Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_exit.c
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1 /* $OpenBSD: kern_exit.c,v 1.210 2022/12/29 01:36:36 guenther Exp $ */ 2 /* $NetBSD: kern_exit.c,v 1.39 1996/04/22 01:38:25 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 38 */ 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/proc.h> 43 #include <sys/time.h> 44 #include <sys/resource.h> 45 #include <sys/wait.h> 46 #include <sys/vnode.h> 47 #include <sys/malloc.h> 48 #include <sys/resourcevar.h> 49 #include <sys/ptrace.h> 50 #include <sys/acct.h> 51 #include <sys/filedesc.h> 52 #include <sys/signalvar.h> 53 #include <sys/sched.h> 54 #include <sys/ktrace.h> 55 #include <sys/pool.h> 56 #include <sys/mutex.h> 57 #ifdef SYSVSEM 58 #include <sys/sem.h> 59 #endif 60 #include <sys/witness.h> 61 62 #include <sys/mount.h> 63 #include <sys/syscallargs.h> 64 65 #include <uvm/uvm_extern.h> 66 67 #include "kcov.h" 68 #if NKCOV > 0 69 #include <sys/kcov.h> 70 #endif 71 72 void proc_finish_wait(struct proc *, struct proc *); 73 void process_clear_orphan(struct process *); 74 void process_zap(struct process *); 75 void proc_free(struct proc *); 76 void unveil_destroy(struct process *ps); 77 78 /* 79 * exit -- 80 * Death of process. 81 */ 82 int 83 sys_exit(struct proc *p, void *v, register_t *retval) 84 { 85 struct sys_exit_args /* { 86 syscallarg(int) rval; 87 } */ *uap = v; 88 89 exit1(p, SCARG(uap, rval), 0, EXIT_NORMAL); 90 /* NOTREACHED */ 91 return (0); 92 } 93 94 int 95 sys___threxit(struct proc *p, void *v, register_t *retval) 96 { 97 struct sys___threxit_args /* { 98 syscallarg(pid_t *) notdead; 99 } */ *uap = v; 100 101 if (SCARG(uap, notdead) != NULL) { 102 pid_t zero = 0; 103 if (copyout(&zero, SCARG(uap, notdead), sizeof(zero))) 104 psignal(p, SIGSEGV); 105 } 106 exit1(p, 0, 0, EXIT_THREAD); 107 108 return (0); 109 } 110 111 /* 112 * Exit: deallocate address space and other resources, change proc state 113 * to zombie, and unlink proc from allproc and parent's lists. Save exit 114 * status and rusage for wait(). Check for child processes and orphan them. 115 */ 116 void 117 exit1(struct proc *p, int xexit, int xsig, int flags) 118 { 119 struct process *pr, *qr, *nqr; 120 struct rusage *rup; 121 int s; 122 123 atomic_setbits_int(&p->p_flag, P_WEXIT); 124 125 pr = p->p_p; 126 127 /* single-threaded? */ 128 if (!P_HASSIBLING(p)) { 129 flags = EXIT_NORMAL; 130 } else { 131 /* nope, multi-threaded */ 132 if (flags == EXIT_NORMAL) 133 single_thread_set(p, SINGLE_EXIT, 1); 134 else if (flags == EXIT_THREAD) 135 single_thread_check(p, 0); 136 } 137 138 if (flags == EXIT_NORMAL && !(pr->ps_flags & PS_EXITING)) { 139 if (pr->ps_pid == 1) 140 panic("init died (signal %d, exit %d)", xsig, xexit); 141 142 atomic_setbits_int(&pr->ps_flags, PS_EXITING); 143 pr->ps_xexit = xexit; 144 pr->ps_xsig = xsig; 145 146 /* 147 * If parent is waiting for us to exit or exec, PS_PPWAIT 148 * is set; we wake up the parent early to avoid deadlock. 