sysmon_wdog.c revision 1.15
1 /* $NetBSD: sysmon_wdog.c,v 1.15 2007/02/18 23:36:39 xtraeme Exp $ */ 2 3 /*- 4 * Copyright (c) 2000 Zembu Labs, Inc. 5 * All rights reserved. 6 * 7 * Author: Jason R. Thorpe <thorpej (at) zembu.com> 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by Zembu Labs, Inc. 20 * 4. Neither the name of Zembu Labs nor the names of its employees may 21 * be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY ZEMBU LABS, INC. ``AS IS'' AND ANY EXPRESS 25 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAR- 26 * RANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DIS- 27 * CLAIMED. IN NO EVENT SHALL ZEMBU LABS BE LIABLE FOR ANY DIRECT, INDIRECT, 28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /* 37 * Watchdog timer framework for sysmon. Hardware (and software) 38 * watchdog timers can register themselves here to provide a 39 * watchdog function, which provides an abstract interface to the 40 * user. 41 */ 42 43 #include <sys/cdefs.h> 44 __KERNEL_RCSID(0, "$NetBSD: sysmon_wdog.c,v 1.15 2007/02/18 23:36:39 xtraeme Exp $"); 45 46 #include <sys/param.h> 47 #include <sys/conf.h> 48 #include <sys/errno.h> 49 #include <sys/fcntl.h> 50 #include <sys/callout.h> 51 #include <sys/kernel.h> 52 #include <sys/mutex.h> 53 #include <sys/systm.h> 54 #include <sys/proc.h> 55 56 #include <dev/sysmon/sysmonvar.h> 57 58 LIST_HEAD(, sysmon_wdog) sysmon_wdog_list = 59 LIST_HEAD_INITIALIZER(&sysmon_wdog_list); 60 int sysmon_wdog_count; 61 kmutex_t sysmon_wdog_list_mtx; 62 63 kmutex_t sysmon_wdog_mtx; 64 struct sysmon_wdog *sysmon_armed_wdog; 65 struct callout sysmon_wdog_callout = CALLOUT_INITIALIZER; 66 void *sysmon_wdog_sdhook; 67 68 #define SYSMON_WDOG_LOCK() \ 69 mutex_enter(&sysmon_wdog_mtx) 70 71 #define SYSMON_WDOG_UNLOCK() \ 72 mutex_exit(&sysmon_wdog_mtx) 73 74 struct sysmon_wdog *sysmon_wdog_find(const char *); 75 void sysmon_wdog_release(struct sysmon_wdog *); 76 int sysmon_wdog_setmode(struct sysmon_wdog *, int, u_int); 77 void sysmon_wdog_ktickle(void *); 78 void sysmon_wdog_shutdown(void *); 79 80 /* 81 * sysmonopen_wdog: 82 * 83 * Open the system monitor device. 84 */ 85 int 86 sysmonopen_wdog(dev_t dev, int flag, int mode, 87 struct lwp *l) 88 { 89 90 mutex_enter(&sysmon_wdog_list_mtx); 91 if (sysmon_wdog_sdhook == NULL) { 92 sysmon_wdog_sdhook = 93 shutdownhook_establish(sysmon_wdog_shutdown, NULL); 94 if (sysmon_wdog_sdhook == NULL) 95 printf("WARNING: unable to register watchdog " 96 "shutdown hook\n"); 97 } 98 mutex_exit(&sysmon_wdog_list_mtx); 99 100 return (0); 101 } 102 103 /* 104 * sysmonclose_wdog: 105 * 106 * Close the system monitor device. 107 */ 108 int 109 sysmonclose_wdog(dev_t dev, int flag, int mode, 110 struct lwp *l) 111 { 112 struct sysmon_wdog *smw; 113 int error = 0; 114 115 /* 116 * If this is the last close, and there is a watchdog 117 * running in UTICKLE mode, we need to disable it, 118 * otherwise the system will reset in short order. 119 * 120 * XXX Maybe we should just go into KTICKLE mode? 121 */ 122 SYSMON_WDOG_LOCK(); 123 if ((smw = sysmon_armed_wdog) != NULL) { 124 if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_UTICKLE) { 125 error = sysmon_wdog_setmode(smw, 126 WDOG_MODE_DISARMED, smw->smw_period); 127 if (error) { 128 printf("WARNING: UNABLE TO DISARM " 129 "WATCHDOG %s ON CLOSE!\n", 130 smw->smw_name); 131 /* 132 * ...we will probably reboot soon. 133 */ 134 } 135 } 136 } 137 SYSMON_WDOG_UNLOCK(); 138 139 return (error); 140 } 141 142 /* 143 * sysmonioctl_wdog: 144 * 145 * Perform a watchdog control request. 