kern_proc.c revision 1.44.2.8
1 /* $NetBSD: kern_proc.c,v 1.44.2.8 2002/07/12 01:40:17 nathanw Exp $ */ 2 3 /*- 4 * Copyright (c) 1999 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright (c) 1982, 1986, 1989, 1991, 1993 42 * The Regents of the University of California. All rights reserved. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. All advertising materials mentioning features or use of this software 53 * must display the following acknowledgement: 54 * This product includes software developed by the University of 55 * California, Berkeley and its contributors. 56 * 4. Neither the name of the University nor the names of its contributors 57 * may be used to endorse or promote products derived from this software 58 * without specific prior written permission. 59 * 60 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 61 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 62 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 63 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 64 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 65 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 66 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 70 * SUCH DAMAGE. 71 * 72 * @(#)kern_proc.c 8.7 (Berkeley) 2/14/95 73 */ 74 75 #include <sys/cdefs.h> 76 __KERNEL_RCSID(0, "$NetBSD: kern_proc.c,v 1.44.2.8 2002/07/12 01:40:17 nathanw Exp $"); 77 78 #include <sys/param.h> 79 #include <sys/systm.h> 80 #include <sys/map.h> 81 #include <sys/kernel.h> 82 #include <sys/proc.h> 83 #include <sys/resourcevar.h> 84 #include <sys/buf.h> 85 #include <sys/acct.h> 86 #include <sys/wait.h> 87 #include <sys/file.h> 88 #include <ufs/ufs/quota.h> 89 #include <sys/uio.h> 90 #include <sys/malloc.h> 91 #include <sys/pool.h> 92 #include <sys/mbuf.h> 93 #include <sys/ioctl.h> 94 #include <sys/tty.h> 95 #include <sys/signalvar.h> 96 #include <sys/sa.h> 97 #include <sys/savar.h> 98 99 /* 100 * Structure associated with user cacheing. 101 */ 102 struct uidinfo { 103 LIST_ENTRY(uidinfo) ui_hash; 104 uid_t ui_uid; 105 long ui_proccnt; 106 }; 107 #define UIHASH(uid) (&uihashtbl[(uid) & uihash]) 108 LIST_HEAD(uihashhead, uidinfo) *uihashtbl; 109 u_long uihash; /* size of hash table - 1 */ 110 111 /* 112 * Other process lists 113 */ 114 struct pidhashhead *pidhashtbl; 115 u_long pidhash; 116 struct pgrphashhead *pgrphashtbl; 117 u_long pgrphash; 118 119 struct proclist allproc; 120 struct proclist zombproc; /* resources have been freed */ 121 122 123 /* 124 * Process list locking: 125 * 126 * We have two types of locks on the proclists: read locks and write 127 * locks. Read locks can be used in interrupt context, so while we 128 * hold the write lock, we must also block clock interrupts to 129 * lock out any scheduling changes that may happen in interrupt 130 * context. 131 * 132 * The proclist lock locks the following structures: 133 * 134 * allproc 135 * zombproc 136 * pidhashtbl 137 */ 138 struct lock proclist_lock; 139 140 /* 141 * Locking of this proclist is special; it's accessed in a 142 * critical section of process exit, and thus locking it can't 143 * modify interrupt state. We use a simple spin lock for this 144 * proclist. Processes on this proclist are also on zombproc; 145 * we use the p_hash member to linkup to deadproc. 146 */ 147 struct simplelock deadproc_slock; 148 struct proclist deadproc; /* dead, but not yet undead */ 149 150 struct pool proc_pool; 151 struct pool lwp_pool; 152 struct pool lwp_uc_pool; 153 struct pool pcred_pool; 154 struct pool plimit_pool; 155 struct pool pstats_pool; 156 struct pool pgrp_pool; 157 struct pool rusage_pool; 158 struct pool sadata_pool; 159 struct pool saupcall_pool; 160 struct pool ptimer_pool; 161 162 /* 163 * The process list descriptors, used during pid allocation and 164 * by sysctl. No locking on this data structure is needed since 165 * it is completely static. 