1 /* 2 * (MPSAFE) 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)kern_proc.c 8.7 (Berkeley) 2/14/95 36 * $FreeBSD: src/sys/kern/kern_proc.c,v 1.63.2.9 2003/05/08 07:47:16 kbyanc Exp $ 37 * $DragonFly: src/sys/kern/kern_proc.c,v 1.45 2008/06/12 23:25:02 dillon Exp $ 38 */ 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/kernel.h> 43 #include <sys/sysctl.h> 44 #include <sys/malloc.h> 45 #include <sys/proc.h> 46 #include <sys/jail.h> 47 #include <sys/filedesc.h> 48 #include <sys/tty.h> 49 #include <sys/dsched.h> 50 #include <sys/signalvar.h> 51 #include <sys/spinlock.h> 52 #include <vm/vm.h> 53 #include <sys/lock.h> 54 #include <vm/pmap.h> 55 #include <vm/vm_map.h> 56 #include <sys/user.h> 57 #include <machine/smp.h> 58 59 #include <sys/refcount.h> 60 #include <sys/spinlock2.h> 61 #include <sys/mplock2.h> 62 63 static MALLOC_DEFINE(M_PGRP, "pgrp", "process group header"); 64 MALLOC_DEFINE(M_SESSION, "session", "session header"); 65 MALLOC_DEFINE(M_PROC, "proc", "Proc structures"); 66 MALLOC_DEFINE(M_LWP, "lwp", "lwp structures"); 67 MALLOC_DEFINE(M_SUBPROC, "subproc", "Proc sub-structures"); 68 69 int ps_showallprocs = 1; 70 static int ps_showallthreads = 1; 71 SYSCTL_INT(_security, OID_AUTO, ps_showallprocs, CTLFLAG_RW, 72 &ps_showallprocs, 0, 73 "Unprivileged processes can see proccesses with different UID/GID"); 74 SYSCTL_INT(_security, OID_AUTO, ps_showallthreads, CTLFLAG_RW, 75 &ps_showallthreads, 0, 76 "Unprivileged processes can see kernel threads"); 77 78 static void pgdelete(struct pgrp *); 79 static void orphanpg(struct pgrp *pg); 80 static pid_t proc_getnewpid_locked(int random_offset); 81 82 /* 83 * Other process lists 84 */ 85 struct pidhashhead *pidhashtbl; 86 u_long pidhash; 87 struct pgrphashhead *pgrphashtbl; 88 u_long pgrphash; 89 struct proclist allproc; 90 struct proclist zombproc; 91 92 /* 93 * Random component to nextpid generation. We mix in a random factor to make 94 * it a little harder to predict. We sanity check the modulus value to avoid 95 * doing it in critical paths. Don't let it be too small or we pointlessly 96 * waste randomness entropy, and don't let it be impossibly large. Using a 97 * modulus that is too big causes a LOT more process table scans and slows 98 * down fork processing as the pidchecked caching is defeated. 99 */ 100 static int randompid = 0; 101 102 /* 103 * No requirements. 104 */ 105 static int 106 sysctl_kern_randompid(SYSCTL_HANDLER_ARGS) 107 { 108 int error, pid; 109 110 pid = randompid; 111 error = sysctl_handle_int(oidp, &pid, 0, req); 112 if (error || !req->newptr) 113 return (error); 114 if (pid < 0 || pid > PID_MAX - 100) /* out of range */ 115 pid = PID_MAX - 100; 116 else if (pid < 2) /* NOP */ 117 pid = 0; 118 else if (pid < 100) /* Make it reasonable */ 119 pid = 100; 120 randompid = pid; 121 return (error); 122 } 123 124 SYSCTL_PROC(_kern, OID_AUTO, randompid, CTLTYPE_INT|CTLFLAG_RW, 125 0, 0, sysctl_kern_randompid, "I", "Random PID modulus"); 126 127 /* 128 * Initialize global process hashing structures. 129 * 130 * Called from the low level boot code only. 131 */ 132 void 133 procinit(void) 134 { 135 LIST_INIT(&allproc); 136 LIST_INIT(&zombproc); 137 lwkt_init(); 138 pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash); 139 pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash); 140 uihashinit(); 141 } 142 143 /* 144 * Process hold/release support functions. These functions must be MPSAFE. 145 * Called via the PHOLD(), PRELE(), and PSTALL() macros. 146 * 147 * p->p_lock is a simple hold count with a waiting interlock. No wakeup() 148 * is issued unless someone is actually waiting for the process. 149 * 150 * Most holds are short-term, allowing a process scan or other similar 151 * operation to access a proc structure without it getting ripped out from 152 * under us. procfs and process-list sysctl ops also use the hold function 153 * interlocked with various p_flags to keep the vmspace intact when reading 154 * or writing a user process's address space. 155 * 156 * There are two situations where a hold count can be longer. Exiting lwps 157 * hold the process until the lwp is reaped, and the parent will hold the 158 * child during vfork()/exec() sequences while the child is marked P_PPWAIT. 