1 /* $OpenBSD: kern_exit.c,v 1.211 2023/04/25 18:14:06 claudio 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); 162 163 if ((p->p_flag & P_THREAD) == 0) { 164 /* main thread gotta wait because it has the pid, et al */ 165 while (pr->ps_threadcnt > 1) 166 tsleep_nsec(&pr->ps_threads, PWAIT, "thrdeath", INFSLP); 167 if (pr->ps_flags & PS_PROFIL) 168 stopprofclock(pr); 169 } 170 171 rup = pr->ps_ru; 172 if (rup == NULL) { 173 rup = pool_get(&rusage_pool, PR_WAITOK | PR_ZERO); 174 if (pr->ps_ru == NULL) { 175 pr->ps_ru = rup; 176 } else { 177 pool_put(&rusage_pool, rup); 178 rup = pr->ps_ru; 179 } 180 } 181 p->p_siglist = 0; 182 if ((p->p_flag & P_THREAD) == 0) 183 pr->ps_siglist = 0; 184 185 kqpoll_exit(); 186 187 #if NKCOV > 0 188 kcov_exit(p); 189 #endif 190 191 if ((p->p_flag & P_THREAD) == 0) { 192 sigio_freelist(&pr->ps_sigiolst); 193 194 /* close open files and release open-file table */ 195 fdfree(p); 196 197 cancel_all_itimers(); 198 199 timeout_del(&pr->ps_rucheck_to); 200 #ifdef SYSVSEM 201 semexit(pr); 202 #endif 203 killjobc(pr); 204 #ifdef ACCOUNTING 205 acct_process(p); 206 #endif 207 208 #ifdef KTRACE 209 /* release trace file */ 210 if (pr->ps_tracevp) 211 ktrcleartrace(pr); 212 #endif 213 214 unveil_destroy(pr); 215 216 /* 217 * If parent has the SAS_NOCLDWAIT flag set, we're not 218 * going to become a zombie. 219 */ 220 if (pr->ps_pptr->ps_sigacts->ps_sigflags & SAS_NOCLDWAIT) 221 atomic_setbits_int(&pr->ps_flags, PS_NOZOMBIE); 222 } 223 224 p->p_fd = NULL; /* zap the thread's copy */ 225 226 /* 227 * Remove proc from pidhash chain and allproc so looking 228 * it up won't work. We will put the proc on the 229 * deadproc list later (using the p_hash member), and 230 * wake up the reaper when we do. If this is the last 231 * thread of a process that isn't PS_NOZOMBIE, we'll put 232 * the process on the zombprocess list below. 233 */ 234 /* 235 * NOTE: WE ARE NO LONGER ALLOWED TO SLEEP! 236 */ 237 p->p_stat = SDEAD; 238 239 LIST_REMOVE(p, p_hash); 240 LIST_REMOVE(p, p_list); 241 242 if ((p->p_flag & P_THREAD) == 0) { 243 LIST_REMOVE(pr, ps_hash); 244 LIST_REMOVE(pr, ps_list); 245 246 if ((pr->ps_flags & PS_NOZOMBIE) == 0) 247 LIST_INSERT_HEAD(&zombprocess, pr, ps_list); 248 else { 249 /* 250 * Not going to be a zombie, so it's now off all 251 * the lists scanned by ispidtaken(), so block 252 * fast reuse of the pid now. 253 */ 254 freepid(pr->ps_pid); 255 } 256 257 /* 258 * Reparent children to their original parent, in case 259 * they were being traced, or to init(8). 260 */ 261 qr = LIST_FIRST(&pr->ps_children); 262 if (qr) /* only need this if any child is S_ZOMB */ 263 wakeup(initprocess); 264 for (; qr != NULL; qr = nqr) { 265 nqr = LIST_NEXT(qr, ps_sibling); 266 /* 267 * Traced processes are killed since their 268 * existence means someone is screwing up. 269 */ 270 if (qr->ps_flags & PS_TRACED && 271 !