1 /* $OpenBSD: kern_exit.c,v 1.231 2024/08/11 15:10:53 mvs 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 process *); 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 struct timespec ts, pts; 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); 134 } 135 136 if (flags == EXIT_NORMAL && !(pr->ps_flags & PS_EXITING)) { 137 if (pr->ps_pid == 1) 138 panic("init died (signal %d, exit %d)", xsig, xexit); 139 140 atomic_setbits_int(&pr->ps_flags, PS_EXITING); 141 pr->ps_xexit = xexit; 142 pr->ps_xsig = xsig; 143 144 /* 145 * If parent is waiting for us to exit or exec, PS_PPWAIT 146 * is set; we wake up the parent early to avoid deadlock. 147 */ 148 if (pr->ps_flags & PS_PPWAIT) { 149 atomic_clearbits_int(&pr->ps_flags, PS_PPWAIT); 150 atomic_clearbits_int(&pr->ps_pptr->ps_flags, 151 PS_ISPWAIT); 152 wakeup(pr->ps_pptr); 153 } 154 155 /* Wait for concurrent `allprocess' loops */ 156 refcnt_finalize(&pr->ps_refcnt, "psdtor"); 157 } 158 159 /* unlink ourselves from the active threads */ 160 mtx_enter(&pr->ps_mtx); 161 TAILQ_REMOVE(&pr->ps_threads, p, p_thr_link); 162 pr->ps_threadcnt--; 163 pr->ps_exitcnt++; 164 165 /* 166 * if somebody else wants to take us to single threaded mode, 167 * count ourselves out. 168 */ 169 if (pr->ps_single) { 170 if (--pr->ps_singlecnt == 0) 171 wakeup(&pr->ps_singlecnt); 172 } 173 174 /* proc is off ps_threads list so update accounting of process now */ 175 nanouptime(&ts); 176 if (timespeccmp(&ts, &curcpu()->ci_schedstate.spc_runtime, <)) 177 timespecclear(&pts); 178 else 179 timespecsub(&ts, &curcpu()->ci_schedstate.spc_runtime, &pts); 180 tu_enter(&p->p_tu); 181 timespecadd(&p->p_tu.tu_runtime, &pts, &p->p_tu.tu_runtime); 182 tu_leave(&p->p_tu); 183 /* adjust spc_runtime to not double account the runtime from above */ 184 curcpu()->ci_schedstate.spc_runtime = ts; 185 tuagg_add_process(p->p_p, p); 186 187 if ((p->p_flag & P_THREAD) == 0) { 188 /* main thread gotta wait because it has the pid, et al */ 189 while (pr->ps_threadcnt + pr->ps_exitcnt > 1) 190 msleep_nsec(&pr->ps_threads, &pr->ps_mtx, PWAIT, 191 "thrdeath", INFSLP); 192 } 193 mtx_leave(&pr->ps_mtx); 194 195 rup = pr->ps_ru; 196 if (rup == NULL) { 197 rup = pool_get(&rusage_pool, PR_WAITOK | PR_ZERO); 198 if (pr->ps_ru == NULL) { 199 pr->ps_ru = rup; 200 } else { 201 pool_put(&rusage_pool, rup); 202 rup = pr->ps_ru; 203 } 204 } 205 p->p_siglist = 0; 206 if ((p->p_flag & P_THREAD) == 0) 207 pr->ps_siglist = 0; 208 209 kqpoll_exit(); 210 211 #if NKCOV > 0 212 kcov_exit(p); 213 #endif 214 215 if ((p->p_flag & P_THREAD) == 0) { 216 if (pr->ps_flags & PS_PROFIL) 217 stopprofclock(pr); 218 219 sigio_freelist(&pr->ps_sigiolst); 220 221 /* close open files and release open-file table */ 222 fdfree(p); 223 224 cancel_all_itimers(); 225 226 timeout_del(&pr->ps_rucheck_to); 227 #ifdef SYSVSEM 228 semexit(pr); 229 #endif 230 killjobc(pr); 231 #ifdef ACCOUNTING 232 acct_process(p); 233 #endif 234 235 #ifdef KTRACE 236 /* release trace file */ 237 if (pr->ps_tracevp) 238 ktrcleartrace(pr); 239 #endif 240 241 unveil_destroy(pr); 242 243 free(pr->ps_pin.pn_pins, M_PINSYSCALL, 244 pr->ps_pin.pn_npins * sizeof(u_int)); 245 free(pr->ps_libcpin.pn_pins, M_PINSYSCALL, 246 pr->ps_libcpin.pn_npins * sizeof(u_int)); 247 248 /* 249 * If parent has the SAS_NOCLDWAIT flag set, we're not 250 * going to become a zombie. 