379 lines · c
1/* Leap second stress test2 * by: John Stultz (john.stultz@linaro.org)3 * (C) Copyright IBM 20124 * (C) Copyright 2013, 2015 Linaro Limited5 * Licensed under the GPLv26 *7 * This test signals the kernel to insert a leap second8 * every day at midnight GMT. This allows for stressing the9 * kernel's leap-second behavior, as well as how well applications10 * handle the leap-second discontinuity.11 *12 * Usage: leap-a-day [-s] [-i <num>]13 *14 * Options:15 * -s: Each iteration, set the date to 10 seconds before midnight GMT.16 * This speeds up the number of leapsecond transitions tested,17 * but because it calls settimeofday frequently, advancing the18 * time by 24 hours every ~16 seconds, it may cause application19 * disruption.20 *21 * -i: Number of iterations to run (default: infinite)22 *23 * Other notes: Disabling NTP prior to running this is advised, as the two24 * may conflict in their commands to the kernel.25 *26 * To build:27 * $ gcc leap-a-day.c -o leap-a-day -lrt28 *29 * This program is free software: you can redistribute it and/or modify30 * it under the terms of the GNU General Public License as published by31 * the Free Software Foundation, either version 2 of the License, or32 * (at your option) any later version.33 *34 * This program is distributed in the hope that it will be useful,35 * but WITHOUT ANY WARRANTY; without even the implied warranty of36 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the37 * GNU General Public License for more details.38 */39 40 41 42#include <stdio.h>43#include <stdlib.h>44#include <time.h>45#include <sys/time.h>46#include <sys/timex.h>47#include <sys/errno.h>48#include <string.h>49#include <signal.h>50#include <unistd.h>51#include "../kselftest.h"52 53#define NSEC_PER_SEC 1000000000ULL54#define CLOCK_TAI 1155 56time_t next_leap;57int error_found;58 59/* returns 1 if a <= b, 0 otherwise */60static inline int in_order(struct timespec a, struct timespec b)61{62 if (a.tv_sec < b.tv_sec)63 return 1;64 if (a.tv_sec > b.tv_sec)65 return 0;66 if (a.tv_nsec > b.tv_nsec)67 return 0;68 return 1;69}70 71struct timespec timespec_add(struct timespec ts, unsigned long long ns)72{73 ts.tv_nsec += ns;74 while (ts.tv_nsec >= NSEC_PER_SEC) {75 ts.tv_nsec -= NSEC_PER_SEC;76 ts.tv_sec++;77 }78 return ts;79}80 81char *time_state_str(int state)82{83 switch (state) {84 case TIME_OK: return "TIME_OK";85 case TIME_INS: return "TIME_INS";86 case TIME_DEL: return "TIME_DEL";87 case TIME_OOP: return "TIME_OOP";88 case TIME_WAIT: return "TIME_WAIT";89 case TIME_BAD: return "TIME_BAD";90 }91 return "ERROR";92}93 94/* clear NTP time_status & time_state */95int clear_time_state(void)96{97 struct timex tx;98 int ret;99 100 /*101 * We have to call adjtime twice here, as kernels102 * prior to 6b1859dba01c7 (included in 3.5 and103 * -stable), had an issue with the state machine104 * and wouldn't clear the STA_INS/DEL flag directly.105 */106 tx.modes = ADJ_STATUS;107 tx.status = STA_PLL;108 ret = adjtimex(&tx);109 110 /* Clear maxerror, as it can cause UNSYNC to be set */111 tx.modes = ADJ_MAXERROR;112 tx.maxerror = 0;113 ret = adjtimex(&tx);114 115 /* Clear the status */116 tx.modes = ADJ_STATUS;117 tx.status = 0;118 ret = adjtimex(&tx);119 120 return ret;121}122 123/* Make sure we cleanup on ctrl-c */124void handler(int unused)125{126 clear_time_state();127 exit(0);128}129 130void sigalarm(int signo)131{132 struct timex tx;133 int ret;134 135 tx.modes = 0;136 ret = adjtimex(&tx);137 138 if (tx.time.tv_sec < next_leap) {139 printf("Error: Early timer expiration! (Should be %ld)\n", next_leap);140 error_found = 1;141 printf("adjtimex: %10ld sec + %6ld us (%i)\t%s\n",142 tx.time.tv_sec,143 tx.time.tv_usec,144 tx.tai,145 time_state_str(ret));146 }147 if (ret != TIME_WAIT) {148 printf("Error: Timer seeing incorrect NTP state? (Should be TIME_WAIT)\n");149 error_found = 1;150 printf("adjtimex: %10ld sec + %6ld us (%i)\t%s\n",151 tx.time.tv_sec,152 tx.time.tv_usec,153 tx.tai,154 time_state_str(ret));155 }156}157 158 159/* Test for known hrtimer failure */160void test_hrtimer_failure(void)161{162 struct timespec now, target;163 164 clock_gettime(CLOCK_REALTIME, &now);165 target = timespec_add(now, NSEC_PER_SEC/2);166 clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &target, NULL);167 clock_gettime(CLOCK_REALTIME, &now);168 169 if (!in_order(target, now)) {170 printf("ERROR: hrtimer early expiration failure observed.\n");171 error_found = 1;172 }173}174 175int main(int argc, char **argv)176{177 timer_t tm1;178 struct itimerspec its1;179 struct sigevent se;180 struct sigaction act;181 int signum = SIGRTMAX;182 int settime = 1;183 int tai_time = 0;184 int insert = 1;185 int iterations = 10;186 int opt;187 188 /* Process arguments */189 while ((opt = getopt(argc, argv, "sti:")) != -1) {190 switch (opt) {191 case 'w':192 printf("Only setting leap-flag, not changing time. It could take up to a day for leap to trigger.