1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 28 #include <sys/param.h> 29 #include <sys/types.h> 30 #include <sys/sysmacros.h> 31 #include <sys/systm.h> 32 #include <sys/errno.h> 33 #include <sys/vfs.h> 34 #include <sys/vnode.h> 35 #include <sys/swap.h> 36 #include <sys/file.h> 37 #include <sys/proc.h> 38 #include <sys/var.h> 39 #include <sys/uadmin.h> 40 #include <sys/signal.h> 41 #include <sys/time.h> 42 #include <vm/seg_kmem.h> 43 #include <sys/modctl.h> 44 #include <sys/callb.h> 45 #include <sys/dumphdr.h> 46 #include <sys/debug.h> 47 #include <sys/ftrace.h> 48 #include <sys/cmn_err.h> 49 #include <sys/panic.h> 50 #include <sys/ddi.h> 51 #include <sys/sunddi.h> 52 #include <sys/policy.h> 53 #include <sys/zone.h> 54 #include <sys/condvar.h> 55 #include <sys/thread.h> 56 #include <sys/sdt.h> 57 58 /* 59 * Administrivia system call. We provide this in two flavors: one for calling 60 * from the system call path (uadmin), and the other for calling from elsewhere 61 * within the kernel (kadmin). Callers must beware that certain uadmin cmd 62 * values (specifically A_SWAPCTL) are only supported by uadmin and not kadmin. 63 */ 64 65 extern ksema_t fsflush_sema; 66 kmutex_t ualock; 67 kcondvar_t uacond; 68 kthread_t *ua_shutdown_thread = NULL; 69 70 int sys_shutdown = 0; 71 volatile int fastreboot_dryrun = 0; 72 73 /* 74 * Kill all user processes in said zone. A special argument of ALL_ZONES is 75 * passed in when the system as a whole is shutting down. The lack of per-zone 76 * process lists is likely to make the following a performance bottleneck on a 77 * system with many zones. 78 */ 79 void 80 killall(zoneid_t zoneid) 81 { 82 proc_t *p; 83 84 ASSERT(zoneid != GLOBAL_ZONEID); 85 /* 86 * Kill all processes except kernel daemons and ourself. 87 * Make a first pass to stop all processes so they won't 88 * be trying to restart children as we kill them. 89 */ 90 mutex_enter(&pidlock); 91 for (p = practive; p != NULL; p = p->p_next) { 92 if ((zoneid == ALL_ZONES || p->p_zone->zone_id == zoneid) && 93 p->p_exec != NULLVP && /* kernel daemons */ 94 p->p_as != &kas && 95 p->p_stat != SZOMB) { 96 mutex_enter(&p->p_lock); 97 p->p_flag |= SNOWAIT; 98 sigtoproc(p, NULL, SIGSTOP); 99 mutex_exit(&p->p_lock); 100 } 101 } 102 p = practive; 103 while (p != NULL) { 104 if ((zoneid == ALL_ZONES || p->p_zone->zone_id == zoneid) && 105 p->p_exec != NULLVP && /* kernel daemons */ 106 p->p_as != &kas && 107 p->p_stat != SIDL && 108 p->p_stat != SZOMB) { 109 mutex_enter(&p->p_lock); 110 if (sigismember(&p->p_sig, SIGKILL)) { 111 mutex_exit(&p->p_lock); 112 p = p->p_next; 113 } else { 114 sigtoproc(p, NULL, SIGKILL); 115 mutex_exit(&p->p_lock); 116 (void) cv_timedwait(&p->p_srwchan_cv, &pidlock, 117 lbolt + hz); 118 p = practive; 119 } 120 } else { 121 p = p->p_next; 122 } 123 } 124 mutex_exit(&pidlock); 125 } 126 127 int 128 kadmin(int cmd, int fcn, void *mdep, cred_t *credp) 129 { 130 int error = 0; 131 char *buf; 132 size_t buflen = 0; 133 boolean_t invoke_cb = B_FALSE; 134 135 /* 136 * We might be called directly by the kernel's fault-handling code, so 137 * we can't assert that the caller is in the global zone. 138 */ 139 140 /* 141 * Make sure that cmd is one of the valid <sys/uadmin.h> command codes 142 * and that we have appropriate privileges for this action. 143 */ 144 switch (cmd) { 145 case A_FTRACE: 146 case A_SHUTDOWN: 147 case A_REBOOT: 148 case A_REMOUNT: 149 case A_FREEZE: 150 case A_DUMP: 151 case A_SDTTEST: 152 case A_CONFIG: 153 if (secpolicy_sys_config(credp, B_FALSE) != 0) 154 return (EPERM); 155 break; 156 157 default: 158 return (EINVAL); 159 } 160 161 /* 162 * Serialize these operations on ualock. If it is held, the 163 * system should shutdown, reboot, or remount shortly, unless there is 164 * an error. We need a cv rather than just a mutex because proper 165 * functioning of A_REBOOT relies on being able to interrupt blocked 166 * userland callers. 