michael@0: # HG changeset patch
michael@0: # User Julian Seward <jseward@acm.org>
michael@0: # Date 1366643454 -7200
michael@0: #      Mon Apr 22 17:10:54 2013 +0200
michael@0: # Node ID 3e64f12d9dab619c90bee02ed071bcda0100844e
michael@0: # Parent  6d06a09b3f5624dd833bd6f905bfd88e3fdec00a
michael@0: Bug 859745 - Install sane unwinding limit for SPS/breakpad.  r=ted
michael@0: 
michael@0: diff --git a/src/google_breakpad/processor/stackwalker.h b/src/google_breakpad/processor/stackwalker.h
michael@0: --- a/src/google_breakpad/processor/stackwalker.h
michael@0: +++ b/src/google_breakpad/processor/stackwalker.h
michael@0: @@ -83,17 +83,20 @@ class Stackwalker {
michael@0:    // argument.  If no suitable concrete subclass exists, returns NULL.
michael@0:    static Stackwalker* StackwalkerForCPU(
michael@0:       const SystemInfo* system_info,
michael@0:       MinidumpContext* context,
michael@0:       MemoryRegion* memory,
michael@0:       const CodeModules* modules,
michael@0:       StackFrameSymbolizer* resolver_helper);
michael@0:  
michael@0: -  static void set_max_frames(uint32_t max_frames) { max_frames_ = max_frames; }
michael@0: +  static void set_max_frames(uint32_t max_frames) {
michael@0: +    max_frames_ = max_frames;
michael@0: +    max_frames_set_ = true;
michael@0: +  }
michael@0:    static uint32_t max_frames() { return max_frames_; }
michael@0:  
michael@0:   protected:
michael@0:    // system_info identifies the operating system, NULL or empty if unknown.
michael@0:    // memory identifies a MemoryRegion that provides the stack memory
michael@0:    // for the stack to walk.  modules, if non-NULL, is a CodeModules
michael@0:    // object that is used to look up which code module each stack frame is
michael@0:    // associated with.  frame_symbolizer is a StackFrameSymbolizer object that
michael@0: @@ -191,14 +194,19 @@ class Stackwalker {
michael@0:    // the end of the stack has been reached).  GetCallerFrame allocates a new
michael@0:    // StackFrame (or StackFrame subclass), ownership of which is taken by
michael@0:    // the caller.
michael@0:    virtual StackFrame* GetCallerFrame(const CallStack* stack) = 0;
michael@0:  
michael@0:    // The maximum number of frames Stackwalker will walk through.
michael@0:    // This defaults to 1024 to prevent infinite loops.
michael@0:    static uint32_t max_frames_;
michael@0: +
michael@0: +  // Keep track of whether max_frames_ has been set by the user, since
michael@0: +  // it affects whether or not an error message is printed in the case
michael@0: +  // where an unwind got stopped by the limit.
michael@0: +  static bool max_frames_set_;
michael@0:  };
michael@0:  
michael@0:  }  // namespace google_breakpad
michael@0:  
michael@0:  
michael@0:  #endif  // GOOGLE_BREAKPAD_PROCESSOR_STACKWALKER_H__
michael@0: diff --git a/src/processor/stackwalker.cc b/src/processor/stackwalker.cc
michael@0: --- a/src/processor/stackwalker.cc
michael@0: +++ b/src/processor/stackwalker.cc
michael@0: @@ -52,16 +52,17 @@
michael@0:  #include "processor/stackwalker_x86.h"
michael@0:  #include "processor/stackwalker_amd64.h"
michael@0:  #include "processor/stackwalker_arm.h"
michael@0:  
michael@0:  namespace google_breakpad {
michael@0:  
michael@0:  const int Stackwalker::kRASearchWords = 30;
michael@0:  uint32_t Stackwalker::max_frames_ = 1024;
michael@0: +bool Stackwalker::max_frames_set_ = false;
michael@0:  
michael@0:  Stackwalker::Stackwalker(const SystemInfo* system_info,
michael@0:                           MemoryRegion* memory,
michael@0:                           const CodeModules* modules,
michael@0:                           StackFrameSymbolizer* frame_symbolizer)
michael@0:      : system_info_(system_info),
michael@0:        memory_(memory),
michael@0:        modules_(modules),
michael@0: @@ -120,17 +121,20 @@ bool Stackwalker::Walk(CallStack* stack,
michael@0:          modules_without_symbols->push_back(frame->module);
michael@0:        }
michael@0:      }
michael@0:  
michael@0:      // Add the frame to the call stack.  Relinquish the ownership claim
michael@0:      // over the frame, because the stack now owns it.
michael@0:      stack->frames_.push_back(frame.release());
michael@0:      if (stack->frames_.size() > max_frames_) {
michael@0: -      BPLOG(ERROR) << "The stack is over " << max_frames_ << " frames.";
michael@0: +      // Only emit an error message in the case where the limit that we
michael@0: +      // reached is the default limit, not set by the user.
michael@0: +      if (!max_frames_set_)
michael@0: +        BPLOG(ERROR) << "The stack is over " << max_frames_ << " frames.";
michael@0:        break;
michael@0:      }
michael@0:  
michael@0:      // Get the next frame and take ownership.
michael@0:      frame.reset(GetCallerFrame(stack));
michael@0:    }
michael@0:  
michael@0:    return true;