root/tools/testing/selftests/timers/leap-a-day.c

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DEFINITIONS

This source file includes following definitions.
  1. in_order
  2. timespec_add
  3. time_state_str
  4. clear_time_state
  5. handler
  6. sigalarm
  7. test_hrtimer_failure
  8. main

   1 /* Leap second stress test
   2  *              by: John Stultz (john.stultz@linaro.org)
   3  *              (C) Copyright IBM 2012
   4  *              (C) Copyright 2013, 2015 Linaro Limited
   5  *              Licensed under the GPLv2
   6  *
   7  *  This test signals the kernel to insert a leap second
   8  *  every day at midnight GMT. This allows for stessing the
   9  *  kernel's leap-second behavior, as well as how well applications
  10  *  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 the
  18  *              time by 24 hours every ~16 seconds, it may cause application
  19  *              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 two
  24  *               may conflict in their commands to the kernel.
  25  *
  26  *  To build:
  27  *      $ gcc leap-a-day.c -o leap-a-day -lrt
  28  *
  29  *   This program is free software: you can redistribute it and/or modify
  30  *   it under the terms of the GNU General Public License as published by
  31  *   the Free Software Foundation, either version 2 of the License, or
  32  *   (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 of
  36  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  37  *   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 1000000000ULL
  54 #define CLOCK_TAI 11
  55 
  56 time_t next_leap;
  57 int error_found;
  58 
  59 /* returns 1 if a <= b, 0 otherwise */
  60 static 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 
  71 struct 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 
  81 char *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 */
  95 int clear_time_state(void)
  96 {
  97         struct timex tx;
  98         int ret;
  99 
 100         /*
 101          * We have to call adjtime twice here, as kernels
 102          * prior to 6b1859dba01c7 (included in 3.5 and
 103          * -stable), had an issue with the state machine
 104          * 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 */
 124 void handler(int unused)
 125 {
 126         clear_time_state();
 127         exit(0);
 128 }
 129 
 130 void 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 */
 160 void 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 
 175 int 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         else
 233                 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                 else
 266                         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                         return 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                         return 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                         return 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                         else
 323                                 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                         return ksft_exit_fail();
 370                 }
 371                 printf("\n");
 372                 if ((iterations != -1) && !(--iterations))
 373                         break;
 374         }
 375 
 376         clear_time_state();
 377         return ksft_exit_pass();
 378 }

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