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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 23 /* 24 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 25 * Use is subject to license terms. 26 */ 27 28 #pragma ident "%Z%%M% %I% %E% SMI" 29 30 #include <sys/param.h> 31 #include <sys/types.h> 32 #include <sys/sysmacros.h> 33 #include <sys/systm.h> 34 #include <sys/errno.h> 35 #include <sys/vfs.h> 36 #include <sys/vnode.h> 37 #include <sys/swap.h> 38 #include <sys/file.h> 39 #include <sys/proc.h> 40 #include <sys/var.h> 41 #include <sys/uadmin.h> 42 #include <sys/signal.h> 43 #include <sys/time.h> 44 #include <vm/seg_kmem.h> 45 #include <sys/modctl.h> 46 #include <sys/callb.h> 47 #include <sys/dumphdr.h> 48 #include <sys/debug.h> 49 #include <sys/ftrace.h> 50 #include <sys/cmn_err.h> 51 #include <sys/panic.h> 52 #include <sys/ddi.h> 53 #include <sys/sunddi.h> 54 #include <sys/policy.h> 55 #include <sys/zone.h> 56 57 /* 58 * Administrivia system call. We provide this in two flavors: one for calling 59 * from the system call path (uadmin), and the other for calling from elsewhere 60 * within the kernel (kadmin). Callers must beware that certain uadmin cmd 61 * values (specifically A_SWAPCTL) are only supported by uadmin and not kadmin. 62 */ 63 64 extern ksema_t fsflush_sema; 65 kmutex_t ualock; 66 67 68 /* 69 * Kill all user processes in said zone. A special argument of ALL_ZONES is 70 * passed in when the system as a whole is shutting down. The lack of per-zone 71 * process lists is likely to make the following a performance bottleneck on a 72 * system with many zones. 73 */ 74 void 75 killall(zoneid_t zoneid) 76 { 77 proc_t *p; 78 79 ASSERT(zoneid != GLOBAL_ZONEID); 80 /* 81 * Kill all processes except kernel daemons and ourself. 82 * Make a first pass to stop all processes so they won't 83 * be trying to restart children as we kill them. 84 */ 85 mutex_enter(&pidlock); 86 for (p = practive; p != NULL; p = p->p_next) { 87 if ((zoneid == ALL_ZONES || p->p_zone->zone_id == zoneid) && 88 p->p_exec != NULLVP && /* kernel daemons */ 89 p->p_as != &kas && 90 p->p_stat != SZOMB) { 91 mutex_enter(&p->p_lock); 92 p->p_flag |= SNOWAIT; 93 sigtoproc(p, NULL, SIGSTOP); 94 mutex_exit(&p->p_lock); 95 } 96 } 97 p = practive; 98 while (p != NULL) { 99 if ((zoneid == ALL_ZONES || p->p_zone->zone_id == zoneid) && 100 p->p_exec != NULLVP && /* kernel daemons */ 101 p->p_as != &kas && 102 p->p_stat != SIDL && 103 p->p_stat != SZOMB) { 104 mutex_enter(&p->p_lock); 105 if (sigismember(&p->p_sig, SIGKILL)) { 106 mutex_exit(&p->p_lock); 107 p = p->p_next; 108 } else { 109 sigtoproc(p, NULL, SIGKILL); 110 mutex_exit(&p->p_lock); 111 (void) cv_timedwait(&p->p_srwchan_cv, 112 &pidlock, lbolt + hz); 113 p = practive; 114 } 115 } else { 116 p = p->p_next; 117 } 118 } 119 mutex_exit(&pidlock); 120 } 121 122 int 123 kadmin(int cmd, int fcn, void *mdep, cred_t *credp) 124 { 125 int error = 0; 126 int locked = 0; 127 char *buf; 128 size_t buflen = 0; 129 boolean_t invoke_cb = B_FALSE; 130 131 /* 132 * We might be called directly by the kernel's fault-handling code, so 133 * we can't assert that the caller is in the global zone. 134 */ 135 136 /* 137 * Make sure that cmd is one of the valid <sys/uadmin.h> command codes 138 * and that we have appropriate privileges for this action. 