251 */ 252 if (pr->ps_pptr->ps_sigacts->ps_sigflags & SAS_NOCLDWAIT) 253 atomic_setbits_int(&pr->ps_flags, PS_NOZOMBIE); 254 } 255 256 p->p_fd = NULL; /* zap the thread's copy */ 257 258 /* Release the thread's read reference of resource limit structure. */ 259 if (p->p_limit != NULL) { 260 struct plimit *limit; 261 262 limit = p->p_limit; 263 p->p_limit = NULL; 264 lim_free(limit); 265 } 266 267 /* 268 * Remove proc from pidhash chain and allproc so looking 269 * it up won't work. We will put the proc on the 270 * deadproc list later (using the p_hash member), and 271 * wake up the reaper when we do. If this is the last 272 * thread of a process that isn't PS_NOZOMBIE, we'll put 273 * the process on the zombprocess list below. 274 */ 275 /* 276 * NOTE: WE ARE NO LONGER ALLOWED TO SLEEP! 277 */ 278 p->p_stat = SDEAD; 279 280 LIST_REMOVE(p, p_hash); 281 LIST_REMOVE(p, p_list); 282 283 if ((p->p_flag & P_THREAD) == 0) { 284 LIST_REMOVE(pr, ps_hash); 285 LIST_REMOVE(pr, ps_list); 286 287 if ((pr->ps_flags & PS_NOZOMBIE) == 0) 288 LIST_INSERT_HEAD(&zombprocess, pr, ps_list); 289 else { 290 /* 291 * Not going to be a zombie, so it's now off all 292 * the lists scanned by ispidtaken(), so block 293 * fast reuse of the pid now. 294 */ 295 freepid(pr->ps_pid); 296 } 297 298 /* 299 * Reparent children to their original parent, in case 300 * they were being traced, or to init(8). 301 */ 302 qr = LIST_FIRST(&pr->ps_children); 303 if (qr) /* only need this if any child is S_ZOMB */ 304 wakeup(initprocess); 305 for (; qr != NULL; qr = nqr) { 306 nqr = LIST_NEXT(qr, ps_sibling); 307 /* 308 * Traced processes are killed since their 309 * existence means someone is screwing up. 310 */ 311 if (qr->ps_flags & PS_TRACED && 312 !(qr->ps_flags & PS_EXITING)) { 313 process_untrace(qr); 314 315 /* 316 * If single threading is active, 317 * direct the signal to the active 318 * thread to avoid deadlock. 319 */ 320 if (qr->ps_single) 321 ptsignal(qr->ps_single, SIGKILL, 322 STHREAD); 323 else 324 prsignal(qr, SIGKILL); 325 } else { 326 process_reparent(qr, initprocess); 327 } 328 } 329 330 /* 331 * Make sure orphans won't remember the exiting process. 332 */ 333 while ((qr = LIST_FIRST(&pr->ps_orphans)) != NULL) { 334 KASSERT(qr->ps_oppid == pr->ps_pid); 335 qr->ps_oppid = 0; 336 process_clear_orphan(qr); 337 } 338 } 339 340 /* add thread's accumulated rusage into the process's total */ 341 ruadd(rup, &p->p_ru); 342 343 /* 344 * clear %cpu usage during swap 345 */ 346 p->p_pctcpu = 0; 347 348 if ((p->p_flag & P_THREAD) == 0) { 349 /* 350 * Final thread has died, so add on our children's rusage 351 * and calculate the total times. 352 */ 353 calcru(&pr->ps_tu, &rup->ru_utime, &rup->ru_stime, NULL); 354 ruadd(rup, &pr->ps_cru); 355 356 /* 357 * Notify parent that we're gone. If we're not going to 358 * become a zombie, reparent to process 1 (init) so that 359 * we can wake our original parent to possibly unblock 360 * wait4() to return ECHILD. 361 */ 362 if (pr->ps_flags & PS_NOZOMBIE) { 363 struct process *ppr = pr->ps_pptr; 364 process_reparent(pr, initprocess); 365 wakeup(ppr); 366 } 367 } 368 369 /* just a thread? check if last one standing. */ 370 if (p->p_flag & P_THREAD) { 371 /* scheduler_wait_hook(pr->ps_mainproc, p); XXX */ 372 mtx_enter(&pr->ps_mtx); 373 pr->ps_exitcnt--; 374 if (pr->ps_threadcnt + pr->ps_exitcnt == 1) 375 wakeup(&pr->ps_threads); 376 mtx_leave(&pr->ps_mtx); 377 } 378 379 /* 380 * Other substructures are freed from reaper and wait(). 