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 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 * 25 * Copyright 2018 Joyent, Inc. 26 */ 27 28 /* 29 * wait.c - asynchronous monitoring of "wait registered" start methods 30 * 31 * Use event ports to poll on the set of fds representing the /proc/[pid]/psinfo 32 * files. If one of these fds returns an event, then we inform the restarter 33 * that it has stopped. 34 * 35 * The wait_info_list holds the series of processes currently being monitored 36 * for exit. The wi_fd member, which contains the file descriptor of the psinfo 37 * file being polled upon ("event ported upon"), will be set to -1 if the file 38 * descriptor is inactive (already closed or not yet opened). 39 */ 40 41 #ifdef _FILE_OFFSET_BITS 42 #undef _FILE_OFFSET_BITS 43 #endif /* _FILE_OFFSET_BITS */ 44 45 #include <sys/resource.h> 46 #include <sys/stat.h> 47 #include <sys/types.h> 48 #include <sys/uio.h> 49 #include <sys/wait.h> 50 51 #include <assert.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <libuutil.h> 55 #include <poll.h> 56 #include <port.h> 57 #include <pthread.h> 58 #include <procfs.h> 59 #include <string.h> 60 #include <stropts.h> 61 #include <unistd.h> 62 63 #include "startd.h" 64 65 #define WAIT_FILES 262144 /* reasonably high maximum */ 66 67 static int port_fd; 68 static scf_handle_t *wait_hndl; 69 static struct rlimit init_fd_rlimit; 70 71 static uu_list_pool_t *wait_info_pool; 72 static uu_list_t *wait_info_list; 73 74 static pthread_mutex_t wait_info_lock; 75 76 /* 77 * void wait_remove(wait_info_t *, int) 78 * Remove the given wait_info structure from our list, performing various 79 * cleanup operations along the way. If the direct flag is false (meaning 80 * that we are being called with from restarter instance list context) and 81 * the instance should not be ignored, then notify the restarter that the 82 * associated instance has exited. If the wi_ignore flag is true then it 83 * means that the stop was initiated from within svc.startd, rather than 84 * from outside it. 85 * 86 * Since we may no longer be the startd that started this process, we only are 87 * concerned with a waitpid(3C) failure if the wi_parent field is non-zero. 88 */ 89 static void 90 wait_remove(wait_info_t *wi, int direct) 91 { 92 int status; 93 stop_cause_t cause = RSTOP_EXIT; 94 95 if (waitpid(wi->wi_pid, &status, 0) == -1) { 96 if (wi->wi_parent) 97 log_framework(LOG_INFO, 98 "instance %s waitpid failure: %s\n", wi->wi_fmri, 99 strerror(errno)); 100 } else { 101 if (WEXITSTATUS(status) != 0) { 102 log_framework(LOG_NOTICE, 103 "instance %s exited with status %d\n", wi->wi_fmri, 104 WEXITSTATUS(status)); 105 if (WEXITSTATUS(status) == SMF_EXIT_ERR_CONFIG) 106 cause = RSTOP_ERR_CFG; 107 else 108 cause = RSTOP_ERR_EXIT; 109 } 110 } 111 112 MUTEX_LOCK(&wait_info_lock); 113 if (wi->wi_fd != -1) { 114 startd_close(wi->wi_fd); 115 wi->wi_fd = -1; 116 } 117 uu_list_remove(wait_info_list, wi); 118 MUTEX_UNLOCK(&wait_info_lock); 119 120 /* 121 * Make an attempt to clear out any utmpx record associated with this 122 * PID. 123 */ 124 utmpx_mark_dead(wi->wi_pid, status, B_FALSE); 125 126 if (!direct && !wi->wi_ignore) { 127 /* 128 * Bind wait_hndl lazily. 