1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/sysproto.h> 48 #include <sys/capsicum.h> 49 #include <sys/eventhandler.h> 50 #include <sys/kernel.h> 51 #include <sys/malloc.h> 52 #include <sys/lock.h> 53 #include <sys/mutex.h> 54 #include <sys/proc.h> 55 #include <sys/procdesc.h> 56 #include <sys/pioctl.h> 57 #include <sys/jail.h> 58 #include <sys/tty.h> 59 #include <sys/wait.h> 60 #include <sys/vmmeter.h> 61 #include <sys/vnode.h> 62 #include <sys/racct.h> 63 #include <sys/resourcevar.h> 64 #include <sys/sbuf.h> 65 #include <sys/signalvar.h> 66 #include <sys/sched.h> 67 #include <sys/sx.h> 68 #include <sys/syscallsubr.h> 69 #include <sys/syslog.h> 70 #include <sys/ptrace.h> 71 #include <sys/acct.h> /* for acct_process() function prototype */ 72 #include <sys/filedesc.h> 73 #include <sys/sdt.h> 74 #include <sys/shm.h> 75 #include <sys/sem.h> 76 #include <sys/umtx.h> 77 #ifdef KTRACE 78 #include <sys/ktrace.h> 79 #endif 80 81 #include <security/audit/audit.h> 82 #include <security/mac/mac_framework.h> 83 84 #include <vm/vm.h> 85 #include <vm/vm_extern.h> 86 #include <vm/vm_param.h> 87 #include <vm/pmap.h> 88 #include <vm/vm_map.h> 89 #include <vm/vm_page.h> 90 #include <vm/uma.h> 91 92 #ifdef KDTRACE_HOOKS 93 #include <sys/dtrace_bsd.h> 94 dtrace_execexit_func_t dtrace_fasttrap_exit; 95 #endif 96 97 SDT_PROVIDER_DECLARE(proc); 98 SDT_PROBE_DEFINE1(proc, , , exit, "int"); 99 100 /* Hook for NFS teardown procedure. */ 101 void (*nlminfo_release_p)(struct proc *p); 102 103 EVENTHANDLER_LIST_DECLARE(process_exit); 104 105 struct proc * 106 proc_realparent(struct proc *child) 107 { 108 struct proc *p, *parent; 109 110 sx_assert(&proctree_lock, SX_LOCKED); 111 if ((child->p_treeflag & P_TREE_ORPHANED) == 0) { 112 if (child->p_oppid == 0 || 113 child->p_pptr->p_pid == child->p_oppid) 114 parent = child->p_pptr; 115 else 116 parent = initproc; 117 return (parent); 118 } 119 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) { 120 /* Cannot use LIST_PREV(), since the list head is not known. */ 121 p = __containerof(p->p_orphan.le_prev, struct proc, 122 p_orphan.le_next); 123 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0, 124 ("missing P_ORPHAN %p", p)); 125 } 126 parent = __containerof(p->p_orphan.le_prev, struct proc, 127 p_orphans.lh_first); 128 return (parent); 129 } 130 131 void 132 reaper_abandon_children(struct proc *p, bool exiting) 133 { 134 struct proc *p1, *p2, *ptmp; 135 136 sx_assert(&proctree_lock, SX_LOCKED); 137 KASSERT(p != initproc, ("reaper_abandon_children for initproc")); 138 if ((p->p_treeflag & P_TREE_REAPER) == 0) 139 return; 140 p1 = p->p_reaper; 141 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) { 142 LIST_REMOVE(p2, p_reapsibling); 143 p2->p_reaper = p1; 144 p2->p_reapsubtree = p->p_reapsubtree; 145 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling); 146 if (exiting && p2->p_pptr == p) { 147 PROC_LOCK(p2); 148 proc_reparent(p2, p1); 149 PROC_UNLOCK(p2); 150 } 151 } 152 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty")); 153 p->p_treeflag &= ~P_TREE_REAPER; 154 } 155 156 static void 157 clear_orphan(struct proc *p) 158 { 159 struct proc *p1; 160 161 sx_assert(&proctree_lock, SA_XLOCKED); 162 if ((p->p_treeflag & P_TREE_ORPHANED) == 0) 163 return; 164 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) { 165 p1 = LIST_NEXT(p, p_orphan); 166 if (p1 != NULL) 167 p1->p_treeflag |= P_TREE_FIRST_ORPHAN; 168 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN; 169 } 170 LIST_REMOVE(p, p_orphan); 171 p->p_treeflag &= ~P_TREE_ORPHANED; 172 } 173 174 /* 175 * exit -- death of process. 176 */ 177 void 178 sys_sys_exit(struct thread *td, struct sys_exit_args *uap) 179 { 180 181 exit1(td, uap->rval, 0); 182 /* NOTREACHED */ 183 } 184 185 /* 186 * Exit: deallocate address space and other resources, change proc state to 187 * zombie, and unlink proc from allproc and parent's lists. Save exit status 188 * and rusage for wait(). Check for child processes and orphan them. 189 */ 190 void 191 exit1(struct thread *td, int rval, int signo) 192 { 193 struct proc *p, *nq, *q, *t; 194 struct thread *tdt; 195 ksiginfo_t *ksi, *ksi1; 196 int signal_parent; 197 198 mtx_assert(&Giant, MA_NOTOWNED); 199 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo)); 200 201 p = td->td_proc; 202 /* 203 * XXX in case we're rebooting we just let init die in order to 204 * work around an unsolved stack overflow seen very late during 205 * shutdown on sparc64 when the gmirror worker process exists. 