381 */ 382 383 /* 384 * Finally, call machine-dependent code to switch to a new 385 * context (possibly the idle context). Once we are no longer 386 * using the dead process's vmspace and stack, exit2() will be 387 * called to schedule those resources to be released by the 388 * reaper thread. 389 * 390 * Note that cpu_exit() will end with a call equivalent to 391 * cpu_switch(), finishing our execution (pun intended). 392 */ 393 uvmexp.swtch++; 394 cpu_exit(p); 395 panic("cpu_exit returned"); 396 } 397 398 /* 399 * Locking of this proclist is special; it's accessed in a 400 * critical section of process exit, and thus locking it can't 401 * modify interrupt state. We use a simple spin lock for this 402 * proclist. We use the p_hash member to linkup to deadproc. 403 */ 404 struct mutex deadproc_mutex = 405 MUTEX_INITIALIZER_FLAGS(IPL_NONE, "deadproc", MTX_NOWITNESS); 406 struct proclist deadproc = LIST_HEAD_INITIALIZER(deadproc); 407 408 /* 409 * We are called from sched_idle() once it is safe to schedule the 410 * dead process's resources to be freed. So this is not allowed to sleep. 411 * 412 * We lock the deadproc list, place the proc on that list (using 413 * the p_hash member), and wake up the reaper. 414 */ 415 void 416 exit2(struct proc *p) 417 { 418 /* account the remainder of time spent in exit1() */ 419 mtx_enter(&p->p_p->ps_mtx); 420 tuagg_add_process(p->p_p, p); 421 mtx_leave(&p->p_p->ps_mtx); 422 423 mtx_enter(&deadproc_mutex); 424 LIST_INSERT_HEAD(&deadproc, p, p_hash); 425 mtx_leave(&deadproc_mutex); 426 427 wakeup(&deadproc); 428 } 429 430 void 431 proc_free(struct proc *p) 432 { 433 crfree(p->p_ucred); 434 pool_put(&proc_pool, p); 435 nthreads--; 436 } 437 438 /* 439 * Process reaper. This is run by a kernel thread to free the resources 440 * of a dead process. Once the resources are free, the process becomes 441 * a zombie, and the parent is allowed to read the undead's status. 442 */ 443 void 444 reaper(void *arg) 445 { 446 struct proc *p; 447 448 KERNEL_UNLOCK(); 449 450 SCHED_ASSERT_UNLOCKED(); 451 452 for (;;) { 453 mtx_enter(&deadproc_mutex); 454 while ((p = LIST_FIRST(&deadproc)) == NULL) 455 msleep_nsec(&deadproc, &deadproc_mutex, PVM, "reaper", 456 INFSLP); 457 458 /* Remove us from the deadproc list. */ 459 LIST_REMOVE(p, p_hash); 460 mtx_leave(&deadproc_mutex); 461 462 WITNESS_THREAD_EXIT(p); 463 464 /* 465 * Free the VM resources we're still holding on to. 466 * We must do this from a valid thread because doing 467 * so may block. 468 */ 469 uvm_uarea_free(p); 470 p->p_vmspace = NULL; /* zap the thread's copy */ 471 472 if (p->p_flag & P_THREAD) { 473 /* Just a thread */ 474 KERNEL_LOCK(); 475 proc_free(p); 476 KERNEL_UNLOCK(); 477 } else { 478 struct process *pr = p->p_p; 479 480 /* Release the rest of the process's vmspace */ 481 uvm_exit(pr); 482 483 KERNEL_LOCK(); 484 if ((pr->ps_flags & PS_NOZOMBIE) == 0) { 485 /* Process is now a true zombie. */ 486 atomic_setbits_int(&pr->ps_flags, PS_ZOMBIE); 487 } 488 489 /* Notify listeners of our demise and clean up. */ 490 