/*
* mono_chain_signal:
*
* Call the original signal handler for the signal given by the arguments, which
* should be the same as for a signal handler. Returns TRUE if the original handler
* was called, false otherwise.
*/
gboolean
MONO_SIG_HANDLER_SIGNATURE (mono_chain_signal)
{
int signal = MONO_SIG_HANDLER_GET_SIGNO ();
struct sigaction *saved_handler = (struct sigaction *)get_saved_signal_handler (signal, FALSE);
if (saved_handler && saved_handler->sa_handler) {
if (!(saved_handler->sa_flags & SA_SIGINFO)) {
saved_handler->sa_handler (signal);
} else {
#ifdef MONO_ARCH_USE_SIGACTION
saved_handler->sa_sigaction (MONO_SIG_HANDLER_PARAMS);
#endif /* MONO_ARCH_USE_SIGACTION */
}
return TRUE;
}
return FALSE;
}
/*
* mono_chain_signal:
*
* Call the original signal handler for the signal given by the arguments, which
* should be the same as for a signal handler. Returns TRUE if the original handler
* was called, false otherwise.
*/
gboolean
SIG_HANDLER_SIGNATURE (mono_chain_signal)
{
int signal = _dummy;
struct sigaction *saved_handler = get_saved_signal_handler (signal);
GET_CONTEXT;
if (saved_handler && saved_handler->sa_handler) {
if (!(saved_handler->sa_flags & SA_SIGINFO)) {
saved_handler->sa_handler (signal);
} else {
#ifdef MONO_ARCH_USE_SIGACTION
saved_handler->sa_sigaction (signal, info, ctx);
#endif /* MONO_ARCH_USE_SIGACTION */
}
return TRUE;
}
return FALSE;
}
static void
add_signal_handler (int signo, gpointer handler)
{
struct sigaction sa;
struct sigaction previous_sa;
#ifdef MONO_ARCH_USE_SIGACTION
sa.sa_sigaction = handler;
sigemptyset (&sa.sa_mask);
sa.sa_flags = SA_SIGINFO;
#ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
/*Apple likes to deliver SIGBUS for *0 */
#ifdef __APPLE__
if (signo == SIGSEGV || signo == SIGBUS) {
#else
if (signo == SIGSEGV) {
#endif
sa.sa_flags |= SA_ONSTACK;
/*
* libgc will crash when trying to do stack marking for threads which are on
* an altstack, so delay the suspend signal after the signal handler has
* executed.
*/
if (mono_gc_get_suspend_signal () != -1)
sigaddset (&sa.sa_mask, mono_gc_get_suspend_signal ());
}
#endif
if (signo == SIGSEGV) {
/*
* Delay abort signals while handling SIGSEGVs since they could go unnoticed.
*/
sigset_t block_mask;
sigemptyset (&block_mask);
sigaddset (&sa.sa_mask, mono_thread_get_abort_signal ());
}
#else
sa.sa_handler = handler;
sigemptyset (&sa.sa_mask);
sa.sa_flags = 0;
#endif
g_assert (sigaction (signo, &sa, &previous_sa) != -1);
/* if there was already a handler in place for this signal, store it */
if (! (previous_sa.sa_flags & SA_SIGINFO) &&
(SIG_DFL == previous_sa.sa_handler)) {
/* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
} else {
if (mono_do_signal_chaining)
save_old_signal_handler (signo, &previous_sa);
}
}
static void
remove_signal_handler (int signo)
{
struct sigaction sa;
struct sigaction *saved_action = get_saved_signal_handler (signo);
if (!saved_action) {
sa.sa_handler = SIG_DFL;
sigemptyset (&sa.sa_mask);
sa.sa_flags = 0;
sigaction (signo, &sa, NULL);
} else {
g_assert (sigaction (signo, saved_action, NULL) != -1);
}
}
void
mono_runtime_posix_install_handlers (void)
{
sigset_t signal_set;
if (mini_get_debug_options ()->handle_sigint)
add_signal_handler (SIGINT, mono_sigint_signal_handler);
add_signal_handler (SIGFPE, mono_sigfpe_signal_handler);
add_signal_handler (SIGQUIT, sigquit_signal_handler);
add_signal_handler (SIGILL, mono_sigill_signal_handler);
add_signal_handler (SIGBUS, mono_sigsegv_signal_handler);
if (mono_jit_trace_calls != NULL)
add_signal_handler (SIGUSR2, sigusr2_signal_handler);
if (!mono_thread_info_new_interrupt_enabled ())
add_signal_handler (mono_thread_get_abort_signal (), sigusr1_signal_handler);
/* it seems to have become a common bug for some programs that run as parents
* of many processes to block signal delivery for real time signals.
* We try to detect and work around their breakage here.
*/
sigemptyset (&signal_set);
sigaddset (&signal_set, mono_thread_get_abort_signal ());
sigprocmask (SIG_UNBLOCK, &signal_set, NULL);
signal (SIGPIPE, SIG_IGN);
add_signal_handler (SIGABRT, sigabrt_signal_handler);
/* catch SIGSEGV */
add_signal_handler (SIGSEGV, mono_sigsegv_signal_handler);
}
static void
add_signal_handler (int signo, gpointer handler, int flags)
{
struct sigaction sa;
struct sigaction previous_sa;
#ifdef MONO_ARCH_USE_SIGACTION
sa.sa_sigaction = (void (*)(int, siginfo_t *, void *))handler;
sigemptyset (&sa.sa_mask);
sa.sa_flags = SA_SIGINFO | flags;
#ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
/*Apple likes to deliver SIGBUS for *0 */
#ifdef HOST_DARWIN
if (signo == SIGSEGV || signo == SIGBUS) {
#else
if (signo == SIGSEGV) {
#endif
sa.sa_flags |= SA_ONSTACK;
/*
* libgc will crash when trying to do stack marking for threads which are on
* an altstack, so delay the suspend signal after the signal handler has
* executed.
*/
if (mono_gc_get_suspend_signal () != -1)
sigaddset (&sa.sa_mask, mono_gc_get_suspend_signal ());
}
#endif
if (signo == SIGSEGV) {
/*
* Delay abort signals while handling SIGSEGVs since they could go unnoticed.
*/
sigset_t block_mask;
sigemptyset (&block_mask);
}
#else
sa.sa_handler = handler;
sigemptyset (&sa.sa_mask);
sa.sa_flags = flags;
#endif
g_assert (sigaction (signo, &sa, &previous_sa) != -1);
/* if there was already a handler in place for this signal, store it */
if (! (previous_sa.sa_flags & SA_SIGINFO) &&
(SIG_DFL == previous_sa.sa_handler)) {
/* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
} else {
if (mono_do_signal_chaining)
save_old_signal_handler (signo, &previous_sa);
}
}
static void
remove_signal_handler (int signo)
{
struct sigaction sa;
struct sigaction *saved_action = get_saved_signal_handler (signo, TRUE);
if (!saved_action) {
sa.sa_handler = SIG_DFL;
sigemptyset (&sa.sa_mask);
sa.sa_flags = 0;
sigaction (signo, &sa, NULL);
} else {
g_assert (sigaction (signo, saved_action, NULL) != -1);
}
}
#ifdef TARGET_OSX
void
mini_register_sigterm_handler (void)
{
/* always catch SIGTERM, conditionals inside of handler */
add_signal_handler (SIGTERM, sigterm_signal_handler, 0);
}