Fix stack walking to notice if the frame is obviously not valid.

base/debug/stack_trace.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/debug/stack_trace.h"
 
 #include <string.h>
 
 #include <algorithm>
 #include <sstream>
@@ skipping 93 matching lines @@
   // With the stack growing downwards, older stack frame must be
   // at a greater address that the current one.
   if (fp <= prev_fp) return false;
 
   // Assume huge stack frames are bogus.
   if (fp - prev_fp > 100000) return false;
 
   // Check alignment.
   if (fp & (sizeof(uintptr_t) - 1)) return false;
 
+  // A PC that is too small means we've gone off the end of the stack.
+  const uintptr_t kMinimumReasonablePC = 32768;
+  if (GetStackFramePC(fp) < kMinimumReasonablePC)
+    return false;
+
   if (stack_end) {
     // Both fp[0] and fp[1] must be within the stack.
     if (fp > stack_end - 2 * sizeof(uintptr_t)) return false;
-
-    // Additional check to filter out false positives.
-    if (GetStackFramePC(fp) < 32768) return false;
   }
 
   return true;
 };
 
 // ScanStackForNextFrame() scans the stack for a valid frame to allow unwinding
 // past system libraries. Only supported on Linux where system libraries are
 // usually in the middle of the trace:
 //
 //   TraceStackFramePointers
@@ skipping 134 matching lines @@
 ScopedStackFrameLinker::~ScopedStackFrameLinker() {
   void* previous_parent_fp = LinkStackFrames(fp_, original_parent_fp_);
   CHECK_EQ(parent_fp_, previous_parent_fp)
       << "Stack frame's parent pointer has changed!";
 }
 
 #endif  // HAVE_TRACE_STACK_FRAME_POINTERS
 
 }  // namespace debug
 }  // namespace base