159 * 160 * The kernel waits for the hold count to drop to 0 (or 1 in some cases) at 161 * various critical points in the fork/exec and exit paths before proceeding. 162 */ 163 #define PLOCK_WAITING 0x40000000 164 #define PLOCK_MASK 0x3FFFFFFF 165 166 void 167 pstall(struct proc *p, const char *wmesg, int count) 168 { 169 int o; 170 int n; 171 172 for (;;) { 173 o = p->p_lock; 174 cpu_ccfence(); 175 if ((o & PLOCK_MASK) <= count) 176 break; 177 n = o | PLOCK_WAITING; 178 tsleep_interlock(&p->p_lock, 0); 179 if (atomic_cmpset_int(&p->p_lock, o, n)) { 180 tsleep(&p->p_lock, PINTERLOCKED, wmesg, 0); 181 } 182 } 183 } 184 185 void 186 phold(struct proc *p) 187 { 188 int o; 189 int n; 190 191 for (;;) { 192 o = p->p_lock; 193 cpu_ccfence(); 194 n = o + 1; 195 if (atomic_cmpset_int(&p->p_lock, o, n)) 196 break; 197 } 198 } 199 200 void 201 prele(struct proc *p) 202 { 203 int o; 204 int n; 205 206 /* 207 * Fast path 208 */ 209 if (atomic_cmpset_int(&p->p_lock, 1, 0)) 210 return; 211 212 /* 213 * Slow path 214 */ 215 for (;;) { 216 o = p->p_lock; 217 KKASSERT((o & PLOCK_MASK) > 0); 218 cpu_ccfence(); 219 n = (o - 1) & ~PLOCK_WAITING; 220 if (atomic_cmpset_int(&p->p_lock, o, n)) { 221 if (o & PLOCK_WAITING) 222 wakeup(&p->p_lock); 223 break; 224 } 225 } 226 } 227 228 /* 229 * Is p an inferior of the current process? 230 * 231 * No requirements. 232 * The caller must hold proc_token if the caller wishes a stable result. 233 */ 234 int 235 inferior(struct proc *p) 236 { 237 lwkt_gettoken(&proc_token); 238 while (p != curproc) { 239 if (p->p_pid == 0) { 240 lwkt_reltoken(&proc_token); 241 return (0); 242 } 243 p = p->p_pptr; 244 } 245 lwkt_reltoken(&proc_token); 246 return (1); 247 } 248 249 /* 250 * Locate a process by number. The returned process will be referenced and 251 * must be released with PRELE(). 252 * 253 * No requirements. 254 */ 255 struct proc * 256 pfind(pid_t pid) 257 { 258 struct proc *p; 259 260 lwkt_gettoken(&proc_token); 261 LIST_FOREACH(p, PIDHASH(pid), p_hash) { 262 if (p->p_pid == pid) { 263 PHOLD(p); 264 lwkt_reltoken(&proc_token); 265 return (p); 266 } 267 } 268 lwkt_reltoken(&proc_token); 269 return (NULL); 270 } 271 272 /* 273 * Locate a process by number. The returned process is NOT referenced. 274 * The caller should hold proc_token if the caller wishes a stable result. 275 * 276 * No requirements. 277 */ 278 struct proc * 279 pfindn(pid_t pid) 280 { 281 struct proc *p; 282 283 lwkt_gettoken(&proc_token); 284 LIST_FOREACH(p, PIDHASH(pid), p_hash) { 285 if (p->p_pid == pid) { 286 lwkt_reltoken(&proc_token); 287 return (p); 288 } 289 } 290 lwkt_reltoken(&proc_token); 291 return (NULL); 292 } 293 294 void 295 pgref(struct pgrp *pgrp) 296 { 297 refcount_acquire(&pgrp->pg_refs); 298 } 299 300 void 301 pgrel(struct pgrp *pgrp) 302 { 303 if (refcount_release(&pgrp->pg_refs)) 304 pgdelete(pgrp); 305 } 306 307 /* 308 * Locate a process group by number. The returned process group will be 309 * referenced w/pgref() and must be released with pgrel() (or assigned 310 * somewhere if you wish to keep the reference). 311 * 312 * No requirements. 313 */ 314 struct pgrp * 315 pgfind(pid_t pgid) 316 { 317 struct pgrp *pgrp; 318 319 lwkt_gettoken(&proc_token); 320 LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash) { 321 if (pgrp->pg_id == pgid) { 322 refcount_acquire(&pgrp->pg_refs); 323 lwkt_reltoken(&proc_token); 324 return (pgrp); 325 } 326 } 327 lwkt_reltoken(&proc_token); 328 return (NULL); 329 } 330 331 /* 332 * Move p to a new or existing process group (and session) 333 * 334 * No requirements. 