(qr->ps_flags & PS_EXITING)) { 272 process_untrace(qr); 273 274 /* 275 * If single threading is active, 276 * direct the signal to the active 277 * thread to avoid deadlock. 278 */ 279 if (qr->ps_single) 280 ptsignal(qr->ps_single, SIGKILL, 281 STHREAD); 282 else 283 prsignal(qr, SIGKILL); 284 } else { 285 process_reparent(qr, initprocess); 286 } 287 } 288 289 /* 290 * Make sure orphans won't remember the exiting process. 291 */ 292 while ((qr = LIST_FIRST(&pr->ps_orphans)) != NULL) { 293 KASSERT(qr->ps_oppid == pr->ps_pid); 294 qr->ps_oppid = 0; 295 process_clear_orphan(qr); 296 } 297 } 298 299 /* add thread's accumulated rusage into the process's total */ 300 ruadd(rup, &p->p_ru); 301 tuagg(pr, p); 302 303 /* 304 * clear %cpu usage during swap 305 */ 306 p->p_pctcpu = 0; 307 308 if ((p->p_flag & P_THREAD) == 0) { 309 /* 310 * Final thread has died, so add on our children's rusage 311 * and calculate the total times 312 */ 313 calcru(&pr->ps_tu, &rup->ru_utime, &rup->ru_stime, NULL); 314 ruadd(rup, &pr->ps_cru); 315 316 /* 317 * Notify parent that we're gone. If we're not going to 318 * become a zombie, reparent to process 1 (init) so that 319 * we can wake our original parent to possibly unblock 320 * wait4() to return ECHILD. 321 */ 322 if (pr->ps_flags & PS_NOZOMBIE) { 323 struct process *ppr = pr->ps_pptr; 324 process_reparent(pr, initprocess); 325 wakeup(ppr); 326 } 327 } 328 329 /* just a thread? detach it from its process */ 330 if (p->p_flag & P_THREAD) { 331 /* scheduler_wait_hook(pr->ps_mainproc, p); XXX */ 332 if (--pr->ps_threadcnt == 1) 333 wakeup(&pr->ps_threads); 334 KASSERT(pr->ps_threadcnt > 0); 335 } 336 337 /* Release the thread's read reference of resource limit structure. */ 338 if (p->p_limit != NULL) { 339 struct plimit *limit; 340 341 limit = p->p_limit; 342 p->p_limit = NULL; 343 lim_free(limit); 344 } 345 346 /* 347 * Other substructures are freed from reaper and wait(). 348 */ 349 350 /* 351 * Finally, call machine-dependent code to switch to a new 352 * context (possibly the idle context). Once we are no longer 353 * using the dead process's vmspace and stack, exit2() will be 354 * called to schedule those resources to be released by the 355 * reaper thread. 356 * 357 * Note that cpu_exit() will end with a call equivalent to 358 * cpu_switch(), finishing our execution (pun intended). 359 */ 360 uvmexp.swtch++; 361 cpu_exit(p); 362 panic("cpu_exit returned"); 363 } 364 365 /* 366 * Locking of this proclist is special; it's accessed in a 367 * critical section of process exit, and thus locking it can't 368 * modify interrupt state. We use a simple spin lock for this 369 * proclist. We use the p_hash member to linkup to deadproc. 370 */ 371 struct mutex deadproc_mutex = 372 MUTEX_INITIALIZER_FLAGS(IPL_NONE, "deadproc", MTX_NOWITNESS); 373 struct proclist deadproc = LIST_HEAD_INITIALIZER(deadproc); 374 375 /* 376 * We are called from cpu_exit() once it is safe to schedule the 377 * dead process's resources to be freed. 