John Stultz | 5bccfe4 | 2015-03-11 17:40:11 -0700 | [diff] [blame] | 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 <string.h> |
| 48 | #include <signal.h> |
| 49 | #include <unistd.h> |
| 50 | #ifdef KTEST |
| 51 | #include "../kselftest.h" |
| 52 | #else |
| 53 | static inline int ksft_exit_pass(void) |
| 54 | { |
| 55 | exit(0); |
| 56 | } |
| 57 | static inline int ksft_exit_fail(void) |
| 58 | { |
| 59 | exit(1); |
| 60 | } |
| 61 | #endif |
| 62 | |
| 63 | #define NSEC_PER_SEC 1000000000ULL |
| 64 | #define CLOCK_TAI 11 |
| 65 | |
| 66 | /* returns 1 if a <= b, 0 otherwise */ |
| 67 | static inline int in_order(struct timespec a, struct timespec b) |
| 68 | { |
| 69 | if (a.tv_sec < b.tv_sec) |
| 70 | return 1; |
| 71 | if (a.tv_sec > b.tv_sec) |
| 72 | return 0; |
| 73 | if (a.tv_nsec > b.tv_nsec) |
| 74 | return 0; |
| 75 | return 1; |
| 76 | } |
| 77 | |
| 78 | struct timespec timespec_add(struct timespec ts, unsigned long long ns) |
| 79 | { |
| 80 | ts.tv_nsec += ns; |
| 81 | while (ts.tv_nsec >= NSEC_PER_SEC) { |
| 82 | ts.tv_nsec -= NSEC_PER_SEC; |
| 83 | ts.tv_sec++; |
| 84 | } |
| 85 | return ts; |
| 86 | } |
| 87 | |
| 88 | char *time_state_str(int state) |
| 89 | { |
| 90 | switch (state) { |
| 91 | case TIME_OK: return "TIME_OK"; |
| 92 | case TIME_INS: return "TIME_INS"; |
| 93 | case TIME_DEL: return "TIME_DEL"; |
| 94 | case TIME_OOP: return "TIME_OOP"; |
| 95 | case TIME_WAIT: return "TIME_WAIT"; |
| 96 | case TIME_BAD: return "TIME_BAD"; |
| 97 | } |
| 98 | return "ERROR"; |
| 99 | } |
| 100 | |
| 101 | /* clear NTP time_status & time_state */ |
| 102 | int clear_time_state(void) |
| 103 | { |
| 104 | struct timex tx; |
| 105 | int ret; |
| 106 | |
| 107 | /* |
| 108 | * We have to call adjtime twice here, as kernels |
| 109 | * prior to 6b1859dba01c7 (included in 3.5 and |
| 110 | * -stable), had an issue with the state machine |
| 111 | * and wouldn't clear the STA_INS/DEL flag directly. |
| 112 | */ |
| 113 | tx.modes = ADJ_STATUS; |
| 114 | tx.status = STA_PLL; |
| 115 | ret = adjtimex(&tx); |
| 116 | |
| 117 | /* Clear maxerror, as it can cause UNSYNC to be set */ |
| 118 | tx.modes = ADJ_MAXERROR; |
| 119 | tx.maxerror = 0; |
| 120 | ret = adjtimex(&tx); |
| 121 | |
| 122 | /* Clear the status */ |
| 123 | tx.modes = ADJ_STATUS; |
| 124 | tx.status = 0; |
| 125 | ret = adjtimex(&tx); |
| 126 | |
| 127 | return ret; |
| 128 | } |
| 129 | |
| 130 | /* Make sure we cleanup on ctrl-c */ |
| 131 | void handler(int unused) |
| 132 | { |
| 133 | clear_time_state(); |
| 134 | exit(0); |
| 135 | } |
| 136 | |
| 137 | /* Test for known hrtimer failure */ |
| 138 | void test_hrtimer_failure(void) |
| 139 | { |
| 140 | struct timespec now, target; |
| 141 | |
| 142 | clock_gettime(CLOCK_REALTIME, &now); |
| 143 | target = timespec_add(now, NSEC_PER_SEC/2); |
| 144 | clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &target, NULL); |
| 145 | clock_gettime(CLOCK_REALTIME, &now); |
| 146 | |
| 147 | if (!in_order(target, now)) |
| 148 | printf("ERROR: hrtimer early expiration failure observed.\n"); |
| 149 | } |
| 150 | |
| 151 | int main(int argc, char **argv) |
| 152 | { |
| 153 | int settime = 0; |
| 154 | int tai_time = 0; |
| 155 | int insert = 1; |
| 156 | int iterations = -1; |
| 157 | int opt; |
| 158 | |
| 159 | /* Process arguments */ |
| 160 | while ((opt = getopt(argc, argv, "sti:")) != -1) { |
| 161 | switch (opt) { |
| 162 | case 's': |
| 163 | printf("Setting time to speed up testing\n"); |
| 164 | settime = 1; |
| 165 | break; |
| 166 | case 'i': |
| 167 | iterations = atoi(optarg); |
| 168 | break; |
| 169 | case 't': |
| 170 | tai_time = 1; |
| 171 | break; |
| 172 | default: |
| 173 | printf("Usage: %s [-s] [-i <iterations>]\n", argv[0]); |
| 174 | printf(" -s: Set time to right before leap second each iteration\n"); |
| 175 | printf(" -i: Number of iterations\n"); |
| 176 | printf(" -t: Print TAI time\n"); |
| 177 | exit(-1); |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | /* Make sure TAI support is present if -t was used */ |
| 182 | if (tai_time) { |
| 183 | struct timespec ts; |
| 184 | |