335 */ 336 int 337 enterpgrp(struct proc *p, pid_t pgid, int mksess) 338 { 339 struct pgrp *pgrp; 340 struct pgrp *opgrp; 341 int error; 342 343 pgrp = pgfind(pgid); 344 345 KASSERT(pgrp == NULL || !mksess, 346 ("enterpgrp: setsid into non-empty pgrp")); 347 KASSERT(!SESS_LEADER(p), 348 ("enterpgrp: session leader attempted setpgrp")); 349 350 if (pgrp == NULL) { 351 pid_t savepid = p->p_pid; 352 struct proc *np; 353 /* 354 * new process group 355 */ 356 KASSERT(p->p_pid == pgid, 357 ("enterpgrp: new pgrp and pid != pgid")); 358 if ((np = pfindn(savepid)) == NULL || np != p) { 359 error = ESRCH; 360 goto fatal; 361 } 362 MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), 363 M_PGRP, M_WAITOK); 364 if (mksess) { 365 struct session *sess; 366 367 /* 368 * new session 369 */ 370 MALLOC(sess, struct session *, sizeof(struct session), 371 M_SESSION, M_WAITOK); 372 sess->s_leader = p; 373 sess->s_sid = p->p_pid; 374 sess->s_count = 1; 375 sess->s_ttyvp = NULL; 376 sess->s_ttyp = NULL; 377 bcopy(p->p_session->s_login, sess->s_login, 378 sizeof(sess->s_login)); 379 pgrp->pg_session = sess; 380 KASSERT(p == curproc, 381 ("enterpgrp: mksession and p != curproc")); 382 lwkt_gettoken(&p->p_token); 383 p->p_flags &= ~P_CONTROLT; 384 lwkt_reltoken(&p->p_token); 385 } else { 386 pgrp->pg_session = p->p_session; 387 sess_hold(pgrp->pg_session); 388 } 389 pgrp->pg_id = pgid; 390 LIST_INIT(&pgrp->pg_members); 391 LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash); 392 pgrp->pg_jobc = 0; 393 SLIST_INIT(&pgrp->pg_sigiolst); 394 lwkt_token_init(&pgrp->pg_token, "pgrp_token"); 395 refcount_init(&pgrp->pg_refs, 1); 396 lockinit(&pgrp->pg_lock, "pgwt", 0, 0); 397 } else if (pgrp == p->p_pgrp) { 398 pgrel(pgrp); 399 goto done; 400 } /* else pgfind() referenced the pgrp */ 401 402 /* 403 * Adjust eligibility of affected pgrps to participate in job control. 404 * Increment eligibility counts before decrementing, otherwise we 405 * could reach 0 spuriously during the first call. 406 */ 407 lwkt_gettoken(&pgrp->pg_token); 408 lwkt_gettoken(&p->p_token); 409 fixjobc(p, pgrp, 1); 410 fixjobc(p, p->p_pgrp, 0); 411 while ((opgrp = p->p_pgrp) != NULL) { 412 opgrp = p->p_pgrp; 413 lwkt_gettoken(&opgrp->pg_token); 414 LIST_REMOVE(p, p_pglist); 415 p->p_pgrp = NULL; 416 lwkt_reltoken(&opgrp->pg_token); 417 pgrel(opgrp); 418 } 419 p->p_pgrp = pgrp; 420 LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist); 421 lwkt_reltoken(&p->p_token); 422 lwkt_reltoken(&pgrp->pg_token); 423 done: 424 error = 0; 425 fatal: 426 return (error); 427 } 428 429 /* 430 * Remove process from process group 431 * 432 * No requirements. 433 */ 434 int 435 leavepgrp(struct proc *p) 436 { 437 struct pgrp *pg = p->p_pgrp; 438 439 lwkt_gettoken(&p->p_token); 440 pg = p->p_pgrp; 441 if (pg) { 442 pgref(pg); 443 lwkt_gettoken(&pg->pg_token); 444 if (p->p_pgrp == pg) { 445 p->p_pgrp = NULL; 446 LIST_REMOVE(p, p_pglist); 447 pgrel(pg); 448 } 449 lwkt_reltoken(&pg->pg_token); 450 lwkt_reltoken(&p->p_token); /* avoid chaining on rel */ 451 pgrel(pg); 452 } else { 453 lwkt_reltoken(&p->p_token); 454 } 455 return (0); 456 } 457 458 /* 459 * Delete a process group. Must be called only after the last ref has been 460 * released. 461 */ 462 static void 463 pgdelete(struct pgrp *pgrp) 464 { 465 /* 466 * Reset any sigio structures pointing to us as a result of 467 * F_SETOWN with our pgid. 468 */ 469 funsetownlst(&pgrp->pg_sigiolst); 470 471 if (pgrp->pg_session->s_ttyp != NULL && 472 pgrp->pg_session->s_ttyp->t_pgrp == pgrp) 473 pgrp->pg_session->s_ttyp->t_pgrp = NULL; 474 LIST_REMOVE(pgrp, pg_hash); 475 sess_rele(pgrp->pg_session); 476 kfree(pgrp, M_PGRP); 477 } 478 479 /* 480 * Adjust the ref count on a session structure. When the ref count falls to 481 * zero the tty is disassociated from the session and the session structure 482 * is freed. Note that tty assocation is not itself ref-counted. 483 * 484 * No requirements. 485 */ 486 void 487 sess_hold(struct session *sp) 488 { 489 lwkt_gettoken(&tty_token); 490 ++sp->s_count; 491 lwkt_reltoken(&tty_token); 492 } 493 494 /* 495 * No requirements. 496 */ 497 void 498 sess_rele(struct session *sp) 499 { 500 struct tty *tp; 501 502 KKASSERT(sp->s_count > 0); 503 lwkt_gettoken(&tty_token); 504 if (--sp->s_count == 0) { 505 if (sp->s_ttyp && sp->s_ttyp->t_session) { 506 #ifdef TTY_DO_FULL_CLOSE 507 /* FULL CLOSE, see ttyclearsession() */ 508 KKASSERT(sp->s_ttyp->t_session == sp); 509 sp->s_ttyp->t_session = NULL; 510 #else 511 /* HALF CLOSE, see ttyclearsession() */ 512 if (sp->s_ttyp->t_session == sp) 513 sp->s_ttyp->t_session = NULL; 514 #endif 515 } 516 if ((tp = sp->s_ttyp) != NULL) { 517 sp->s_ttyp = NULL; 518 ttyunhold(tp); 519 } 520 kfree(sp, M_SESSION); 521 } 522 lwkt_reltoken(&tty_token); 523 } 524 525 /* 526 * Adjust pgrp jobc counters when specified process changes process group. 