139 */ 140 switch (cmd) { 141 case A_FTRACE: 142 case A_SHUTDOWN: 143 case A_REBOOT: 144 case A_REMOUNT: 145 case A_FREEZE: 146 case A_DUMP: 147 if (secpolicy_sys_config(credp, B_FALSE) != 0) 148 return (EPERM); 149 break; 150 151 default: 152 return (EINVAL); 153 } 154 155 /* 156 * Serialize these operations on ualock. If it is held, just return 157 * as if successful since the system will soon reset or remount. 158 */ 159 if (cmd == A_SHUTDOWN || cmd == A_REBOOT || cmd == A_REMOUNT) { 160 if (!mutex_tryenter(&ualock)) 161 return (0); 162 locked = 1; 163 } 164 165 switch (cmd) { 166 case A_SHUTDOWN: 167 { 168 proc_t *p = ttoproc(curthread); 169 170 /* 171 * Release (almost) all of our own resources if we are called 172 * from a user context, however if we are calling kadmin() from 173 * a kernel context then we do not release these resources. 174 */ 175 if (p != &p0) { 176 proc_is_exiting(p); 177 if ((error = exitlwps(0)) != 0) 178 return (error); 179 mutex_enter(&p->p_lock); 180 p->p_flag |= SNOWAIT; 181 sigfillset(&p->p_ignore); 182 curthread->t_lwp->lwp_cursig = 0; 183 curthread->t_lwp->lwp_extsig = 0; 184 if (p->p_exec) { 185 vnode_t *exec_vp = p->p_exec; 186 p->p_exec = NULLVP; 187 mutex_exit(&p->p_lock); 188 VN_RELE(exec_vp); 189 } else { 190 mutex_exit(&p->p_lock); 191 } 192 193 pollcleanup(); 194 closeall(P_FINFO(curproc)); 195 relvm(); 196 197 } else { 198 /* 199 * Reset t_cred if not set because much of the 200 * filesystem code depends on CRED() being valid. 201 */ 202 if (curthread->t_cred == NULL) 203 curthread->t_cred = kcred; 204 } 205 206 /* 207 * Communcate that init shouldn't be restarted. 208 */ 209 zone_shutdown_global(); 210 211 killall(ALL_ZONES); 212 /* 213 * If we are calling kadmin() from a kernel context then we 214 * do not release these resources. 215 */ 216 if (ttoproc(curthread) != &p0) { 217 VN_RELE(u.u_cdir); 218 if (u.u_rdir) 219 VN_RELE(u.u_rdir); 220 if (u.u_cwd) 221 refstr_rele(u.u_cwd); 222 223 u.u_cdir = rootdir; 224 u.u_rdir = NULL; 225 u.u_cwd = NULL; 226 } 227 228 /* 229 * Allow the reboot/halt/poweroff code a chance to do 230 * anything it needs to whilst we still have filesystems 231 * mounted, like loading any modules necessary for later 232 * performing the actual poweroff. 