149 */ 150 if (pr->ps_flags & PS_PPWAIT) { 151 atomic_clearbits_int(&pr->ps_flags, PS_PPWAIT); 152 atomic_clearbits_int(&pr->ps_pptr->ps_flags, 153 PS_ISPWAIT); 154 wakeup(pr->ps_pptr); 155 } 156 } 157 158 /* unlink ourselves from the active threads */ 159 SCHED_LOCK(s); 160 TAILQ_REMOVE(&pr->ps_threads, p, p_thr_link); 161 SCHED_UNLOCK(s); 162 if ((p->p_flag & P_THREAD) == 0) { 163 /* main thread gotta wait because it has the pid, et al */ 164 while (pr->ps_refcnt > 1) 165 tsleep_nsec(&pr->ps_threads, PWAIT, "thrdeath", INFSLP); 166 if (pr->ps_flags & PS_PROFIL) 167 stopprofclock(pr); 168 } 169 170 rup = pr->ps_ru; 171 if (rup == NULL) { 172 rup = pool_get(&rusage_pool, PR_WAITOK | PR_ZERO); 173 if (pr->ps_ru == NULL) { 174 pr->ps_ru = rup; 175 } else { 176 pool_put(&rusage_pool, rup); 177 rup = pr->ps_ru; 178 } 179 } 180 p->p_siglist = 0; 181 if ((p->p_flag & P_THREAD) == 0) 182 pr->ps_siglist = 0; 183 184 kqpoll_exit(); 185 186 #if NKCOV > 0 187 kcov_exit(p); 188 #endif 189 190 if ((p->p_flag & P_THREAD) == 0) { 191 sigio_freelist(&pr->ps_sigiolst); 192 193 /* close open files and release open-file table */ 194 fdfree(p); 195 196 cancel_all_itimers(); 197 198 timeout_del(&pr->ps_rucheck_to); 199 #ifdef SYSVSEM 200 semexit(pr); 201 #endif 202 killjobc(pr); 203 #ifdef ACCOUNTING 204 acct_process(p); 205 #endif 206 207 #ifdef KTRACE 208 /* release trace file */ 209 if (pr->ps_tracevp) 210 ktrcleartrace(pr); 211 #endif 212 213 unveil_destroy(pr); 214 215 /* 216 * If parent has the SAS_NOCLDWAIT flag set, we're not 217 * going to become a zombie. 218 */ 219 if (pr->ps_pptr->ps_sigacts->ps_sigflags & SAS_NOCLDWAIT) 220 atomic_setbits_int(&pr->ps_flags, PS_NOZOMBIE); 221 } 222 223 p->p_fd = NULL; /* zap the thread's copy */ 224 225 /* 226 * Remove proc from pidhash chain and allproc so looking 227 * it up won't work. We will put the proc on the 228 * deadproc list later (using the p_hash member), and 229 * wake up the reaper when we do. If this is the last 230 * thread of a process that isn't PS_NOZOMBIE, we'll put 231 * the process on the zombprocess list below. 232 */ 233 /* 234 * NOTE: WE ARE NO LONGER ALLOWED TO SLEEP! 235 */ 236 p->p_stat = SDEAD; 237 238 LIST_REMOVE(p, p_hash); 239 LIST_REMOVE(p, p_list); 240 241 if ((p->p_flag & P_THREAD) == 0) { 242 LIST_REMOVE(pr, ps_hash); 243 LIST_REMOVE(pr, ps_list); 244 245 if ((pr->ps_flags & PS_NOZOMBIE) == 0) 246 LIST_INSERT_HEAD(&zombprocess, pr, ps_list); 247 else { 248 /* 249 * Not going to be a zombie, so it's now off all 250 * the lists scanned by ispidtaken(), so block 251 * fast reuse of the pid now. 252 */ 253 freepid(pr->ps_pid); 254 } 255 256 /* 257 * Reparent children to their original parent, in case 258 * they were being traced, or to init(8). 259 */ 260 qr = LIST_FIRST(&pr->ps_children); 261 if (qr) /* only need this if any child is S_ZOMB */ 262 wakeup(initprocess); 263 for (; qr != NULL; qr = nqr) { 264 nqr = LIST_NEXT(qr, ps_sibling); 265 /* 266 * Traced processes are killed since their 267 * existence means someone is screwing up. 268 */ 269 if (qr->ps_flags & PS_TRACED && 270 !