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Issue 182: linux handler doesn't have sigcontext if called from a previous signal handler. r=mento / Liu Li

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git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@188 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
ted.mielczarek 2007-06-11 16:01:46 +00:00
parent 2e86dfe705
commit 21d58c7281
7 changed files with 87 additions and 25 deletions
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26
src/client/linux/handler/exception_handler.cc
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@ -118,7 +118,7 @@ ExceptionHandler::~ExceptionHandler() {
}
bool ExceptionHandler::WriteMinidump() {
return InternalWriteMinidump(0, NULL);
return InternalWriteMinidump(0, 0, NULL);
}
// static
@ -127,7 +127,7 @@ bool ExceptionHandler::WriteMinidump(const string &dump_path,
void *callback_context) {
ExceptionHandler handler(dump_path, NULL, callback,
callback_context, false);
return handler.InternalWriteMinidump(0, NULL);
return handler.InternalWriteMinidump(0, 0, NULL);
}
void ExceptionHandler::SetupHandler() {
@ -176,8 +176,15 @@ void ExceptionHandler::HandleException(int signo) {
// the signal handler frame as value parameter. For some reasons, the
// prototype of the handler doesn't declare this information as parameter, we
// will do it by hand. It is the second parameter above the signal number.
const struct sigcontext *sig_ctx =
reinterpret_cast<const struct sigcontext *>(&signo + 1);
// However, if we are being called by another signal handler passing the
// signal up the chain, then we may not have this random extra parameter,
// so we may have to walk the stack to find it. We do the actual work
// on another thread, where it's a little safer, but we want the ebp
// from this frame to find it.
uintptr_t current_ebp = 0;
asm volatile ("movl %%ebp, %0"
:"=m"(current_ebp));
pthread_mutex_lock(&handler_stack_mutex_);
ExceptionHandler *current_handler =
handler_stack_->at(handler_stack_->size() - ++handler_stack_index_);
@ -185,7 +192,9 @@ void ExceptionHandler::HandleException(int signo) {
// Restore original handler.
current_handler->TeardownHandler(signo);
if (current_handler->InternalWriteMinidump(signo, sig_ctx)) {
struct sigcontext *sig_ctx = NULL;
if (current_handler->InternalWriteMinidump(signo, current_ebp, &sig_ctx)) {
// Fully handled this exception, safe to exit.
exit(EXIT_FAILURE);
} else {
@ -194,7 +203,7 @@ void ExceptionHandler::HandleException(int signo) {
typedef void (*SignalHandler)(int signo, struct sigcontext);
SignalHandler old_handler =
reinterpret_cast<SignalHandler>(current_handler->old_handlers_[signo]);
if (old_handler != NULL)
if (old_handler != NULL && sig_ctx != NULL)
old_handler(signo, *sig_ctx);
}
@ -212,7 +221,8 @@ void ExceptionHandler::HandleException(int signo) {
}
bool ExceptionHandler::InternalWriteMinidump(int signo,
const struct sigcontext *sig_ctx) {
uintptr_t sighandler_ebp,
struct sigcontext **sig_ctx) {
if (filter_ && !filter_(callback_context_))
return false;
@ -239,7 +249,7 @@ bool ExceptionHandler::InternalWriteMinidump(int signo,
}
success = minidump_generator_.WriteMinidumpToFile(
minidump_path, signo, sig_ctx);
minidump_path, signo, sighandler_ebp, sig_ctx);
// Unblock the signals.
if (blocked) {