swwdog.c revision 1.16
1 /* $NetBSD: swwdog.c,v 1.16 2015/04/23 23:23:01 pgoyette 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 1.16 2015/04/23 23:23:01 pgoyette 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 CFDRIVER_DECL(swwdog, DV_DULL, NULL); 75 76 int swwdogattach(int); 77 78 static int swwdog_setmode(struct sysmon_wdog *); 79 static int swwdog_tickle(struct sysmon_wdog *); 80 static bool swwdog_suspend(device_t, const pmf_qual_t *); 81 static int swwdog_arm(struct swwdog_softc *); 82 static int swwdog_disarm(struct swwdog_softc *); 83 84 static void swwdog_panic(void *); 85 86 static void swwdog_sysctl_setup(void); 87 static struct sysctllog *swwdog_sysctllog = NULL; 88 89 static int swwdog_match(device_t, cfdata_t, void *); 90 static void swwdog_attach(device_t, device_t, void *); 91 static int swwdog_detach(device_t, int); 92 static bool swwdog_suspend(device_t, const pmf_qual_t *); 93 94 static int swwdog_init(void *); 95 static int swwdog_fini(void *); 96 static int swwdog_modcmd(modcmd_t, void *); 97 98 CFATTACH_DECL_NEW(swwdog, sizeof(struct swwdog_softc), 99 swwdog_match, swwdog_attach, swwdog_detach, NULL); 100 extern struct cfdriver swwdog_cd; 101 102 #define SWDOG_DEFAULT 60 /* 60-second default period */ 103 104 static void 105 doreboot(struct work *wrkwrkwrk, void *p) 106 { 107 108 cpu_reboot(0, NULL); 109 } 110 111 int 112 swwdogattach(int n __unused) 113 { 114 int error; 115 static struct cfdata cf; 116 117 if (workqueue_create(&wq, "swwreboot", doreboot, NULL, 118 PRI_NONE, IPL_NONE, 0) != 0) { 119 aprint_error("failed to create swwdog reboot wq"); 120 return 1; 121 } 122 123 error = config_cfattach_attach(swwdog_cd.cd_name, &swwdog_ca); 124 if (error) { 125 aprint_error("%s: unable to attach cfattach\n", 126 swwdog_cd.cd_name); 127 workqueue_destroy(wq); 128 return error; 129 } 130 131 cf.cf_name = swwdog_cd.cd_name; 132 cf.cf_atname = swwdog_cd.cd_name; 133 cf.cf_unit = 0; 134 cf.cf_fstate = FSTATE_STAR; 135 cf.cf_pspec = NULL; 136 cf.cf_loc = NULL; 137 cf.cf_flags = 0; 138 139 swwdog_dev = config_attach_pseudo(&cf); 140 141 if (swwdog_dev == NULL) { 142 config_cfattach_detach(swwdog_cd.cd_name, &swwdog_ca); 143 workqueue_destroy(wq); 144 return 1; 145 } 146 return 0; 147 } 148 149 static int 150 swwdog_match(device_t parent, cfdata_t data, void *aux) 151 { 152 153 return 1; 154 } 155 156 static void 157 swwdog_attach(device_t parent, device_t self, void *aux) 158 { 159 struct swwdog_softc *sc = device_private(self); 160 161 if (workqueue_create(&wq, "swwreboot", doreboot, NULL, 162 PRI_NONE, IPL_NONE, 0) != 0) { 163 aprint_error_dev(self, "failed to create reboot workqueue"); 164 } 165 166 sc->sc_dev = self; 167 sc->sc_smw.smw_name = device_xname(self); 168 sc->sc_smw.smw_cookie = sc; 169 sc->sc_smw.smw_setmode = swwdog_setmode; 170 sc->sc_smw.smw_tickle = swwdog_tickle; 171 sc->sc_smw.smw_period = SWDOG_DEFAULT; 172 173 callout_init(&sc->sc_c, 0); 174 callout_setfunc(&sc->sc_c, swwdog_panic, sc); 175 176 if (sysmon_wdog_register(&sc->sc_smw) == 0) 177 aprint_normal_dev(self, "software watchdog initialized\n"); 178 else { 179 aprint_error_dev(self, "unable to register software " 180 "watchdog with sysmon\n"); 181 callout_destroy(&sc->sc_c); 182 workqueue_destroy(wq); 183 return; 184 } 185 186 if (!pmf_device_register(self, swwdog_suspend, NULL)) 187 aprint_error_dev(self, "couldn't establish power handler\n"); 188 189 swwdog_sysctl_setup(); 190 } 191 192 static int 193 swwdog_detach(device_t self, int flags) 194 { 195 struct swwdog_softc *sc = device_private(self); 196 197 