206 */ 207 if (p == initproc && rebooting == 0) { 208 printf("init died (signal %d, exit %d)\n", signo, rval); 209 panic("Going nowhere without my init!"); 210 } 211 212 /* 213 * Deref SU mp, since the thread does not return to userspace. 214 */ 215 td_softdep_cleanup(td); 216 217 /* 218 * MUST abort all other threads before proceeding past here. 219 */ 220 PROC_LOCK(p); 221 /* 222 * First check if some other thread or external request got 223 * here before us. If so, act appropriately: exit or suspend. 224 * We must ensure that stop requests are handled before we set 225 * P_WEXIT. 226 */ 227 thread_suspend_check(0); 228 while (p->p_flag & P_HADTHREADS) { 229 /* 230 * Kill off the other threads. This requires 231 * some co-operation from other parts of the kernel 232 * so it may not be instantaneous. With this state set 233 * any thread entering the kernel from userspace will 234 * thread_exit() in trap(). Any thread attempting to 235 * sleep will return immediately with EINTR or EWOULDBLOCK 236 * which will hopefully force them to back out to userland 237 * freeing resources as they go. Any thread attempting 238 * to return to userland will thread_exit() from userret(). 239 * thread_exit() will unsuspend us when the last of the 240 * other threads exits. 241 * If there is already a thread singler after resumption, 242 * calling thread_single will fail; in that case, we just 243 * re-check all suspension request, the thread should 244 * either be suspended there or exit. 245 */ 246 if (!thread_single(p, SINGLE_EXIT)) 247 /* 248 * All other activity in this process is now 249 * stopped. Threading support has been turned 250 * off. 251 */ 252 break; 253 /* 254 * Recheck for new stop or suspend requests which 255 * might appear while process lock was dropped in 256 * thread_single(). 257 */ 258 thread_suspend_check(0); 259 } 260 KASSERT(p->p_numthreads == 1, 261 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads)); 262 racct_sub(p, RACCT_NTHR, 1); 263 264 /* Let event handler change exit status */ 265 p->p_xexit = rval; 266 p->p_xsig = signo; 267 268 /* 269 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold 270 * on our vmspace, so we should block below until they have 271 * released their reference to us. Note that if they have 272 * requested S_EXIT stops we will block here until they ack 273 * via PIOCCONT. 274 */ 275 _STOPEVENT(p, S_EXIT, 0); 276 277 /* 278 * Ignore any pending request to stop due to a stop signal. 279 * Once P_WEXIT is set, future requests will be ignored as 280 * well. 281 */ 282 p->p_flag &= ~P_STOPPED_SIG; 283 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped")); 284 285 /* 286 * Note that we are exiting and do another wakeup of anyone in 287 * PIOCWAIT in case they aren't listening for S_EXIT stops or 288 * decided to wait again after we told them we are exiting. 289 */ 290 p->p_flag |= P_WEXIT; 291 wakeup(&p->p_stype); 292 293 /* 294 * Wait for any processes that have a hold on our vmspace to 295 * release their reference. 296 */ 297 while (p->p_lock > 0) 298 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0); 299 300 PROC_UNLOCK(p); 301 /* Drain the limit callout while we don't have the proc locked */ 302 callout_drain(&p->p_limco); 303 304 #ifdef AUDIT 305 /* 306 * The Sun BSM exit token contains two components: an exit status as 307 * passed to exit(), and a return value to indicate what sort of exit 308 * it was. The exit status is WEXITSTATUS(rv), but it's not clear 309 * what the return value is. 310 */ 311 AUDIT_ARG_EXIT(rval, 0); 312 AUDIT_SYSCALL_EXIT(0, td); 313 #endif 314 315 /* Are we a task leader with peers? */ 316 if (p->p_peers != NULL && p == p->p_leader) { 317 mtx_lock(&ppeers_lock); 318 q = p->p_peers; 319 while (q != NULL) { 320 PROC_LOCK(q); 321 kern_psignal(q, SIGKILL); 322 PROC_UNLOCK(q); 323 q = q->p_peers; 324 } 325 while (p->p_peers != NULL) 326 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 327 mtx_unlock(&ppeers_lock); 328 } 329 330 /* 331 * Check if any loadable modules need anything done at process exit. 332 * E.g. SYSV IPC stuff. 333 * Event handler could change exit status. 334 * XXX what if one of these generates an error? 335 */ 336 EVENTHANDLER_DIRECT_INVOKE(process_exit, p); 337 338 /* 339 * If parent is waiting for us to exit or exec, 340 * P_PPWAIT is set; we will wakeup the parent below. 