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 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/param.h> 30 #include <sys/types.h> 31 #include <sys/sysmacros.h> 32 #include <sys/systm.h> 33 #include <sys/errno.h> 34 #include <sys/vfs.h> 35 #include <sys/vnode.h> 36 #include <sys/swap.h> 37 #include <sys/file.h> 38 #include <sys/proc.h> 39 #include <sys/var.h> 40 #include <sys/uadmin.h> 41 #include <sys/signal.h> 42 #include <sys/time.h> 43 #include <vm/seg_kmem.h> 44 #include <sys/modctl.h> 45 #include <sys/callb.h> 46 #include <sys/dumphdr.h> 47 #include <sys/debug.h> 48 #include <sys/ftrace.h> 49 #include <sys/cmn_err.h> 50 #include <sys/panic.h> 51 #include <sys/ddi.h> 52 #include <sys/sunddi.h> 53 #include <sys/policy.h> 54 #include <sys/zone.h> 55 #include <sys/condvar.h> 56 #include <sys/thread.h> 57 #include <sys/sdt.h> 58 59 /* 60 * Administrivia system call. We provide this in two flavors: one for calling 61 * from the system call path (uadmin), and the other for calling from elsewhere 62 * within the kernel (kadmin). Callers must beware that certain uadmin cmd 63 * values (specifically A_SWAPCTL) are only supported by uadmin and not kadmin. 64 */ 65 66 extern ksema_t fsflush_sema; 67 kmutex_t ualock; 68 kcondvar_t uacond; 69 kthread_t *ua_shutdown_thread = NULL; 70 71 int sys_shutdown = 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 if (secpolicy_sys_config(credp, B_FALSE) != 0) 153 return (EPERM); 154 break; 155 156 default: 157 return (EINVAL); 158 } 159 160 /* 161 * Serialize these operations on ualock. If it is held, the 162 * system should shutdown, reboot, or remount shortly, unless there is 163 * an error. We need a cv rather than just a mutex because proper 164 * functioning of A_REBOOT relies on being able to interrupt blocked 165 * userland callers. 166 * 167 * We only clear ua_shutdown_thread after A_REMOUNT, because A_SHUTDOWN 168 * and A_REBOOT should never return. 169 */ 170 if (cmd == A_SHUTDOWN || cmd == A_REBOOT || cmd == A_REMOUNT) { 171 mutex_enter(&ualock); 172 while (ua_shutdown_thread != NULL) { 173 if (cv_wait_sig(&uacond, &ualock) == 0) { 174 /* 175 * If we were interrupted, leave, and handle 176 * the signal (or exit, depending on what 177 * happened) 178 */ 179 mutex_exit(&ualock); 180 return (EINTR); 181 } 182 } 183 ua_shutdown_thread = curthread; 184 mutex_exit(&ualock); 185 } 186 187 switch (cmd) { 188 case A_SHUTDOWN: 189 { 190 proc_t *p = ttoproc(curthread); 191 192 /* 193 * Release (almost) all of our own resources if we are called 194 * from a user context, however if we are calling kadmin() from 195 * a kernel context then we do not release these resources. 196 */ 197 if (p != &p0) { 198 proc_is_exiting(p); 199 if ((error = exitlwps(0)) != 0) { 200 /* 201 * Another thread in this process also called 202 * exitlwps(). 203 */ 204 mutex_enter(&ualock); 205 ua_shutdown_thread = NULL; 206 cv_signal(&uacond); 207 mutex_exit(&ualock); 208 return (error); 209 } 210 mutex_enter(&p->p_lock); 211 p->p_flag |= SNOWAIT; 212 sigfillset(&p->p_ignore); 213 curthread->t_lwp->lwp_cursig = 0; 214 curthread->t_lwp->lwp_extsig = 0; 215 if (p->p_exec) { 216 vnode_t *exec_vp = p->p_exec; 217 p->p_exec = NULLVP; 218 mutex_exit(&p->p_lock); 219 VN_RELE(exec_vp); 220 } else { 221 mutex_exit(&p->p_lock); 222 } 223 224 pollcleanup(); 225 closeall(P_FINFO(curproc)); 226 relvm(); 227 228 } else { 229 /* 230 * Reset t_cred if not set because much of the 231 * filesystem code depends on CRED() being valid. 232 */ 233 if (curthread->t_cred == NULL) 234 curthread->t_cred = kcred; 235 } 236 237 /* indicate shutdown in progress */ 238 sys_shutdown = 1; 239 240 /* 241 * Communcate that init shouldn't be restarted. 242 */ 243 zone_shutdown_global(); 244 245 killall(ALL_ZONES); 246 /* 247 * If we are calling kadmin() from a kernel context then we 248 * do not release these resources. 