(qr->ps_flags & PS_EXITING)) { 271 process_untrace(qr); 272 273 /* 274 * If single threading is active, 275 * direct the signal to the active 276 * thread to avoid deadlock. 277 */ 278 if (qr->ps_single) 279 ptsignal(qr->ps_single, SIGKILL, 280 STHREAD); 281 else 282 prsignal(qr, SIGKILL); 283 } else { 284 process_reparent(qr, initprocess); 285 } 286 } 287 288 /* 289 * Make sure orphans won't remember the exiting process. 290 */ 291 while ((qr = LIST_FIRST(&pr->ps_orphans)) != NULL) { 292 KASSERT(qr->ps_oppid == pr->ps_pid); 293 qr->ps_oppid = 0; 294 process_clear_orphan(qr); 295 } 296 } 297 298 /* add thread's accumulated rusage into the process's total */ 299 ruadd(rup, &p->p_ru); 300 tuagg(pr, p); 301 302 /* 303 * clear %cpu usage during swap 304 */ 305 p->p_pctcpu = 0; 306 307 if ((p->p_flag & P_THREAD) == 0) { 308 /* 309 * Final thread has died, so add on our children's rusage 310 * and calculate the total times 311 */ 312 calcru(&pr->ps_tu, &rup->ru_utime, &rup->ru_stime, NULL); 313 ruadd(rup, &pr->ps_cru); 314 315 /* 316 * Notify parent that we're gone. If we're not going to 317 * become a zombie, reparent to process 1 (init) so that 318 * we can wake our original parent to possibly unblock 319 * wait4() to return ECHILD. 320 */ 321 if (pr->ps_flags & PS_NOZOMBIE) { 322 struct process *ppr = pr->ps_pptr; 323 process_reparent(pr, initprocess); 324 wakeup(ppr); 325 } 326 } 327 328 /* just a thread? detach it from its process */ 329 if (p->p_flag & P_THREAD) { 330 /* scheduler_wait_hook(pr->ps_mainproc, p); XXX */ 331 if (--pr->ps_refcnt == 1) 332 wakeup(&pr->ps_threads); 333 KASSERT(pr->ps_refcnt > 0); 334 } 335 336 /* Release the thread's read reference of resource limit structure. */ 337 if (p->p_limit != NULL) { 338 struct plimit *limit; 339 340 limit = p->p_limit; 341 p->p_limit = NULL; 342 lim_free(limit); 343 } 344 345 /* 346 * Other substructures are freed from reaper and wait(). 347 */ 348 349 /* 350 * Finally, call machine-dependent code to switch to a new 351 * context (possibly the idle context). Once we are no longer 352 * using the dead process's vmspace and stack, exit2() will be 353 * called to schedule those resources to be released by the 354 * reaper thread. 355 * 356 * Note that cpu_exit() will end with a call equivalent to 357 * cpu_switch(), finishing our execution (pun intended). 358 */ 359 uvmexp.swtch++; 360 cpu_exit(p); 361 panic("cpu_exit returned"); 362 } 363 364 /* 365 * Locking of this proclist is special; it's accessed in a 366 * critical section of process exit, and thus locking it can't 367 * modify interrupt state. We use a simple spin lock for this 368 * proclist. We use the p_hash member to linkup to deadproc. 369 */ 370 struct mutex deadproc_mutex = 371 MUTEX_INITIALIZER_FLAGS(IPL_NONE, "deadproc", MTX_NOWITNESS); 372 struct proclist deadproc = LIST_HEAD_INITIALIZER(deadproc); 373 374 /* 375 * We are called from cpu_exit() once it is safe to schedule the 376 * dead process's resources to be freed. 