341 */ 342 PROC_LOCK(p); 343 stopprofclock(p); 344 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE); 345 p->p_ptevents = 0; 346 347 /* 348 * Stop the real interval timer. If the handler is currently 349 * executing, prevent it from rearming itself and let it finish. 350 */ 351 if (timevalisset(&p->p_realtimer.it_value) && 352 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) { 353 timevalclear(&p->p_realtimer.it_interval); 354 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 355 KASSERT(!timevalisset(&p->p_realtimer.it_value), 356 ("realtime timer is still armed")); 357 } 358 359 PROC_UNLOCK(p); 360 361 umtx_thread_exit(td); 362 363 /* 364 * Reset any sigio structures pointing to us as a result of 365 * F_SETOWN with our pid. 366 */ 367 funsetownlst(&p->p_sigiolst); 368 369 /* 370 * If this process has an nlminfo data area (for lockd), release it 371 */ 372 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL) 373 (*nlminfo_release_p)(p); 374 375 /* 376 * Close open files and release open-file table. 377 * This may block! 378 */ 379 fdescfree(td); 380 381 /* 382 * If this thread tickled GEOM, we need to wait for the giggling to 383 * stop before we return to userland 384 */ 385 if (td->td_pflags & TDP_GEOM) 386 g_waitidle(); 387 388 /* 389 * Remove ourself from our leader's peer list and wake our leader. 390 */ 391 if (p->p_leader->p_peers != NULL) { 392 mtx_lock(&ppeers_lock); 393 if (p->p_leader->p_peers != NULL) { 394 q = p->p_leader; 395 while (q->p_peers != p) 396 q = q->p_peers; 397 q->p_peers = p->p_peers; 398 wakeup(p->p_leader); 399 } 400 mtx_unlock(&ppeers_lock); 401 } 402 403 vmspace_exit(td); 404 killjobc(); 405 (void)acct_process(td); 406 407 #ifdef KTRACE 408 ktrprocexit(td); 409 #endif 410 /* 411 * Release reference to text vnode 412 */ 413 if (p->p_textvp != NULL) { 414 vrele(p->p_textvp); 415 p->p_textvp = NULL; 416 } 417 418 /* 419 * Release our limits structure. 420 */ 421 lim_free(p->p_limit); 422 p->p_limit = NULL; 423 424 tidhash_remove(td); 425 426 /* 427 * Call machine-dependent code to release any 428 * machine-dependent resources other than the address space. 429 * The address space is released by "vmspace_exitfree(p)" in 430 * vm_waitproc(). 431 */ 432 cpu_exit(td); 433 434 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); 435 436 sx_xlock(&proctree_lock); 437 /* 438 * Remove proc from allproc queue and pidhash chain. 439 * Place onto zombproc. Unlink from parent's child list. 440 */ 441 sx_xlock(&allproc_lock); 442 LIST_REMOVE(p, p_list); 443 LIST_INSERT_HEAD(&zombproc, p, p_list); 444 LIST_REMOVE(p, p_hash); 445 sx_xunlock(&allproc_lock); 446 447 /* 448 * Reparent all children processes: 449 * - traced ones to the original parent (or init if we are that parent) 450 * - the rest to init 451 */ 452 q = LIST_FIRST(&p->p_children); 453 if (q != NULL) /* only need this if any child is S_ZOMB */ 454 wakeup(q->p_reaper); 455 for (; q != NULL; q = nq) { 456 nq = LIST_NEXT(q, p_sibling); 457 ksi = ksiginfo_alloc(TRUE); 458 PROC_LOCK(q); 459 q->p_sigparent = SIGCHLD; 460 461 if (!(q->p_flag & P_TRACED)) { 462 proc_reparent(q, q->p_reaper); 463 if (q->p_state == PRS_ZOMBIE) { 464 /* 465 * Inform reaper about the reparented 466 * zombie, since wait(2) has something 467 * new to report. Guarantee queueing 468 * of the SIGCHLD signal, similar to 469 * the _exit() behaviour, by providing 470 * our ksiginfo. Ksi is freed by the 471 * signal delivery. 472 */ 473 if (q->p_ksi == NULL) { 474 ksi1 = NULL; 475 } else { 476 ksiginfo_copy(q->p_ksi, ksi); 477 ksi->ksi_flags |= KSI_INS; 478 ksi1 = ksi; 479 ksi = NULL; 480 } 481 PROC_LOCK(q->p_reaper); 482 pksignal(q->p_reaper, SIGCHLD, ksi1); 483 PROC_UNLOCK(q->p_reaper); 484 } 485 } else { 486 /* 487 * Traced processes are killed since their existence 488 * means someone is screwing up. 489 */ 490 t = proc_realparent(q); 491 if (t == p) { 492 proc_reparent(q, q->p_reaper); 493 } else { 494 PROC_LOCK(t); 495 proc_reparent(q, t); 496 PROC_UNLOCK(t); 497 } 498 /* 499 * Since q was found on our children list, the 500 * proc_reparent() call moved q to the orphan 501 * list due to present P_TRACED flag. Clear 502 * orphan link for q now while q is locked. 503 */ 504 clear_orphan(q); 505 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE); 506 q->p_flag2 &= ~P2_PTRACE_FSTP; 507 q->p_ptevents = 0; 508 FOREACH_THREAD_IN_PROC(q, tdt) { 509 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG | 510 TDB_FSTP); 511 } 512 kern_psignal(q, SIGKILL); 513 } 514 PROC_UNLOCK(q); 515 if (ksi != NULL) 516 ksiginfo_free(ksi); 517 } 518 519 /* 520 * Also get rid of our orphans. 