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33 * @(#)kern_proc.c 8.7 (Berkeley) 2/14/95
34 * $FreeBSD: src/sys/kern/kern_proc.c,v 1.63.2.9 2003/05/08 07:47:16 kbyanc Exp $
35 * $DragonFly: src/sys/kern/kern_proc.c,v 1.41 2008/01/04 12:16:19 matthias Exp $
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/sysctl.h>
42 #include <sys/malloc.h>
45 #include <sys/filedesc.h>
47 #include <sys/signalvar.h>
48 #include <sys/spinlock.h>
52 #include <vm/vm_map.h>
54 #include <vm/vm_zone.h>
55 #include <machine/smp.h>
57 #include <sys/spinlock2.h>
59 static MALLOC_DEFINE(M_PGRP, "pgrp", "process group header");
60 MALLOC_DEFINE(M_SESSION, "session", "session header");
61 static MALLOC_DEFINE(M_PROC, "proc", "Proc structures");
62 MALLOC_DEFINE(M_SUBPROC, "subproc", "Proc sub-structures");
64 int ps_showallprocs = 1;
65 static int ps_showallthreads = 1;
66 SYSCTL_INT(_security, OID_AUTO, ps_showallprocs, CTLFLAG_RW,
68 "Unprivileged processes can see proccesses with different UID/GID");
69 SYSCTL_INT(_security, OID_AUTO, ps_showallthreads, CTLFLAG_RW,
70 &ps_showallthreads, 0,
71 "Unprivileged processes can see kernel threads");
73 static void pgdelete(struct pgrp *);
74 static void orphanpg(struct pgrp *pg);
75 static pid_t proc_getnewpid_locked(int random_offset);
80 struct pidhashhead *pidhashtbl;
82 struct pgrphashhead *pgrphashtbl;
84 struct proclist allproc;
85 struct proclist zombproc;
86 struct spinlock allproc_spin;
89 vm_zone_t thread_zone;
92 * Random component to nextpid generation. We mix in a random factor to make
93 * it a little harder to predict. We sanity check the modulus value to avoid
94 * doing it in critical paths. Don't let it be too small or we pointlessly
95 * waste randomness entropy, and don't let it be impossibly large. Using a
96 * modulus that is too big causes a LOT more process table scans and slows
97 * down fork processing as the pidchecked caching is defeated.
99 static int randompid = 0;
102 sysctl_kern_randompid(SYSCTL_HANDLER_ARGS)
107 error = sysctl_handle_int(oidp, &pid, 0, req);
108 if (error || !req->newptr)
110 if (pid < 0 || pid > PID_MAX - 100) /* out of range */
112 else if (pid < 2) /* NOP */
114 else if (pid < 100) /* Make it reasonable */
120 SYSCTL_PROC(_kern, OID_AUTO, randompid, CTLTYPE_INT|CTLFLAG_RW,
121 0, 0, sysctl_kern_randompid, "I", "Random PID modulus");
124 * Initialize global process hashing structures.
130 LIST_INIT(&zombproc);
131 spin_init(&allproc_spin);
132 pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
133 pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
134 proc_zone = zinit("PROC", sizeof (struct proc), 0, 0, 5);
135 lwp_zone = zinit("LWP", sizeof (struct lwp), 0, 0, 5);
136 thread_zone = zinit("THREAD", sizeof (struct thread), 0, 0, 5);
141 * Is p an inferior of the current process?
144 inferior(struct proc *p)
146 for (; p != curproc; p = p->p_pptr)
153 * Locate a process by number
160 LIST_FOREACH(p, PIDHASH(pid), p_hash) {
168 * Locate a process group by number
175 LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash) {
176 if (pgrp->pg_id == pgid)
183 * Move p to a new or existing process group (and session)
186 enterpgrp(struct proc *p, pid_t pgid, int mksess)
188 struct pgrp *pgrp = pgfind(pgid);
190 KASSERT(pgrp == NULL || !mksess,
191 ("enterpgrp: setsid into non-empty pgrp"));
192 KASSERT(!SESS_LEADER(p),
193 ("enterpgrp: session leader attempted setpgrp"));
196 pid_t savepid = p->p_pid;
201 KASSERT(p->p_pid == pgid,
202 ("enterpgrp: new pgrp and pid != pgid"));
203 if ((np = pfind(savepid)) == NULL || np != p)
205 MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
208 struct session *sess;
213 MALLOC(sess, struct session *, sizeof(struct session),
214 M_SESSION, M_WAITOK);
216 sess->s_sid = p->p_pid;
218 sess->s_ttyvp = NULL;
220 bcopy(p->p_session->s_login, sess->s_login,
221 sizeof(sess->s_login));
222 p->p_flag &= ~P_CONTROLT;
223 pgrp->pg_session = sess;
224 KASSERT(p == curproc,
225 ("enterpgrp: mksession and p != curproc"));
227 pgrp->pg_session = p->p_session;
228 sess_hold(pgrp->pg_session);
231 LIST_INIT(&pgrp->pg_members);
232 LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
234 SLIST_INIT(&pgrp->pg_sigiolst);
235 lockinit(&pgrp->pg_lock, "pgwt", 0, 0);
236 } else if (pgrp == p->p_pgrp)
240 * Adjust eligibility of affected pgrps to participate in job control.
