[checkmk-commits] Make sure SIGALRM can be delivered. Check fork() for errors.

Module: check_mk Branch: master Commit: 84730d34a011306f3f7495c2eecd042113b65474 URL: http://git.mathias-kettner.de/git/?p=check_mk.git;a=commit;h=84730d34a01130… Author: Sven Panne &lt;sp(a)mathias-kettner.de&gt; Date: Tue Nov 24 13:43:40 2015 +0100 Make sure SIGALRM can be delivered. Check fork() for errors. --- agents/waitmax.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/agents/waitmax.c b/agents/waitmax.c index c4ce4c7..0a1cf4c 100644 --- a/agents/waitmax.c +++ b/agents/waitmax.c @@ -92,6 +92,15 @@ static void signalhandler(int signum __attribute__((__unused__))) if (kill(g_pid, g_signum) == 0) g_timeout = 1; } +static void unblock_signal(int signum) +{ + sigset_t signals_to_unblock; + sigemptyset(&signals_to_unblock); + sigaddset(&signals_to_unblock, signum); + if (sigprocmask(SIG_UNBLOCK, &signals_to_unblock, NULL) == -1) + exit_with("sigprocmask failed", errno, 1); +} + static struct option long_options[] = {{"version", no_argument, 0, 'V'}, {"help", no_argument, 0, 'h'}, {"signal", required_argument, 0, 's'}, @@ -124,12 +133,16 @@ int main(int argc, char **argv) if (maxtime <= 0) usage(1); g_pid = fork(); + if (g_pid == -1) exit_with("fork() failed", errno, 1); + if (g_pid == 0) { signal(SIGALRM, signalhandler); execvp(argv[optind + 1], argv + optind + 1); exit_with(argv[optind + 1], errno, 253); } + /* Make sure SIGALRM is not blocked (e.g. by parent). */ + unblock_signal(SIGALRM); signal(SIGALRM, signalhandler); alarm(maxtime);