diff options
Diffstat (limited to 'lib/igt_aux.c')
| -rw-r--r-- | lib/igt_aux.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/lib/igt_aux.c b/lib/igt_aux.c index 4d08d68b..ebee119c 100644 --- a/lib/igt_aux.c +++ b/lib/igt_aux.c @@ -79,7 +79,7 @@ static void __attribute__((noreturn)) signal_helper_process(pid_t pid) /* Interrupt the parent process at 500Hz, just to be annoying */ while (1) { usleep(1000 * 1000 / 500); - if (kill(pid, SIGUSR1)) /* Parent has died, so must we. */ + if (kill(pid, SIGCONT)) /* Parent has died, so must we. */ exit(0); } } @@ -93,7 +93,7 @@ static void sig_handler(int i) * igt_fork_signal_helper: * * Fork a child process using #igt_fork_helper to interrupt the parent process - * with a SIGUSR1 signal at regular quick intervals. The corresponding dummy + * with a SIGCONT signal at regular quick intervals. The corresponding dummy * signal handler is installed in the parent process. * * This is useful to exercise ioctl error paths, at least where those can be @@ -108,10 +108,23 @@ void igt_fork_signal_helper(void) if (igt_only_list_subtests()) return; - signal(SIGUSR1, sig_handler); + /* We pick SIGCONT as it is a "safe" signal - if we send SIGCONT to + * an unexpecting process it spuriously wakes up and does nothing. + * Most other signals (e.g. SIGUSR1) cause the process to die if they + * are not handled. This is an issue in case the sighandler is not + * inherited correctly (or if there is a race in the inheritance + * and we send the signal at exactly the wrong time). + */ + signal(SIGCONT, sig_handler); + setpgrp(); /* define a new process group for the tests */ igt_fork_helper(&signal_helper) { - signal_helper_process(getppid()); + setpgrp(); /* Escape from the test process group */ + + /* Pass along the test process group identifier, + * negative pid => send signal to everyone in the group. + */ + signal_helper_process(-getppid()); } } |