129 */ 130 if (wait_hndl == NULL) { 131 for (wait_hndl = 132 libscf_handle_create_bound(SCF_VERSION); 133 wait_hndl == NULL; 134 wait_hndl = 135 libscf_handle_create_bound(SCF_VERSION)) { 136 log_error(LOG_INFO, "[wait_remove] Unable to " 137 "bind a new repository handle: %s\n", 138 scf_strerror(scf_error())); 139 (void) sleep(2); 140 } 141 } 142 143 log_framework(LOG_DEBUG, 144 "wait_remove requesting stop of %s\n", wi->wi_fmri); 145 (void) stop_instance_fmri(wait_hndl, wi->wi_fmri, cause); 146 } 147 148 uu_list_node_fini(wi, &wi->wi_link, wait_info_pool); 149 startd_free(wi, sizeof (wait_info_t)); 150 } 151 152 /* 153 * void wait_ignore_by_fmri(const char *) 154 * wait_ignore_by_fmri is called when svc.startd is going to stop the 155 * instance. Since we need to wait on the process and close the utmpx record, 156 * we're going to set the wi_ignore flag, so that when the process exits we 157 * clean up, but don't tell the restarter to stop it. 158 */ 159 void 160 wait_ignore_by_fmri(const char *fmri) 161 { 162 wait_info_t *wi; 163 164 MUTEX_LOCK(&wait_info_lock); 165 166 for (wi = uu_list_first(wait_info_list); wi != NULL; 167 wi = uu_list_next(wait_info_list, wi)) { 168 if (strcmp(wi->wi_fmri, fmri) == 0) 169 break; 170 } 171 172 if (wi != NULL) { 173 wi->wi_ignore = 1; 174 } 175 176 MUTEX_UNLOCK(&wait_info_lock); 177 } 178 179 /* 180 * int wait_register(pid_t, char *, int, int) 181 * wait_register is called after we have called fork(2), and know which pid we 182 * wish to monitor. However, since the child may have already exited by the 183 * time we are called, we must handle the error cases from open(2) 184 * appropriately. The am_parent flag is recorded to handle waitpid(2) 185 * behaviour on removal; similarly, the direct flag is passed through to a 186 * potential call to wait_remove() to govern its behaviour in different 187 * contexts. 188 * 189 * Returns 0 if registration successful, 1 if child pid did not exist, and -1 190 * if a different error occurred. 191 */ 192 int 193 wait_register(pid_t pid, const char *inst_fmri, int am_parent, int direct) 194 { 195 char *fname = uu_msprintf("/proc/%ld/psinfo", pid); 196 int fd; 197 wait_info_t *wi; 198 199 assert(pid != 0); 200 201 if (fname == NULL) 202 return (-1); 203 204 wi = startd_alloc(sizeof (wait_info_t)); 205 206 uu_list_node_init(wi, &wi->wi_link, wait_info_pool); 207 208 wi->wi_fd = -1; 209 wi->wi_pid = pid; 210 wi->wi_fmri = inst_fmri; 211 wi->wi_parent = am_parent; 212 wi->wi_ignore = 0; 213 214 MUTEX_LOCK(&wait_info_lock); 215 (void) uu_list_insert_before(wait_info_list, NULL, wi); 216 MUTEX_UNLOCK(&wait_info_lock); 217 218 if ((fd = open(fname, O_RDONLY)) == -1) { 219 if (errno == ENOENT) { 220 /* 221 * Child has already exited. 222 */ 223 wait_remove(wi, direct); 224 uu_free(fname); 225 return (1); 226 } else { 227 log_error(LOG_WARNING, 228 "open %s failed; not monitoring %s: %s\n", fname, 229 inst_fmri, strerror(errno)); 230 uu_free(fname); 231 return (-1); 232 } 233 } 234 235 uu_free(fname); 236 237 wi->wi_fd = fd; 238 239 if (port_associate(port_fd, PORT_SOURCE_FD, fd, 0, wi)) { 240 log_error(LOG_WARNING, 241 "initial port_association of %d / %s failed: %s\n", fd, 242 inst_fmri, strerror(errno)); 243 return (-1); 244 } 245 246 log_framework(LOG_DEBUG, "monitoring