/* $OpenBSD: kern_proc.c,v 1.7 2000/06/05 11:02:50 art Exp $ */ /* $NetBSD: kern_proc.c,v 1.14 1996/02/09 18:59:41 christos Exp $ */ /* * Copyright (c) 1982, 1986, 1989, 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_proc.c 8.4 (Berkeley) 1/4/94 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Structure associated with user cacheing. */ struct uidinfo { LIST_ENTRY(uidinfo) ui_hash; uid_t ui_uid; long ui_proccnt; }; #define UIHASH(uid) (&uihashtbl[(uid) & uihash]) LIST_HEAD(uihashhead, uidinfo) *uihashtbl; u_long uihash; /* size of hash table - 1 */ /* * Other process lists */ struct pidhashhead *pidhashtbl; u_long pidhash; struct pgrphashhead *pgrphashtbl; u_long pgrphash; struct proclist allproc; struct proclist zombproc; /* * Locking of this proclist is special; it's accessed in a * critical section of process exit, and thus locking it can't * modify interrupt state. We use a simple spin lock for this * proclist. Processes on this proclist are also on zombproc; * we use the p_hash member to linkup to deadproc. */ struct simplelock deadproc_slock; struct proclist deadproc; /* dead, but not yet undead */ static void orphanpg __P((struct pgrp *)); #ifdef DEBUG void pgrpdump __P((void)); #endif /* * Initialize global process hashing structures. */ void procinit() { LIST_INIT(&allproc); LIST_INIT(&zombproc); LIST_INIT(&deadproc); simple_lock_init(&deadproc_slock); pidhashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pidhash); pgrphashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pgrphash); uihashtbl = hashinit(maxproc / 16, M_PROC, M_WAITOK, &uihash); } /* * Change the count associated with number of processes * a given user is using. */ int chgproccnt(uid, diff) uid_t uid; int diff; { register struct uidinfo *uip; register struct uihashhead *uipp; uipp = UIHASH(uid); for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next) if (uip->ui_uid == uid) break; if (uip) { uip->ui_proccnt += diff; if (uip->ui_proccnt > 0) return (uip->ui_proccnt); if (uip->ui_proccnt < 0) panic("chgproccnt: procs < 0"); LIST_REMOVE(uip, ui_hash); FREE(uip, M_PROC); return (0); } if (diff <= 0) { if (diff == 0) return(0); panic("chgproccnt: lost user"); } MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK); LIST_INSERT_HEAD(uipp, uip, ui_hash); uip->ui_uid = uid; uip->ui_proccnt = diff; return (diff); } /* * Is p an inferior of the current process? */ int inferior(p) register struct proc *p; { for (; p != curproc; p = p->p_pptr) if (p->p_pid == 0) return (0); return (1); } /* * Locate a process by number */ struct proc * pfind(pid) register pid_t pid; { register struct proc *p; for (p = PIDHASH(pid)->lh_first; p != 0; p = p->p_hash.le_next) if (p->p_pid == pid) return (p); return (NULL); } /* * Locate a process group by number */ struct pgrp * pgfind(pgid) register pid_t pgid; { register struct pgrp *pgrp; for (pgrp = PGRPHASH(pgid)->lh_first; pgrp != 0; pgrp = pgrp->pg_hash.le_next) if (pgrp->pg_id == pgid) return (pgrp); return (NULL); } /* * Move p to a new or existing process group (and session) */ int enterpgrp(p, pgid, mksess) register struct proc *p; pid_t pgid; int mksess; { register struct pgrp *pgrp = pgfind(pgid); #ifdef DIAGNOSTIC if (pgrp != NULL && mksess) /* firewalls */ panic("enterpgrp: setsid into non-empty pgrp"); if (SESS_LEADER(p)) panic("enterpgrp: session leader attempted setpgrp"); #endif if (pgrp == NULL) { pid_t savepid = p->p_pid; struct proc *np; /* * new process group */ #ifdef DIAGNOSTIC if (p->p_pid != pgid) panic("enterpgrp: new pgrp and pid != pgid"); #endif if ((np = pfind(savepid)) == NULL || np != p) return (ESRCH); MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP, M_WAITOK); if (mksess) { register struct session *sess; /* * new session */ MALLOC(sess, struct session *, sizeof(struct session), M_SESSION, M_WAITOK); sess->s_leader = p; sess->s_count = 1; sess->s_ttyvp = NULL; sess->s_ttyp = NULL; bcopy(p->p_session->s_login, sess->s_login, sizeof(sess->s_login)); p->p_flag &= ~P_CONTROLT; pgrp->pg_session = sess; #ifdef DIAGNOSTIC if (p != curproc) panic("enterpgrp: mksession and p != curproc"); #endif } else { pgrp->pg_session = p->p_session; pgrp->pg_session->s_count++; } pgrp->pg_id = pgid; LIST_INIT(&pgrp->pg_members); LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash); pgrp->pg_jobc = 0; } else if (pgrp == p->p_pgrp) return (0); /* * Adjust eligibility of affected pgrps to participate in job control. * Increment eligibility counts before decrementing, otherwise we * could reach 0 spuriously during the first call. */ fixjobc(p, pgrp, 1); fixjobc(p, p->p_pgrp, 0); LIST_REMOVE(p, p_pglist); if (p->p_pgrp->pg_members.lh_first == 0) pgdelete(p->p_pgrp); p->p_pgrp = pgrp; LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist); return (0); } /* * remove process from process group */ int leavepgrp(p) register struct proc *p; { LIST_REMOVE(p, p_pglist); if (p->p_pgrp->pg_members.lh_first == 0) pgdelete(p->p_pgrp); p->p_pgrp = 0; return (0); } /* * delete a process group */ void pgdelete(pgrp) register struct pgrp *pgrp; { if (pgrp->pg_session->s_ttyp != NULL && pgrp->pg_session->s_ttyp->t_pgrp == pgrp) pgrp->pg_session->s_ttyp->t_pgrp = NULL; LIST_REMOVE(pgrp, pg_hash); if (--pgrp->pg_session->s_count == 0) FREE(pgrp->pg_session, M_SESSION); FREE(pgrp, M_PGRP); } /* * Adjust pgrp jobc counters when specified process changes process group. * We count the number of processes in each process group that "qualify" * the group for terminal job control (those with a parent in a different * process group of the same session). If that count reaches zero, the * process group becomes orphaned. Check both the specified process' * process group and that of its children. * entering == 0 => p is leaving specified group. * entering == 1 => p is entering specified group. */ void fixjobc(p, pgrp, entering) register struct proc *p; register struct pgrp *pgrp; int entering; { register struct pgrp *hispgrp; register struct session *mysession = pgrp->pg_session; /* * Check p's parent to see whether p qualifies its own process * group; if so, adjust count for p's process group. */ if ((hispgrp = p->p_pptr->p_pgrp) != pgrp && hispgrp->pg_session == mysession) { if (entering) pgrp->pg_jobc++; else if (--pgrp->pg_jobc == 0) orphanpg(pgrp); } /* * Check this process' children to see whether they qualify * their process groups; if so, adjust counts for children's * process groups. */ for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next) if ((hispgrp = p->p_pgrp) != pgrp && hispgrp->pg_session == mysession && P_ZOMBIE(p) == 0) { if (entering) hispgrp->pg_jobc++; else if (--hispgrp->pg_jobc == 0) orphanpg(hispgrp); } } /* * A process group has become orphaned; * if there are any stopped processes in the group, * hang-up all process in that group. */ static void orphanpg(pg) struct pgrp *pg; { register struct proc *p; for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) { if (p->p_stat == SSTOP) { for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) { psignal(p, SIGHUP); psignal(p, SIGCONT); } return; } } } #ifdef DEBUG void pgrpdump() { register struct pgrp *pgrp; register struct proc *p; register int i; for (i = 0; i <= pgrphash; i++) { if ((pgrp = pgrphashtbl[i].lh_first) != NULL) { printf("\tindx %d\n", i); for (; pgrp != 0; pgrp = pgrp->pg_hash.le_next) { printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n", pgrp, pgrp->pg_id, pgrp->pg_session, pgrp->pg_session->s_count, pgrp->pg_members.lh_first); for (p = pgrp->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) { printf("\t\tpid %d addr %p pgrp %p\n", p->p_pid, p, p->p_pgrp); } } } } } #endif /* DEBUG */