Allow writing on-request minidumps with an exception stream

R=mark at http://breakpad.appspot.com/172001/show

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@745 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
ted.mielczarek@gmail.com 2010-12-15 16:28:28 +00:00
parent cae59b4ae4
commit 0d9bd40775
3 changed files with 123 additions and 36 deletions

View File

@ -53,9 +53,6 @@ namespace google_breakpad {
using std::map;
// Message ID telling the handler thread to quit.
static const mach_msg_id_t kQuitMessage = 1;
// These structures and techniques are illustrated in
// Mac OS X Internals, Amit Singh, ch 9.7
struct ExceptionMessage {
@ -272,7 +269,7 @@ ExceptionHandler::~ExceptionHandler() {
Teardown();
}
bool ExceptionHandler::WriteMinidump() {
bool ExceptionHandler::WriteMinidump(bool write_exception_stream) {
// If we're currently writing, just return
if (use_minidump_write_mutex_)
return false;
@ -284,7 +281,9 @@ bool ExceptionHandler::WriteMinidump() {
if (pthread_mutex_lock(&minidump_write_mutex_) == 0) {
// Send an empty message to the handle port so that a minidump will
// be written
SendEmptyMachMessage(false);
SendMessageToHandlerThread(write_exception_stream ?
kWriteDumpWithExceptionMessage :
kWriteDumpMessage);
// Wait for the minidump writer to complete its writing. It will unlock
// the mutex when completed
@ -298,11 +297,12 @@ bool ExceptionHandler::WriteMinidump() {
// static
bool ExceptionHandler::WriteMinidump(const string &dump_path,
bool write_exception_stream,
MinidumpCallback callback,
void *callback_context) {
ExceptionHandler handler(dump_path, NULL, callback, callback_context, false,
NULL);
return handler.WriteMinidump();
return handler.WriteMinidump(write_exception_stream);
}
// static
@ -323,7 +323,7 @@ bool ExceptionHandler::WriteMinidumpForChild(mach_port_t child,
#elif defined (__ppc__) || defined (__ppc64__)
EXC_PPC_BREAKPOINT,
#else
#error architecture not supported
#error architecture not supported
#endif
0,
child_blamed_thread);
@ -339,7 +339,8 @@ bool ExceptionHandler::WriteMinidumpForChild(mach_port_t child,
bool ExceptionHandler::WriteMinidumpWithException(int exception_type,
int exception_code,
int exception_subcode,
mach_port_t thread_name) {
mach_port_t thread_name,
bool exit_after_write) {
bool result = false;
if (directCallback_) {
@ -348,7 +349,7 @@ bool ExceptionHandler::WriteMinidumpWithException(int exception_type,
exception_code,
exception_subcode,
thread_name) ) {
if (exception_type && exception_code)
if (exit_after_write)
_exit(exception_type);
}
} else if (IsOutOfProcess()) {
@ -390,7 +391,7 @@ bool ExceptionHandler::WriteMinidumpWithException(int exception_type,
// forwarding the exception to the next handler.
if (callback_(dump_path_c_, next_minidump_id_c_, callback_context_,
result)) {
if (exception_type && exception_code)
if (exit_after_write)
_exit(exception_type);
}
}
@ -527,7 +528,7 @@ void *ExceptionHandler::WaitForMessage(void *exception_handler_class) {
if (!receive.exception) {
// Don't touch self, since this message could have been sent