| 185 | if (clock_gettime(CLOCK_TAI, &ts)) { |
| 186 | printf("System doesn't support CLOCK_TAI\n"); |
| 187 | ksft_exit_fail(); |
| 188 | } |
| 189 | } |
| 190 | |
| 191 | signal(SIGINT, handler); |
| 192 | signal(SIGKILL, handler); |
| 193 | |
| 194 | if (iterations < 0) |
| 195 | printf("This runs continuously. Press ctrl-c to stop\n"); |
| 196 | else |
| 197 | printf("Running for %i iterations. Press ctrl-c to stop\n", iterations); |
| 198 | |
| 199 | printf("\n"); |
| 200 | while (1) { |
| 201 | int ret; |
| 202 | struct timespec ts; |
| 203 | struct timex tx; |
| 204 | time_t now, next_leap; |
| 205 | |
| 206 | /* Get the current time */ |
| 207 | clock_gettime(CLOCK_REALTIME, &ts); |
| 208 | |
| 209 | /* Calculate the next possible leap second 23:59:60 GMT */ |
| 210 | next_leap = ts.tv_sec; |
| 211 | next_leap += 86400 - (next_leap % 86400); |
| 212 | |
| 213 | if (settime) { |
| 214 | struct timeval tv; |
| 215 | |
| 216 | tv.tv_sec = next_leap - 10; |
| 217 | tv.tv_usec = 0; |
| 218 | settimeofday(&tv, NULL); |
| 219 | printf("Setting time to %s", ctime(&tv.tv_sec)); |
| 220 | } |
| 221 | |
| 222 | /* Reset NTP time state */ |
| 223 | clear_time_state(); |
| 224 | |
| 225 | /* Set the leap second insert flag */ |
| 226 | tx.modes = ADJ_STATUS; |
| 227 | if (insert) |
| 228 | tx.status = STA_INS; |
| 229 | else |
| 230 | tx.status = STA_DEL; |
| 231 | ret = adjtimex(&tx); |
| 232 | if (ret < 0) { |
| 233 | printf("Error: Problem setting STA_INS/STA_DEL!: %s\n", |
| 234 | time_state_str(ret)); |
| 235 | return ksft_exit_fail(); |
| 236 | } |
| 237 | |
| 238 | /* Validate STA_INS was set */ |
| 239 | tx.modes = 0; |
| 240 | ret = adjtimex(&tx); |
| 241 | if (tx.status != STA_INS && tx.status != STA_DEL) { |
| 242 | printf("Error: STA_INS/STA_DEL not set!: %s\n", |
| 243 | time_state_str(ret)); |
| 244 | return ksft_exit_fail(); |
| 245 | } |
| 246 | |
| 247 | if (tai_time) { |
| 248 | printf("Using TAI time," |
| 249 | " no inconsistencies should be seen!\n"); |
| 250 | } |
| 251 | |
| 252 | printf("Scheduling leap second for %s", ctime(&next_leap)); |
| 253 | |
| 254 | /* Wake up 3 seconds before leap */ |
| 255 | ts.tv_sec = next_leap - 3; |
| 256 | ts.tv_nsec = 0; |
| 257 | |
| 258 | while (clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &ts, NULL)) |
| 259 | printf("Something woke us up, returning to sleep\n"); |
| 260 | |
| 261 | /* Validate STA_INS is still set */ |
| 262 | tx.modes = 0; |
| 263 | ret = adjtimex(&tx); |
| 264 | if (tx.status != STA_INS && tx.status != STA_DEL) { |
| 265 | printf("Something cleared STA_INS/STA_DEL, setting it again.\n"); |
| 266 | tx.modes = ADJ_STATUS; |
| 267 | if (insert) |
| 268 | tx.status = STA_INS; |
| 269 | else |
| 270 | tx.status = STA_DEL; |
| 271 | ret = adjtimex(&tx); |
| 272 | } |
| 273 | |
| 274 | /* Check adjtimex output every half second */ |
| 275 | now = tx.time.tv_sec; |
| 276 | while (now < next_leap + 2) { |
| 277 | char buf[26]; |
| 278 | struct timespec tai; |
| 279 | |
| 280 | tx.modes = 0; |
| 281 | ret = adjtimex(&tx); |
| 282 | |
| 283 | if (tai_time) { |
| 284 | clock_gettime(CLOCK_TAI, &tai); |
| 285 | printf("%ld sec, %9ld ns\t%s\n", |
| 286 | tai.tv_sec, |
| 287 | tai.tv_nsec, |
| 288 | time_state_str(ret)); |
| 289 | } else { |
| 290 | ctime_r(&tx.time.tv_sec, buf); |
| 291 | buf[strlen(buf)-1] = 0; /*remove trailing\n */ |
| 292 | |
| 293 | printf("%s + %6ld us (%i)\t%s\n", |
| 294 | buf, |
| 295 | tx.time.tv_usec, |
| 296 | tx.tai, |
| 297 | time_state_str(ret)); |
| 298 | } |
| 299 | now = tx.time.tv_sec; |
| 300 | /* Sleep for another half second */ |
| 301 | ts.tv_sec = 0; |
| 302 | ts.tv_nsec = NSEC_PER_SEC / 2; |
| 303 | clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL); |
| 304 | } |
| 305 | /* Switch to using other mode */ |
| 306 | insert = !insert; |
| 307 | |
| 308 | /* Note if kernel has known hrtimer failure */ |
| 309 | test_hrtimer_failure(); |
| 310 | |
| 311 | printf("Leap complete\n\n"); |
| 312 | |
| 313 | if ((iterations != -1) && !(--iterations)) |
| 314 | break; |
| 315 | } |
| 316 | |
| 317 | clear_time_state(); |
| 318 | return ksft_exit_pass(); |
| 319 | } |