pmf_device_deregister(self); 198 swwdog_disarm(sc); 199 sysctl_teardown(&swwdog_sysctllog); 200 sysmon_wdog_unregister(&sc->sc_smw); 201 callout_destroy(&sc->sc_c); 202 workqueue_destroy(wq); 203 204 return 0; 205 } 206 207 static bool 208 swwdog_suspend(device_t dev, const pmf_qual_t *qual) 209 { 210 struct swwdog_softc *sc = device_private(dev); 211 212 /* Don't allow suspend if watchdog is armed */ 213 if ((sc->sc_smw.smw_mode & WDOG_MODE_MASK) != WDOG_MODE_DISARMED) 214 return false; 215 return true; 216 } 217 218 static int 219 swwdog_setmode(struct sysmon_wdog *smw) 220 { 221 struct swwdog_softc *sc = smw->smw_cookie; 222 int error = 0; 223 224 if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) { 225 error = swwdog_disarm(sc); 226 } else { 227 if (smw->smw_period == 0) 228 return EINVAL; 229 else if (smw->smw_period == WDOG_PERIOD_DEFAULT) 230 sc->sc_smw.smw_period = SWDOG_DEFAULT; 231 else 232 sc->sc_smw.smw_period = smw->smw_period; 233 error = swwdog_arm(sc); 234 } 235 return error; 236 } 237 238 static int 239 swwdog_tickle(struct sysmon_wdog *smw) 240 { 241 242 return swwdog_arm(smw->smw_cookie); 243 } 244 245 static int 246 swwdog_arm(struct swwdog_softc *sc) 247 { 248 249 callout_schedule(&sc->sc_c, sc->sc_smw.smw_period * hz); 250 return 0; 251 } 252 253 static int 254 swwdog_disarm(struct swwdog_softc *sc) 255 { 256 257 callout_stop(&sc->sc_c); 258 return 0; 259 } 260 261 static void 262 swwdog_panic(void *vsc) 263 { 264 struct swwdog_softc *sc = vsc; 265 static struct work wk; /* we'll need it max once */ 266 bool do_panic; 267 268 do_panic = !swwdog_reboot; 269 swwdog_reboot = false; 270 callout_schedule(&sc->sc_c, 60 * hz); /* deliberate double-panic */ 271 272 printf("%s: %d second timer expired\n", "swwdog", 273 sc->sc_smw.smw_period); 274 275 if (do_panic) 276 panic("watchdog timer expired"); 277 else 278 workqueue_enqueue(wq, &wk, NULL); 279 } 280 281 static void 282 swwdog_sysctl_setup(void) 283 { 284 const struct sysctlnode *me; 285 286 KASSERT(swwdog_sysctllog == NULL); 287 288 sysctl_createv(&swwdog_sysctllog, 0, NULL, &me, CTLFLAG_READWRITE, 289 CTLTYPE_NODE, "swwdog", NULL, 290 NULL, 0, NULL, 0, 291 CTL_HW, CTL_CREATE, CTL_EOL); 292 sysctl_createv(&swwdog_sysctllog, 0, NULL, NULL, CTLFLAG_READWRITE, 293 CTLTYPE_BOOL, "reboot", "reboot if timer expires", 294 NULL, 0, &swwdog_reboot, sizeof(bool), 295 CTL_HW, me->sysctl_num, CTL_CREATE, CTL_EOL); 296 } 297 298 /* 299 * Module management 300 */ 301 302 static 303 int 304 swwdog_init(void *arg) 305 { 306 /* 307 * Merge the driver info into the kernel tables and attach the 308 * pseudo-device 309 */ 310 int error; 311 312 error = config_cfdriver_attach(&swwdog_cd); 313 if (error) { 314 aprint_error("%s: unable to attach cfdriver\n", 315 swwdog_cd.cd_name); 316 return error; 317 } 318 error = swwdogattach(1); 319 if (error) { 320 aprint_error("%s: device attach failed\n", swwdog_cd.cd_name); 321 config_cfdriver_detach(&swwdog_cd); 322 } 323 324 return error; 325 } 326 327 static 328 int 329 swwdog_fini(void *arg) 330 { 331 int error; 332 333 error = config_detach(swwdog_dev, 0); 334 335 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); 344 345 return error; 346 } 347 348 static 349 int 350 swwdog_modcmd(modcmd_t cmd, void *arg) 351 { 352 int ret; 353 354 switch (cmd) { 355 case MODULE_CMD_INIT: 356 ret = swwdog_init(arg); 357 break; 358 359 case MODULE_CMD_FINI: 360 ret = swwdog_fini(arg); 361 break; 362 363 case MODULE_CMD_STAT: 364 default: 365 ret = ENOTTY; 366 } 367 368 return ret; 369 } 370 371
Indexes created Thu Oct 02 01:09:59 GMT 2025