233 */ 234 if ((mdep != NULL) && (*(char *)mdep == '/')) { 235 buf = i_convert_boot_device_name(mdep, NULL, &buflen); 236 mdpreboot(cmd, fcn, buf); 237 } else 238 mdpreboot(cmd, fcn, mdep); 239 240 /* 241 * Allow fsflush to finish running and then prevent it 242 * from ever running again so that vfs_unmountall() and 243 * vfs_syncall() can acquire the vfs locks they need. 244 */ 245 sema_p(&fsflush_sema); 246 (void) callb_execute_class(CB_CL_UADMIN_PRE_VFS, NULL); 247 248 vfs_unmountall(); 249 (void) VFS_MOUNTROOT(rootvfs, ROOT_UNMOUNT); 250 vfs_syncall(); 251 252 dump_ereports(); 253 dump_messages(); 254 255 invoke_cb = B_TRUE; 256 257 /* FALLTHROUGH */ 258 } 259 260 case A_REBOOT: 261 if ((mdep != NULL) && (*(char *)mdep == '/')) { 262 buf = i_convert_boot_device_name(mdep, NULL, &buflen); 263 mdboot(cmd, fcn, buf, invoke_cb); 264 } else 265 mdboot(cmd, fcn, mdep, invoke_cb); 266 /* no return expected */ 267 break; 268 269 case A_REMOUNT: 270 (void) VFS_MOUNTROOT(rootvfs, ROOT_REMOUNT); 271 break; 272 273 case A_FREEZE: 274 { 275 /* XXX: declare in some header file */ 276 extern int cpr(int); 277 278 if (modload("misc", "cpr") == -1) 279 return (ENOTSUP); 280 error = cpr(fcn); 281 break; 282 } 283 284 case A_FTRACE: 285 { 286 switch (fcn) { 287 case AD_FTRACE_START: 288 (void) FTRACE_START(); 289 break; 290 case AD_FTRACE_STOP: 291 (void) FTRACE_STOP(); 292 break; 293 default: 294 error = EINVAL; 295 } 296 break; 297 } 298 299 case A_DUMP: 300 { 301 if (fcn == AD_NOSYNC) { 302 in_sync = 1; 303 break; 304 } 305 306 panic_bootfcn = fcn; 307 panic_forced = 1; 308 309 if ((mdep != NULL) && (*(char *)mdep == '/')) { 310 panic_bootstr = i_convert_boot_device_name(mdep, 311 NULL, &buflen); 312 } else 313 panic_bootstr = mdep; 314 315 panic("forced crash dump initiated at user request"); 316 /*NOTREACHED*/ 317 } 318 319 default: 320 error = EINVAL; 321 } 322 323 if (locked) 324 mutex_exit(&ualock); 325 326 return (error); 327 } 328 329 int 330 uadmin(int cmd, int fcn, uintptr_t mdep) 331 { 332 int error = 0, rv = 0; 333 size_t nbytes = 0; 334 char buf[257]; 335 cred_t *credp = CRED(); 336 337 /* 338 * The swapctl system call doesn't have its own entry point: it uses 339 * uadmin as a wrapper so we just call it directly from here. 340 */ 341 if (cmd == A_SWAPCTL) { 342 if (get_udatamodel() == DATAMODEL_NATIVE) 343 error = swapctl(fcn, (void *)mdep, &rv); 344 #if defined(_SYSCALL32_IMPL) 345 else 346 error = swapctl32(fcn, (void *)mdep, &rv); 347 #endif /* _SYSCALL32_IMPL */ 348 return (error ? set_errno(error) : rv); 349 } 350 351 /* 352 * Handle zones. 353 */ 354 if (getzoneid() != GLOBAL_ZONEID) { 355 error = zone_uadmin(cmd, fcn, credp); 356 return (error ? set_errno(error) : 0); 357 } 358 359 /* 360 * Certain subcommands intepret a non-NULL mdep value as a pointer to 361 * a boot string. Attempt to copy it in now, or reset mdep to NULL. 362 */ 363 if (cmd == A_SHUTDOWN || cmd == A_REBOOT || cmd == A_DUMP) { 364 if (mdep != NULL && copyinstr((const char *)mdep, buf, 365 sizeof (buf) - 1, &nbytes) == 0) { 366 buf[nbytes] = '\0'; 367 mdep = (uintptr_t)buf; 368 } else 369 mdep = NULL; 370 } 371 372 if ((error = kadmin(cmd, fcn, (void *)mdep, credp)) != 0) 373 return (set_errno(error)); 374 375 return (0); 376 } 377