diff options
| -rw-r--r-- | src/sig-monitor.c | 48 |
1 files changed, 37 insertions, 11 deletions
diff --git a/src/sig-monitor.c b/src/sig-monitor.c index a92fc814..75982507 100644 --- a/src/sig-monitor.c +++ b/src/sig-monitor.c @@ -34,6 +34,7 @@ /* local handler */ static _Thread_local sigjmp_buf *error_handler; +static _Thread_local int in_safe_dumpstack; /* local timers */ static _Thread_local int thread_timer_set; @@ -75,6 +76,24 @@ static void dumpstack(int crop, int signum) } } +static void safe_dumpstack_cb(int signum, void *closure) +{ + int *args = closure; + if (signum) + ERROR("Can't provide backtrace: raised signal %s", strsignal(signum)); + else + dumpstack(args[0], args[1]); +} + +static void safe_dumpstack(int crop, int signum) +{ + int args[2] = { crop, signum }; + + in_safe_dumpstack = 1; + sig_monitor(0, safe_dumpstack_cb, args); + in_safe_dumpstack = 0; +} + /* * Creates a timer for the current thread * @@ -146,9 +165,11 @@ static inline void timeout_delete() /* Handles signals that terminate the process */ static void on_signal_terminate (int signum) { - ERROR("Terminating signal %d received: %s", signum, strsignal(signum)); - if (signum == SIGABRT) - dumpstack(3, signum); + if (!in_safe_dumpstack) { + ERROR("Terminating signal %d received: %s", signum, strsignal(signum)); + if (signum == SIGABRT) + safe_dumpstack(3, signum); + } exit(1); } @@ -157,19 +178,19 @@ static void on_signal_error(int signum) { sigset_t sigset; + if (in_safe_dumpstack) + longjmp(*error_handler, signum); + ERROR("ALERT! signal %d received: %s", signum, strsignal(signum)); if (error_handler == NULL && signum == SIG_FOR_TIMER) return; - dumpstack(3, signum); + safe_dumpstack(3, signum); // unlock signal to allow a new signal to come - if (error_handler != NULL) { - sigemptyset(&sigset); - sigaddset(&sigset, signum); - sigprocmask(SIG_UNBLOCK, &sigset, 0); + if (error_handler != NULL) longjmp(*error_handler, signum); - } + ERROR("Unmonitored signal %d received: %s", signum, strsignal(signum)); exit(2); } @@ -178,9 +199,14 @@ static void on_signal_error(int signum) static int install(void (*handler)(int), int *signals) { int result = 1; + struct sigaction sa; + + sa.sa_handler = handler; + sigemptyset(&sa.sa_mask); + sa.sa_flags = SA_NODEFER; while(*signals > 0) { - if (signal(*signals, handler) == SIG_ERR) { - ERROR("failed to install signal handler for signal %s", strsignal(*signals)); + if (sigaction(*signals, &sa, NULL) < 0) { + ERROR("failed to install signal handler for signal %s: %m", strsignal(*signals)); result = 0; } signals++; |