[igt-dev] [PATCH v2 i-g-t 3/3] runner: Make sure that we are closing watchdogs on signals
Ser, Simon
simon.ser at intel.com
Fri Jul 19 12:04:26 UTC 2019
On Fri, 2019-07-19 at 15:01 +0300, Arkadiusz Hiler wrote:
> There are few short windows of opportunity when watchdogs are primed but
> there is no signal handling in place, so the process may exit without
> proper shutdown sequence.
>
> This patch rearranges the existing code so that we set up the signalfd
> and BLOCK the signals before setting up watchdogs and UNBLOCK only after
> the watchdogs are closed properly.
>
> If igt_runner exits due to signal, non-zero status code is returned.
>
> v2: more error handling and minor touch ups (Simon)
>
> Cc: Petri Latvala <petri.latvala at intel.com>
> Cc: Simon Ser <simon.ser at intel.com>
> Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler at intel.com>
LGTM, thanks for the delta!
Reviewed-by: Simon Ser <simon.ser at intel.com>
> ---
>
> delta with v1: https://hiler.eu/p/9d79f730.txt
>
> runner/executor.c | 107 ++++++++++++++++++++++++++++++++++------------
> 1 file changed, 80 insertions(+), 27 deletions(-)
>
> diff --git a/runner/executor.c b/runner/executor.c
> index 6463ab96..52fee7d1 100644
> --- a/runner/executor.c
> +++ b/runner/executor.c
> @@ -7,6 +7,7 @@
> #include <string.h>
> #include <sys/ioctl.h>
> #include <sys/select.h>
> +#include <sys/poll.h>
> #include <sys/signalfd.h>
> #include <sys/stat.h>
> #include <sys/time.h>
> @@ -604,7 +605,6 @@ static int monitor_output(pid_t child,
> close(outfd);
> close(errfd);
> close(kmsgfd);
> - close(sigfd);
> return -1;
> }
>
> @@ -776,9 +776,8 @@ static int monitor_output(pid_t child,
> *time_spent = time;
> }
>
> - close(sigfd);
> - sigfd = -1;
> child = 0;
> + sigfd = -1; /* we are dying, no signal handling for now */
> }
> }
>
> @@ -790,7 +789,6 @@ static int monitor_output(pid_t child,
> close(outfd);
> close(errfd);
> close(kmsgfd);
> - close(sigfd);
>
> if (aborting)
> return -1;
> @@ -908,13 +906,12 @@ static int execute_next_entry(struct execute_state *state,
> double *time_spent,
> struct settings *settings,
> struct job_list_entry *entry,
> - int testdirfd, int resdirfd)
> + int testdirfd, int resdirfd,
> + int sigfd, sigset_t *sigmask)
> {
> int dirfd;
> int outputs[_F_LAST];
> int kmsgfd;
> - int sigfd;
> - sigset_t mask;
> int outpipe[2] = { -1, -1 };
> int errpipe[2] = { -1, -1 };
> int outfd, errfd;
> @@ -954,21 +951,6 @@ static int execute_next_entry(struct execute_state *state,
> lseek(kmsgfd, 0, SEEK_END);
> }
>
> - sigemptyset(&mask);
> - sigaddset(&mask, SIGCHLD);
> - sigaddset(&mask, SIGINT);
> - sigaddset(&mask, SIGTERM);
> - sigaddset(&mask, SIGQUIT);
> - sigaddset(&mask, SIGHUP);
> - sigprocmask(SIG_BLOCK, &mask, NULL);
> - sigfd = signalfd(-1, &mask, O_CLOEXEC);
> -
> - if (sigfd < 0) {
> - /* TODO: Handle better */
> - fprintf(stderr, "Cannot monitor child process with signalfd\n");
> - result = -1;
> - goto out_kmsgfd;
> - }
>
> if (settings->log_level >= LOG_LEVEL_NORMAL) {
> char *displayname;
> @@ -1002,7 +984,7 @@ static int execute_next_entry(struct execute_state *state,
> close(outpipe[0]);
> close(errpipe[0]);
>
> - sigprocmask(SIG_UNBLOCK, &mask, NULL);
> + sigprocmask(SIG_UNBLOCK, sigmask, NULL);
>
> setenv("IGT_SENTINEL_ON_STDERR", "1", 1);
>