377 * 378 * NOTE: One must be careful with locking in this routine. It's 379 * called from a critical section in machine-dependent code, so 380 * we should refrain from changing any interrupt state. 381 * 382 * We lock the deadproc list, place the proc on that list (using 383 * the p_hash member), and wake up the reaper. 384 */ 385 void 386 exit2(struct proc *p) 387 { 388 mtx_enter(&deadproc_mutex); 389 LIST_INSERT_HEAD(&deadproc, p, p_hash); 390 mtx_leave(&deadproc_mutex); 391 392 wakeup(&deadproc); 393 } 394 395 void 396 proc_free(struct proc *p) 397 { 398 crfree(p->p_ucred); 399 pool_put(&proc_pool, p); 400 nthreads--; 401 } 402 403 /* 404 * Process reaper. This is run by a kernel thread to free the resources 405 * of a dead process. Once the resources are free, the process becomes 406 * a zombie, and the parent is allowed to read the undead's status. 407 */ 408 void 409 reaper(void *arg) 410 { 411 struct proc *p; 412 413 KERNEL_UNLOCK(); 414 415 SCHED_ASSERT_UNLOCKED(); 416 417 for (;;) { 418 mtx_enter(&deadproc_mutex); 419 while ((p = LIST_FIRST(&deadproc)) == NULL) 420 msleep_nsec(&deadproc, &deadproc_mutex, PVM, "reaper", 421 INFSLP); 422 423 /* Remove us from the deadproc list. */ 424 LIST_REMOVE(p, p_hash); 425 mtx_leave(&deadproc_mutex); 426 427 WITNESS_THREAD_EXIT(p); 428 429 KERNEL_LOCK(); 430 431 /* 432 * Free the VM resources we're still holding on to. 433 * We must do this from a valid thread because doing 434 * so may block. 435 */ 436 uvm_uarea_free(p); 437 p->p_vmspace = NULL; /* zap the thread's copy */ 438 439 if (p->p_flag & P_THREAD) { 440 /* Just a thread */ 441 proc_free(p); 442 } else { 443 struct process *pr = p->p_p; 444 445 /* Release the rest of the process's vmspace */ 446 uvm_exit(pr); 447 448 if ((pr->ps_flags & PS_NOZOMBIE) == 0) { 449 /* Process is now a true zombie. */ 450 atomic_setbits_int(&pr->ps_flags, PS_ZOMBIE); 451 } 452 453 /* Notify listeners of our demise and clean up. */ 454 knote_processexit(pr); 455 456 if (pr->ps_flags & PS_ZOMBIE) { 457 /* Post SIGCHLD and wake up parent. */ 458 prsignal(pr->ps_pptr, SIGCHLD); 459 wakeup(pr->ps_pptr); 460 } else { 461 /* No one will wait for us, just zap it. */ 462 process_zap(pr); 463 } 464 } 465 466 KERNEL_UNLOCK(); 467 } 468 } 469 470 int 471 dowait6(struct proc *q, idtype_t idtype, id_t id, int *statusp, int options, 472 struct rusage *rusage, siginfo_t *info, register_t *retval) 473 { 474 int nfound; 475 struct process *pr; 476 struct proc *p; 477 int error; 478 479 if (info != NULL) 480 memset(info, 0, sizeof(*info)); 481 482 loop: 483 nfound = 0; 484 LIST_FOREACH(pr, &q->p_p->ps_children, ps_sibling) { 485 if ((pr->ps_flags & PS_NOZOMBIE) || 486 (idtype == P_PID && id != pr->ps_pid) || 487 (idtype == P_PGID && id != pr->ps_pgid)) 488 continue; 489 490 p = pr->ps_mainproc; 491 492 nfound++; 493 if ((options & WEXITED) && (pr->ps_flags & PS_ZOMBIE)) { 494 *retval = pr->ps_pid; 495 