378 * 379 * NOTE: One must be careful with locking in this routine. It's 380 * called from a critical section in machine-dependent code, so 381 * we should refrain from changing any interrupt state. 382 * 383 * We lock the deadproc list, place the proc on that list (using 384 * the p_hash member), and wake up the reaper. 385 */ 386 void 387 exit2(struct proc *p) 388 { 389 mtx_enter(&deadproc_mutex); 390 LIST_INSERT_HEAD(&deadproc, p, p_hash); 391 mtx_leave(&deadproc_mutex); 392 393 wakeup(&deadproc); 394 } 395 396 void 397 proc_free(struct proc *p) 398 { 399 crfree(p->p_ucred); 400 pool_put(&proc_pool, p); 401 nthreads--; 402 } 403 404 /* 405 * Process reaper. This is run by a kernel thread to free the resources 406 * of a dead process. Once the resources are free, the process becomes 407 * a zombie, and the parent is allowed to read the undead's status. 408 */ 409 void 410 reaper(void *arg) 411 { 412 struct proc *p; 413 414 KERNEL_UNLOCK(); 415 416 SCHED_ASSERT_UNLOCKED(); 417 418 for (;;) { 419 mtx_enter(&deadproc_mutex); 420 while ((p = LIST_FIRST(&deadproc)) == NULL) 421 msleep_nsec(&deadproc, &deadproc_mutex, PVM, "reaper", 422 INFSLP); 423 424 /* Remove us from the deadproc list. */ 425 LIST_REMOVE(p, p_hash); 426 mtx_leave(&deadproc_mutex); 427 428 WITNESS_THREAD_EXIT(p); 429 430 KERNEL_LOCK(); 431 432 /* 433 * Free the VM resources we're still holding on to. 434 * We must do this from a valid thread because doing 435 * so may block. 436 */ 437 uvm_uarea_free(p); 438 p->p_vmspace = NULL; /* zap the thread's copy */ 439 440 if (p->p_flag & P_THREAD) { 441 /* Just a thread */ 442 proc_free(p); 443 } else { 444 struct process *pr = p->p_p; 445 446 /* Release the rest of the process's vmspace */ 447 uvm_exit(pr); 448 449 if ((pr->ps_flags & PS_NOZOMBIE) == 0) { 450 /* Process is now a true zombie. */ 451 atomic_setbits_int(&pr->ps_flags, PS_ZOMBIE); 452 } 453 454 /* Notify listeners of our demise and clean up. */ 455 knote_processexit(pr); 456 457 if (pr->ps_flags & PS_ZOMBIE) { 458 /* Post SIGCHLD and wake up parent. */ 459 prsignal(pr->ps_pptr, SIGCHLD); 460 wakeup(pr->ps_pptr); 461 } else { 462 /* No one will wait for us, just zap it. */ 463 process_zap(pr); 464 } 465 } 466 467 KERNEL_UNLOCK(); 468 } 469 } 470 471 int 472 dowait6(struct proc *q, idtype_t idtype, id_t id, int *statusp, int options, 473 struct rusage *rusage, siginfo_t *info, register_t *retval) 474 { 475 int nfound; 476 struct process *pr; 477 struct proc *p; 478 int error; 479 480 if (info != NULL) 481 memset(info, 0, sizeof(*info)); 482 483 loop: 484 nfound = 0; 485 LIST_FOREACH(pr, &q->p_p->ps_children, ps_sibling) { 486 if ((pr->ps_flags & PS_NOZOMBIE) || 487 (idtype == P_PID && id != pr->ps_pid) || 488 (idtype == P_PGID && id != pr->ps_pgid)) 489 continue; 490 491 p = pr->ps_mainproc; 492 493 nfound++; 494 if ((options & WEXITED) && (pr->ps_flags & PS_ZOMBIE)) { 495 *retval = pr->ps_pid; 496 if (info != NULL) { 497 info->si_pid = pr->ps_pid; 498 info->si_uid = pr->ps_ucred->cr_uid; 499 info->si_signo = SIGCHLD; 500 if (pr->ps_xsig == 0) { 501 info->si_code = CLD_EXITED; 502 info->si_status = pr->ps_xexit; 503 } else if (WCOREDUMP(pr->ps_xsig)) { 504 info->si_code = CLD_DUMPED; 505 info->si_status = _WSTATUS(pr->ps_xsig); 506 } else { 507 info->si_code = CLD_KILLED; 508 info->si_status = _WSTATUS(pr->ps_xsig); 509 } 510 } 511 512 if (statusp != NULL) 513 *statusp = W_EXITCODE(pr->ps_xexit, 514 pr->ps_xsig); 515 if (rusage != NULL) 516 memcpy(rusage, pr->ps_ru, sizeof(*rusage)); 517 if ((options & WNOWAIT) == 0) 518 proc_finish_wait(q, p); 519 return (0); 520 } 521 if ((options & WTRAPPED) && 522 pr->ps_flags & PS_TRACED && 523 (pr->ps_flags & PS_WAITED) == 0 && pr->ps_single && 524 pr->ps_single->p_stat == SSTOP && 525 (pr->ps_single->p_flag & P_SUSPSINGLE) == 0) { 526 if (single_thread_wait(pr, 0)) 527 goto loop; 528 529 if ((options & WNOWAIT) == 0) 530 atomic_setbits_int(&pr->ps_flags, PS_WAITED); 531 532 *retval = pr->ps_pid; 533 if (info != NULL) { 534 info->si_pid = pr->ps_pid; 535 info->si_uid = pr->ps_ucred->cr_uid; 536 info->si_signo = SIGCHLD; 537 info->si_code = CLD_TRAPPED; 538 info->si_status = pr->ps_xsig; 539 } 540 541 if (statusp != NULL) 542 *statusp = W_STOPCODE(pr->ps_xsig); 543 if (rusage != NULL) 544 memset(rusage, 0, sizeof(*rusage)); 545 return (0); 546 } 547 if (p->p_stat == SSTOP && 548 (pr->ps_flags & PS_WAITED) == 0 && 549 (p->p_flag & P_SUSPSINGLE) == 0 && 550 (pr->ps_flags & PS_TRACED || 551 options & WUNTRACED)) { 552 if ((options & WNOWAIT) == 0) 553 atomic_setbits_int(&pr->ps_flags, PS_WAITED); 554 555 *retval = pr->ps_pid; 556 if (info != 0) { 557 info->si_pid = pr->ps_pid; 558 info->si_uid = pr->ps_ucred->cr_uid; 559 info->si_signo = SIGCHLD; 560 info->si_code = CLD_STOPPED; 561 info->si_status = pr->ps_xsig; 562 } 563 564 if (statusp != NULL) 565 *statusp = W_STOPCODE(pr->ps_xsig); 566 if (rusage != NULL) 567 memset(rusage, 0, sizeof(*rusage)); 568 return (0); 569 } 570 if ((options & WCONTINUED) && (p->p_flag & P_CONTINUED)) { 571 if ((options & WNOWAIT) == 0) 572 atomic_clearbits_int(&p->p_flag, P_CONTINUED); 573 574 *retval = pr->ps_pid; 575 if (info != NULL) { 576 info->si_pid = pr->ps_pid; 577 info->si_uid = pr->ps_ucred->cr_uid; 578 info->si_signo = SIGCHLD; 579 info->si_code = CLD_CONTINUED; 580 info->si_status = SIGCONT; 581 } 582 583 if (statusp != NULL) 584 *statusp = _WCONTINUED; 585 if (rusage != NULL) 586 memset(rusage, 0, sizeof(*rusage)); 587 return (0); 588 } 589 } 590 /* 591 * Look in the orphans list too, to allow the parent to 592 * collect its child's exit status even if child is being 593 * debugged. 594 * 595 * Debugger detaches from the parent upon successful 596 * switch-over from parent to child. At this point due to 597 * re-parenting the parent loses the child to debugger and a 598 * wait4(2) call would report that it has no children to wait 599 * for. By maintaining a list of orphans we allow the parent 600 * to successfully wait until the child becomes a zombie. 