166 */ 167 const struct proclist_desc proclists[] = { 168 { &allproc }, 169 { &zombproc }, 170 { NULL }, 171 }; 172 173 static void orphanpg __P((struct pgrp *)); 174 #ifdef DEBUG 175 void pgrpdump __P((void)); 176 #endif 177 178 /* 179 * Initialize global process hashing structures. 180 */ 181 void 182 procinit() 183 { 184 const struct proclist_desc *pd; 185 186 for (pd = proclists; pd->pd_list != NULL; pd++) 187 LIST_INIT(pd->pd_list); 188 189 spinlockinit(&proclist_lock, "proclk", 0); 190 191 LIST_INIT(&deadproc); 192 simple_lock_init(&deadproc_slock); 193 194 LIST_INIT(&alllwp); 195 LIST_INIT(&deadlwp); 196 LIST_INIT(&zomblwp); 197 198 pidhashtbl = 199 hashinit(maxproc / 4, HASH_LIST, M_PROC, M_WAITOK, &pidhash); 200 pgrphashtbl = 201 hashinit(maxproc / 4, HASH_LIST, M_PROC, M_WAITOK, &pgrphash); 202 uihashtbl = 203 hashinit(maxproc / 16, HASH_LIST, M_PROC, M_WAITOK, &uihash); 204 205 pool_init(&proc_pool, sizeof(struct proc), 0, 0, 0, "procpl", 206 &pool_allocator_nointr); 207 pool_init(&lwp_pool, sizeof(struct lwp), 0, 0, 0, "lwppl", 208 &pool_allocator_nointr); 209 pool_init(&lwp_uc_pool, sizeof(ucontext_t), 0, 0, 0, "lwpucpl", 210 &pool_allocator_nointr); 211 pool_init(&pgrp_pool, sizeof(struct pgrp), 0, 0, 0, "pgrppl", 212 &pool_allocator_nointr); 213 pool_init(&pcred_pool, sizeof(struct pcred), 0, 0, 0, "pcredpl", 214 &pool_allocator_nointr); 215 pool_init(&plimit_pool, sizeof(struct plimit), 0, 0, 0, "plimitpl", 216 &pool_allocator_nointr); 217 pool_init(&pstats_pool, sizeof(struct pstats), 0, 0, 0, "pstatspl", 218 &pool_allocator_nointr); 219 pool_init(&rusage_pool, sizeof(struct rusage), 0, 0, 0, "rusgepl", 220 &pool_allocator_nointr); 221 pool_init(&sadata_pool, sizeof(struct sadata), 0, 0, 0, "sadatapl", 222 &pool_allocator_nointr); 223 pool_init(&saupcall_pool, sizeof(struct sadata_upcall), 0, 0, 0, 224 "saupcpl", 225 &pool_allocator_nointr); 226 pool_init(&ptimer_pool, sizeof(struct ptimer), 0, 0, 0, "ptimerpl", 227 &pool_allocator_nointr); 228 } 229 230 /* 231 * Acquire a read lock on the proclist. 232 */ 233 void 234 proclist_lock_read() 235 { 236 int error; 237 238 error = spinlockmgr(&proclist_lock, LK_SHARED, NULL); 239 #ifdef DIAGNOSTIC 240 if (__predict_false(error != 0)) 241 panic("proclist_lock_read: failed to acquire lock"); 242 #endif 243 } 244 245 /* 246 * Release a read lock on the proclist. 247 */ 248 void 249 proclist_unlock_read() 250 { 251 252 (void) spinlockmgr(&proclist_lock, LK_RELEASE, NULL); 253 } 254 255 /* 256 * Acquire a write lock on the proclist. 257 */ 258 int 259 proclist_lock_write() 260 { 261 int s, error; 262 263 s = splclock(); 264 error = spinlockmgr(&proclist_lock, LK_EXCLUSIVE, NULL); 265 #ifdef DIAGNOSTIC 266 if (__predict_false(error != 0)) 267 panic("proclist_lock: failed to acquire lock"); 268 #endif 269 return (s); 270 } 271 272 /* 273 * Release a write lock on the proclist. 274 */ 275 void 276 proclist_unlock_write(s) 277 int s; 278 { 279 280 (void) spinlockmgr(&proclist_lock, LK_RELEASE, NULL); 281 splx(s); 282 } 283 284 /* 285 * Change the count associated with number of processes 286 * a given user is using. 