if (info != NULL) { 496 info->si_pid = pr->ps_pid; 497 info->si_uid = pr->ps_ucred->cr_uid; 498 info->si_signo = SIGCHLD; 499 if (pr->ps_xsig == 0) { 500 info->si_code = CLD_EXITED; 501 info->si_status = pr->ps_xexit; 502 } else if (WCOREDUMP(pr->ps_xsig)) { 503 info->si_code = CLD_DUMPED; 504 info->si_status = _WSTATUS(pr->ps_xsig); 505 } else { 506 info->si_code = CLD_KILLED; 507 info->si_status = _WSTATUS(pr->ps_xsig); 508 } 509 } 510 511 if (statusp != NULL) 512 *statusp = W_EXITCODE(pr->ps_xexit, 513 pr->ps_xsig); 514 if (rusage != NULL) 515 memcpy(rusage, pr->ps_ru, sizeof(*rusage)); 516 if ((options & WNOWAIT) == 0) 517 proc_finish_wait(q, p); 518 return (0); 519 } 520 if ((options & WTRAPPED) && 521 pr->ps_flags & PS_TRACED && 522 (pr->ps_flags & PS_WAITED) == 0 && pr->ps_single && 523 pr->ps_single->p_stat == SSTOP && 524 (pr->ps_single->p_flag & P_SUSPSINGLE) == 0) { 525 if (single_thread_wait(pr, 0)) 526 goto loop; 527 528 if ((options & WNOWAIT) == 0) 529 atomic_setbits_int(&pr->ps_flags, PS_WAITED); 530 531 *retval = pr->ps_pid; 532 if (info != NULL) { 533 info->si_pid = pr->ps_pid; 534 info->si_uid = pr->ps_ucred->cr_uid; 535 info->si_signo = SIGCHLD; 536 info->si_code = CLD_TRAPPED; 537 info->si_status = pr->ps_xsig; 538 } 539 540 if (statusp != NULL) 541 *statusp = W_STOPCODE(pr->ps_xsig); 542 if (rusage != NULL) 543 memset(rusage, 0, sizeof(*rusage)); 544 return (0); 545 } 546 if (p->p_stat == SSTOP && 547 (pr->ps_flags & PS_WAITED) == 0 && 548 (p->p_flag & P_SUSPSINGLE) == 0 && 549 (pr->ps_flags & PS_TRACED || 550 options & WUNTRACED)) { 551 if ((options & WNOWAIT) == 0) 552 atomic_setbits_int(&pr->ps_flags, PS_WAITED); 553 554 *retval = pr->ps_pid; 555 if (info != 0) { 556 info->si_pid = pr->ps_pid; 557 info->si_uid = pr->ps_ucred->cr_uid; 558 info->si_signo = SIGCHLD; 559 info->si_code = CLD_STOPPED; 560 info->si_status = pr->ps_xsig; 561 } 562 563 if (statusp != NULL) 564 *statusp = W_STOPCODE(pr->ps_xsig); 565 if (rusage != NULL) 566 memset(rusage, 0, sizeof(*rusage)); 567 return (0); 568 } 569 if ((options & WCONTINUED) && (p->p_flag & P_CONTINUED)) { 570 if ((options & WNOWAIT) == 0) 571 atomic_clearbits_int(&p->p_flag, P_CONTINUED); 572 573 *retval = pr->ps_pid; 574 if (info != NULL) { 575 info->si_pid = pr->ps_pid; 576 info->si_uid = pr->ps_ucred->cr_uid; 577 info->si_signo = SIGCHLD; 578 info->si_code = CLD_CONTINUED; 579 info->si_status = SIGCONT; 580 } 581 582 if (statusp != NULL) 583 *statusp = _WCONTINUED; 584 if (rusage != NULL) 585 memset(rusage, 0, sizeof(*rusage)); 586 return (0); 587 } 588 } 589 /* 590 * Look in the orphans list too, to allow the parent to 591 * collect its child's exit status even if child is being 592 * debugged. 593 * 594 * Debugger detaches from the parent upon successful 595 * switch-over from parent to child. At this point due to 596 * re-parenting the parent loses the child to debugger and a 597 * wait4(2) call would report that it has no children to wait 598 * for. By maintaining a list of orphans we allow the parent 599 * to successfully wait until the child becomes a zombie. 