146 */ 147 int 148 sysmonioctl_wdog(dev_t dev, u_long cmd, caddr_t data, int flag, 149 struct lwp *l) 150 { 151 struct sysmon_wdog *smw; 152 int error = 0; 153 154 switch (cmd) { 155 case WDOGIOC_GMODE: 156 { 157 struct wdog_mode *wm = (void *) data; 158 159 wm->wm_name[sizeof(wm->wm_name) - 1] = '\0'; 160 smw = sysmon_wdog_find(wm->wm_name); 161 if (smw == NULL) { 162 error = ESRCH; 163 break; 164 } 165 166 wm->wm_mode = smw->smw_mode; 167 wm->wm_period = smw->smw_period; 168 sysmon_wdog_release(smw); 169 break; 170 } 171 172 case WDOGIOC_SMODE: 173 { 174 struct wdog_mode *wm = (void *) data; 175 176 if ((flag & FWRITE) == 0) { 177 error = EPERM; 178 break; 179 } 180 181 wm->wm_name[sizeof(wm->wm_name) - 1] = '\0'; 182 smw = sysmon_wdog_find(wm->wm_name); 183 if (smw == NULL) { 184 error = ESRCH; 185 break; 186 } 187 188 if (wm->wm_mode & ~(WDOG_MODE_MASK|WDOG_FEATURE_MASK)) 189 error = EINVAL; 190 else { 191 SYSMON_WDOG_LOCK(); 192 error = sysmon_wdog_setmode(smw, wm->wm_mode, 193 wm->wm_period); 194 SYSMON_WDOG_UNLOCK(); 195 } 196 197 sysmon_wdog_release(smw); 198 break; 199 } 200 201 case WDOGIOC_WHICH: 202 { 203 struct wdog_mode *wm = (void *) data; 204 205 SYSMON_WDOG_LOCK(); 206 if ((smw = sysmon_armed_wdog) != NULL) { 207 strcpy(wm->wm_name, smw->smw_name); 208 wm->wm_mode = smw->smw_mode; 209 wm->wm_period = smw->smw_period; 210 } else 211 error = ESRCH; 212 SYSMON_WDOG_UNLOCK(); 213 break; 214 } 215 216 case WDOGIOC_TICKLE: 217 if ((flag & FWRITE) == 0) { 218 error = EPERM; 219 break; 220 } 221 222 SYSMON_WDOG_LOCK(); 223 if ((smw = sysmon_armed_wdog) != NULL) { 224 error = (*smw->smw_tickle)(smw); 225 if (error == 0) 226 smw->smw_tickler = l->l_proc->p_pid; 227 } else 228 error = ESRCH; 229 SYSMON_WDOG_UNLOCK(); 230 break; 231 232 case WDOGIOC_GTICKLER: 233 if ((smw = sysmon_armed_wdog) != NULL) 234 *(pid_t *)data = smw->smw_tickler; 235 else 236 error = ESRCH; 237 break; 238 239 case WDOGIOC_GWDOGS: 240 { 241 struct wdog_conf *wc = (void *) data; 242 char *cp; 243 int i; 244 245 mutex_enter(&sysmon_wdog_list_mtx); 246 if (wc->wc_names == NULL) 247 wc->wc_count = sysmon_wdog_count; 248 else { 249 for (i = 0, cp = wc->wc_names, 250 smw = LIST_FIRST(&sysmon_wdog_list); 251 i < sysmon_wdog_count && smw != NULL && error == 0; 252 i++, cp += WDOG_NAMESIZE, 253 smw = LIST_NEXT(smw, smw_list)) 254 error = copyout(smw->smw_name, cp, 255 strlen(smw->smw_name) + 1); 256 wc->wc_count = i; 257 } 258 mutex_exit(&sysmon_wdog_list_mtx); 259 break; 260 } 261 262 default: 263 error = ENOTTY; 264 } 265 266 return (error); 267 } 268 269 /* 270 * sysmon_wdog_register: 271 * 272 * Register a watchdog device. 273 */ 274 int 275 sysmon_wdog_register(struct sysmon_wdog *smw) 276 { 277 struct sysmon_wdog *lsmw; 278 int error = 0; 279 280 mutex_init(&sysmon_wdog_mtx, MUTEX_DRIVER, IPL_NONE); 281 mutex_init(&sysmon_wdog_list_mtx, MUTEX_DRIVER, IPL_NONE); 282 mutex_enter(&sysmon_wdog_list_mtx); 283 284 for (lsmw = LIST_FIRST(&sysmon_wdog_list); lsmw != NULL; 285 lsmw = LIST_NEXT(lsmw, smw_list)) { 286 if (strcmp(lsmw->smw_name, smw->smw_name) == 0) { 287 error = EEXIST; 288 goto out; 289 } 290 } 291 292 smw->smw_mode = WDOG_MODE_DISARMED; 293 smw->smw_tickler = (pid_t) -1; 294 smw->smw_refcnt = 0; 295 sysmon_wdog_count++; 296 LIST_INSERT_HEAD(&sysmon_wdog_list, smw, smw_list); 297 298 out: 299 mutex_exit(&sysmon_wdog_list_mtx); 300 return (error); 301 } 302 303 /* 304 * sysmon_wdog_unregister: 305 * 306 * Unregister a watchdog device. 