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authorJohn Stultz <john.stultz@linaro.org>2015-06-17 18:16:43 (GMT)
committerThomas Gleixner <tglx@linutronix.de>2015-06-18 13:28:14 (GMT)
commit51a16c1e887a5975ada27a3ae935a4f2783005da (patch)
treef2cae7425bb14b2e9b0d4a4e50dd7b841e9dd44a /tools
parent906c55579a6360dd9ef5a3101bb2e3ae396dfb97 (diff)
downloadlinux-51a16c1e887a5975ada27a3ae935a4f2783005da.tar.xz
selftest: Timers: Avoid signal deadlock in leap-a-day
In 0c4a5fc95b1df (Add leap-second timer edge testing to leap-a-day.c), we added a timer to the test which checks to make sure timers near the leapsecond edge behave correctly. However, the output generated from the timer uses ctime_r, which isn't async-signal safe, and should that signal land while the main test is using ctime_r to print its output, its possible for the test to deadlock on glibc internal locks. Thus this patch reworks the output to avoid using ctime_r in the signal handler. Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Jiri Bohac <jbohac@suse.cz> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/1434565003-3386-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/timers/leap-a-day.c23
1 files changed, 12 insertions, 11 deletions
diff --git a/tools/testing/selftests/timers/leap-a-day.c b/tools/testing/selftests/timers/leap-a-day.c
index 331c4f7..fb46ad6 100644
--- a/tools/testing/selftests/timers/leap-a-day.c
+++ b/tools/testing/selftests/timers/leap-a-day.c
@@ -141,27 +141,28 @@ void handler(int unused)
void sigalarm(int signo)
{
struct timex tx;
- char buf[26];
int ret;
tx.modes = 0;
ret = adjtimex(&tx);
- ctime_r(&tx.time.tv_sec, buf);
- buf[strlen(buf)-1] = 0; /*remove trailing\n */
- printf("%s + %6ld us (%i)\t%s - TIMER FIRED\n",
- buf,
+ if (tx.time.tv_sec < next_leap) {
+ printf("Error: Early timer expiration! (Should be %ld)\n", next_leap);
+ error_found = 1;
+ printf("adjtimex: %10ld sec + %6ld us (%i)\t%s\n",
+ tx.time.tv_sec,
tx.time.tv_usec,
tx.tai,
time_state_str(ret));
-
- if (tx.time.tv_sec < next_leap) {
- printf("Error: Early timer expiration!\n");
- error_found = 1;
}
if (ret != TIME_WAIT) {
- printf("Error: Incorrect NTP state?\n");
+ printf("Error: Timer seeing incorrect NTP state? (Should be TIME_WAIT)\n");
error_found = 1;
+ printf("adjtimex: %10ld sec + %6ld us (%i)\t%s\n",
+ tx.time.tv_sec,
+ tx.time.tv_usec,
+ tx.tai,
+ time_state_str(ret));
}
}
@@ -297,7 +298,7 @@ int main(int argc, char **argv)
printf("Scheduling leap second for %s", ctime(&next_leap));
/* Set up timer */
- printf("Setting timer for %s", ctime(&next_leap));
+ printf("Setting timer for %ld - %s", next_leap, ctime(&next_leap));
memset(&se, 0, sizeof(se));
se.sigev_notify = SIGEV_SIGNAL;
se.sigev_signo = signum;