> @@ -1261,12 +1243,48 @@ static void oom_immortal(void)
> close(fd);
> }
>
> +static bool should_die_because_signal(int sigfd)
> +{
> + struct signalfd_siginfo siginfo;
> + int ret;
> + struct pollfd sigpoll = { .fd = sigfd, .events = POLLIN | POLLRDBAND };
> +
> + ret = poll(&sigpoll, 1, 0);
> +
> + if (ret != 0) {
> + if (ret == -1) {
> + fprintf(stderr, "Poll on signalfd failed with %s\n", strerror(errno));
> + return true; /* something is wrong, let's die */
> + }
> +
> + ret = read(sigfd, &siginfo, sizeof(siginfo));
> +
> + if (ret == -1) {
> + fprintf(stderr, "Error reading from signalfd: %s\n", strerror(errno));
> + return false; /* we may want to retry later */
> + }
> +
> + if (siginfo.ssi_signo == SIGCHLD) {
> + fprintf(stderr, "Runner got stray SIGCHLD while not executing any tests.\n");
> + } else {
> + fprintf(stderr, "Runner is being killed by %s\n",
> + strsignal(siginfo.ssi_signo));
> + return true;
> + }
> +
> + }
> +
> + return false;
> +}
> +
> bool execute(struct execute_state *state,
> struct settings *settings,
> struct job_list *job_list)
> {
> struct utsname unamebuf;
> int resdirfd, testdirfd, unamefd, timefd;
> + sigset_t sigmask;
> + int sigfd;
> double time_spent = 0.0;
> bool status = true;
>
> @@ -1310,6 +1328,22 @@ bool execute(struct execute_state *state,
>
> oom_immortal();
>
> + sigemptyset(&sigmask);
> + sigaddset(&sigmask, SIGCHLD);
> + sigaddset(&sigmask, SIGINT);
> + sigaddset(&sigmask, SIGTERM);
> + sigaddset(&sigmask, SIGQUIT);
> + sigaddset(&sigmask, SIGHUP);
> + sigfd = signalfd(-1, &sigmask, O_CLOEXEC);
> + sigprocmask(SIG_BLOCK, &sigmask, NULL);
> +
> + if (sigfd < 0) {
> + /* TODO: Handle better */
> + fprintf(stderr, "Cannot mask signals\n");
> + status = false;
> + goto end;
> + }
> +
> init_watchdogs(settings);
>
> if (!uname(&unamebuf)) {
> @@ -1345,12 +1379,18 @@ bool execute(struct execute_state *state,
> char *reason;
> int result;
>
> + if (should_die_because_signal(sigfd)) {
> + status = false;
> + goto end;
> + }
> +
> result = execute_next_entry(state,
> job_list->size,
> &time_spent,
> settings,
> &job_list->entries[state->next],
> - testdirfd, resdirfd);
> + testdirfd, resdirfd,
> + sigfd, &sigmask);
>
> if (result < 0) {
> status = false;
> @@ -1383,8 +1423,15 @@ bool execute(struct execute_state *state,
> if (result > 0) {
> double time_left = state->time_left;
>
> - close(testdirfd);
> close_watchdogs(settings);
> + sigprocmask(SIG_UNBLOCK, &sigmask, NULL);
> + /* make sure that we do not leave any signals unhandled */
> + if (should_die_because_signal(sigfd)) {
> + status = false;
> + goto end_post_signal_restore;
> + }
> + close(sigfd);
> + close(testdirfd);
> initialize_execute_state_from_resume(resdirfd, state, settings, job_list);
> state->time_left = time_left;
> return execute(state, settings, job_list);
> @@ -1397,8 +1444,14 @@ bool execute(struct execute_state *state,
> }
>
> end:
> - close(testdirfd);
> - close(resdirfd);
> close_watchdogs(settings);
> + sigprocmask(SIG_UNBLOCK, &sigmask, NULL);
> + /* make sure that we do not leave any signals unhandled */
> + if (should_die_because_signal(sigfd))
> + status = false;
> + end_post_signal_restore:
> + close(sigfd);
> + close(testdirfd);
> + close(resdirfd);
> return status;
> }
More information about the igt-dev
mailing list