diff options
| -rw-r--r-- | tools/testing/selftests/timers/Makefile | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/timers/leapcrash.c | 120 |
2 files changed, 122 insertions, 1 deletions
diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile index da35dddaa985..d73332495c2e 100644 --- a/tools/testing/selftests/timers/Makefile +++ b/tools/testing/selftests/timers/Makefile @@ -5,7 +5,7 @@ LDFLAGS += -lrt -lpthread bins = posix_timers nanosleep inconsistency-check nsleep-lat raw_skew \ set-timer-lat threadtest mqueue-lat valid-adjtimex \ alarmtimer-suspend change_skew skew_consistency clocksource-switch \ - leap-a-day + leap-a-day leapcrash all: ${bins} @@ -31,6 +31,7 @@ run_destructive_tests: run_tests ./skew_consistency ./clocksource-switch ./leap-a-day -s -i 10 + ./leapcrash clean: rm -f ${bins} diff --git a/tools/testing/selftests/timers/leapcrash.c b/tools/testing/selftests/timers/leapcrash.c new file mode 100644 index 000000000000..a1071bdbdeb7 --- /dev/null +++ b/tools/testing/selftests/timers/leapcrash.c @@ -0,0 +1,120 @@ +/* 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> +#ifdef KTEST +#include "../kselftest.h" +#else +static inline int ksft_exit_pass(void) +{ + exit(0); +} +static inline int ksft_exit_fail(void) +{ + exit(1); +} +#endif + + + +/* 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("."); + } + printf("[OK]\n"); + return ksft_exit_pass(); +} |