knote_processexit(pr); 491 492 if (pr->ps_flags & PS_ZOMBIE) { 493 /* Post SIGCHLD and wake up parent. */ 494 prsignal(pr->ps_pptr, SIGCHLD); 495 wakeup(pr->ps_pptr); 496 } else { 497 /* No one will wait for us, just zap it. */ 498 process_zap(pr); 499 } 500 KERNEL_UNLOCK(); 501 } 502 } 503 } 504 505 int 506 dowait6(struct proc *q, idtype_t idtype, id_t id, int *statusp, int options, 507 struct rusage *rusage, siginfo_t *info, register_t *retval) 508 { 509 int nfound; 510 struct process *pr; 511 struct proc *p; 512 int error; 513 514 if (info != NULL) 515 memset(info, 0, sizeof(*info)); 516 517 loop: 518 nfound = 0; 519 LIST_FOREACH(pr, &q->p_p->ps_children, ps_sibling) { 520 if ((pr->ps_flags & PS_NOZOMBIE) || 521 (idtype == P_PID && id != pr->ps_pid) || 522 (idtype == P_PGID && id != pr->ps_pgid)) 523 continue; 524 525 p = pr->ps_mainproc; 526 527 nfound++; 528 if ((options & WEXITED) && (pr->ps_flags & PS_ZOMBIE)) { 529 *retval = pr->ps_pid; 530 if (info != NULL) { 531 info->si_pid = pr->ps_pid; 532 info->si_uid = pr->ps_ucred->cr_uid; 533 info->si_signo = SIGCHLD; 534 if (pr->ps_xsig == 0) { 535 info->si_code = CLD_EXITED; 536 info->si_status = pr->ps_xexit; 537 } else if (WCOREDUMP(pr->ps_xsig)) { 538 info->si_code = CLD_DUMPED; 539 info->si_status = _WSTATUS(pr->ps_xsig); 540 } else { 541 info->si_code = CLD_KILLED; 542 info->si_status = _WSTATUS(pr->ps_xsig); 543 } 544 } 545 546 if (statusp != NULL) 547 *statusp = W_EXITCODE(pr->ps_xexit, 548 pr->ps_xsig); 549 if (rusage != NULL) 550 memcpy(rusage, pr->ps_ru, sizeof(*rusage)); 551 if ((options & WNOWAIT) == 0) 552 proc_finish_wait(q, pr); 553 return (0); 554 } 555 if ((options & WTRAPPED) && 556 (pr->ps_flags & PS_TRACED) && 557 (pr->ps_flags & PS_WAITED) == 0 && pr->ps_single && 558 pr->ps_single->p_stat == SSTOP) { 559 if (single_thread_wait(pr, 0)) 560 goto loop; 561 562 if ((options & WNOWAIT) == 0) 563 atomic_setbits_int(&pr->ps_flags, PS_WAITED); 564 565 *retval = pr->ps_pid; 566 if (info != NULL) { 567 info->si_pid = pr->ps_pid; 568 info->si_uid = pr->ps_ucred->cr_uid; 569 info->si_signo = SIGCHLD; 570 info->si_code = CLD_TRAPPED; 571 info->si_status = pr->ps_xsig; 572 } 573 574 if (statusp != NULL) 575 *statusp = W_STOPCODE(pr->ps_xsig); 576 if (rusage != NULL) 577 memset(rusage, 0, sizeof(*rusage)); 578 return (0); 579 } 580 if (p->p_stat == SSTOP && 581 (pr->ps_flags & PS_WAITED) == 0 && 582 (p->p_flag & P_SUSPSINGLE) == 0 && 583 ((pr->ps_flags & PS_TRACED) || 584 (options & WUNTRACED))) { 585 if ((options & WNOWAIT) == 0) 586 atomic_setbits_int(&pr->ps_flags, PS_WAITED); 587 588 *retval = pr->ps_pid; 589 if (info != 0) { 590 info->si_pid = pr->ps_pid; 591 info->si_uid = pr->ps_ucred->cr_uid; 592 info->si_signo = SIGCHLD; 593 info->si_code = CLD_STOPPED; 594 info->si_status = pr->ps_xsig; 595 } 596 597 if (statusp != NULL) 598 *statusp = W_STOPCODE(pr->ps_xsig); 599 if (rusage != NULL) 600 memset(rusage, 0, sizeof(*rusage)); 601 return (0); 602 } 603 if ((options & WCONTINUED) && (pr->ps_flags & PS_CONTINUED)) { 604 if ((options & WNOWAIT) == 0) 605 atomic_clearbits_int(&pr->ps_flags, 606 PS_CONTINUED); 607 608 *retval = pr->ps_pid; 609 if (info != NULL) { 610 info->si_pid = pr->ps_pid; 611 info->si_uid = pr->ps_ucred->cr_uid; 612 info->si_signo = SIGCHLD; 613 info->si_code = CLD_CONTINUED; 614 info->si_status = SIGCONT; 615 } 616 617 if (statusp != NULL) 618 *statusp = _WCONTINUED; 619 if (rusage != NULL) 620 memset(rusage, 0, sizeof(*rusage)); 621 return (0); 622 } 623 } 624 /* 625 * Look in the orphans list too, to allow the parent to 626 * collect its child's exit status even if child is being 627 * debugged. 