307 */ 308 void 309 sysmon_wdog_unregister(struct sysmon_wdog *smw) 310 { 311 312 mutex_enter(&sysmon_wdog_list_mtx); 313 sysmon_wdog_count--; 314 LIST_REMOVE(smw, smw_list); 315 mutex_exit(&sysmon_wdog_list_mtx); 316 } 317 318 /* 319 * sysmon_wdog_find: 320 * 321 * Find a watchdog device. We increase the reference 322 * count on a match. 323 */ 324 struct sysmon_wdog * 325 sysmon_wdog_find(const char *name) 326 { 327 struct sysmon_wdog *smw; 328 329 mutex_enter(&sysmon_wdog_list_mtx); 330 331 for (smw = LIST_FIRST(&sysmon_wdog_list); smw != NULL; 332 smw = LIST_NEXT(smw, smw_list)) { 333 if (strcmp(smw->smw_name, name) == 0) 334 break; 335 } 336 337 if (smw != NULL) 338 smw->smw_refcnt++; 339 340 mutex_exit(&sysmon_wdog_list_mtx); 341 return (smw); 342 } 343 344 /* 345 * sysmon_wdog_release: 346 * 347 * Release a watchdog device. 348 */ 349 void 350 sysmon_wdog_release(struct sysmon_wdog *smw) 351 { 352 353 mutex_enter(&sysmon_wdog_list_mtx); 354 KASSERT(smw->smw_refcnt != 0); 355 smw->smw_refcnt--; 356 mutex_exit(&sysmon_wdog_list_mtx); 357 } 358 359 /* 360 * sysmon_wdog_setmode: 361 * 362 * Set the mode of a watchdog device. 363 */ 364 int 365 sysmon_wdog_setmode(struct sysmon_wdog *smw, int mode, u_int period) 366 { 367 u_int operiod = smw->smw_period; 368 int omode = smw->smw_mode; 369 int error = 0; 370 371 smw->smw_period = period; 372 smw->smw_mode = mode; 373 374 switch (mode & WDOG_MODE_MASK) { 375 case WDOG_MODE_DISARMED: 376 if (smw != sysmon_armed_wdog) { 377 error = EINVAL; 378 goto out; 379 } 380 break; 381 382 case WDOG_MODE_KTICKLE: 383 case WDOG_MODE_UTICKLE: 384 case WDOG_MODE_ETICKLE: 385 if (sysmon_armed_wdog != NULL) { 386 error = EBUSY; 387 goto out; 388 } 389 break; 390 391 default: 392 error = EINVAL; 393 goto out; 394 } 395 396 error = (*smw->smw_setmode)(smw); 397 398 out: 399 if (error) { 400 smw->smw_period = operiod; 401 smw->smw_mode = omode; 402 } else { 403 if ((mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) { 404 sysmon_armed_wdog = NULL; 405 smw->smw_tickler = (pid_t) -1; 406 smw->smw_refcnt--; 407 if ((omode & WDOG_MODE_MASK) == WDOG_MODE_KTICKLE) 408 callout_stop(&sysmon_wdog_callout); 409 } else { 410 sysmon_armed_wdog = smw; 411 smw->smw_refcnt++; 412 if ((mode & WDOG_MODE_MASK) == WDOG_MODE_KTICKLE) { 413 callout_reset(&sysmon_wdog_callout, 414 WDOG_PERIOD_TO_TICKS(smw->smw_period) / 2, 415 sysmon_wdog_ktickle, NULL); 416 } 417 } 418 } 419 return (error); 420 } 421 422 /* 423 * sysmon_wdog_ktickle: 424 * 425 * Kernel watchdog tickle routine. 426 */ 427 void 428 sysmon_wdog_ktickle(void *arg) 429 { 430 struct sysmon_wdog *smw; 431 432 SYSMON_WDOG_LOCK(); 433 if ((smw = sysmon_armed_wdog) != NULL) { 434 if ((*smw->smw_tickle)(smw) != 0) { 435 printf("WARNING: KERNEL TICKLE OF WATCHDOG %s " 436 "FAILED!\n", smw->smw_name); 437 /* 438 * ...we will probably reboot soon. 439 */ 440 } 441 callout_reset(&sysmon_wdog_callout, 442 WDOG_PERIOD_TO_TICKS(smw->smw_period) / 2, 443 sysmon_wdog_ktickle, NULL); 444 } 445 SYSMON_WDOG_UNLOCK(); 446 } 447 448 /* 449 * sysmon_wdog_shutdown: 450 * 451 * Perform shutdown-time operations. 452 */ 453 void 454 sysmon_wdog_shutdown(void *arg) 455 { 456 struct sysmon_wdog *smw; 457 458 /* 459 * XXX Locking here? I don't think it's necessary. 460 */ 461 462 if ((smw = sysmon_armed_wdog) != NULL) { 463 if (sysmon_wdog_setmode(smw, WDOG_MODE_DISARMED, 464 smw->smw_period)) 465 printf("WARNING: FAILED TO SHUTDOWN WATCHDOG %s!\n", 466 smw->smw_name); 467 } 468 } 469
Indexes created Wed Oct 01 15:09:59 GMT 2025