241 * Increment eligibility counts before decrementing, otherwise we
242 * could reach 0 spuriously during the first call.
245 fixjobc(p, p->p_pgrp, 0);
247 LIST_REMOVE(p, p_pglist);
248 if (LIST_EMPTY(&p->p_pgrp->pg_members))
251 LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist);
256 * remove process from process group
259 leavepgrp(struct proc *p)
262 LIST_REMOVE(p, p_pglist);
263 if (LIST_EMPTY(&p->p_pgrp->pg_members))
270 * delete a process group
273 pgdelete(struct pgrp *pgrp)
277 * Reset any sigio structures pointing to us as a result of
278 * F_SETOWN with our pgid.
280 funsetownlst(&pgrp->pg_sigiolst);
282 if (pgrp->pg_session->s_ttyp != NULL &&
283 pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
284 pgrp->pg_session->s_ttyp->t_pgrp = NULL;
285 LIST_REMOVE(pgrp, pg_hash);
286 sess_rele(pgrp->pg_session);
291 * Adjust the ref count on a session structure. When the ref count falls to
292 * zero the tty is disassociated from the session and the session structure
293 * is freed. Note that tty assocation is not itself ref-counted.
296 sess_hold(struct session *sp)
302 sess_rele(struct session *sp)
304 KKASSERT(sp->s_count > 0);
305 if (--sp->s_count == 0) {
306 if (sp->s_ttyp && sp->s_ttyp->t_session) {
307 #ifdef TTY_DO_FULL_CLOSE
308 /* FULL CLOSE, see ttyclearsession() */
309 KKASSERT(sp->s_ttyp->t_session == sp);
310 sp->s_ttyp->t_session = NULL;
312 /* HALF CLOSE, see ttyclearsession() */
313 if (sp->s_ttyp->t_session == sp)
314 sp->s_ttyp->t_session = NULL;
317 kfree(sp, M_SESSION);
322 * Adjust pgrp jobc counters when specified process changes process group.
323 * We count the number of processes in each process group that "qualify"
324 * the group for terminal job control (those with a parent in a different
325 * process group of the same session). If that count reaches zero, the
326 * process group becomes orphaned. Check both the specified process'
327 * process group and that of its children.
328 * entering == 0 => p is leaving specified group.
329 * entering == 1 => p is entering specified group.
332 fixjobc(struct proc *p, struct pgrp *pgrp, int entering)
334 struct pgrp *hispgrp;
335 struct session *mysession = pgrp->pg_session;
338 * Check p's parent to see whether p qualifies its own process
339 * group; if so, adjust count for p's process group.
341 if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
342 hispgrp->pg_session == mysession) {
345 else if (--pgrp->pg_jobc == 0)
350 * Check this process' children to see whether they qualify
351 * their process groups; if so, adjust counts for children's
354 LIST_FOREACH(p, &p->p_children, p_sibling)
355 if ((hispgrp = p->p_pgrp) != pgrp &&
356 hispgrp->pg_session == mysession &&
357 p->p_stat != SZOMB) {
360 else if (--hispgrp->pg_jobc == 0)
366 * A process group has become orphaned;
367 * if there are any stopped processes in the group,
368 * hang-up all process in that group.
371 orphanpg(struct pgrp *pg)
375 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
376 if (p->p_stat == SSTOP) {
377 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
387 * Add a new process to the allproc list and the PID hash. This
388 * also assigns a pid to the new process.