628 * 629 * Debugger detaches from the parent upon successful 630 * switch-over from parent to child. At this point due to 631 * re-parenting the parent loses the child to debugger and a 632 * wait4(2) call would report that it has no children to wait 633 * for. By maintaining a list of orphans we allow the parent 634 * to successfully wait until the child becomes a zombie. 635 */ 636 if (nfound == 0) { 637 LIST_FOREACH(pr, &q->p_p->ps_orphans, ps_orphan) { 638 if ((pr->ps_flags & PS_NOZOMBIE) || 639 (idtype == P_PID && id != pr->ps_pid) || 640 (idtype == P_PGID && id != pr->ps_pgid)) 641 continue; 642 nfound++; 643 break; 644 } 645 } 646 if (nfound == 0) 647 return (ECHILD); 648 if (options & WNOHANG) { 649 *retval = 0; 650 return (0); 651 } 652 if ((error = tsleep_nsec(q->p_p, PWAIT | PCATCH, "wait", INFSLP)) != 0) 653 return (error); 654 goto loop; 655 } 656 657 int 658 sys_wait4(struct proc *q, void *v, register_t *retval) 659 { 660 struct sys_wait4_args /* { 661 syscallarg(pid_t) pid; 662 syscallarg(int *) status; 663 syscallarg(int) options; 664 syscallarg(struct rusage *) rusage; 665 } */ *uap = v; 666 struct rusage ru; 667 pid_t pid = SCARG(uap, pid); 668 int options = SCARG(uap, options); 669 int status, error; 670 idtype_t idtype; 671 id_t id; 672 673 if (SCARG(uap, options) &~ (WUNTRACED|WNOHANG|WCONTINUED)) 674 return (EINVAL); 675 options |= WEXITED | WTRAPPED; 676 677 if (SCARG(uap, pid) == WAIT_MYPGRP) { 678 idtype = P_PGID; 679 id = q->p_p->ps_pgid; 680 } else if (SCARG(uap, pid) == WAIT_ANY) { 681 idtype = P_ALL; 682 id = 0; 683 } else if (pid < 0) { 684 idtype = P_PGID; 685 id = -pid; 686 } else { 687 idtype = P_PID; 688 id = pid; 689 } 690 691 error = dowait6(q, idtype, id, 692 SCARG(uap, status) ? &status : NULL, options, 693 SCARG(uap, rusage) ? &ru : NULL, NULL, retval); 694 if (error == 0 && *retval > 0 && SCARG(uap, status)) { 695 error = copyout(&status, SCARG(uap, status), sizeof(status)); 696 } 697 if (error == 0 && *retval > 0 && SCARG(uap, rusage)) { 698 error = copyout(&ru, SCARG(uap, rusage), sizeof(ru)); 699 #ifdef KTRACE 700 if (error == 0 && KTRPOINT(q, KTR_STRUCT)) 701 ktrrusage(q, &ru); 702 #endif 703 } 704 return (error); 705 } 706 707 int 708 sys_waitid(struct proc *q, void *v, register_t *retval) 709 { 710 struct sys_waitid_args /* { 711 syscallarg(idtype_t) idtype; 712 syscallarg(id_t) id; 713 syscallarg(siginfo_t) info; 714 syscallarg(int) options; 715 } */ *uap = v; 716 siginfo_t info; 717 idtype_t idtype = SCARG(uap, idtype); 718 int options = SCARG(uap, options); 719 int error; 720 721 if (options &~ (WSTOPPED|WCONTINUED|WEXITED|WTRAPPED|WNOHANG|WNOWAIT)) 722 return (EINVAL); 723 if ((options & (WSTOPPED|WCONTINUED|WEXITED|WTRAPPED)) == 0) 724 return (EINVAL); 725 if (idtype != P_ALL && idtype != P_PID && idtype != P_PGID) 726 return (EINVAL); 727 728 error = dowait6(q, idtype, SCARG(uap, id), NULL, 729 options, NULL, &info, retval); 730 if (error == 0) { 731 error = copyout(&info, SCARG(uap, info), sizeof(info)); 732 #ifdef KTRACE 733 if (error == 0 && KTRPOINT(q, KTR_STRUCT)) 734 ktrsiginfo(q, &info); 735 #endif 736 } 737 if (error == 0) 738 *retval = 0; 739 return (error); 740 } 741 742 void 743 proc_finish_wait(struct proc *waiter, struct process *pr) 744 { 745 struct process *tr; 746 struct rusage *rup; 747 748 /* 749 * If we got the child via a ptrace 'attach', 750 * we need to give it back to the old parent. 