521 */ 522 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) { 523 PROC_LOCK(q); 524 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid, 525 q->p_pid); 526 clear_orphan(q); 527 PROC_UNLOCK(q); 528 } 529 530 /* Save exit status. */ 531 PROC_LOCK(p); 532 p->p_xthread = td; 533 534 #ifdef KDTRACE_HOOKS 535 /* 536 * Tell the DTrace fasttrap provider about the exit if it 537 * has declared an interest. 538 */ 539 if (dtrace_fasttrap_exit) 540 dtrace_fasttrap_exit(p); 541 #endif 542 543 /* 544 * Notify interested parties of our demise. 545 */ 546 KNOTE_LOCKED(p->p_klist, NOTE_EXIT); 547 548 #ifdef KDTRACE_HOOKS 549 int reason = CLD_EXITED; 550 if (WCOREDUMP(signo)) 551 reason = CLD_DUMPED; 552 else if (WIFSIGNALED(signo)) 553 reason = CLD_KILLED; 554 SDT_PROBE1(proc, , , exit, reason); 555 #endif 556 557 /* 558 * If this is a process with a descriptor, we may not need to deliver 559 * a signal to the parent. proctree_lock is held over 560 * procdesc_exit() to serialize concurrent calls to close() and 561 * exit(). 562 */ 563 signal_parent = 0; 564 if (p->p_procdesc == NULL || procdesc_exit(p)) { 565 /* 566 * Notify parent that we're gone. If parent has the 567 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN, 568 * notify process 1 instead (and hope it will handle this 569 * situation). 570 */ 571 PROC_LOCK(p->p_pptr); 572 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 573 if (p->p_pptr->p_sigacts->ps_flag & 574 (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 575 struct proc *pp; 576 577 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 578 pp = p->p_pptr; 579 PROC_UNLOCK(pp); 580 proc_reparent(p, p->p_reaper); 581 p->p_sigparent = SIGCHLD; 582 PROC_LOCK(p->p_pptr); 583 584 /* 585 * Notify parent, so in case he was wait(2)ing or 586 * executing waitpid(2) with our pid, he will 587 * continue. 588 */ 589 wakeup(pp); 590 } else 591 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 592 593 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) { 594 signal_parent = 1; 595 } else if (p->p_sigparent != 0) { 596 if (p->p_sigparent == SIGCHLD) { 597 signal_parent = 1; 598 } else { /* LINUX thread */ 599 signal_parent = 2; 600 } 601 } 602 } else 603 PROC_LOCK(p->p_pptr); 604 sx_xunlock(&proctree_lock); 605 606 if (signal_parent == 1) { 607 childproc_exited(p); 608 } else if (signal_parent == 2) { 609 kern_psignal(p->p_pptr, p->p_sigparent); 610 } 611 612 /* Tell the prison that we are gone. */ 613 prison_proc_free(p->p_ucred->cr_prison); 614 615 /* 616 * The state PRS_ZOMBIE prevents other proesses from sending 617 * signal to the process, to avoid memory leak, we free memory 618 * for signal queue at the time when the state is set. 619 */ 620 sigqueue_flush(&p->p_sigqueue); 621 sigqueue_flush(&td->td_sigqueue); 622 623 /* 624 * We have to wait until after acquiring all locks before 625 * changing p_state. We need to avoid all possible context 626 * switches (including ones from blocking on a mutex) while 627 * marked as a zombie. We also have to set the zombie state 628 * before we release the parent process' proc lock to avoid 629 * a lost wakeup. So, we first call wakeup, then we grab the 630 * sched lock, update the state, and release the parent process' 631 * proc lock. 632 */ 633 wakeup(p->p_pptr); 634 cv_broadcast(&p->p_pwait); 635 sched_exit(p->p_pptr, td); 636 PROC_SLOCK(p); 637 p->p_state = PRS_ZOMBIE; 638 PROC_UNLOCK(p->p_pptr); 639 640 /* 641 * Save our children's rusage information in our exit rusage. 642 */ 643 PROC_STATLOCK(p); 644 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux); 645 PROC_STATUNLOCK(p); 646 647 /* 648 * Make sure the scheduler takes this thread out of its tables etc. 649 * This will also release this thread's reference to the ucred. 650 * Other thread parts to release include pcb bits and such. 651 */ 652 thread_exit(); 653 } 654 655 656 #ifndef _SYS_SYSPROTO_H_ 657 struct abort2_args { 658 char *why; 659 int nargs; 660 void **args; 661 }; 662 #endif 663 664 int 665 sys_abort2(struct thread *td, struct abort2_args *uap) 666 { 667 struct proc *p = td->td_proc; 668 struct sbuf *sb; 669 void *uargs[16]; 670 int error, i, sig; 671 672 /* 673 * Do it right now so we can log either proper call of abort2(), or 674 * note, that invalid argument was passed. 