601 */ 602 if (nfound == 0) { 603 LIST_FOREACH(pr, &q->p_p->ps_orphans, ps_orphan) { 604 if ((pr->ps_flags & PS_NOZOMBIE) || 605 (idtype == P_PID && id != pr->ps_pid) || 606 (idtype == P_PGID && id != pr->ps_pgid)) 607 continue; 608 nfound++; 609 break; 610 } 611 } 612 if (nfound == 0) 613 return (ECHILD); 614 if (options & WNOHANG) { 615 *retval = 0; 616 return (0); 617 } 618 if ((error = tsleep_nsec(q->p_p, PWAIT | PCATCH, "wait", INFSLP)) != 0) 619 return (error); 620 goto loop; 621 } 622 623 int 624 sys_wait4(struct proc *q, void *v, register_t *retval) 625 { 626 struct sys_wait4_args /* { 627 syscallarg(pid_t) pid; 628 syscallarg(int *) status; 629 syscallarg(int) options; 630 syscallarg(struct rusage *) rusage; 631 } */ *uap = v; 632 struct rusage ru; 633 pid_t pid = SCARG(uap, pid); 634 int options = SCARG(uap, options); 635 int status, error; 636 idtype_t idtype; 637 id_t id; 638 639 if (SCARG(uap, options) &~ (WUNTRACED|WNOHANG|WCONTINUED)) 640 return (EINVAL); 641 options |= WEXITED | WTRAPPED; 642 643 if (SCARG(uap, pid) == WAIT_MYPGRP) { 644 idtype = P_PGID; 645 id = q->p_p->ps_pgid; 646 } else if (SCARG(uap, pid) == WAIT_ANY) { 647 idtype = P_ALL; 648 id = 0; 649 } else if (pid < 0) { 650 idtype = P_PGID; 651 id = -pid; 652 } else { 653 idtype = P_PID; 654 id = pid; 655 } 656 657 error = dowait6(q, idtype, id, 658 SCARG(uap, status) ? &status : NULL, options, 659 SCARG(uap, rusage) ? &ru : NULL, NULL, retval); 660 if (error == 0 && *retval > 0 && SCARG(uap, status)) { 661 error = copyout(&status, SCARG(uap, status), sizeof(status)); 662 } 663 if (error == 0 && *retval > 0 && SCARG(uap, rusage)) { 664 error = copyout(&ru, SCARG(uap, rusage), sizeof(ru)); 665 #ifdef KTRACE 666 if (error == 0 && KTRPOINT(q, KTR_STRUCT)) 667 ktrrusage(q, &ru); 668 #endif 669 } 670 return (error); 671 } 672 673 int 674 sys_waitid(struct proc *q, void *v, register_t *retval) 675 { 676 struct sys_waitid_args /* { 677 syscallarg(idtype_t) idtype; 678 syscallarg(id_t) id; 679 syscallarg(siginfo_t) info; 680 syscallarg(int) options; 681 } */ *uap = v; 682 siginfo_t info; 683 idtype_t idtype = SCARG(uap, idtype); 684 int options = SCARG(uap, options); 685 int error; 686 687 if (options &~ (WSTOPPED|WCONTINUED|WEXITED|WTRAPPED|WNOHANG|WNOWAIT)) 688 return (EINVAL); 689 if ((options & (WSTOPPED|WCONTINUED|WEXITED|WTRAPPED)) == 0) 690 return (EINVAL); 691 if (idtype != P_ALL && idtype != P_PID && idtype != P_PGID) 692 return (EINVAL); 693 694 error = dowait6(q, idtype, SCARG(uap, id), NULL, 695 options, NULL, &info, retval); 696 if (error == 0) { 697 error = copyout(&info, SCARG(uap, info), sizeof(info)); 698 #ifdef KTRACE 699 if (error == 0 && KTRPOINT(q, KTR_STRUCT)) 700 ktrsiginfo(q, &info); 701 #endif 702 } 703 if (error == 0) 704 *retval = 0; 705 return (error); 706 } 707 708 void 709 proc_finish_wait(struct proc *waiter, struct proc *p) 710 { 711 struct process *pr, *tr; 712 struct rusage *rup; 713 714 /* 715 * If we got the child via a ptrace 'attach', 716 * we need to give it back to the old parent. 