PID %ld on fd %d (%s)\n", pid, fd, 247 inst_fmri); 248 249 return (0); 250 } 251 252 /*ARGSUSED*/ 253 void * 254 wait_thread(void *args) 255 { 256 (void) pthread_setname_np(pthread_self(), "wait"); 257 258 for (;;) { 259 port_event_t pe; 260 int fd; 261 wait_info_t *wi; 262 263 if (port_get(port_fd, &pe, NULL) != 0) { 264 if (errno == EINTR) 265 continue; 266 else { 267 log_error(LOG_WARNING, 268 "port_get() failed with %s\n", 269 strerror(errno)); 270 bad_error("port_get", errno); 271 } 272 } 273 274 fd = pe.portev_object; 275 wi = pe.portev_user; 276 assert(wi != NULL); 277 assert(fd == wi->wi_fd); 278 279 if ((pe.portev_events & POLLHUP) == POLLHUP) { 280 psinfo_t psi; 281 282 if (lseek(fd, 0, SEEK_SET) != 0 || 283 read(fd, &psi, sizeof (psinfo_t)) != 284 sizeof (psinfo_t)) { 285 log_framework(LOG_WARNING, 286 "couldn't get psinfo data for %s (%s); " 287 "assuming failed\n", wi->wi_fmri, 288 strerror(errno)); 289 goto err_remove; 290 } 291 292 if (psi.pr_nlwp != 0 || 293 psi.pr_nzomb != 0 || 294 psi.pr_lwp.pr_lwpid != 0) { 295 /* 296 * We have determined, in accordance with the 297 * definition in proc(5), this process is not a 298 * zombie. Reassociate. 299 */ 300 if (port_associate(port_fd, PORT_SOURCE_FD, fd, 301 0, wi)) 302 log_error(LOG_WARNING, 303 "port_association of %d / %s " 304 "failed\n", fd, wi->wi_fmri); 305 continue; 306 } 307 } else if ( 308 (pe.portev_events & POLLERR) == 0) { 309 if (port_associate(port_fd, PORT_SOURCE_FD, fd, 0, wi)) 310 log_error(LOG_WARNING, 311 "port_association of %d / %s " 312 "failed\n", fd, wi->wi_fmri); 313 continue; 314 } 315 316 err_remove: 317 wait_remove(wi, 0); 318 } 319 320 /*LINTED E_FUNC_HAS_NO_RETURN_STMT*/ 321 } 322 323 void 324 wait_prefork() 325 { 326 MUTEX_LOCK(&wait_info_lock); 327 } 328 329 void 330 wait_postfork(pid_t pid) 331 { 332 wait_info_t *wi; 333 334 MUTEX_UNLOCK(&wait_info_lock); 335 336 if (pid != 0) 337 return; 338 339 /* 340 * Close all of the child's wait-related fds. The wait_thread() is 341 * gone, so no need to worry about returning events. We always exec(2) 342 * after a fork request, so we needn't free the list elements 343 * themselves. 344 */ 345 346 for (wi = uu_list_first(wait_info_list); 347 wi != NULL; 348 wi = uu_list_next(wait_info_list, wi)) { 349 if (wi->wi_fd != -1) 350 startd_close(wi->wi_fd); 351 } 352 353 startd_close(port_fd); 354 355 (void) setrlimit(RLIMIT_NOFILE, &init_fd_rlimit); 356 } 357 358 void 359 wait_init() 360 { 361 struct rlimit fd_new; 362 363 (void) getrlimit(RLIMIT_NOFILE, &init_fd_rlimit); 364 (void) getrlimit(RLIMIT_NOFILE, &fd_new); 365 366 fd_new.rlim_max = fd_new.rlim_cur = WAIT_FILES; 367 368 (void) setrlimit(RLIMIT_NOFILE, &fd_new); 369 370 if ((port_fd = port_create()) == -1) 371 uu_die("wait_init couldn't port_create"); 372 373 wait_info_pool = uu_list_pool_create("wait_info", sizeof (wait_info_t), 374 offsetof(wait_info_t, wi_link), NULL, UU_LIST_POOL_DEBUG); 375 if (wait_info_pool == NULL) 376 uu_die("wait_init couldn't create wait_info_pool"); 377 378 wait_info_list = uu_list_create(wait_info_pool, wait_info_list, 0); 379 if (wait_info_list == NULL) 380 uu_die("wait_init couldn't create wait_info_list"); 381 382 (void) pthread_mutex_init(&wait_info_lock, &mutex_attrs); 383 } 384