512 is big enough to 675 * handle 16 arguments' descriptions with additional comments. 676 */ 677 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN); 678 sbuf_clear(sb); 679 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ", 680 p->p_comm, p->p_pid, td->td_ucred->cr_uid); 681 /* 682 * Since we can't return from abort2(), send SIGKILL in cases, where 683 * abort2() was called improperly 684 */ 685 sig = SIGKILL; 686 /* Prevent from DoSes from user-space. */ 687 if (uap->nargs < 0 || uap->nargs > 16) 688 goto out; 689 if (uap->nargs > 0) { 690 if (uap->args == NULL) 691 goto out; 692 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *)); 693 if (error != 0) 694 goto out; 695 } 696 /* 697 * Limit size of 'reason' string to 128. Will fit even when 698 * maximal number of arguments was chosen to be logged. 699 */ 700 if (uap->why != NULL) { 701 error = sbuf_copyin(sb, uap->why, 128); 702 if (error < 0) 703 goto out; 704 } else { 705 sbuf_printf(sb, "(null)"); 706 } 707 if (uap->nargs > 0) { 708 sbuf_printf(sb, "("); 709 for (i = 0;i < uap->nargs; i++) 710 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]); 711 sbuf_printf(sb, ")"); 712 } 713 /* 714 * Final stage: arguments were proper, string has been 715 * successfully copied from userspace, and copying pointers 716 * from user-space succeed. 717 */ 718 sig = SIGABRT; 719 out: 720 if (sig == SIGKILL) { 721 sbuf_trim(sb); 722 sbuf_printf(sb, " (Reason text inaccessible)"); 723 } 724 sbuf_cat(sb, "\n"); 725 sbuf_finish(sb); 726 log(LOG_INFO, "%s", sbuf_data(sb)); 727 sbuf_delete(sb); 728 exit1(td, 0, sig); 729 return (0); 730 } 731 732 733 #ifdef COMPAT_43 734 /* 735 * The dirty work is handled by kern_wait(). 736 */ 737 int 738 owait(struct thread *td, struct owait_args *uap __unused) 739 { 740 int error, status; 741 742 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 743 if (error == 0) 744 td->td_retval[1] = status; 745 return (error); 746 } 747 #endif /* COMPAT_43 */ 748 749 /* 750 * The dirty work is handled by kern_wait(). 751 */ 752 int 753 sys_wait4(struct thread *td, struct wait4_args *uap) 754 { 755 struct rusage ru, *rup; 756 int error, status; 757 758 if (uap->rusage != NULL) 759 rup = &ru; 760 else 761 rup = NULL; 762 error = kern_wait(td, uap->pid, &status, uap->options, rup); 763 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 764 error = copyout(&status, uap->status, sizeof(status)); 765 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0) 766 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 767 return (error); 768 } 769 770 int 771 sys_wait6(struct thread *td, struct wait6_args *uap) 772 { 773 struct __wrusage wru, *wrup; 774 siginfo_t si, *sip; 775 idtype_t idtype; 776 id_t id; 777 int error, status; 778 779 idtype = uap->idtype; 780 id = uap->id; 781 782 if (uap->wrusage != NULL) 783 wrup = &wru; 784 else 785 wrup = NULL; 786 787 if (uap->info != NULL) { 788 sip = &si; 789 bzero(sip, sizeof(*sip)); 790 } else 791 sip = NULL; 792 793 /* 794 * We expect all callers of wait6() to know about WEXITED and 795 * WTRAPPED. 796 */ 797 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip); 798 799 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) 800 error = copyout(&status, uap->status, sizeof(status)); 801 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0) 802 error = copyout(&wru, uap->wrusage, sizeof(wru)); 803 if (uap->info != NULL && error == 0) 804 error = copyout(&si, uap->info, sizeof(si)); 805 return (error); 806 } 807 808 /* 809 * Reap the remains of a zombie process and optionally return status and 810 * rusage. Asserts and will release both the proctree_lock and the process 811 * lock as part of its work. 812 */ 813 void 814 proc_reap(struct thread *td, struct proc *p, int *status, int options) 815 { 816 struct proc *q, *t; 817 818 sx_assert(&proctree_lock, SA_XLOCKED); 819 PROC_LOCK_ASSERT(p, MA_OWNED); 820 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE")); 821 822 mtx_spin_wait_unlocked(&p->p_slock); 823 824 q = td->td_proc; 825 826 if (status) 827 *status = KW_EXITCODE(p->p_xexit, p->p_xsig); 828 if (options & WNOWAIT) { 829 /* 830 * Only poll, returning the status. Caller does not wish to 831 * release the proc struct just yet. 832 */ 833 PROC_UNLOCK(p); 834 sx_xunlock(&proctree_lock); 835 return; 836 } 837 838 PROC_LOCK(q); 839 sigqueue_take(p->p_ksi); 840 PROC_UNLOCK(q); 841 842 /* 843 * If we got the child via a ptrace 'attach', we need to give it back 844 * to the old parent. 