527 * We count the number of processes in each process group that "qualify" 528 * the group for terminal job control (those with a parent in a different 529 * process group of the same session). If that count reaches zero, the 530 * process group becomes orphaned. Check both the specified process' 531 * process group and that of its children. 532 * entering == 0 => p is leaving specified group. 533 * entering == 1 => p is entering specified group. 534 * 535 * No requirements. 536 */ 537 void 538 fixjobc(struct proc *p, struct pgrp *pgrp, int entering) 539 { 540 struct pgrp *hispgrp; 541 struct session *mysession; 542 struct proc *np; 543 544 /* 545 * Check p's parent to see whether p qualifies its own process 546 * group; if so, adjust count for p's process group. 547 */ 548 lwkt_gettoken(&p->p_token); /* p_children scan */ 549 lwkt_gettoken(&pgrp->pg_token); 550 551 mysession = pgrp->pg_session; 552 if ((hispgrp = p->p_pptr->p_pgrp) != pgrp && 553 hispgrp->pg_session == mysession) { 554 if (entering) 555 pgrp->pg_jobc++; 556 else if (--pgrp->pg_jobc == 0) 557 orphanpg(pgrp); 558 } 559 560 /* 561 * Check this process' children to see whether they qualify 562 * their process groups; if so, adjust counts for children's 563 * process groups. 564 */ 565 LIST_FOREACH(np, &p->p_children, p_sibling) { 566 PHOLD(np); 567 lwkt_gettoken(&np->p_token); 568 if ((hispgrp = np->p_pgrp) != pgrp && 569 hispgrp->pg_session == mysession && 570 np->p_stat != SZOMB) { 571 pgref(hispgrp); 572 lwkt_gettoken(&hispgrp->pg_token); 573 if (entering) 574 hispgrp->pg_jobc++; 575 else if (--hispgrp->pg_jobc == 0) 576 orphanpg(hispgrp); 577 lwkt_reltoken(&hispgrp->pg_token); 578 pgrel(hispgrp); 579 } 580 lwkt_reltoken(&np->p_token); 581 PRELE(np); 582 } 583 KKASSERT(pgrp->pg_refs > 0); 584 lwkt_reltoken(&pgrp->pg_token); 585 lwkt_reltoken(&p->p_token); 586 } 587 588 /* 589 * A process group has become orphaned; 590 * if there are any stopped processes in the group, 591 * hang-up all process in that group. 592 * 593 * The caller must hold pg_token. 594 */ 595 static void 596 orphanpg(struct pgrp *pg) 597 { 598 struct proc *p; 599 600 LIST_FOREACH(p, &pg->pg_members, p_pglist) { 601 if (p->p_stat == SSTOP) { 602 LIST_FOREACH(p, &pg->pg_members, p_pglist) { 603 ksignal(p, SIGHUP); 604 ksignal(p, SIGCONT); 605 } 606 return; 607 } 608 } 609 } 610 611 /* 612 * Add a new process to the allproc list and the PID hash. This 613 * also assigns a pid to the new process. 614 * 615 * No requirements. 616 */ 617 void 618 proc_add_allproc(struct proc *p) 619 { 620 int random_offset; 621 622 if ((random_offset = randompid) != 0) { 623 get_mplock(); 624 random_offset = karc4random() % random_offset; 625 rel_mplock(); 626 } 627 628 lwkt_gettoken(&proc_token); 629 p->p_pid = proc_getnewpid_locked(random_offset); 630 LIST_INSERT_HEAD(&allproc, p, p_list); 631 LIST_INSERT_HEAD(PIDHASH(p->p_pid), p, p_hash); 632 lwkt_reltoken(&proc_token); 633 } 634 635 /* 636 * Calculate a new process pid. This function is integrated into 637 * proc_add_allproc() to guarentee that the new pid is not reused before 638 * the new process can be added to the allproc list. 639 * 640 * The caller must hold proc_token. 641 */ 642 static 643 pid_t 644 proc_getnewpid_locked(int random_offset) 645 { 646 static pid_t nextpid; 647 static pid_t pidchecked; 648 struct proc *p; 649 650 /* 651 * Find an unused process ID. We remember a range of unused IDs 652 * ready to use (from nextpid+1 through pidchecked-1). 653 */ 654 nextpid = nextpid + 1 + random_offset; 655 retry: 656 /* 657 * If the process ID prototype has wrapped around, 658 * restart somewhat above 0, as the low-numbered procs 659 * tend to include daemons that don't exit. 660 */ 661 if (nextpid >= PID_MAX) { 662 nextpid = nextpid % PID_MAX; 663 if (nextpid < 100) 664 nextpid += 100; 665 pidchecked = 0; 666 } 667 if (nextpid >= pidchecked) { 668 int doingzomb = 0; 669 670 pidchecked = PID_MAX; 671 672 /* 673 * Scan the active and zombie procs to check whether this pid 674 * is in use. Remember the lowest pid that's greater 675 * than nextpid, so we can avoid checking for a while. 