390 * MPALMOSTSAFE - acquires mplock for karc4random() call
393 proc_add_allproc(struct proc *p)
397 if ((random_offset = randompid) != 0) {
399 random_offset = karc4random() % random_offset;
403 spin_lock_wr(&allproc_spin);
404 p->p_pid = proc_getnewpid_locked(random_offset);
405 LIST_INSERT_HEAD(&allproc, p, p_list);
406 LIST_INSERT_HEAD(PIDHASH(p->p_pid), p, p_hash);
407 spin_unlock_wr(&allproc_spin);
411 * Calculate a new process pid. This function is integrated into
412 * proc_add_allproc() to guarentee that the new pid is not reused before
413 * the new process can be added to the allproc list.
415 * MPSAFE - must be called with allproc_spin held.
419 proc_getnewpid_locked(int random_offset)
421 static pid_t nextpid;
422 static pid_t pidchecked;
426 * Find an unused process ID. We remember a range of unused IDs
427 * ready to use (from nextpid+1 through pidchecked-1).
429 nextpid = nextpid + 1 + random_offset;
432 * If the process ID prototype has wrapped around,
433 * restart somewhat above 0, as the low-numbered procs
434 * tend to include daemons that don't exit.
436 if (nextpid >= PID_MAX) {
437 nextpid = nextpid % PID_MAX;
442 if (nextpid >= pidchecked) {
445 pidchecked = PID_MAX;
447 * Scan the active and zombie procs to check whether this pid
448 * is in use. Remember the lowest pid that's greater
449 * than nextpid, so we can avoid checking for a while.
451 p = LIST_FIRST(&allproc);
453 for (; p != 0; p = LIST_NEXT(p, p_list)) {
454 while (p->p_pid == nextpid ||
455 p->p_pgrp->pg_id == nextpid ||
456 p->p_session->s_sid == nextpid) {
458 if (nextpid >= pidchecked)
461 if (p->p_pid > nextpid && pidchecked > p->p_pid)
462 pidchecked = p->p_pid;
463 if (p->p_pgrp->pg_id > nextpid &&
464 pidchecked > p->p_pgrp->pg_id)
465 pidchecked = p->p_pgrp->pg_id;
466 if (p->p_session->s_sid > nextpid &&
467 pidchecked > p->p_session->s_sid)
468 pidchecked = p->p_session->s_sid;
472 p = LIST_FIRST(&zombproc);
480 * Called from exit1 to remove a process from the allproc
481 * list and move it to the zombie list.
486 proc_move_allproc_zombie(struct proc *p)
488 spin_lock_wr(&allproc_spin);
490 spin_unlock_wr(&allproc_spin);
491 tsleep(p, 0, "reap1", hz / 10);
492 spin_lock_wr(&allproc_spin);
494 LIST_REMOVE(p, p_list);
495 LIST_INSERT_HEAD(&zombproc, p, p_list);
496 LIST_REMOVE(p, p_hash);
498 spin_unlock_wr(&allproc_spin);
502 * This routine is called from kern_wait() and will remove the process
503 * from the zombie list and the sibling list. This routine will block
504 * if someone has a lock on the proces (p_lock).
509 proc_remove_zombie(struct proc *p)
511 spin_lock_wr(&allproc_spin);
513 spin_unlock_wr(&allproc_spin);
514 tsleep(p, 0, "reap1", hz / 10);
515 spin_lock_wr(&allproc_spin);
517 LIST_REMOVE(p, p_list); /* off zombproc */
518 LIST_REMOVE(p, p_sibling);
519 spin_unlock_wr(&allproc_spin);
523 * Scan all processes on the allproc list. The process is automatically
524 * held for the callback. A return value of -1 terminates the loop.
529 allproc_scan(int (*callback)(struct proc *, void *), void *data)
534 spin_lock_rd(&allproc_spin);
535 LIST_FOREACH(p, &allproc, p_list) {
537 spin_unlock_rd(&allproc_spin);
538 r = callback(p, data);
539 spin_lock_rd(&allproc_spin);
544 spin_unlock_rd(&allproc_spin);
548 * Scan all lwps of processes on the allproc list. The lwp is automatically
549 * held for the callback. A return value of -1 terminates the loop.
