Allow adding extra memory regions to minidump on linux/windows

A=Bill McCloskey <wmccloskey@mozilla.com> R=ted at https://bugzilla.mozilla.org/show_bug.cgi?id=662646

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@989 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/client/windows/handler/exception_handler.cc

@@ -46,9 +46,7 @@ static const int kExceptionHandlerThreadInitialStackSize = 64 * 1024;
 
 // This is passed as the context to the MinidumpWriteDump callback.
 typedef struct {
-  ULONG64 memory_base;
-  ULONG memory_size;
-  bool finished;
+  AppMemoryList::const_iterator iter, end;
 } MinidumpCallbackContext;
 
 vector<ExceptionHandler*>* ExceptionHandler::handler_stack_ = NULL;
@@ -220,6 +218,9 @@ void ExceptionHandler::Initialize(const wstring& dump_path,
     set_dump_path(dump_path);
   }
 
+  // Reserve one element for the instruction memory
+  app_memory_info_.push_back(AppMemory(0, 0));
+
   // There is a race condition here. If the first instance has not yet
   // initialized the critical section, the second (and later) instances may
   // try to use uninitialized critical section object. The feature of multiple
@@ -795,9 +796,6 @@ bool ExceptionHandler::WriteMinidumpWithException(
           ++user_streams.UserStreamCount;
         }
 
-        MINIDUMP_CALLBACK_INFORMATION callback;
-        MinidumpCallbackContext context;
-        MINIDUMP_CALLBACK_INFORMATION* callback_pointer = NULL;
         // Older versions of DbgHelp.dll don't correctly put the memory around
         // the faulting instruction pointer into the minidump. This
         // callback will ensure that it gets included.
@@ -822,23 +820,33 @@ bool ExceptionHandler::WriteMinidumpWithException(
             // pointer, but settle for whatever's available up to the
             // boundaries of the memory region.
             const ULONG64 kIPMemorySize = 256;
-            context.memory_base =
+            ULONG64 base =
               (std::max)(reinterpret_cast<ULONG64>(info.BaseAddress),
                        instruction_pointer - (kIPMemorySize / 2));
             ULONG64 end_of_range =
               (std::min)(instruction_pointer + (kIPMemorySize / 2),
                        reinterpret_cast<ULONG64>(info.BaseAddress)
                        + info.RegionSize);
-            context.memory_size =
-                static_cast<ULONG>(end_of_range - context.memory_base);
+            ULONG size = static_cast<ULONG>(end_of_range - base);
 
-            context.finished = false;
-            callback.CallbackRoutine = MinidumpWriteDumpCallback;
-            callback.CallbackParam = reinterpret_cast<void*>(&context);
-            callback_pointer = &callback;
+           AppMemory &elt = app_memory_info_.front();
+           elt.ptr = base;
+           elt.length = size;
           }
         }
 
+        MinidumpCallbackContext context;
+        context.iter = app_memory_info_.begin();
+        context.end = app_memory_info_.end();
+
+       // Skip the reserved element if there was no instruction memory
+       if (context.iter->ptr == 0)
+ 	context.iter++;
+        
+        MINIDUMP_CALLBACK_INFORMATION callback;
+        callback.CallbackRoutine = MinidumpWriteDumpCallback;
+        callback.CallbackParam = reinterpret_cast<void*>(&context);
+
         // The explicit comparison to TRUE avoids a warning (C4800).
         success = (minidump_write_dump_(GetCurrentProcess(),
                                         GetCurrentProcessId(),
@@ -846,7 +854,7 @@ bool ExceptionHandler::WriteMinidumpWithException(
                                         dump_type_,
                                         exinfo ? &except_info : NULL,
                                         &user_streams,
-                                        callback_pointer) == TRUE);
+                                        &callback) == TRUE);
 
         CloseHandle(dump_file);
       }
@@ -874,13 +882,13 @@ BOOL CALLBACK ExceptionHandler::MinidumpWriteDumpCallback(
   case MemoryCallback: {
     MinidumpCallbackContext* callback_context =
         reinterpret_cast<MinidumpCallbackContext*>(context);
-    if (callback_context->finished)
+    if (callback_context->iter == callback_context->end)
       return FALSE;
 
     // Include the specified memory region.
-    callback_output->MemoryBase = callback_context->memory_base;
-    callback_output->MemorySize = callback_context->memory_size;
-    callback_context->finished = true;
+    callback_output->MemoryBase = callback_context->iter->ptr;
+    callback_output->MemorySize = callback_context->iter->length;
+    callback_context->iter++;
     return TRUE;
   }
     
@@ -924,4 +932,20 @@ void ExceptionHandler::UpdateNextID() {
   next_minidump_path_c_ = next_minidump_path_.c_str();
 }
 
+void ExceptionHandler::RegisterAppMemory(void *ptr, size_t length) {
+  app_memory_info_.push_back(AppMemory(reinterpret_cast<ULONG64>(ptr),
+                                       static_cast<ULONG>(length)));
+}
+
+void ExceptionHandler::UnregisterAppMemory(void *ptr) {
+  for (AppMemoryList::iterator iter = app_memory_info_.begin();
+       iter != app_memory_info_.end();
+       ++iter) {
+    if (iter->ptr == reinterpret_cast<ULONG64>(ptr)) {
+      app_memory_info_.erase(iter);
+      return;
+    }
+  }
+}
+
 }  // namespace google_breakpad

src/client/windows/handler/exception_handler.h

@@ -67,6 +67,7 @@
 
 #include <string>
 #include <vector>
+#include <list>
 
 #include "client/windows/common/ipc_protocol.h"
 #include "client/windows/crash_generation/crash_generation_client.h"
@@ -78,6 +79,16 @@ namespace google_breakpad {
 using std::vector;
 using std::wstring;
 
+// These entries store a list of memory regions that the client wants included
+// in the minidump.
+struct AppMemory {
+  AppMemory(ULONG64 ptr, ULONG length) : ptr(ptr), length(length) {}
+
+  ULONG64 ptr;
+  ULONG length;
+};
+typedef std::list<AppMemory> AppMemoryList;
+
 class ExceptionHandler {
  public:
   // A callback function to run before Breakpad performs any substantial
@@ -219,6 +230,11 @@ class ExceptionHandler {
   // Returns whether out-of-process dump generation is used or not.
   bool IsOutOfProcess() const { return crash_generation_client_.get() != NULL; }
 
+  // Calling RegisterAppMemory(p, len) causes len bytes starting
+  // at address p to be copied to the minidump when a crash happens.
+  void RegisterAppMemory(void *ptr, size_t length);
+  void UnregisterAppMemory(void *ptr);
+
  private:
   friend class AutoExceptionHandler;
 
@@ -404,6 +420,10 @@ class ExceptionHandler {
   // to not interfere with debuggers.
   bool handle_debug_exceptions_;
 
+  // Callers can request additional memory regions to be included in
+  // the dump.
+  AppMemoryList app_memory_info_;
+
   // A stack of ExceptionHandler objects that have installed unhandled
   // exception filters.  This vector is used by HandleException to determine
   // which ExceptionHandler object to route an exception to.  When an