// from its destructor.
if (receive.header.msgh_id == kQuitMessage)
if (receive.header.msgh_id == kShutdownMessage)
return NULL;
self->SuspendThreads();
@ -537,11 +538,26 @@ void *ExceptionHandler::WaitForMessage(void *exception_handler_class) {
gBreakpadAllocator->Unprotect();
#endif
mach_port_t thread = MACH_PORT_NULL;
int exception_type = 0;
int exception_code = 0;
if (receive.header.msgh_id == kWriteDumpWithExceptionMessage) {
thread = receive.thread.name;
exception_type = EXC_BREAKPOINT;
#if defined (__i386__) || defined(__x86_64__)
exception_code = EXC_I386_BPT;
#elif defined (__ppc__) || defined (__ppc64__)
exception_code = EXC_PPC_BREAKPOINT;
#else
#error architecture not supported
#endif
}
// Write out the dump and save the result for later retrieval
self->last_minidump_write_result_ =
self->WriteMinidumpWithException(0, 0, 0, 0);
self->UninstallHandler(false);
self->WriteMinidumpWithException(exception_type, exception_code,
0, thread,
false);
#if USE_PROTECTED_ALLOCATIONS
if(gBreakpadAllocator)
@ -575,7 +591,7 @@ void *ExceptionHandler::WaitForMessage(void *exception_handler_class) {
// Generate the minidump with the exception data.
self->WriteMinidumpWithException(receive.exception, receive.code[0],
subcode, receive.thread.name);
subcode, receive.thread.name, true);
self->UninstallHandler(true);
@ -710,7 +726,7 @@ bool ExceptionHandler::Teardown() {
return false;
// Send an empty message so that the handler_thread exits
if (SendEmptyMachMessage(true)) {
if (SendMessageToHandlerThread(kShutdownMessage)) {
mach_port_t current_task = mach_task_self();
result = mach_port_deallocate(current_task, handler_port_);
if (result != KERN_SUCCESS)
@ -726,18 +742,25 @@ bool ExceptionHandler::Teardown() {
return result == KERN_SUCCESS;
}
bool ExceptionHandler::SendEmptyMachMessage(bool quit) {
ExceptionMessage empty;
memset(&empty, 0, sizeof(empty));
if (quit)
empty.header.msgh_id = kQuitMessage;
empty.header.msgh_size = sizeof(empty) - sizeof(empty.padding);
empty.header.msgh_remote_port = handler_port_;
empty.header.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND,
bool ExceptionHandler::SendMessageToHandlerThread(
HandlerThreadMessage message_id) {
ExceptionMessage msg;
memset(&msg, 0, sizeof(msg));
msg.header.msgh_id = message_id;
if (message_id == kWriteDumpMessage ||
message_id == kWriteDumpWithExceptionMessage) {
// Include this thread's port.
msg.thread.name = mach_thread_self();
msg.thread.disposition = MACH_MSG_TYPE_PORT_SEND;
msg.thread.type = MACH_MSG_PORT_DESCRIPTOR;
}
msg.header.msgh_size = sizeof(msg) - sizeof(msg.padding);
msg.header.msgh_remote_port = handler_port_;
msg.header.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND,
MACH_MSG_TYPE_MAKE_SEND_ONCE);
kern_return_t result = mach_msg(&(empty.header),
kern_return_t result = mach_msg(&(msg.header),
MACH_SEND_MSG | MACH_SEND_TIMEOUT,
empty.header.msgh_size, 0, 0,
msg.header.msgh_size, 0, 0,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
return result == KERN_SUCCESS;