551 * possibly not MPSAFE, needs to access foreingn proc structures
554 alllwp_scan(int (*callback)(struct lwp *, void *), void *data)
560 spin_lock_rd(&allproc_spin);
561 LIST_FOREACH(p, &allproc, p_list) {
563 spin_unlock_rd(&allproc_spin);
564 FOREACH_LWP_IN_PROC(lp, p) {
566 r = callback(lp, data);
569 spin_lock_rd(&allproc_spin);
574 spin_unlock_rd(&allproc_spin);
578 * Scan all processes on the zombproc list. The process is automatically
579 * held for the callback. A return value of -1 terminates the loop.
584 zombproc_scan(int (*callback)(struct proc *, void *), void *data)
589 spin_lock_rd(&allproc_spin);
590 LIST_FOREACH(p, &zombproc, p_list) {
592 spin_unlock_rd(&allproc_spin);
593 r = callback(p, data);
594 spin_lock_rd(&allproc_spin);
599 spin_unlock_rd(&allproc_spin);
606 DB_SHOW_COMMAND(pgrpdump, pgrpdump)
612 for (i = 0; i <= pgrphash; i++) {
613 if (!LIST_EMPTY(&pgrphashtbl[i])) {
614 kprintf("\tindx %d\n", i);
615 LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
617 "\tpgrp %p, pgid %ld, sess %p, sesscnt %d, mem %p\n",
618 (void *)pgrp, (long)pgrp->pg_id,
619 (void *)pgrp->pg_session,
620 pgrp->pg_session->s_count,
621 (void *)LIST_FIRST(&pgrp->pg_members));
622 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
623 kprintf("\t\tpid %ld addr %p pgrp %p\n",
624 (long)p->p_pid, (void *)p,
634 * Locate a process on the zombie list. Return a held process or NULL.
641 LIST_FOREACH(p, &zombproc, p_list)
648 sysctl_out_proc(struct proc *p, struct sysctl_req *req, int flags)
650 struct kinfo_proc ki;
652 int skp = 0, had_output = 0;
655 fill_kinfo_proc(p, &ki);
656 if ((flags & KERN_PROC_FLAG_LWP) == 0)
658 FOREACH_LWP_IN_PROC(lp, p) {
659 fill_kinfo_lwp(lp, &ki.kp_lwp);
662 error = SYSCTL_OUT(req, &ki, sizeof(ki));
668 /* We need to output at least the proc, even if there is no lwp. */
672 if (!doingzomb && pid && (pfind(pid) != p))
674 if (doingzomb && zpfind(pid) != p)
681 sysctl_out_proc_kthread(struct thread *td, struct sysctl_req *req, int flags)
683 struct kinfo_proc ki;
686 fill_kinfo_proc_kthread(td, &ki);
687 error = SYSCTL_OUT(req, &ki, sizeof(ki));
694 sysctl_kern_proc(SYSCTL_HANDLER_ARGS)
696 int *name = (int*) arg1;
697 int oid = oidp->oid_number;
698 u_int namelen = arg2;
700 struct proclist *plist;
702 int doingzomb, flags = 0;
706 struct ucred *cr1 = curproc->p_ucred;
708 flags = oid & KERN_PROC_FLAGMASK;
709 oid &= ~KERN_PROC_FLAGMASK;
711 if ((oid == KERN_PROC_ALL && namelen != 0) ||
712 (oid != KERN_PROC_ALL && namelen != 1))
715 if (oid == KERN_PROC_PID) {
716 p = pfind((pid_t)name[0]);
719 if (!PRISON_CHECK(cr1, p->p_ucred))
722 error = sysctl_out_proc(p, req, flags);
728 /* overestimate by 5 procs */
729 error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5);
733 for (doingzomb = 0; doingzomb <= 1; doingzomb++) {
738 LIST_FOREACH_MUTABLE(p, plist, p_list, np) {
740 * Show a user only their processes.
742 if ((!ps_showallprocs) && p_trespass(cr1, p->p_ucred))
745 * Skip embryonic processes.
747 if (p->p_stat == SIDL)
750 * TODO - make more efficient (see notes below).