167 * 168 * We only clear ua_shutdown_thread after A_REMOUNT or A_CONFIG. 169 * Other commands should never return. 170 */ 171 if (cmd == A_SHUTDOWN || cmd == A_REBOOT || cmd == A_REMOUNT || 172 cmd == A_CONFIG) { 173 mutex_enter(&ualock); 174 while (ua_shutdown_thread != NULL) { 175 if (cv_wait_sig(&uacond, &ualock) == 0) { 176 /* 177 * If we were interrupted, leave, and handle 178 * the signal (or exit, depending on what 179 * happened) 180 */ 181 mutex_exit(&ualock); 182 return (EINTR); 183 } 184 } 185 ua_shutdown_thread = curthread; 186 mutex_exit(&ualock); 187 } 188 189 switch (cmd) { 190 case A_SHUTDOWN: 191 { 192 proc_t *p = ttoproc(curthread); 193 194 /* 195 * Release (almost) all of our own resources if we are called 196 * from a user context, however if we are calling kadmin() from 197 * a kernel context then we do not release these resources. 198 */ 199 if (p != &p0) { 200 proc_is_exiting(p); 201 if ((error = exitlwps(0)) != 0) { 202 /* 203 * Another thread in this process also called 204 * exitlwps(). 205 */ 206 mutex_enter(&ualock); 207 ua_shutdown_thread = NULL; 208 cv_signal(&uacond); 209 mutex_exit(&ualock); 210 return (error); 211 } 212 mutex_enter(&p->p_lock); 213 p->p_flag |= SNOWAIT; 214 sigfillset(&p->p_ignore); 215 curthread->t_lwp->lwp_cursig = 0; 216 curthread->t_lwp->lwp_extsig = 0; 217 if (p->p_exec) { 218 vnode_t *exec_vp = p->p_exec; 219 p->p_exec = NULLVP; 220 mutex_exit(&p->p_lock); 221 VN_RELE(exec_vp); 222 } else { 223 mutex_exit(&p->p_lock); 224 } 225 226 pollcleanup(); 227 closeall(P_FINFO(curproc)); 228 relvm(); 229 230 } else { 231 /* 232 * Reset t_cred if not set because much of the 233 * filesystem code depends on CRED() being valid. 234 */ 235 if (curthread->t_cred == NULL) 236 curthread->t_cred = kcred; 237 } 238 239 /* indicate shutdown in progress */ 240 sys_shutdown = 1; 241 242 /* 243 * Communcate that init shouldn't be restarted. 244 */ 245 zone_shutdown_global(); 246 247 killall(ALL_ZONES); 248 /* 249 * If we are calling kadmin() from a kernel context then we 250 * do not release these resources. 251 */ 252 if (ttoproc(curthread) != &p0) { 253 VN_RELE(PTOU(curproc)->u_cdir); 254 if (PTOU(curproc)->u_rdir) 255 VN_RELE(PTOU(curproc)->u_rdir); 256 if (PTOU(curproc)->u_cwd) 257 refstr_rele(PTOU(curproc)->u_cwd); 258 259 PTOU(curproc)->u_cdir = rootdir; 260 PTOU(curproc)->u_rdir = NULL; 261 PTOU(curproc)->u_cwd = NULL; 262 } 263 264 /* 265 * Allow the reboot/halt/poweroff code a chance to do 266 * anything it needs to whilst we still have filesystems 267 * mounted, like loading any modules necessary for later 268 * performing the actual poweroff. 269 */ 270 if ((mdep != NULL) && (*(char *)mdep == '/')) { 271 buf = i_convert_boot_device_name(mdep, NULL, &buflen); 272 mdpreboot(cmd, fcn, buf); 273 } else 274 mdpreboot(cmd, fcn, mdep); 275 276 /* 277 * Allow fsflush to finish running and then prevent it 278 * from ever running again so that vfs_unmountall() and 279 * vfs_syncall() can acquire the vfs locks they need. 280 */ 281 sema_p(&fsflush_sema); 282 (void) callb_execute_class(CB_CL_UADMIN_PRE_VFS, NULL); 283 284 vfs_unmountall(); 285 (void) VFS_MOUNTROOT(rootvfs, ROOT_UNMOUNT); 286 vfs_syncall(); 287 288 dump_ereports(); 289 dump_messages(); 290 291 invoke_cb = B_TRUE; 292 293 /* FALLTHROUGH */ 294 } 295 296 case A_REBOOT: 297 if ((mdep != NULL) && (*(char *)mdep == '/')) { 298 buf = i_convert_boot_device_name(mdep, NULL, &buflen); 299 mdboot(cmd, fcn, buf, invoke_cb); 