676 * 677 * NOTE: Processes in the midst of being forked may not 678 * yet have p_pgrp and p_pgrp->pg_session set up 679 * yet, so we have to check for NULL. 680 * 681 * Processes being torn down should be interlocked 682 * with proc_token prior to the clearing of their 683 * p_pgrp. 684 */ 685 p = LIST_FIRST(&allproc); 686 again: 687 for (; p != NULL; p = LIST_NEXT(p, p_list)) { 688 while (p->p_pid == nextpid || 689 (p->p_pgrp && p->p_pgrp->pg_id == nextpid) || 690 (p->p_pgrp && p->p_session && 691 p->p_session->s_sid == nextpid)) { 692 nextpid++; 693 if (nextpid >= pidchecked) 694 goto retry; 695 } 696 if (p->p_pid > nextpid && pidchecked > p->p_pid) 697 pidchecked = p->p_pid; 698 if (p->p_pgrp && 699 p->p_pgrp->pg_id > nextpid && 700 pidchecked > p->p_pgrp->pg_id) { 701 pidchecked = p->p_pgrp->pg_id; 702 } 703 if (p->p_pgrp && p->p_session && 704 p->p_session->s_sid > nextpid && 705 pidchecked > p->p_session->s_sid) { 706 pidchecked = p->p_session->s_sid; 707 } 708 } 709 if (!doingzomb) { 710 doingzomb = 1; 711 p = LIST_FIRST(&zombproc); 712 goto again; 713 } 714 } 715 return(nextpid); 716 } 717 718 /* 719 * Called from exit1 to remove a process from the allproc 720 * list and move it to the zombie list. 721 * 722 * Caller must hold p->p_token. We are required to wait until p_lock 723 * becomes zero before we can manipulate the list, allowing allproc 724 * scans to guarantee consistency during a list scan. 725 */ 726 void 727 proc_move_allproc_zombie(struct proc *p) 728 { 729 lwkt_gettoken(&proc_token); 730 PSTALL(p, "reap1", 0); 731 LIST_REMOVE(p, p_list); 732 LIST_INSERT_HEAD(&zombproc, p, p_list); 733 LIST_REMOVE(p, p_hash); 734 p->p_stat = SZOMB; 735 lwkt_reltoken(&proc_token); 736 dsched_exit_proc(p); 737 } 738 739 /* 740 * This routine is called from kern_wait() and will remove the process 741 * from the zombie list and the sibling list. This routine will block 742 * if someone has a lock on the proces (p_lock). 743 * 744 * Caller must hold p->p_token. We are required to wait until p_lock 745 * becomes zero before we can manipulate the list, allowing allproc 746 * scans to guarantee consistency during a list scan. 747 */ 748 void 749 proc_remove_zombie(struct proc *p) 750 { 751 lwkt_gettoken(&proc_token); 752 PSTALL(p, "reap2", 0); 753 LIST_REMOVE(p, p_list); /* off zombproc */ 754 LIST_REMOVE(p, p_sibling); 755 lwkt_reltoken(&proc_token); 756 } 757 758 /* 759 * Scan all processes on the allproc list. The process is automatically 760 * held for the callback. A return value of -1 terminates the loop. 761 * 762 * The callback is made with the process held and proc_token held. 763 * 764 * We limit the scan to the number of processes as-of the start of 765 * the scan so as not to get caught up in an endless loop if new processes 766 * are created more quickly than we can scan the old ones. Add a little 767 * slop to try to catch edge cases since nprocs can race. 768 * 769 * No requirements. 770 */ 771 void 772 allproc_scan(int (*callback)(struct proc *, void *), void *data) 773 { 774 struct proc *p; 775 int r; 776 int limit = nprocs + ncpus; 777 778 /* 779 * proc_token protects the allproc list and PHOLD() prevents the 780 * process from being removed from the allproc list or the zombproc 781 * list. 782 */ 783 lwkt_gettoken(&proc_token); 784 LIST_FOREACH(p, &allproc, p_list) { 785 PHOLD(p); 786 r = callback(p, data); 787 PRELE(p); 788 if (r < 0) 789 break; 790 if (--limit < 0) 791 break; 792 } 793 lwkt_reltoken(&proc_token); 794 } 795 796 /* 797 * Scan all lwps of processes on the allproc list. The lwp is automatically 798 * held for the callback. A return value of -1 terminates the loop. 799 * 800 * The callback is made with the proces and lwp both held, and proc_token held. 801 * 802 * No requirements. 