845 */ 846 if (p->p_oppid != 0 && p->p_oppid != p->p_pptr->p_pid) { 847 PROC_UNLOCK(p); 848 t = proc_realparent(p); 849 PROC_LOCK(t); 850 PROC_LOCK(p); 851 CTR2(KTR_PTRACE, 852 "wait: traced child %d moved back to parent %d", p->p_pid, 853 t->p_pid); 854 proc_reparent(p, t); 855 p->p_oppid = 0; 856 PROC_UNLOCK(p); 857 pksignal(t, SIGCHLD, p->p_ksi); 858 wakeup(t); 859 cv_broadcast(&p->p_pwait); 860 PROC_UNLOCK(t); 861 sx_xunlock(&proctree_lock); 862 return; 863 } 864 p->p_oppid = 0; 865 PROC_UNLOCK(p); 866 867 /* 868 * Remove other references to this process to ensure we have an 869 * exclusive reference. 870 */ 871 sx_xlock(&allproc_lock); 872 LIST_REMOVE(p, p_list); /* off zombproc */ 873 sx_xunlock(&allproc_lock); 874 LIST_REMOVE(p, p_sibling); 875 reaper_abandon_children(p, true); 876 LIST_REMOVE(p, p_reapsibling); 877 PROC_LOCK(p); 878 clear_orphan(p); 879 PROC_UNLOCK(p); 880 leavepgrp(p); 881 if (p->p_procdesc != NULL) 882 procdesc_reap(p); 883 sx_xunlock(&proctree_lock); 884 885 PROC_LOCK(p); 886 knlist_detach(p->p_klist); 887 p->p_klist = NULL; 888 PROC_UNLOCK(p); 889 890 /* 891 * Removal from allproc list and process group list paired with 892 * PROC_LOCK which was executed during that time should guarantee 893 * nothing can reach this process anymore. As such further locking 894 * is unnecessary. 895 */ 896 p->p_xexit = p->p_xsig = 0; /* XXX: why? */ 897 898 PROC_LOCK(q); 899 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux); 900 PROC_UNLOCK(q); 901 902 /* 903 * Decrement the count of procs running with this uid. 904 */ 905 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 906 907 /* 908 * Destroy resource accounting information associated with the process. 909 */ 910 #ifdef RACCT 911 if (racct_enable) { 912 PROC_LOCK(p); 913 racct_sub(p, RACCT_NPROC, 1); 914 PROC_UNLOCK(p); 915 } 916 #endif 917 racct_proc_exit(p); 918 919 /* 920 * Free credentials, arguments, and sigacts. 921 */ 922 crfree(p->p_ucred); 923 proc_set_cred(p, NULL); 924 pargs_drop(p->p_args); 925 p->p_args = NULL; 926 sigacts_free(p->p_sigacts); 927 p->p_sigacts = NULL; 928 929 /* 930 * Do any thread-system specific cleanups. 931 */ 932 thread_wait(p); 933 934 /* 935 * Give vm and machine-dependent layer a chance to free anything that 936 * cpu_exit couldn't release while still running in process context. 937 */ 938 vm_waitproc(p); 939 #ifdef MAC 940 mac_proc_destroy(p); 941 #endif 942 943 KASSERT(FIRST_THREAD_IN_PROC(p), 944 ("proc_reap: no residual thread!")); 945 uma_zfree(proc_zone, p); 946 atomic_add_int(&nprocs, -1); 947 } 948 949 static int 950 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id, 951 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo, 952 int check_only) 953 { 954 struct rusage *rup; 955 956 sx_assert(&proctree_lock, SA_XLOCKED); 957 958 PROC_LOCK(p); 959 960 switch (idtype) { 961 case P_ALL: 962 if (p->p_procdesc != NULL) { 963 PROC_UNLOCK(p); 964 return (0); 965 } 966 break; 967 case P_PID: 968 if (p->p_pid != (pid_t)id) { 969 PROC_UNLOCK(p); 970 return (0); 971 } 972 break; 973 case P_PGID: 974 if (p->p_pgid != (pid_t)id) { 975 PROC_UNLOCK(p); 976 return (0); 977 } 978 break; 979 case P_SID: 980 if (p->p_session->s_sid != (pid_t)id) { 981 PROC_UNLOCK(p); 982 return (0); 983 } 984 break; 985 case P_UID: 986 if (p->p_ucred->cr_uid != (uid_t)id) { 987 PROC_UNLOCK(p); 988 return (0); 989 } 990 break; 991 case P_GID: 992 if (p->p_ucred->cr_gid != (gid_t)id) { 993 PROC_UNLOCK(p); 994 return (0); 995 } 996 break; 997 case P_JAILID: 998 if (p->p_ucred->cr_prison->pr_id != (int)id) { 999 PROC_UNLOCK(p); 1000 return (0); 1001 } 1002 break; 1003 /* 1004 * It seems that the thread structures get zeroed out 1005 * at process exit. This makes it impossible to 1006 * support P_SETID, P_CID or P_CPUID. 1007 */ 1008 default: 1009 PROC_UNLOCK(p); 1010 return (0); 1011 } 1012 1013 if (p_canwait(td, p)) { 1014 PROC_UNLOCK(p); 1015 return (0); 1016 } 1017 1018 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) { 1019 PROC_UNLOCK(p); 1020 return (0); 1021 } 1022 1023 /* 1024 * This special case handles a kthread spawned by linux_clone 1025 * (see linux_misc.c). The linux_wait4 and linux_waitpid 1026 * functions need to be able to distinguish between waiting 1027 * on a process and waiting on a thread. It is a thread if 1028 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 1029 * signifies we want to wait for threads and not processes. 