   242   frame->context = last_frame->context;

   243   frame->context.iregs[fp_register_] = caller_fp;

   244   frame->context.iregs[MD_CONTEXT_ARM_REG_SP] = caller_sp;

   245   frame->context.iregs[MD_CONTEXT_ARM_REG_PC] =

   246       last_frame->context.iregs[MD_CONTEXT_ARM_REG_LR];

   247   frame->context.iregs[MD_CONTEXT_ARM_REG_LR] = caller_lr;

   248   frame->context_validity = StackFrameARM::CONTEXT_VALID_PC |

   249                             StackFrameARM::CONTEXT_VALID_LR |

   250                             StackFrameARM::RegisterValidFlag(fp_register_) |

   251                             StackFrameARM::CONTEXT_VALID_SP;

   252   return frame;

   253 }

   255 StackFrame* StackwalkerARM::GetCallerFrame(const CallStack* stack,

   256                                            bool stack_scan_allowed) {

   257   if (!memory_ || !stack) {

   258     BPLOG(ERROR) << "Can't get caller frame without memory or stack";

   259     return NULL;

   260   }

   262   const vector<StackFrame*> &frames = *stack->frames();

   263   StackFrameARM* last_frame = static_cast<StackFrameARM*>(frames.back());

   264   scoped_ptr<StackFrameARM> frame;

   266   // See if there is DWARF call frame information covering this address.

   267   scoped_ptr<CFIFrameInfo> cfi_frame_info(

   268       frame_symbolizer_->FindCFIFrameInfo(last_frame));

   269   if (cfi_frame_info.get())

   270     frame.reset(GetCallerByCFIFrameInfo(frames, cfi_frame_info.get()));

   272   // If CFI failed, or there wasn't CFI available, fall back

   273   // to frame pointer, if this is configured.

   274   if (fp_register_ >= 0 && !frame.get())

   275     frame.reset(GetCallerByFramePointer(frames));

   277   // If everuthing failed, fall back to stack scanning.

   278   if (stack_scan_allowed && !frame.get())

   279     frame.reset(GetCallerByStackScan(frames));

   281   // If nothing worked, tell the caller.

   282   if (!frame.get())

   283     return NULL;

   286   // An instruction address of zero marks the end of the stack.

   287   if (frame->context.iregs[MD_CONTEXT_ARM_REG_PC] == 0)

   288     return NULL;

   290   // If the new stack pointer is at a lower address than the old, then

   291   // that's clearly incorrect. Treat this as end-of-stack to enforce

   292   // progress and avoid infinite loops.

   293   if (frame->context.iregs[MD_CONTEXT_ARM_REG_SP]

   294       < last_frame->context.iregs[MD_CONTEXT_ARM_REG_SP])

   295     return NULL;

   297   // The new frame's context's PC is the return address, which is one

   298   // instruction past the instruction that caused us to arrive at the

   299   // callee. Set new_frame->instruction to one less than the PC. This won't

   300   // reference the beginning of the call instruction, but it's at least

   301   // within it, which is sufficient to get the source line information to

   302   // match up with the line that contains the function call. Callers that

   303   // require the exact return address value may access

   304   // frame->context.iregs[MD_CONTEXT_ARM_REG_PC].

   305   frame->instruction = frame->context.iregs[MD_CONTEXT_ARM_REG_PC] - 2;

   307   return frame.release();

   308 }

   311 }  // namespace google_breakpad

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

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