Bug 944612 - Guard the ElfLoader sigaction wrapper against the SIGSEGV handler not being installed. r=glandium

This commit is contained in:
Douglas Crosher 2014-03-20 12:35:15 +11:00
parent 845933d8ec
commit a33e69853e

View File

@ -992,24 +992,23 @@ SEGVHandler::SEGVHandler()
sigemptyset(&action.sa_mask);
action.sa_flags = SA_SIGINFO | SA_NODEFER;
action.sa_restorer = nullptr;
if (sys_sigaction(SIGSEGV, &action, nullptr))
return;
stackPtr.Assign(MemoryRange::mmap(nullptr, PageSize(),
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
if (stackPtr.get() == MAP_FAILED)
return;
if (sys_sigaction(SIGSEGV, &action, nullptr))
return;
TmpData *data = reinterpret_cast<TmpData*>(stackPtr.get());
data->crash_timestamp = ProcessTimeStamp_Now();
mprotect(stackPtr, stackPtr.GetLength(), PROT_NONE);
data->crash_int = 123;
/* Restore the original segfault signal handler. */
sys_sigaction(SIGSEGV, &this->action, nullptr);
stackPtr.Assign(MAP_FAILED, 0);
if (signalHandlingBroken || signalHandlingSlow) {
/* Restore the original segfault signal handler. */
sys_sigaction(SIGSEGV, &this->action, nullptr);
if (signalHandlingBroken || signalHandlingSlow)
return;
}
/* Setup an alternative stack if the already existing one is not big
* enough, or if there is none. */
@ -1111,11 +1110,12 @@ int
SEGVHandler::__wrap_sigaction(int signum, const struct sigaction *act,
struct sigaction *oldact)
{
SEGVHandler &that = ElfLoader::Singleton;
/* Use system sigaction() function for all but SIGSEGV signals. */
if (signum != SIGSEGV)
if (!that.registeredHandler || (signum != SIGSEGV))
return sys_sigaction(signum, act, oldact);
SEGVHandler &that = ElfLoader::Singleton;
if (oldact)
*oldact = that.action;
if (act)