600 */ 601 if (nfound == 0) { 602 LIST_FOREACH(pr, &q->p_p->ps_orphans, ps_orphan) { 603 if ((pr->ps_flags & PS_NOZOMBIE) || 604 (idtype == P_PID && id != pr->ps_pid) || 605 (idtype == P_PGID && id != pr->ps_pgid)) 606 continue; 607 nfound++; 608 break; 609 } 610 } 611 if (nfound == 0) 612 return (ECHILD); 613 if (options & WNOHANG) { 614 *retval = 0; 615 return (0); 616 } 617 if ((error = tsleep_nsec(q->p_p, PWAIT | PCATCH, "wait", INFSLP)) != 0) 618 return (error); 619 goto loop; 620 } 621 622 int 623 sys_wait4(struct proc *q, void *v, register_t *retval) 624 { 625 struct sys_wait4_args /* { 626 syscallarg(pid_t) pid; 627 syscallarg(int *) status; 628 syscallarg(int) options; 629 syscallarg(struct rusage *) rusage; 630 } */ *uap = v; 631 struct rusage ru; 632 pid_t pid = SCARG(uap, pid); 633 int options = SCARG(uap, options); 634 int status, error; 635 idtype_t idtype; 636 id_t id; 637 638 if (SCARG(uap, options) &~ (WUNTRACED|WNOHANG|WCONTINUED)) 639 return (EINVAL); 640 options |= WEXITED | WTRAPPED; 641 642 if (SCARG(uap, pid) == WAIT_MYPGRP) { 643 idtype = P_PGID; 644 id = q->p_p->ps_pgid; 645 } else if (SCARG(uap, pid) == WAIT_ANY) { 646 idtype = P_ALL; 647 id = 0; 648 } else if (pid < 0) { 649 idtype = P_PGID; 650 id = -pid; 651 } else { 652 idtype = P_PID; 653 id = pid; 654 } 655 656 error = dowait6(q, idtype, id, 657 SCARG(uap, status) ? &status : NULL, options, 658 SCARG(uap, rusage) ? &ru : NULL, NULL, retval); 659 if (error == 0 && *retval > 0 && SCARG(uap, status)) { 660 error = copyout(&status, SCARG(uap, status), sizeof(status)); 661 } 662 if (error == 0 && *retval > 0 && SCARG(uap, rusage)) { 663 error = copyout(&ru, SCARG(uap, rusage), sizeof(ru)); 664 #ifdef KTRACE 665 if (error == 0 && KTRPOINT(q, KTR_STRUCT)) 666 ktrrusage(q, &ru); 667 #endif 668 } 669 return (error); 670 } 671 672 int 673 sys_waitid(struct proc *q, void *v, register_t *retval) 674 { 675 struct sys_waitid_args /* { 676 syscallarg(idtype_t) idtype; 677 syscallarg(id_t) id; 678 syscallarg(siginfo_t) info; 679 syscallarg(int) options; 680 } */ *uap = v; 681 siginfo_t info; 682 idtype_t idtype = SCARG(uap, idtype); 683 int options = SCARG(uap, options); 684 int error; 685 686 if (options &~ (WSTOPPED|WCONTINUED|WEXITED|WTRAPPED|WNOHANG|WNOWAIT)) 687 return (EINVAL); 688 if ((options & (WSTOPPED|WCONTINUED|WEXITED|WTRAPPED)) == 0) 689 return (EINVAL); 690 if (idtype != P_ALL && idtype != P_PID && idtype != P_PGID) 691 return (EINVAL); 692 693 error = dowait6(q, idtype, SCARG(uap, id), NULL, 694 options, NULL, &info, retval); 695 if (error == 0) { 696 error = copyout(&info, SCARG(uap, info), sizeof(info)); 697 #ifdef KTRACE 698 if (error == 0 && KTRPOINT(q, KTR_STRUCT)) 699 ktrsiginfo(q, &info); 700 #endif 701 } 702 if (error == 0) 703 *retval = 0; 704 return (error); 705 } 706 707 void 708 proc_finish_wait(struct proc *waiter, struct proc *p) 709 { 710 struct process *pr, *tr; 711 struct rusage *rup; 712 713 /* 714 * If we got the child via a ptrace 'attach', 715 * we need to give it back to the old parent. 