249 */ 250 if (ttoproc(curthread) != &p0) { 251 VN_RELE(PTOU(curproc)->u_cdir); 252 if (PTOU(curproc)->u_rdir) 253 VN_RELE(PTOU(curproc)->u_rdir); 254 if (PTOU(curproc)->u_cwd) 255 refstr_rele(PTOU(curproc)->u_cwd); 256 257 PTOU(curproc)->u_cdir = rootdir; 258 PTOU(curproc)->u_rdir = NULL; 259 PTOU(curproc)->u_cwd = NULL; 260 } 261 262 /* 263 * Allow the reboot/halt/poweroff code a chance to do 264 * anything it needs to whilst we still have filesystems 265 * mounted, like loading any modules necessary for later 266 * performing the actual poweroff. 267 */ 268 if ((mdep != NULL) && (*(char *)mdep == '/')) { 269 buf = i_convert_boot_device_name(mdep, NULL, &buflen); 270 mdpreboot(cmd, fcn, buf); 271 } else 272 mdpreboot(cmd, fcn, mdep); 273 274 /* 275 * Allow fsflush to finish running and then prevent it 276 * from ever running again so that vfs_unmountall() and 277 * vfs_syncall() can acquire the vfs locks they need. 278 */ 279 sema_p(&fsflush_sema); 280 (void) callb_execute_class(CB_CL_UADMIN_PRE_VFS, NULL); 281 282 vfs_unmountall(); 283 (void) VFS_MOUNTROOT(rootvfs, ROOT_UNMOUNT); 284 vfs_syncall(); 285 286 dump_ereports(); 287 dump_messages(); 288 289 invoke_cb = B_TRUE; 290 291 /* FALLTHROUGH */ 292 } 293 294 case A_REBOOT: 295 if ((mdep != NULL) && (*(char *)mdep == '/')) { 296 buf = i_convert_boot_device_name(mdep, NULL, &buflen); 297 mdboot(cmd, fcn, buf, invoke_cb); 298 } else 299 mdboot(cmd, fcn, mdep, invoke_cb); 300 /* no return expected */ 301 break; 302 303 case A_REMOUNT: 304 (void) VFS_MOUNTROOT(rootvfs, ROOT_REMOUNT); 305 /* Let other threads enter the shutdown path now */ 306 mutex_enter(&ualock); 307 ua_shutdown_thread = NULL; 308 cv_signal(&uacond); 309 mutex_exit(&ualock); 310 break; 311 312 case A_FREEZE: 313 { 314 /* 315 * This is the entrypoint for all suspend/resume actions. 316 */ 317 extern int cpr(int, void *); 318 319 if (modload("misc", "cpr") == -1) 320 return (ENOTSUP); 321 /* Let the CPR module decide what to do with mdep */ 322 error = cpr(fcn, mdep); 323 break; 324 } 325 326 case A_FTRACE: 327 { 328 switch (fcn) { 329 case AD_FTRACE_START: 330 (void) FTRACE_START(); 331 break; 332 case AD_FTRACE_STOP: 333 (void) FTRACE_STOP(); 334 break; 335 default: 336 error = EINVAL; 337 } 338 break; 339 } 340 341 case A_DUMP: 342 { 343 if (fcn == AD_NOSYNC) { 344 in_sync = 1; 345 break; 346 } 347 348 panic_bootfcn = fcn; 349 panic_forced = 1; 350 351 if ((mdep != NULL) && (*(char *)mdep == '/')) { 352 panic_bootstr = i_convert_boot_device_name(mdep, 353 NULL, &buflen); 354 } else 355 panic_bootstr = mdep; 356 357 panic("forced crash dump initiated at user request"); 358 /*NOTREACHED*/ 359 } 360 361 case A_SDTTEST: 362 { 363 DTRACE_PROBE7(test, int, 1, int, 2, int, 3, int, 4, int, 5, 364 int, 6, int, 7); 365 break; 366 } 367 368 default: 369 error = EINVAL; 370 } 371 372 return (error); 373 } 374 375 int 376 uadmin(int cmd, int fcn, uintptr_t mdep) 377 { 378 int error = 0, rv = 0; 379 size_t nbytes = 0; 380 cred_t *credp = CRED(); 381 char *bootargs = NULL; 382 383 /* 384 * The swapctl system call doesn't have its own entry point: it uses 385 * uadmin as a wrapper so we just call it directly from here. 386 */ 387 if (cmd == A_SWAPCTL) { 388 if (get_udatamodel() == DATAMODEL_NATIVE) 389 error = swapctl(fcn, (void *)mdep, &rv); 390 #if defined(_SYSCALL32_IMPL) 391 else 392 error = swapctl32(fcn, (void *)mdep, &rv); 393 #endif /* _SYSCALL32_IMPL */ 394 return (error ? set_errno(error) : rv); 395 } 396 397 /* 398 * Certain subcommands intepret a non-NULL mdep value as a pointer to 399 * a boot string. We pull that in as bootargs, if applicable. 400 */ 401 if (mdep != NULL && 402 (cmd == A_SHUTDOWN || cmd == A_REBOOT || cmd == A_DUMP || 403 cmd == A_FREEZE)) { 404 bootargs = kmem_zalloc(BOOTARGS_MAX, KM_SLEEP); 405 if ((error = copyinstr((const char *)mdep, bootargs, 406 BOOTARGS_MAX, &nbytes)) != 0) { 407 kmem_free(bootargs, BOOTARGS_MAX); 408 return (set_errno(error)); 409 } 410 } 411 412 /* 413 * Invoke the appropriate kadmin() routine. 414 */ 415 if (getzoneid() != GLOBAL_ZONEID) 416 error = zone_kadmin(cmd, fcn, bootargs, credp); 417 else 418 error = kadmin(cmd, fcn, bootargs, credp); 419 420 if (bootargs != NULL) 421 kmem_free(bootargs, BOOTARGS_MAX); 422 return (error ? set_errno(error) : 0); 423 } 424