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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/timers/leapcrash.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/timers/leapcrash.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/tools/testing/selftests/timers/leapcrash.c b/tools/testing/selftests/timers/leapcrash.c new file mode 100644 index 000000000..dc80728ed --- /dev/null +++ b/tools/testing/selftests/timers/leapcrash.c @@ -0,0 +1,108 @@ +/* Demo leapsecond deadlock + * by: John Stultz (john.stultz@linaro.org) + * (C) Copyright IBM 2012 + * (C) Copyright 2013, 2015 Linaro Limited + * Licensed under the GPL + * + * This test demonstrates leapsecond deadlock that is possibe + * on kernels from 2.6.26 to 3.3. + * + * WARNING: THIS WILL LIKELY HARDHANG SYSTEMS AND MAY LOSE DATA + * RUN AT YOUR OWN RISK! + * To build: + * $ gcc leapcrash.c -o leapcrash -lrt + */ + + + +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <sys/time.h> +#include <sys/timex.h> +#include <string.h> +#include <signal.h> +#include "../kselftest.h" + +/* clear NTP time_status & time_state */ +int clear_time_state(void) +{ + struct timex tx; + int ret; + + /* + * We have to call adjtime twice here, as kernels + * prior to 6b1859dba01c7 (included in 3.5 and + * -stable), had an issue with the state machine + * and wouldn't clear the STA_INS/DEL flag directly. + */ + tx.modes = ADJ_STATUS; + tx.status = STA_PLL; + ret = adjtimex(&tx); + + tx.modes = ADJ_STATUS; + tx.status = 0; + ret = adjtimex(&tx); + + return ret; +} + +/* Make sure we cleanup on ctrl-c */ +void handler(int unused) +{ + clear_time_state(); + exit(0); +} + + +int main(void) +{ + struct timex tx; + struct timespec ts; + time_t next_leap; + int count = 0; + + setbuf(stdout, NULL); + + signal(SIGINT, handler); + signal(SIGKILL, handler); + printf("This runs for a few minutes. Press ctrl-c to stop\n"); + + clear_time_state(); + + + /* Get the current time */ + clock_gettime(CLOCK_REALTIME, &ts); + + /* Calculate the next possible leap second 23:59:60 GMT */ + next_leap = ts.tv_sec; + next_leap += 86400 - (next_leap % 86400); + + for (count = 0; count < 20; count++) { + struct timeval tv; + + + /* set the time to 2 seconds before the leap */ + tv.tv_sec = next_leap - 2; + tv.tv_usec = 0; + if (settimeofday(&tv, NULL)) { + printf("Error: You're likely not running with proper (ie: root) permissions\n"); + return ksft_exit_fail(); + } + tx.modes = 0; + adjtimex(&tx); + + /* hammer on adjtime w/ STA_INS */ + while (tx.time.tv_sec < next_leap + 1) { + /* Set the leap second insert flag */ + tx.modes = ADJ_STATUS; + tx.status = STA_INS; + adjtimex(&tx); + } + clear_time_state(); + printf("."); + fflush(stdout); + } + printf("[OK]\n"); + return ksft_exit_pass(); +} |