716 */ 717 pr = p->p_p; 718 if (pr->ps_oppid != 0 && (pr->ps_oppid != pr->ps_pptr->ps_pid) && 719 (tr = prfind(pr->ps_oppid))) { 720 pr->ps_oppid = 0; 721 atomic_clearbits_int(&pr->ps_flags, PS_TRACED); 722 process_reparent(pr, tr); 723 prsignal(tr, SIGCHLD); 724 wakeup(tr); 725 } else { 726 scheduler_wait_hook(waiter, p); 727 rup = &waiter->p_p->ps_cru; 728 ruadd(rup, pr->ps_ru); 729 LIST_REMOVE(pr, ps_list); /* off zombprocess */ 730 freepid(pr->ps_pid); 731 process_zap(pr); 732 } 733 } 734 735 /* 736 * give process back to original parent or init(8) 737 */ 738 void 739 process_untrace(struct process *pr) 740 { 741 struct process *ppr = NULL; 742 743 KASSERT(pr->ps_flags & PS_TRACED); 744 745 if (pr->ps_oppid != 0 && 746 (pr->ps_oppid != pr->ps_pptr->ps_pid)) 747 ppr = prfind(pr->ps_oppid); 748 749 /* not being traced any more */ 750 pr->ps_oppid = 0; 751 atomic_clearbits_int(&pr->ps_flags, PS_TRACED); 752 process_reparent(pr, ppr ? ppr : initprocess); 753 } 754 755 void 756 process_clear_orphan(struct process *pr) 757 { 758 if (pr->ps_flags & PS_ORPHAN) { 759 LIST_REMOVE(pr, ps_orphan); 760 atomic_clearbits_int(&pr->ps_flags, PS_ORPHAN); 761 } 762 } 763 764 /* 765 * make process 'parent' the new parent of process 'child'. 766 */ 767 void 768 process_reparent(struct process *child, struct process *parent) 769 { 770 771 if (child->ps_pptr == parent) 772 return; 773 774 KASSERT(child->ps_oppid == 0 || 775 child->ps_oppid == child->ps_pptr->ps_pid); 776 777 LIST_REMOVE(child, ps_sibling); 778 LIST_INSERT_HEAD(&parent->ps_children, child, ps_sibling); 779 780 process_clear_orphan(child); 781 if (child->ps_flags & PS_TRACED) { 782 atomic_setbits_int(&child->ps_flags, PS_ORPHAN); 783 LIST_INSERT_HEAD(&child->ps_pptr->ps_orphans, child, ps_orphan); 784 } 785 786 child->ps_pptr = parent; 787 child->ps_ppid = parent->ps_pid; 788 } 789 790 void 791 process_zap(struct process *pr) 792 { 793 struct vnode *otvp; 794 struct proc *p = pr->ps_mainproc; 795 796 /* 797 * Finally finished with old proc entry. 798 * Unlink it from its process group and free it. 799 */ 800 leavepgrp(pr); 801 LIST_REMOVE(pr, ps_sibling); 802 process_clear_orphan(pr); 803 804 /* 805 * Decrement the count of procs running with this uid. 806 */ 807 (void)chgproccnt(pr->ps_ucred->cr_ruid, -1); 808 809 /* 810 * Release reference to text vnode 811 */ 812 otvp = pr->ps_textvp; 813 pr->ps_textvp = NULL; 814 if (otvp) 815 vrele(otvp); 816 817 KASSERT(pr->ps_refcnt == 1); 818 if (pr->ps_ptstat != NULL) 819 free(pr->ps_ptstat, M_SUBPROC, sizeof(*pr->ps_ptstat)); 820 pool_put(&rusage_pool, pr->ps_ru); 821 KASSERT(TAILQ_EMPTY(&pr->ps_threads)); 822 sigactsfree(pr->ps_sigacts); 823 lim_free(pr->ps_limit); 824 crfree(pr->ps_ucred); 825 pool_put(&process_pool, pr); 826 nprocesses--; 827 828 proc_free(p); 829 }
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