755 /* could do this by traversing pgrp */
756 if (p->p_pgrp == NULL ||
757 p->p_pgrp->pg_id != (pid_t)name[0])
762 if ((p->p_flag & P_CONTROLT) == 0 ||
763 p->p_session == NULL ||
764 p->p_session->s_ttyp == NULL ||
765 dev2udev(p->p_session->s_ttyp->t_dev) !=
771 if (p->p_ucred == NULL ||
772 p->p_ucred->cr_uid != (uid_t)name[0])
777 if (p->p_ucred == NULL ||
778 p->p_ucred->cr_ruid != (uid_t)name[0])
783 if (!PRISON_CHECK(cr1, p->p_ucred))
786 error = sysctl_out_proc(p, req, flags);
794 * Iterate over all active cpus and scan their thread list. Start
795 * with the next logical cpu and end with our original cpu. We
796 * migrate our own thread to each target cpu in order to safely scan
797 * its thread list. In the last loop we migrate back to our original
800 origcpu = mycpu->gd_cpuid;
801 if (!ps_showallthreads || jailed(cr1))
803 for (n = 1; n <= ncpus; ++n) {
807 nid = (origcpu + n) % ncpus;
808 if ((smp_active_mask & (1 << nid)) == 0)
810 rgd = globaldata_find(nid);
811 lwkt_setcpu_self(rgd);
813 TAILQ_FOREACH(td, &mycpu->gd_tdallq, td_allq) {
826 error = sysctl_out_proc_kthread(td, req, doingzomb);
837 * This sysctl allows a process to retrieve the argument list or process
838 * title for another process without groping around in the address space
839 * of the other process. It also allow a process to set its own "process
840 * title to a string of its own choice.
843 sysctl_kern_proc_args(SYSCTL_HANDLER_ARGS)
845 int *name = (int*) arg1;
846 u_int namelen = arg2;
850 struct ucred *cr1 = curproc->p_ucred;
855 p = pfind((pid_t)name[0]);
859 if ((!ps_argsopen) && p_trespass(cr1, p->p_ucred))
862 if (req->newptr && curproc != p)
865 if (req->oldptr && p->p_args != NULL)
866 error = SYSCTL_OUT(req, p->p_args->ar_args, p->p_args->ar_length);
867 if (req->newptr == NULL)
870 if (p->p_args && --p->p_args->ar_ref == 0)
871 FREE(p->p_args, M_PARGS);
874 if (req->newlen + sizeof(struct pargs) > ps_arg_cache_limit)
877 MALLOC(pa, struct pargs *, sizeof(struct pargs) + req->newlen,
880 pa->ar_length = req->newlen;
881 error = SYSCTL_IN(req, pa->ar_args, req->newlen);
889 SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD, 0, "Process table");
891 SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT,
892 0, 0, sysctl_kern_proc, "S,proc", "Return entire process table");
894 SYSCTL_NODE(_kern_proc, KERN_PROC_PGRP, pgrp, CTLFLAG_RD,
895 sysctl_kern_proc, "Process table");
897 SYSCTL_NODE(_kern_proc, KERN_PROC_TTY, tty, CTLFLAG_RD,
898 sysctl_kern_proc, "Process table");
900 SYSCTL_NODE(_kern_proc, KERN_PROC_UID, uid, CTLFLAG_RD,
901 sysctl_kern_proc, "Process table");
903 SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD,
904 sysctl_kern_proc, "Process table");
906 SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD,
907 sysctl_kern_proc, "Process table");
909 SYSCTL_NODE(_kern_proc, (KERN_PROC_ALL | KERN_PROC_FLAG_LWP), all_lwp, CTLFLAG_RD,
910 sysctl_kern_proc, "Process table");
912 SYSCTL_NODE(_kern_proc, (KERN_PROC_PGRP | KERN_PROC_FLAG_LWP), pgrp_lwp, CTLFLAG_RD,
913 sysctl_kern_proc, "Process table");
915 SYSCTL_NODE(_kern_proc, (KERN_PROC_TTY | KERN_PROC_FLAG_LWP), tty_lwp, CTLFLAG_RD,
916 sysctl_kern_proc, "Process table");
918 SYSCTL_NODE(_kern_proc, (KERN_PROC_UID | KERN_PROC_FLAG_LWP), uid_lwp, CTLFLAG_RD,
919 sysctl_kern_proc, "Process table");
921 SYSCTL_NODE(_kern_proc, (KERN_PROC_RUID | KERN_PROC_FLAG_LWP), ruid_lwp, CTLFLAG_RD,
922 sysctl_kern_proc, "Process table");
924 SYSCTL_NODE(_kern_proc, (KERN_PROC_PID | KERN_PROC_FLAG_LWP), pid_lwp, CTLFLAG_RD,
925 sysctl_kern_proc, "Process table");
927 SYSCTL_NODE(_kern_proc, KERN_PROC_ARGS, args, CTLFLAG_RW | CTLFLAG_ANYBODY,
928 sysctl_kern_proc_args, "Process argument list");