803 */ 804 void 805 alllwp_scan(int (*callback)(struct lwp *, void *), void *data) 806 { 807 struct proc *p; 808 struct lwp *lp; 809 int r = 0; 810 811 /* 812 * proc_token protects the allproc list and PHOLD() prevents the 813 * process from being removed from the allproc list or the zombproc 814 * list. 815 */ 816 lwkt_gettoken(&proc_token); 817 LIST_FOREACH(p, &allproc, p_list) { 818 PHOLD(p); 819 FOREACH_LWP_IN_PROC(lp, p) { 820 LWPHOLD(lp); 821 r = callback(lp, data); 822 LWPRELE(lp); 823 } 824 PRELE(p); 825 if (r < 0) 826 break; 827 } 828 lwkt_reltoken(&proc_token); 829 } 830 831 /* 832 * Scan all processes on the zombproc list. The process is automatically 833 * held for the callback. A return value of -1 terminates the loop. 834 * 835 * No requirements. 836 * The callback is made with the proces held and proc_token held. 837 */ 838 void 839 zombproc_scan(int (*callback)(struct proc *, void *), void *data) 840 { 841 struct proc *p; 842 int r; 843 844 lwkt_gettoken(&proc_token); 845 LIST_FOREACH(p, &zombproc, p_list) { 846 PHOLD(p); 847 r = callback(p, data); 848 PRELE(p); 849 if (r < 0) 850 break; 851 } 852 lwkt_reltoken(&proc_token); 853 } 854 855 #include "opt_ddb.h" 856 #ifdef DDB 857 #include <ddb/ddb.h> 858 859 /* 860 * Debugging only 861 */ 862 DB_SHOW_COMMAND(pgrpdump, pgrpdump) 863 { 864 struct pgrp *pgrp; 865 struct proc *p; 866 int i; 867 868 for (i = 0; i <= pgrphash; i++) { 869 if (!LIST_EMPTY(&pgrphashtbl[i])) { 870 kprintf("\tindx %d\n", i); 871 LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) { 872 kprintf( 873 "\tpgrp %p, pgid %ld, sess %p, sesscnt %d, mem %p\n", 874 (void *)pgrp, (long)pgrp->pg_id, 875 (void *)pgrp->pg_session, 876 pgrp->pg_session->s_count, 877 (void *)LIST_FIRST(&pgrp->pg_members)); 878 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 879 kprintf("\t\tpid %ld addr %p pgrp %p\n", 880 (long)p->p_pid, (void *)p, 881 (void *)p->p_pgrp); 882 } 883 } 884 } 885 } 886 } 887 #endif /* DDB */ 888 889 /* 890 * Locate a process on the zombie list. Return a process or NULL. 891 * The returned process will be referenced and the caller must release 892 * it with PRELE(). 893 * 894 * No other requirements. 895 */ 896 struct proc * 897 zpfind(pid_t pid) 898 { 899 struct proc *p; 900 901 lwkt_gettoken(&proc_token); 902 LIST_FOREACH(p, &zombproc, p_list) { 903 if (p->p_pid == pid) { 904 PHOLD(p); 905 lwkt_reltoken(&proc_token); 906 return (p); 907 } 908 } 909 lwkt_reltoken(&proc_token); 910 return (NULL); 911 } 912 913 /* 914 * The caller must hold proc_token. 915 */ 916 static int 917 sysctl_out_proc(struct proc *p, struct sysctl_req *req, int flags) 918 { 919 struct kinfo_proc ki; 920 struct lwp *lp; 921 int skp = 0, had_output = 0; 922 int error; 923 924 bzero(&ki, sizeof(ki)); 925 lwkt_gettoken(&p->p_token); 926 fill_kinfo_proc(p, &ki); 927 if ((flags & KERN_PROC_FLAG_LWP) == 0) 928 skp = 1; 929 error = 0; 930 FOREACH_LWP_IN_PROC(lp, p) { 931 LWPHOLD(lp); 932 fill_kinfo_lwp(lp, &ki.kp_lwp); 933 had_output = 1; 934 error = SYSCTL_OUT(req, &ki, sizeof(ki)); 935 LWPRELE(lp); 936 if (error) 937 break; 938 if (skp) 939 break; 940 } 941 lwkt_reltoken(&p->p_token); 942 /* We need to output at least the proc, even if there is no lwp. */ 943 if (had_output == 0) { 944 error = SYSCTL_OUT(req, &ki, sizeof(ki)); 945 } 946 return (error); 947 } 948 949 /* 950 * The caller must hold proc_token. 951 */ 952 static int 953 sysctl_out_proc_kthread(struct thread *td, struct sysctl_req *req, int flags) 954 { 955 struct kinfo_proc ki; 956 int error; 957 958 fill_kinfo_proc_kthread(td, &ki); 959 error = SYSCTL_OUT(req, &ki, sizeof(ki)); 960 if (error) 961 return error; 962 return(0); 963 } 964 965 /* 966 * No requirements. 967 */ 968 static int 969 sysctl_kern_proc(SYSCTL_HANDLER_ARGS) 970 { 971 int *name = (int*) arg1; 972 int oid = oidp->oid_number; 973 u_int namelen = arg2; 974 struct proc *p; 975 struct proclist *plist; 976 struct thread *td; 977 struct thread *marker; 978 int doingzomb, flags = 0; 979 int error = 0; 980 int n; 981 int origcpu; 982 struct ucred *cr1 = curproc->p_ucred; 983 984 flags = oid & KERN_PROC_FLAGMASK; 985 oid &= ~KERN_PROC_FLAGMASK; 986 987 if ((oid == KERN_PROC_ALL && namelen != 0) || 988 (oid != KERN_PROC_ALL && namelen != 1)) { 989 return (EINVAL); 990 } 991 992 /* 993 * proc_token protects the allproc list and PHOLD() prevents the 994 * process from being removed from the allproc list or the zombproc 995 * list. 996 */ 997 lwkt_gettoken(&proc_token); 998 if (oid == KERN_PROC_PID) { 999 p = pfindn((pid_t)name[0]); 1000 if (p == NULL) 1001 goto post_threads; 1002 if (!PRISON_CHECK(cr1, p->p_ucred)) 1003 goto post_threads; 1004 PHOLD(p); 1005 error = sysctl_out_proc(p, req, flags); 1006 PRELE(p); 1007 goto post_threads; 1008 } 1009 1010 if (!req->oldptr) { 1011 /* overestimate by 5 procs */ 1012 error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5); 1013 if (error) 1014 goto post_threads; 1015 } 1016 for (doingzomb = 0; doingzomb <= 1; doingzomb++) { 1017 if (doingzomb) 1018 plist = &zombproc; 1019 else 1020 plist = &allproc; 1021 LIST_FOREACH(p, plist, p_list) { 1022 /* 1023 * Show a user only their processes. 