717 */ 718 pr = p->p_p; 719 if (pr->ps_oppid != 0 && (pr->ps_oppid != pr->ps_pptr->ps_pid) && 720 (tr = prfind(pr->ps_oppid))) { 721 pr->ps_oppid = 0; 722 atomic_clearbits_int(&pr->ps_flags, PS_TRACED); 723 process_reparent(pr, tr); 724 prsignal(tr, SIGCHLD); 725 wakeup(tr); 726 } else { 727 scheduler_wait_hook(waiter, p); 728 rup = &waiter->p_p->ps_cru; 729 ruadd(rup, pr->ps_ru); 730 LIST_REMOVE(pr, ps_list); /* off zombprocess */ 731 freepid(pr->ps_pid); 732 process_zap(pr); 733 } 734 } 735 736 /* 737 * give process back to original parent or init(8) 738 */ 739 void 740 process_untrace(struct process *pr) 741 { 742 struct process *ppr = NULL; 743 744 KASSERT(pr->ps_flags & PS_TRACED); 745 746 if (pr->ps_oppid != 0 && 747 (pr->ps_oppid != pr->ps_pptr->ps_pid)) 748 ppr = prfind(pr->ps_oppid); 749 750 /* not being traced any more */ 751 pr->ps_oppid = 0; 752 atomic_clearbits_int(&pr->ps_flags, PS_TRACED); 753 process_reparent(pr, ppr ? ppr : initprocess); 754 } 755 756 void 757 process_clear_orphan(struct process *pr) 758 { 759 if (pr->ps_flags & PS_ORPHAN) { 760 LIST_REMOVE(pr, ps_orphan); 761 atomic_clearbits_int(&pr->ps_flags, PS_ORPHAN); 762 } 763 } 764 765 /* 766 * make process 'parent' the new parent of process 'child'. 767 */ 768 void 769 process_reparent(struct process *child, struct process *parent) 770 { 771 772 if (child->ps_pptr == parent) 773 return; 774 775 KASSERT(child->ps_oppid == 0 || 776 child->ps_oppid == child->ps_pptr->ps_pid); 777 778 LIST_REMOVE(child, ps_sibling); 779 LIST_INSERT_HEAD(&parent->ps_children, child, ps_sibling); 780 781 process_clear_orphan(child); 782 if (child->ps_flags & PS_TRACED) { 783 atomic_setbits_int(&child->ps_flags, PS_ORPHAN); 784 LIST_INSERT_HEAD(&child->ps_pptr->ps_orphans, child, ps_orphan); 785 } 786 787 child->ps_pptr = parent; 788 child->ps_ppid = parent->ps_pid; 789 } 790 791 void 792 process_zap(struct process *pr) 793 { 794 struct vnode *otvp; 795 struct proc *p = pr->ps_mainproc; 796 797 /* 798 * Finally finished with old proc entry. 799 * Unlink it from its process group and free it. 800 */ 801 leavepgrp(pr); 802 LIST_REMOVE(pr, ps_sibling); 803 process_clear_orphan(pr); 804 805 /* 806 * Decrement the count of procs running with this uid. 807 */ 808 (void)chgproccnt(pr->ps_ucred->cr_ruid, -1); 809 810 /* 811 * Release reference to text vnode 812 */ 813 otvp = pr->ps_textvp; 814 pr->ps_textvp = NULL; 815 if (otvp) 816 vrele(otvp); 817 818 KASSERT(pr->ps_threadcnt == 1); 819 if (pr->ps_ptstat != NULL) 820 free(pr->ps_ptstat, M_SUBPROC, sizeof(*pr->ps_ptstat)); 821 pool_put(&rusage_pool, pr->ps_ru); 822 KASSERT(TAILQ_EMPTY(&pr->ps_threads)); 823 sigactsfree(pr->ps_sigacts); 824 lim_free(pr->ps_limit); 825 crfree(pr->ps_ucred); 826 pool_put(&process_pool, pr); 827 nprocesses--; 828 829 proc_free(p); 830 } 831