1030 */ 1031 if ((p->p_sigparent != SIGCHLD) ^ 1032 ((options & WLINUXCLONE) != 0)) { 1033 PROC_UNLOCK(p); 1034 return (0); 1035 } 1036 1037 if (siginfo != NULL) { 1038 bzero(siginfo, sizeof(*siginfo)); 1039 siginfo->si_errno = 0; 1040 1041 /* 1042 * SUSv4 requires that the si_signo value is always 1043 * SIGCHLD. Obey it despite the rfork(2) interface 1044 * allows to request other signal for child exit 1045 * notification. 1046 */ 1047 siginfo->si_signo = SIGCHLD; 1048 1049 /* 1050 * This is still a rough estimate. We will fix the 1051 * cases TRAPPED, STOPPED, and CONTINUED later. 1052 */ 1053 if (WCOREDUMP(p->p_xsig)) { 1054 siginfo->si_code = CLD_DUMPED; 1055 siginfo->si_status = WTERMSIG(p->p_xsig); 1056 } else if (WIFSIGNALED(p->p_xsig)) { 1057 siginfo->si_code = CLD_KILLED; 1058 siginfo->si_status = WTERMSIG(p->p_xsig); 1059 } else { 1060 siginfo->si_code = CLD_EXITED; 1061 siginfo->si_status = p->p_xexit; 1062 } 1063 1064 siginfo->si_pid = p->p_pid; 1065 siginfo->si_uid = p->p_ucred->cr_uid; 1066 1067 /* 1068 * The si_addr field would be useful additional 1069 * detail, but apparently the PC value may be lost 1070 * when we reach this point. bzero() above sets 1071 * siginfo->si_addr to NULL. 1072 */ 1073 } 1074 1075 /* 1076 * There should be no reason to limit resources usage info to 1077 * exited processes only. A snapshot about any resources used 1078 * by a stopped process may be exactly what is needed. 1079 */ 1080 if (wrusage != NULL) { 1081 rup = &wrusage->wru_self; 1082 *rup = p->p_ru; 1083 PROC_STATLOCK(p); 1084 calcru(p, &rup->ru_utime, &rup->ru_stime); 1085 PROC_STATUNLOCK(p); 1086 1087 rup = &wrusage->wru_children; 1088 *rup = p->p_stats->p_cru; 1089 calccru(p, &rup->ru_utime, &rup->ru_stime); 1090 } 1091 1092 if (p->p_state == PRS_ZOMBIE && !check_only) { 1093 proc_reap(td, p, status, options); 1094 return (-1); 1095 } 1096 return (1); 1097 } 1098 1099 int 1100 kern_wait(struct thread *td, pid_t pid, int *status, int options, 1101 struct rusage *rusage) 1102 { 1103 struct __wrusage wru, *wrup; 1104 idtype_t idtype; 1105 id_t id; 1106 int ret; 1107 1108 /* 1109 * Translate the special pid values into the (idtype, pid) 1110 * pair for kern_wait6. The WAIT_MYPGRP case is handled by 1111 * kern_wait6() on its own. 1112 */ 1113 if (pid == WAIT_ANY) { 1114 idtype = P_ALL; 1115 id = 0; 1116 } else if (pid < 0) { 1117 idtype = P_PGID; 1118 id = (id_t)-pid; 1119 } else { 1120 idtype = P_PID; 1121 id = (id_t)pid; 1122 } 1123 1124 if (rusage != NULL) 1125 wrup = &wru; 1126 else 1127 wrup = NULL; 1128 1129 /* 1130 * For backward compatibility we implicitly add flags WEXITED 1131 * and WTRAPPED here. 1132 */ 1133 options |= WEXITED | WTRAPPED; 1134 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL); 1135 if (rusage != NULL) 1136 *rusage = wru.wru_self; 1137 return (ret); 1138 } 1139 1140 static void 1141 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo, 1142 int *status, int options, int si_code) 1143 { 1144 bool cont; 1145 1146 PROC_LOCK_ASSERT(p, MA_OWNED); 1147 sx_assert(&proctree_lock, SA_XLOCKED); 1148 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED || 1149 si_code == CLD_CONTINUED); 1150 1151 cont = si_code == CLD_CONTINUED; 1152 if ((options & WNOWAIT) == 0) { 1153 if (cont) 1154 p->p_flag &= ~P_CONTINUED; 1155 else 1156 p->p_flag |= P_WAITED; 1157 PROC_LOCK(td->td_proc); 1158 sigqueue_take(p->p_ksi); 1159 PROC_UNLOCK(td->td_proc); 1160 } 1161 sx_xunlock(&proctree_lock); 1162 if (siginfo != NULL) { 1163 siginfo->si_code = si_code; 1164 siginfo->si_status = cont ? SIGCONT : p->p_xsig; 1165 } 1166 if (status != NULL) 1167 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig); 1168 PROC_UNLOCK(p); 1169 td->td_retval[0] = p->p_pid; 1170 } 1171 1172 int 1173 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status, 1174 int options, struct __wrusage *wrusage, siginfo_t *siginfo) 1175 { 1176 struct proc *p, *q; 1177 pid_t pid; 1178 int error, nfound, ret; 1179 bool report; 1180 1181 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ 1182 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */ 1183 AUDIT_ARG_VALUE(options); 1184 1185 q = td->td_proc; 1186 1187 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) { 1188 PROC_LOCK(q); 1189 id = (id_t)q->p_pgid; 1190 PROC_UNLOCK(q); 1191 idtype = P_PGID; 1192 } 1193 1194 /* If we don't know the option, just return. */ 1195 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT | 1196 WEXITED | WTRAPPED | WLINUXCLONE)) != 0) 1197 return (EINVAL); 1198 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) { 1199 /* 1200 * We will be unable to find any matching processes, 1201 * because there are no known events to look for. 1202 * Prefer to return error instead of blocking 1203 * indefinitely. 