1024 */ 1025 if ((!ps_showallprocs) && p_trespass(cr1, p->p_ucred)) 1026 continue; 1027 /* 1028 * Skip embryonic processes. 1029 */ 1030 if (p->p_stat == SIDL) 1031 continue; 1032 /* 1033 * TODO - make more efficient (see notes below). 1034 * do by session. 1035 */ 1036 switch (oid) { 1037 case KERN_PROC_PGRP: 1038 /* could do this by traversing pgrp */ 1039 if (p->p_pgrp == NULL || 1040 p->p_pgrp->pg_id != (pid_t)name[0]) 1041 continue; 1042 break; 1043 1044 case KERN_PROC_TTY: 1045 if ((p->p_flags & P_CONTROLT) == 0 || 1046 p->p_session == NULL || 1047 p->p_session->s_ttyp == NULL || 1048 dev2udev(p->p_session->s_ttyp->t_dev) != 1049 (udev_t)name[0]) 1050 continue; 1051 break; 1052 1053 case KERN_PROC_UID: 1054 if (p->p_ucred == NULL || 1055 p->p_ucred->cr_uid != (uid_t)name[0]) 1056 continue; 1057 break; 1058 1059 case KERN_PROC_RUID: 1060 if (p->p_ucred == NULL || 1061 p->p_ucred->cr_ruid != (uid_t)name[0]) 1062 continue; 1063 break; 1064 } 1065 1066 if (!PRISON_CHECK(cr1, p->p_ucred)) 1067 continue; 1068 PHOLD(p); 1069 error = sysctl_out_proc(p, req, flags); 1070 PRELE(p); 1071 if (error) 1072 goto post_threads; 1073 } 1074 } 1075 1076 /* 1077 * Iterate over all active cpus and scan their thread list. Start 1078 * with the next logical cpu and end with our original cpu. We 1079 * migrate our own thread to each target cpu in order to safely scan 1080 * its thread list. In the last loop we migrate back to our original 1081 * cpu. 1082 */ 1083 origcpu = mycpu->gd_cpuid; 1084 if (!ps_showallthreads || jailed(cr1)) 1085 goto post_threads; 1086 1087 marker = kmalloc(sizeof(struct thread), M_TEMP, M_WAITOK|M_ZERO); 1088 marker->td_flags = TDF_MARKER; 1089 error = 0; 1090 1091 for (n = 1; n <= ncpus; ++n) { 1092 globaldata_t rgd; 1093 int nid; 1094 1095 nid = (origcpu + n) % ncpus; 1096 if ((smp_active_mask & CPUMASK(nid)) == 0) 1097 continue; 1098 rgd = globaldata_find(nid); 1099 lwkt_setcpu_self(rgd); 1100 1101 crit_enter(); 1102 TAILQ_INSERT_TAIL(&rgd->gd_tdallq, marker, td_allq); 1103 1104 while ((td = TAILQ_PREV(marker, lwkt_queue, td_allq)) != NULL) { 1105 TAILQ_REMOVE(&rgd->gd_tdallq, marker, td_allq); 1106 TAILQ_INSERT_BEFORE(td, marker, td_allq); 1107 if (td->td_flags & TDF_MARKER) 1108 continue; 1109 if (td->td_proc) 1110 continue; 1111 1112 lwkt_hold(td); 1113 crit_exit(); 1114 1115 switch (oid) { 1116 case KERN_PROC_PGRP: 1117 case KERN_PROC_TTY: 1118 case KERN_PROC_UID: 1119 case KERN_PROC_RUID: 1120 break; 1121 default: 1122 error = sysctl_out_proc_kthread(td, req, 1123 doingzomb); 1124 break; 1125 } 1126 lwkt_rele(td); 1127 crit_enter(); 1128 if (error) 1129 break; 1130 } 1131 TAILQ_REMOVE(&rgd->gd_tdallq, marker, td_allq); 1132 crit_exit(); 1133 1134 if (error) 1135 break; 1136 } 1137 kfree(marker, M_TEMP); 1138 1139 post_threads: 1140 lwkt_reltoken(&proc_token); 1141 return (error); 1142 } 1143 1144 /* 1145 * This sysctl allows a process to retrieve the argument list or process 1146 * title for another process without groping around in the address space 1147 * of the other process. It also allow a process to set its own "process 1148 * title to a string of its own choice. 1149 * 1150 * No requirements. 