751 */ 752 if (pr->ps_oppid != 0 && (pr->ps_oppid != pr->ps_pptr->ps_pid) && 753 (tr = prfind(pr->ps_oppid))) { 754 pr->ps_oppid = 0; 755 atomic_clearbits_int(&pr->ps_flags, PS_TRACED); 756 process_reparent(pr, tr); 757 prsignal(tr, SIGCHLD); 758 wakeup(tr); 759 } else { 760 scheduler_wait_hook(waiter, pr->ps_mainproc); 761 rup = &waiter->p_p->ps_cru; 762 ruadd(rup, pr->ps_ru); 763 LIST_REMOVE(pr, ps_list); /* off zombprocess */ 764 freepid(pr->ps_pid); 765 process_zap(pr); 766 } 767 } 768 769 /* 770 * give process back to original parent or init(8) 771 */ 772 void 773 process_untrace(struct process *pr) 774 { 775 struct process *ppr = NULL; 776 777 KASSERT(pr->ps_flags & PS_TRACED); 778 779 if (pr->ps_oppid != 0 && 780 (pr->ps_oppid != pr->ps_pptr->ps_pid)) 781 ppr = prfind(pr->ps_oppid); 782 783 /* not being traced any more */ 784 pr->ps_oppid = 0; 785 atomic_clearbits_int(&pr->ps_flags, PS_TRACED); 786 process_reparent(pr, ppr ? ppr : initprocess); 787 } 788 789 void 790 process_clear_orphan(struct process *pr) 791 { 792 if (pr->ps_flags & PS_ORPHAN) { 793 LIST_REMOVE(pr, ps_orphan); 794 atomic_clearbits_int(&pr->ps_flags, PS_ORPHAN); 795 } 796 } 797 798 /* 799 * make process 'parent' the new parent of process 'child'. 800 */ 801 void 802 process_reparent(struct process *child, struct process *parent) 803 { 804 805 if (child->ps_pptr == parent) 806 return; 807 808 KASSERT(child->ps_oppid == 0 || 809 child->ps_oppid == child->ps_pptr->ps_pid); 810 811 LIST_REMOVE(child, ps_sibling); 812 LIST_INSERT_HEAD(&parent->ps_children, child, ps_sibling); 813 814 process_clear_orphan(child); 815 if (child->ps_flags & PS_TRACED) { 816 atomic_setbits_int(&child->ps_flags, PS_ORPHAN); 817 LIST_INSERT_HEAD(&child->ps_pptr->ps_orphans, child, ps_orphan); 818 } 819 820 child->ps_pptr = parent; 821 child->ps_ppid = parent->ps_pid; 822 } 823 824 void 825 process_zap(struct process *pr) 826 { 827 struct vnode *otvp; 828 struct proc *p = pr->ps_mainproc; 829 830 /* 831 * Finally finished with old proc entry. 832 * Unlink it from its process group and free it. 833 */ 834 leavepgrp(pr); 835 LIST_REMOVE(pr, ps_sibling); 836 process_clear_orphan(pr); 837 838 /* 839 * Decrement the count of procs running with this uid. 840 */ 841 (void)chgproccnt(pr->ps_ucred->cr_ruid, -1); 842 843 /* 844 * Release reference to text vnode 845 */ 846 otvp = pr->ps_textvp; 847 pr->ps_textvp = NULL; 848 if (otvp) 849 vrele(otvp); 850 851 KASSERT(pr->ps_threadcnt == 0); 852 KASSERT(pr->ps_exitcnt == 1); 853 if (pr->ps_ptstat != NULL) 854 free(pr->ps_ptstat, M_SUBPROC, sizeof(*pr->ps_ptstat)); 855 pool_put(&rusage_pool, pr->ps_ru); 856 KASSERT(TAILQ_EMPTY(&pr->ps_threads)); 857 sigactsfree(pr->ps_sigacts); 858 lim_free(pr->ps_limit); 859 crfree(pr->ps_ucred); 860 pool_put(&process_pool, pr); 861 nprocesses--; 862 863 proc_free(p); 864 } 865