300 } else 301 mdboot(cmd, fcn, mdep, invoke_cb); 302 /* no return expected */ 303 break; 304 305 case A_CONFIG: 306 switch (fcn) { 307 case AD_UPDATE_BOOT_CONFIG: 308 #ifndef __sparc 309 { 310 extern void fastboot_update_config(const char *); 311 312 fastboot_update_config(mdep); 313 } 314 #endif 315 316 break; 317 } 318 /* Let other threads enter the shutdown path now */ 319 mutex_enter(&ualock); 320 ua_shutdown_thread = NULL; 321 cv_signal(&uacond); 322 mutex_exit(&ualock); 323 break; 324 325 case A_REMOUNT: 326 (void) VFS_MOUNTROOT(rootvfs, ROOT_REMOUNT); 327 /* Let other threads enter the shutdown path now */ 328 mutex_enter(&ualock); 329 ua_shutdown_thread = NULL; 330 cv_signal(&uacond); 331 mutex_exit(&ualock); 332 break; 333 334 case A_FREEZE: 335 { 336 /* 337 * This is the entrypoint for all suspend/resume actions. 338 */ 339 extern int cpr(int, void *); 340 341 if (modload("misc", "cpr") == -1) 342 return (ENOTSUP); 343 /* Let the CPR module decide what to do with mdep */ 344 error = cpr(fcn, mdep); 345 break; 346 } 347 348 case A_FTRACE: 349 { 350 switch (fcn) { 351 case AD_FTRACE_START: 352 (void) FTRACE_START(); 353 break; 354 case AD_FTRACE_STOP: 355 (void) FTRACE_STOP(); 356 break; 357 default: 358 error = EINVAL; 359 } 360 break; 361 } 362 363 case A_DUMP: 364 { 365 if (fcn == AD_NOSYNC) { 366 in_sync = 1; 367 break; 368 } 369 370 panic_bootfcn = fcn; 371 panic_forced = 1; 372 373 if ((mdep != NULL) && (*(char *)mdep == '/')) { 374 panic_bootstr = i_convert_boot_device_name(mdep, 375 NULL, &buflen); 376 } else 377 panic_bootstr = mdep; 378 379 #ifndef __sparc 380 extern void fastboot_update_and_load(int, char *); 381 382 fastboot_update_and_load(fcn, mdep); 383 #endif 384 385 panic("forced crash dump initiated at user request"); 386 /*NOTREACHED*/ 387 } 388 389 case A_SDTTEST: 390 { 391 DTRACE_PROBE7(test, int, 1, int, 2, int, 3, int, 4, int, 5, 392 int, 6, int, 7); 393 break; 394 } 395 396 default: 397 error = EINVAL; 398 } 399 400 return (error); 401 } 402 403 int 404 uadmin(int cmd, int fcn, uintptr_t mdep) 405 { 406 int error = 0, rv = 0; 407 size_t nbytes = 0; 408 cred_t *credp = CRED(); 409 char *bootargs = NULL; 410 int reset_status = 0; 411 412 if (cmd == A_SHUTDOWN && fcn == AD_FASTREBOOT_DRYRUN) { 413 ddi_walk_devs(ddi_root_node(), check_driver_quiesce, 414 &reset_status); 415 if (reset_status != 0) 416 return (EIO); 417 else 418 return (0); 419 } 420 421 /* 422 * The swapctl system call doesn't have its own entry point: it uses 423 * uadmin as a wrapper so we just call it directly from here. 424 */ 425 if (cmd == A_SWAPCTL) { 426 if (get_udatamodel() == DATAMODEL_NATIVE) 427 error = swapctl(fcn, (void *)mdep, &rv); 428 #if defined(_SYSCALL32_IMPL) 429 else 430 error = swapctl32(fcn, (void *)mdep, &rv); 431 #endif /* _SYSCALL32_IMPL */ 432 return (error ? set_errno(error) : rv); 433 } 434 435 /* 436 * Certain subcommands intepret a non-NULL mdep value as a pointer to 437 * a boot string. We pull that in as bootargs, if applicable. 438 */ 439 if (mdep != NULL && 440 (cmd == A_SHUTDOWN || cmd == A_REBOOT || cmd == A_DUMP || 441 cmd == A_FREEZE || cmd == A_CONFIG)) { 442 bootargs = kmem_zalloc(BOOTARGS_MAX, KM_SLEEP); 443 if ((error = copyinstr((const char *)mdep, bootargs, 444 BOOTARGS_MAX, &nbytes)) != 0) { 445 kmem_free(bootargs, BOOTARGS_MAX); 446 return (set_errno(error)); 447 } 448 } 449 450 /* 451 * Invoke the appropriate kadmin() routine. 452 */ 453 if (getzoneid() != GLOBAL_ZONEID) 454 error = zone_kadmin(cmd, fcn, bootargs, credp); 455 else 456 error = kadmin(cmd, fcn, bootargs, credp); 457 458 if (bootargs != NULL) 459 kmem_free(bootargs, BOOTARGS_MAX); 460 return (error ? set_errno(error) : 0); 461 } 462