View File

@ -49,6 +49,16 @@ using std::string;
struct ExceptionParameters;
enum HandlerThreadMessage {
// Message ID telling the handler thread to write a dump.
kWriteDumpMessage = 0,
// Message ID telling the handler thread to write a dump and include
// an exception stream.
kWriteDumpWithExceptionMessage = 1,
// Message ID telling the handler thread to quit.
kShutdownMessage = 2
};
class ExceptionHandler {
public:
// A callback function to run before Breakpad performs any substantial
@ -114,11 +124,22 @@ class ExceptionHandler {
// Writes a minidump immediately. This can be used to capture the
// execution state independently of a crash. Returns true on success.
bool WriteMinidump();
bool WriteMinidump() {
return WriteMinidump(false);
}
bool WriteMinidump(bool write_exception_stream);
// Convenience form of WriteMinidump which does not require an
// ExceptionHandler instance.
static bool WriteMinidump(const string &dump_path, MinidumpCallback callback,
void *callback_context) {
return WriteMinidump(dump_path, false, callback, callback_context);
}
static bool WriteMinidump(const string &dump_path,
bool write_exception_stream,
MinidumpCallback callback,
void *callback_context);
// Write a minidump of child immediately. This can be used to capture
@ -149,14 +170,16 @@ class ExceptionHandler {
// thread
bool Teardown();
// Send an "empty" mach message to the exception handler. Return true on
// success, false otherwise. If quit is true, the handler thread should
// simply quit.
bool SendEmptyMachMessage(bool quit);
// Send a mach message to the exception handler. Return true on
// success, false otherwise.
bool SendMessageToHandlerThread(HandlerThreadMessage message_id);
// All minidump writing goes through this one routine
bool WriteMinidumpWithException(int exception_type, int exception_code,
int exception_subcode, mach_port_t thread_name);
bool WriteMinidumpWithException(int exception_type,
int exception_code,
int exception_subcode,
mach_port_t thread_name,
bool exit_after_write);
// When installed, this static function will be call from a newly created
// pthread with |this| as the argument

View File

@ -128,8 +128,8 @@ TEST_F(ExceptionHandlerTest, InProcess) {
EXPECT_EQ(0, WEXITSTATUS(ret));
}
static bool ChildMDCallback(const char *dump_dir, const char *file_name,
void *context, bool success) {
static bool DumpNameMDCallback(const char *dump_dir, const char *file_name,
void *context, bool success) {
ExceptionHandlerTest *self = reinterpret_cast<ExceptionHandlerTest*>(context);
if (dump_dir && file_name) {
self->lastDumpName = dump_dir;
@ -140,6 +140,47 @@ static bool ChildMDCallback(const char *dump_dir, const char *file_name,
return true;
}
TEST_F(ExceptionHandlerTest, WriteMinidump) {
ExceptionHandler eh(tempDir.path, NULL, DumpNameMDCallback, this, true, NULL);
ASSERT_TRUE(eh.WriteMinidump());
// Ensure that minidump file exists and is > 0 bytes.
ASSERT_FALSE(lastDumpName.empty());
struct stat st;
ASSERT_EQ(0, stat(lastDumpName.c_str(), &st));
ASSERT_LT(0, st.st_size);
// The minidump should not contain an exception stream.
Minidump minidump(lastDumpName);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
EXPECT_FALSE(exception);
}
TEST_F(ExceptionHandlerTest, WriteMinidumpWithException) {
ExceptionHandler eh(tempDir.path, NULL, DumpNameMDCallback, this, true, NULL);
ASSERT_TRUE(eh.WriteMinidump(true));
// Ensure that minidump file exists and is > 0 bytes.
ASSERT_FALSE(lastDumpName.empty());
struct stat st;
ASSERT_EQ(0, stat(lastDumpName.c_str(), &st));
ASSERT_LT(0, st.st_size);
// The minidump should contain an exception stream.
Minidump minidump(lastDumpName);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
ASSERT_TRUE(exception);
const MDRawExceptionStream* raw_exception = exception->exception();
ASSERT_TRUE(raw_exception);
EXPECT_EQ(MD_EXCEPTION_MAC_BREAKPOINT,
raw_exception->exception_record.exception_code);
}
TEST_F(ExceptionHandlerTest, DumpChildProcess) {
const int kTimeoutMs = 2000;
// Create a mach port to receive the child task on.
@ -188,7 +229,7 @@ TEST_F(ExceptionHandlerTest, DumpChildProcess) {
bool result = ExceptionHandler::WriteMinidumpForChild(child_task,
child_thread,
tempDir.path,
ChildMDCallback,
DumpNameMDCallback,
this);
ASSERT_EQ(true, result);