287 */ 288 int 289 chgproccnt(uid, diff) 290 uid_t uid; 291 int diff; 292 { 293 struct uidinfo *uip; 294 struct uihashhead *uipp; 295 296 uipp = UIHASH(uid); 297 for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next) 298 if (uip->ui_uid == uid) 299 break; 300 if (uip) { 301 uip->ui_proccnt += diff; 302 if (uip->ui_proccnt > 0) 303 return (uip->ui_proccnt); 304 if (uip->ui_proccnt < 0) 305 panic("chgproccnt: procs < 0"); 306 LIST_REMOVE(uip, ui_hash); 307 FREE(uip, M_PROC); 308 return (0); 309 } 310 if (diff <= 0) { 311 if (diff == 0) 312 return(0); 313 panic("chgproccnt: lost user"); 314 } 315 MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK); 316 LIST_INSERT_HEAD(uipp, uip, ui_hash); 317 uip->ui_uid = uid; 318 uip->ui_proccnt = diff; 319 return (diff); 320 } 321 322 /* 323 * Is p an inferior of q? 324 */ 325 int 326 inferior(p, q) 327 struct proc *p; 328 struct proc *q; 329 { 330 331 for (; p != q; p = p->p_pptr) 332 if (p->p_pid == 0) 333 return (0); 334 return (1); 335 } 336 337 /* 338 * Locate a process by number 339 */ 340 struct proc * 341 pfind(pid) 342 pid_t pid; 343 { 344 struct proc *p; 345 346 proclist_lock_read(); 347 for (p = PIDHASH(pid)->lh_first; p != 0; p = p->p_hash.le_next) 348 if (p->p_pid == pid) 349 goto out; 350 out: 351 proclist_unlock_read(); 352 return (p); 353 } 354 355 /* 356 * Locate a process group by number 357 */ 358 struct pgrp * 359 pgfind(pgid) 360 pid_t pgid; 361 { 362 struct pgrp *pgrp; 363 364 for (pgrp = PGRPHASH(pgid)->lh_first; pgrp != 0; pgrp = pgrp->pg_hash.le_next) 365 if (pgrp->pg_id == pgid) 366 return (pgrp); 367 return (NULL); 368 } 369 370 /* 371 * Move p to a new or existing process group (and session) 372 */ 373 int 374 enterpgrp(p, pgid, mksess) 375 struct proc *p; 376 pid_t pgid; 377 int mksess; 378 { 379 struct pgrp *pgrp = pgfind(pgid); 380 381 #ifdef DIAGNOSTIC 382 if (__predict_false(pgrp != NULL && mksess)) /* firewalls */ 383 panic("enterpgrp: setsid into non-empty pgrp"); 384 if (__predict_false(SESS_LEADER(p))) 385 panic("enterpgrp: session leader attempted setpgrp"); 386 #endif 387 if (pgrp == NULL) { 388 pid_t savepid = p->p_pid; 389 struct proc *np; 390 /* 391 * new process group 392 */ 393 #ifdef DIAGNOSTIC 394 if (__predict_false(p->p_pid != pgid)) 395 panic("enterpgrp: new pgrp and pid != pgid"); 396 #endif 397 pgrp = pool_get(&pgrp_pool, PR_WAITOK); 398 if ((np = pfind(savepid)) == NULL || np != p) 399 return (ESRCH); 400 if (mksess) { 401 struct session *sess; 402 403 /* 404 * new session 405 */ 406 MALLOC(sess, struct session *, sizeof(struct session), 407 M_SESSION, M_WAITOK); 408 sess->s_sid = p->p_pid; 409 sess->s_leader = p; 410 sess->s_count = 1; 411 sess->s_ttyvp = NULL; 412 sess->s_ttyp = NULL; 413 memcpy(sess->s_login, p->p_session->s_login, 414 sizeof(sess->s_login)); 415 p->p_flag &= ~P_CONTROLT; 416 pgrp->pg_session = sess; 417 #ifdef DIAGNOSTIC 418 if (__predict_false(p != curproc)) 419 panic("enterpgrp: mksession and p != curlwp"); 420 #endif 421 } else { 422 SESSHOLD(p->p_session); 423 pgrp->pg_session = p->p_session; 424 } 425 pgrp->pg_id = pgid; 426 LIST_INIT(&pgrp->pg_members); 427 LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash); 428 pgrp->pg_jobc = 0; 429 } else if (pgrp == p->p_pgrp) 430 return (0); 431 432 /* 433 * Adjust eligibility of affected pgrps to participate in job control. 434 * Increment eligibility counts before decrementing, otherwise we 435 * could reach 0 spuriously during the first call. 436 */ 437 fixjobc(p, pgrp, 1); 438 fixjobc(p, p->p_pgrp, 0); 439 440 LIST_REMOVE(p, p_pglist); 441 if (p->p_pgrp->pg_members.lh_first == 0) 442 pgdelete(p->p_pgrp); 443 p->p_pgrp = pgrp; 444 LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist); 445 return (0); 446 } 447 448 /* 449 * remove process from process group 450 */ 451 int 452 leavepgrp(p) 453 struct proc *p; 454 { 455 456 LIST_REMOVE(p, p_pglist); 457 if (p->p_pgrp->pg_members.lh_first == 0) 458 pgdelete(p->p_pgrp); 459 p->p_pgrp = 0; 460 return (0); 461 } 462 463 /* 464 * delete a process group 465 */ 466 void 467 pgdelete(pgrp) 468 struct pgrp *pgrp; 469 { 470 471 /* Remove reference (if any) from tty to this process group */ 472 if (pgrp->pg_session->s_ttyp != NULL && 473 pgrp->pg_session->s_ttyp->t_pgrp == pgrp) 474 pgrp->pg_session->s_ttyp->t_pgrp = NULL; 475 LIST_REMOVE(pgrp, pg_hash); 476 SESSRELE(pgrp->pg_session); 477 pool_put(&pgrp_pool, pgrp); 478 } 479 480 /* 481 * Adjust pgrp jobc counters when specified process changes process group. 