1151 */ 1152 static int 1153 sysctl_kern_proc_args(SYSCTL_HANDLER_ARGS) 1154 { 1155 int *name = (int*) arg1; 1156 u_int namelen = arg2; 1157 struct proc *p; 1158 struct pargs *opa; 1159 struct pargs *pa; 1160 int error = 0; 1161 struct ucred *cr1 = curproc->p_ucred; 1162 1163 if (namelen != 1) 1164 return (EINVAL); 1165 1166 p = pfind((pid_t)name[0]); 1167 if (p == NULL) 1168 goto done; 1169 lwkt_gettoken(&p->p_token); 1170 1171 if ((!ps_argsopen) && p_trespass(cr1, p->p_ucred)) 1172 goto done; 1173 1174 if (req->newptr && curproc != p) { 1175 error = EPERM; 1176 goto done; 1177 } 1178 if (req->oldptr && (pa = p->p_args) != NULL) { 1179 refcount_acquire(&pa->ar_ref); 1180 error = SYSCTL_OUT(req, pa->ar_args, pa->ar_length); 1181 if (refcount_release(&pa->ar_ref)) 1182 kfree(pa, M_PARGS); 1183 } 1184 if (req->newptr == NULL) 1185 goto done; 1186 1187 if (req->newlen + sizeof(struct pargs) > ps_arg_cache_limit) { 1188 goto done; 1189 } 1190 1191 pa = kmalloc(sizeof(struct pargs) + req->newlen, M_PARGS, M_WAITOK); 1192 refcount_init(&pa->ar_ref, 1); 1193 pa->ar_length = req->newlen; 1194 error = SYSCTL_IN(req, pa->ar_args, req->newlen); 1195 if (error) { 1196 kfree(pa, M_PARGS); 1197 goto done; 1198 } 1199 1200 1201 /* 1202 * Replace p_args with the new pa. p_args may have previously 1203 * been NULL. 1204 */ 1205 opa = p->p_args; 1206 p->p_args = pa; 1207 1208 if (opa) { 1209 KKASSERT(opa->ar_ref > 0); 1210 if (refcount_release(&opa->ar_ref)) { 1211 kfree(opa, M_PARGS); 1212 /* opa = NULL; */ 1213 } 1214 } 1215 done: 1216 if (p) { 1217 lwkt_reltoken(&p->p_token); 1218 PRELE(p); 1219 } 1220 return (error); 1221 } 1222 1223 static int 1224 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 1225 { 1226 int *name = (int*) arg1; 1227 u_int namelen = arg2; 1228 struct proc *p; 1229 int error = 0; 1230 char *fullpath, *freepath; 1231 struct ucred *cr1 = curproc->p_ucred; 1232 1233 if (namelen != 1) 1234 return (EINVAL); 1235 1236 p = pfind((pid_t)name[0]); 1237 if (p == NULL) 1238 goto done; 1239 lwkt_gettoken(&p->p_token); 1240 1241 /* 1242 * If we are not allowed to see other args, we certainly shouldn't 1243 * get the cwd either. Also check the usual trespassing. 1244 */ 1245 if ((!ps_argsopen) && p_trespass(cr1, p->p_ucred)) 1246 goto done; 1247 1248 if (req->oldptr && p->p_fd != NULL && p->p_fd->fd_ncdir.ncp) { 1249 struct nchandle nch; 1250 1251 cache_copy(&p->p_fd->fd_ncdir, &nch); 1252 error = cache_fullpath(p, &nch, &fullpath, &freepath, 0); 1253 cache_drop(&nch); 1254 if (error) 1255 goto done; 1256 error = SYSCTL_OUT(req, fullpath, strlen(fullpath) + 1); 1257 kfree(freepath, M_TEMP); 1258 } 1259 1260 done: 1261 if (p) { 1262 lwkt_reltoken(&p->p_token); 1263 PRELE(p); 1264 } 1265 return (error); 1266 } 1267 1268 SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD, 0, "Process table"); 1269 1270 SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT, 1271 0, 0, sysctl_kern_proc, "S,proc", "Return entire process table"); 1272 1273 SYSCTL_NODE(_kern_proc, KERN_PROC_PGRP, pgrp, CTLFLAG_RD, 1274 sysctl_kern_proc, "Process table"); 1275 1276 SYSCTL_NODE(_kern_proc, KERN_PROC_TTY, tty, CTLFLAG_RD, 1277 sysctl_kern_proc, "Process table"); 1278 1279 SYSCTL_NODE(_kern_proc, KERN_PROC_UID, uid, CTLFLAG_RD, 1280 sysctl_kern_proc, "Process table"); 1281 1282 SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD, 1283 sysctl_kern_proc, "Process table"); 1284 1285 SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD, 1286 sysctl_kern_proc, "Process table"); 1287 1288 SYSCTL_NODE(_kern_proc, (KERN_PROC_ALL | KERN_PROC_FLAG_LWP), all_lwp, CTLFLAG_RD, 1289 sysctl_kern_proc, "Process table"); 1290 1291 SYSCTL_NODE(_kern_proc, (KERN_PROC_PGRP | KERN_PROC_FLAG_LWP), pgrp_lwp, CTLFLAG_RD, 1292 sysctl_kern_proc, "Process table"); 1293 1294 SYSCTL_NODE(_kern_proc, (KERN_PROC_TTY | KERN_PROC_FLAG_LWP), tty_lwp, CTLFLAG_RD, 1295 sysctl_kern_proc, "Process table"); 1296 1297 SYSCTL_NODE(_kern_proc, (KERN_PROC_UID | KERN_PROC_FLAG_LWP), uid_lwp, CTLFLAG_RD, 1298 sysctl_kern_proc, "Process table"); 1299 1300 SYSCTL_NODE(_kern_proc, (KERN_PROC_RUID | KERN_PROC_FLAG_LWP), ruid_lwp, CTLFLAG_RD, 1301 sysctl_kern_proc, "Process table"); 1302 1303 SYSCTL_NODE(_kern_proc, (KERN_PROC_PID | KERN_PROC_FLAG_LWP), pid_lwp, CTLFLAG_RD, 1304 sysctl_kern_proc, "Process table"); 1305 1306 SYSCTL_NODE(_kern_proc, KERN_PROC_ARGS, args, CTLFLAG_RW | CTLFLAG_ANYBODY, 1307 sysctl_kern_proc_args, "Process argument list"); 1308 1309 SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD | CTLFLAG_ANYBODY, 1310 sysctl_kern_proc_cwd, "Process argument list"); 1311