1204 */ 1205 return (EINVAL); 1206 } 1207 1208 loop: 1209 if (q->p_flag & P_STATCHILD) { 1210 PROC_LOCK(q); 1211 q->p_flag &= ~P_STATCHILD; 1212 PROC_UNLOCK(q); 1213 } 1214 sx_xlock(&proctree_lock); 1215 loop_locked: 1216 nfound = 0; 1217 LIST_FOREACH(p, &q->p_children, p_sibling) { 1218 pid = p->p_pid; 1219 ret = proc_to_reap(td, p, idtype, id, status, options, 1220 wrusage, siginfo, 0); 1221 if (ret == 0) 1222 continue; 1223 else if (ret != 1) { 1224 td->td_retval[0] = pid; 1225 return (0); 1226 } 1227 1228 nfound++; 1229 PROC_LOCK_ASSERT(p, MA_OWNED); 1230 1231 if ((options & WTRAPPED) != 0 && 1232 (p->p_flag & P_TRACED) != 0) { 1233 PROC_SLOCK(p); 1234 report = 1235 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) && 1236 p->p_suspcount == p->p_numthreads && 1237 (p->p_flag & P_WAITED) == 0); 1238 PROC_SUNLOCK(p); 1239 if (report) { 1240 CTR4(KTR_PTRACE, 1241 "wait: returning trapped pid %d status %#x " 1242 "(xstat %d) xthread %d", 1243 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig, 1244 p->p_xthread != NULL ? 1245 p->p_xthread->td_tid : -1); 1246 report_alive_proc(td, p, siginfo, status, 1247 options, CLD_TRAPPED); 1248 return (0); 1249 } 1250 } 1251 if ((options & WUNTRACED) != 0 && 1252 (p->p_flag & P_STOPPED_SIG) != 0) { 1253 PROC_SLOCK(p); 1254 report = (p->p_suspcount == p->p_numthreads && 1255 ((p->p_flag & P_WAITED) == 0)); 1256 PROC_SUNLOCK(p); 1257 if (report) { 1258 report_alive_proc(td, p, siginfo, status, 1259 options, CLD_STOPPED); 1260 return (0); 1261 } 1262 } 1263 if ((options & WCONTINUED) != 0 && 1264 (p->p_flag & P_CONTINUED) != 0) { 1265 report_alive_proc(td, p, siginfo, status, options, 1266 CLD_CONTINUED); 1267 return (0); 1268 } 1269 PROC_UNLOCK(p); 1270 } 1271 1272 /* 1273 * Look in the orphans list too, to allow the parent to 1274 * collect it's child exit status even if child is being 1275 * debugged. 1276 * 1277 * Debugger detaches from the parent upon successful 1278 * switch-over from parent to child. At this point due to 1279 * re-parenting the parent loses the child to debugger and a 1280 * wait4(2) call would report that it has no children to wait 1281 * for. By maintaining a list of orphans we allow the parent 1282 * to successfully wait until the child becomes a zombie. 1283 */ 1284 if (nfound == 0) { 1285 LIST_FOREACH(p, &q->p_orphans, p_orphan) { 1286 ret = proc_to_reap(td, p, idtype, id, NULL, options, 1287 NULL, NULL, 1); 1288 if (ret != 0) { 1289 KASSERT(ret != -1, ("reaped an orphan (pid %d)", 1290 (int)td->td_retval[0])); 1291 PROC_UNLOCK(p); 1292 nfound++; 1293 break; 1294 } 1295 } 1296 } 1297 if (nfound == 0) { 1298 sx_xunlock(&proctree_lock); 1299 return (ECHILD); 1300 } 1301 if (options & WNOHANG) { 1302 sx_xunlock(&proctree_lock); 1303 td->td_retval[0] = 0; 1304 return (0); 1305 } 1306 PROC_LOCK(q); 1307 if (q->p_flag & P_STATCHILD) { 1308 q->p_flag &= ~P_STATCHILD; 1309 PROC_UNLOCK(q); 1310 goto loop_locked; 1311 } 1312 sx_xunlock(&proctree_lock); 1313 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0); 1314 if (error) 1315 return (error); 1316 goto loop; 1317 } 1318 1319 /* 1320 * Make process 'parent' the new parent of process 'child'. 1321 * Must be called with an exclusive hold of proctree lock. 1322 */ 1323 void 1324 proc_reparent(struct proc *child, struct proc *parent) 1325 { 1326 1327 sx_assert(&proctree_lock, SX_XLOCKED); 1328 PROC_LOCK_ASSERT(child, MA_OWNED); 1329 if (child->p_pptr == parent) 1330 return; 1331 1332 PROC_LOCK(child->p_pptr); 1333 sigqueue_take(child->p_ksi); 1334 PROC_UNLOCK(child->p_pptr); 1335 LIST_REMOVE(child, p_sibling); 1336 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 1337 1338 clear_orphan(child); 1339 if (child->p_flag & P_TRACED) { 1340 if (LIST_EMPTY(&child->p_pptr->p_orphans)) { 1341 child->p_treeflag |= P_TREE_FIRST_ORPHAN; 1342 LIST_INSERT_HEAD(&child->p_pptr->p_orphans, child, 1343 p_orphan); 1344 } else { 1345 LIST_INSERT_AFTER(LIST_FIRST(&child->p_pptr->p_orphans), 1346 child, p_orphan); 1347 } 1348 child->p_treeflag |= P_TREE_ORPHANED; 1349 } 1350 1351 child->p_pptr = parent; 1352 } 1353