482 * We count the number of processes in each process group that "qualify" 483 * the group for terminal job control (those with a parent in a different 484 * process group of the same session). If that count reaches zero, the 485 * process group becomes orphaned. Check both the specified process' 486 * process group and that of its children. 487 * entering == 0 => p is leaving specified group. 488 * entering == 1 => p is entering specified group. 489 */ 490 void 491 fixjobc(p, pgrp, entering) 492 struct proc *p; 493 struct pgrp *pgrp; 494 int entering; 495 { 496 struct pgrp *hispgrp; 497 struct session *mysession = pgrp->pg_session; 498 499 /* 500 * Check p's parent to see whether p qualifies its own process 501 * group; if so, adjust count for p's process group. 502 */ 503 if ((hispgrp = p->p_pptr->p_pgrp) != pgrp && 504 hispgrp->pg_session == mysession) { 505 if (entering) 506 pgrp->pg_jobc++; 507 else if (--pgrp->pg_jobc == 0) 508 orphanpg(pgrp); 509 } 510 511 /* 512 * Check this process' children to see whether they qualify 513 * their process groups; if so, adjust counts for children's 514 * process groups. 515 */ 516 for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next) { 517 if ((hispgrp = p->p_pgrp) != pgrp && 518 hispgrp->pg_session == mysession && 519 P_ZOMBIE(p) == 0) { 520 if (entering) 521 hispgrp->pg_jobc++; 522 else if (--hispgrp->pg_jobc == 0) 523 orphanpg(hispgrp); 524 } 525 } 526 } 527 528 /* 529 * A process group has become orphaned; 530 * if there are any stopped processes in the group, 531 * hang-up all process in that group. 532 */ 533 static void 534 orphanpg(pg) 535 struct pgrp *pg; 536 { 537 struct proc *p; 538 539 for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) { 540 if (p->p_stat == SSTOP) { 541 for (p = pg->pg_members.lh_first; p != 0; 542 p = p->p_pglist.le_next) { 543 psignal(p, SIGHUP); 544 psignal(p, SIGCONT); 545 } 546 return; 547 } 548 } 549 } 550 551 /* mark process as suid/sgid, reset some values do defaults */ 552 void 553 p_sugid(p) 554 struct proc *p; 555 { 556 struct plimit *newlim; 557 558 p->p_flag |= P_SUGID; 559 /* reset what needs to be reset in plimit */ 560 if (p->p_limit->pl_corename != defcorename) { 561 if (p->p_limit->p_refcnt > 1 && 562 (p->p_limit->p_lflags & PL_SHAREMOD) == 0) { 563 newlim = limcopy(p->p_limit); 564 limfree(p->p_limit); 565 p->p_limit = newlim; 566 } else { 567 free(p->p_limit->pl_corename, M_TEMP); 568 } 569 p->p_limit->pl_corename = defcorename; 570 } 571 } 572 573 574 #ifdef DEBUG 575 void 576 pgrpdump() 577 { 578 struct pgrp *pgrp; 579 struct proc *p; 580 int i; 581 582 for (i = 0; i <= pgrphash; i++) { 583 if ((pgrp = pgrphashtbl[i].lh_first) != NULL) { 584 printf("\tindx %d\n", i); 585 for (; pgrp != 0; pgrp = pgrp->pg_hash.le_next) { 586 printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n", 587 pgrp, pgrp->pg_id, pgrp->pg_session, 588 pgrp->pg_session->s_count, 589 pgrp->pg_members.lh_first); 590 for (p = pgrp->pg_members.lh_first; p != 0; 591 p = p->p_pglist.le_next) { 592 printf("\t\tpid %d addr %p pgrp %p\n", 593 p->p_pid, p, p->p_pgrp); 594 } 595 } 596 } 597 } 598 } 599 #endif /* DEBUG */ 600
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