swwdog.c revision 1.19.18.1
1 /* $NetBSD: swwdog.c,v 1.19.18.1 2019/06/10 22:07:33 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2004, 2005 Steven M. Bellovin 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Steven M. Bellovin 18 * 4. The name of the author contributors may not be used to endorse or 19 * promote products derived from this software without specific prior 20 * written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS 26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: swwdog.c,v 1.19.18.1 2019/06/10 22:07:33 christos Exp $"); 37 38 /* 39 * 40 * Software watchdog timer 41 * 42 */ 43 #include <sys/param.h> 44 #include <sys/device.h> 45 #include <sys/callout.h> 46 #include <sys/kernel.h> 47 #include <sys/kmem.h> 48 #include <sys/reboot.h> 49 #include <sys/systm.h> 50 #include <sys/sysctl.h> 51 #include <sys/wdog.h> 52 #include <sys/workqueue.h> 53 #include <sys/module.h> 54 #include <dev/sysmon/sysmonvar.h> 55 56 #ifndef _MODULE 57 #include "opt_modular.h" 58 #endif 59 60 struct swwdog_softc { 61 device_t sc_dev; 62 struct sysmon_wdog sc_smw; 63 struct callout sc_c; 64 int sc_armed; 65 }; 66 67 bool swwdog_reboot = false; /* false --> panic , true --> reboot */ 68 69 static struct workqueue *wq; 70 static device_t swwdog_dev; 71 72 MODULE(MODULE_CLASS_DRIVER, swwdog, "sysmon_wdog"); 73 74 #ifdef _MODULE 75 CFDRIVER_DECL(swwdog, DV_DULL, NULL); 76 #endif 77 78 int swwdogattach(int); 79 80 static int swwdog_setmode(struct sysmon_wdog *); 81 static int swwdog_tickle(struct sysmon_wdog *); 82 static bool swwdog_suspend(device_t, const pmf_qual_t *); 83 static int swwdog_arm(struct swwdog_softc *); 84 static int swwdog_disarm(struct swwdog_softc *); 85 86 static void swwdog_panic(void *); 87 88 static void swwdog_sysctl_setup(void); 89 static struct sysctllog *swwdog_sysctllog = NULL; 90 91 static int swwdog_match(device_t, cfdata_t, void *); 92 static void swwdog_attach(device_t, device_t, void *); 93 static int swwdog_detach(device_t, int); 94 static bool swwdog_suspend(device_t, const pmf_qual_t *); 95 96 static int swwdog_init(void *); 97 static int swwdog_fini(void *); 98 static int swwdog_modcmd(modcmd_t, void *); 99 100 CFATTACH_DECL_NEW(swwdog, sizeof(struct swwdog_softc), 101 swwdog_match, swwdog_attach, swwdog_detach, NULL); 102 extern struct cfdriver swwdog_cd; 103 104 #define SWDOG_DEFAULT 60 /* 60-second default period */ 105 106 static void 107 doreboot(struct work *wrkwrkwrk, void *p) 108 { 109 110 cpu_reboot(0, NULL); 111 } 112 113 int 114 swwdogattach(int n __unused) 115 { 116 int error; 117 static struct cfdata cf; 118 119 if (workqueue_create(&wq, "swwreboot", doreboot, NULL, 120 PRI_NONE, IPL_NONE, 0) != 0) { 121 aprint_error("failed to create swwdog reboot wq"); 122 return 1; 123 } 124 125 error = config_cfattach_attach(swwdog_cd.cd_name, &swwdog_ca); 126 if (error) { 127 aprint_error("%s: unable to attach cfattach\n", 128 swwdog_cd.cd_name); 129 workqueue_destroy(wq); 130 return error; 131 } 132 133 cf.cf_name = swwdog_cd.cd_name; 134 cf.cf_atname = swwdog_cd.cd_name; 135 cf.cf_unit = 0; 136 cf.cf_fstate = FSTATE_STAR; 137 cf.cf_pspec = NULL; 138 cf.cf_loc = NULL; 139 cf.cf_flags = 0; 140 141 swwdog_dev = config_attach_pseudo(&cf); 142 143 if (swwdog_dev == NULL) { 144 config_cfattach_detach(swwdog_cd.cd_name, &swwdog_ca); 145 workqueue_destroy(wq); 146 return 1; 147 } 148 return 0; 149 } 150 151 static int 152 swwdog_match(device_t parent, cfdata_t data, void *aux) 153 { 154 155 return 1; 156 } 157 158 static void 159 swwdog_attach(device_t parent, device_t self, void *aux) 160 { 161 struct swwdog_softc *sc = device_private(self); 162 163 sc->sc_dev = self; 164 sc->sc_smw.smw_name = device_xname(self); 165 sc->sc_smw.smw_cookie = sc; 166 sc->sc_smw.smw_setmode = swwdog_setmode; 167 sc->sc_smw.smw_tickle = swwdog_tickle; 168 sc->sc_smw.smw_period = SWDOG_DEFAULT; 169 170 callout_init(&sc->sc_c, 0); 171 callout_setfunc(&sc->sc_c, swwdog_panic, sc); 172 173 if (sysmon_wdog_register(&sc->sc_smw) == 0) 174 aprint_normal_dev(self, "software watchdog initialized\n"); 175 else { 176 aprint_error_dev(self, "unable to register software " 177 "watchdog with sysmon\n"); 178 callout_destroy(&sc->sc_c); 179 