\n");193 settime = 0;194 break;195 case 'i':196 iterations = atoi(optarg);197 break;198 case 't':199 tai_time = 1;200 break;201 default:202 printf("Usage: %s [-w] [-i <iterations>]\n", argv[0]);203 printf(" -w: Set flag and wait for leap second each iteration");204 printf(" (default sets time to right before leapsecond)\n");205 printf(" -i: Number of iterations (-1 = infinite, default is 10)\n");206 printf(" -t: Print TAI time\n");207 exit(-1);208 }209 }210 211 /* Make sure TAI support is present if -t was used */212 if (tai_time) {213 struct timespec ts;214 215 if (clock_gettime(CLOCK_TAI, &ts)) {216 printf("System doesn't support CLOCK_TAI\n");217 ksft_exit_fail();218 }219 }220 221 signal(SIGINT, handler);222 signal(SIGKILL, handler);223 224 /* Set up timer signal handler: */225 sigfillset(&act.sa_mask);226 act.sa_flags = 0;227 act.sa_handler = sigalarm;228 sigaction(signum, &act, NULL);229 230 if (iterations < 0)231 printf("This runs continuously. Press ctrl-c to stop\n");232 else233 printf("Running for %i iterations. Press ctrl-c to stop\n", iterations);234 235 printf("\n");236 while (1) {237 int ret;238 struct timespec ts;239 struct timex tx;240 time_t now;241 242 /* Get the current time */243 clock_gettime(CLOCK_REALTIME, &ts);244 245 /* Calculate the next possible leap second 23:59:60 GMT */246 next_leap = ts.tv_sec;247 next_leap += 86400 - (next_leap % 86400);248 249 if (settime) {250 struct timeval tv;251 252 tv.tv_sec = next_leap - 10;253 tv.tv_usec = 0;254 settimeofday(&tv, NULL);255 printf("Setting time to %s", ctime(&tv.tv_sec));256 }257 258 /* Reset NTP time state */259 clear_time_state();260 261 /* Set the leap second insert flag */262 tx.modes = ADJ_STATUS;263 if (insert)264 tx.status = STA_INS;265 else266 tx.status = STA_DEL;267 ret = adjtimex(&tx);268 if (ret < 0) {269 printf("Error: Problem setting STA_INS/STA_DEL!: %s\n",270 time_state_str(ret));271 ksft_exit_fail();272 }273 274 /* Validate STA_INS was set */275 tx.modes = 0;276 ret = adjtimex(&tx);277 if (tx.status != STA_INS && tx.status != STA_DEL) {278 printf("Error: STA_INS/STA_DEL not set!: %s\n",279 time_state_str(ret));280 ksft_exit_fail();281 }282 283 if (tai_time) {284 printf("Using TAI time,"285 " no inconsistencies should be seen!\n");286 }287 288 printf("Scheduling leap second for %s", ctime(&next_leap));289 290 /* Set up timer */291 printf("Setting timer for %ld - %s", next_leap, ctime(&next_leap));292 memset(&se, 0, sizeof(se));293 se.sigev_notify = SIGEV_SIGNAL;294 se.sigev_signo = signum;295 se.sigev_value.sival_int = 0;296 if (timer_create(CLOCK_REALTIME, &se, &tm1) == -1) {297 printf("Error: timer_create failed\n");298 ksft_exit_fail();299 }300 its1.it_value.tv_sec = next_leap;301 its1.it_value.tv_nsec = 0;302 its1.it_interval.tv_sec = 0;303 its1.it_interval.tv_nsec = 0;304 timer_settime(tm1, TIMER_ABSTIME, &its1, NULL);305 306 /* Wake up 3 seconds before leap */307 ts.tv_sec = next_leap - 3;308 ts.tv_nsec = 0;309 310 311 while (clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &ts, NULL))312 printf("Something woke us up, returning to sleep\n");313 314 /* Validate STA_INS is still set */315 tx.modes = 0;316 ret = adjtimex(&tx);317 if (tx.status != STA_INS && tx.status != STA_DEL) {318 printf("Something cleared STA_INS/STA_DEL, setting it again.\n");319 tx.modes = ADJ_STATUS;320 if (insert)321 tx.status = STA_INS;322 else323 tx.status = STA_DEL;324 ret = adjtimex(&tx);325 }326 327 /* Check adjtimex output every half second */328 now = tx.time.tv_sec;329 while (now < next_leap + 2) {330 char buf[26];331 struct timespec tai;332 int ret;333 334 tx.modes = 0;335 ret = adjtimex(&tx);336 337 if (tai_time) {338 clock_gettime(CLOCK_TAI, &tai);339 printf("%ld sec, %9ld ns\t%s\n",340 tai.tv_sec,341 tai.tv_nsec,342 time_state_str(ret));343 } else {344 ctime_r(&tx.time.tv_sec, buf);345 buf[strlen(buf)-1] = 0; /*remove trailing\n */346 347 printf("%s + %6ld us (%i)\t%s\n",348 buf,349 tx.time.tv_usec,350 tx.tai,351 time_state_str(ret));352 }353 now = tx.time.tv_sec;354 /* Sleep for another half second */355 ts.tv_sec = 0;356 ts.tv_nsec = NSEC_PER_SEC / 2;357 clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL);358 }359 /* Switch to using other mode */360 insert = !insert;361 362 /* Note if kernel has known hrtimer failure */363 test_hrtimer_failure();364 365 printf("Leap complete\n");366 if (error_found) {367 printf("Errors observed\n");368 clear_time_state();369 ksft_exit_fail();370 }371 printf("\n");372 if ((iterations != -1) && !(--iterations))373 break;374 }375 376 clear_time_state();377 ksft_exit_pass();378}379