return; 180 } 181 182 if (!pmf_device_register(self, swwdog_suspend, NULL)) 183 aprint_error_dev(self, "couldn't establish power handler\n"); 184 185 swwdog_sysctl_setup(); 186 } 187 188 static int 189 swwdog_detach(device_t self, int flags) 190 { 191 struct swwdog_softc *sc = device_private(self); 192 193 pmf_device_deregister(self); 194 swwdog_disarm(sc); 195 sysctl_teardown(&swwdog_sysctllog); 196 sysmon_wdog_unregister(&sc->sc_smw); 197 callout_destroy(&sc->sc_c); 198 workqueue_destroy(wq); 199 200 return 0; 201 } 202 203 static bool 204 swwdog_suspend(device_t dev, const pmf_qual_t *qual) 205 { 206 struct swwdog_softc *sc = device_private(dev); 207 208 /* Don't allow suspend if watchdog is armed */ 209 if ((sc->sc_smw.smw_mode & WDOG_MODE_MASK) != WDOG_MODE_DISARMED) 210 return false; 211 return true; 212 } 213 214 static int 215 swwdog_setmode(struct sysmon_wdog *smw) 216 { 217 struct swwdog_softc *sc = smw->smw_cookie; 218 int error = 0; 219 220 if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) { 221 error = swwdog_disarm(sc); 222 } else { 223 if (smw->smw_period == 0) 224 return EINVAL; 225 else if (smw->smw_period == WDOG_PERIOD_DEFAULT) 226 sc->sc_smw.smw_period = SWDOG_DEFAULT; 227 else 228 sc->sc_smw.smw_period = smw->smw_period; 229 error = swwdog_arm(sc); 230 } 231 return error; 232 } 233 234 static int 235 swwdog_tickle(struct sysmon_wdog *smw) 236 { 237 238 return swwdog_arm(smw->smw_cookie); 239 } 240 241 static int 242 swwdog_arm(struct swwdog_softc *sc) 243 { 244 245 callout_schedule(&sc->sc_c, sc->sc_smw.smw_period * hz); 246 return 0; 247 } 248 249 static int 250 swwdog_disarm(struct swwdog_softc *sc) 251 { 252 253 callout_stop(&sc->sc_c); 254 return 0; 255 } 256 257 static void 258 swwdog_panic(void *vsc) 259 { 260 struct swwdog_softc *sc = vsc; 261 static struct work wk; /* we'll need it max once */ 262 bool do_panic; 263 264 do_panic = !swwdog_reboot; 265 swwdog_reboot = false; 266 callout_schedule(&sc->sc_c, 60 * hz); /* deliberate double-panic */ 267 268 printf("%s: %d second timer expired\n", "swwdog", 269 sc->sc_smw.smw_period); 270 271 if (do_panic) 272 panic("watchdog timer expired"); 273 else 274 workqueue_enqueue(wq, &wk, NULL); 275 } 276 277 static void 278 swwdog_sysctl_setup(void) 279 { 280 const struct sysctlnode *me; 281 282 KASSERT(swwdog_sysctllog == NULL); 283 284 sysctl_createv(&swwdog_sysctllog, 0, NULL, &me, CTLFLAG_READWRITE, 285 CTLTYPE_NODE, "swwdog", NULL, 286 NULL, 0, NULL, 0, 287 CTL_HW, CTL_CREATE, CTL_EOL); 288 sysctl_createv(&swwdog_sysctllog, 0, NULL, NULL, CTLFLAG_READWRITE, 289 CTLTYPE_BOOL, "reboot", "reboot if timer expires", 290 NULL, 0, &swwdog_reboot, sizeof(bool), 291 CTL_HW, me->sysctl_num, CTL_CREATE, CTL_EOL); 292 } 293 294 /* 295 * Module management 296 */ 297 298 static 299 int 300 swwdog_init(void *arg) 301 { 302 /* 303 * Merge the driver info into the kernel tables and attach the 304 * pseudo-device 305 */ 306 int error = 0; 307 308 309 #ifdef _MODULE 310 error = config_cfdriver_attach(&swwdog_cd); 311 if (error) { 312 aprint_error("%s: unable to attach cfdriver\n", 313 swwdog_cd.cd_name); 314 return error; 315 } 316 error = swwdogattach(1); 317 if (error) { 318 aprint_error("%s: device attach failed\n", swwdog_cd.cd_name); 319 config_cfdriver_detach(&swwdog_cd); 320 } 321 #endif 322 323 return error; 324 } 325 326 static 327 int 328 swwdog_fini(void *arg) 329 { 330 int error; 331 332 error = config_detach(swwdog_dev, 0); 333 334 #ifdef _MODULE 335 error = config_cfattach_detach(swwdog_cd.cd_name, &swwdog_ca); 336 if (error) 337 aprint_error("%s: error detaching cfattach: %d\n", 338 swwdog_cd.cd_name, error); 339 340 error = config_cfdriver_detach(&swwdog_cd); 341 if (error) 342 aprint_error("%s: error detaching cfdriver: %d\n", 343 swwdog_cd.cd_name, error); 344 #endif 345 346 return error; 347 } 348 349 static 350 int 351 swwdog_modcmd(modcmd_t cmd, void *arg) 352 { 353 int ret; 354 355 switch (cmd) { 356 case MODULE_CMD_INIT: 357 ret = swwdog_init(arg); 358 break; 359 360 case MODULE_CMD_FINI: 361 ret = swwdog_fini(arg); 362 break; 363 364 case MODULE_CMD_STAT: 365 default: 366 ret = ENOTTY; 367 } 368 369 return ret; 370 } 371 372
Indexes created Thu Oct 16 14:10:15 GMT 2025