/* $NetBSD: kern_proc.c,v 1.54 2002/09/27 15:37:45 provos Exp $ */ /*- * Copyright (c) 1999 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, * NASA Ames Research Center. * * 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 NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ /* * 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 8.7 (Berkeley) 2/14/95 */ #include __KERNEL_RCSID(0, "$NetBSD: kern_proc.c,v 1.54 2002/09/27 15:37:45 provos Exp $"); #include "opt_kstack.h" #include #include #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; /* resources have been freed */ /* * Process list locking: * * We have two types of locks on the proclists: read locks and write * locks. Read locks can be used in interrupt context, so while we * hold the write lock, we must also block clock interrupts to * lock out any scheduling changes that may happen in interrupt * context. * * The proclist lock locks the following structures: * * allproc * zombproc * pidhashtbl */ struct lock proclist_lock; /* * 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 */ struct pool proc_pool; struct pool pcred_pool; struct pool plimit_pool; struct pool pgrp_pool; struct pool rusage_pool; struct pool ras_pool; /* * The process list descriptors, used during pid allocation and * by sysctl. No locking on this data structure is needed since * it is completely static. */ const struct proclist_desc proclists[] = { { &allproc }, { &zombproc }, { NULL }, }; static void orphanpg __P((struct pgrp *)); #ifdef DEBUG void pgrpdump __P((void)); #endif /* * Initialize global process hashing structures. */ void procinit() { const struct proclist_desc *pd; for (pd = proclists; pd->pd_list != NULL; pd++) LIST_INIT(pd->pd_list); spinlockinit(&proclist_lock, "proclk", 0); LIST_INIT(&deadproc); simple_lock_init(&deadproc_slock); pidhashtbl = hashinit(maxproc / 4, HASH_LIST, M_PROC, M_WAITOK, &pidhash); pgrphashtbl = hashinit(maxproc / 4, HASH_LIST, M_PROC, M_WAITOK, &pgrphash); uihashtbl = hashinit(maxproc / 16, HASH_LIST, M_PROC, M_WAITOK, &uihash); pool_init(&proc_pool, sizeof(struct proc), 0, 0, 0, "procpl", &pool_allocator_nointr); pool_init(&pgrp_pool, sizeof(struct pgrp), 0, 0, 0, "pgrppl", &pool_allocator_nointr); pool_init(&pcred_pool, sizeof(struct pcred), 0, 0, 0, "pcredpl", &pool_allocator_nointr); pool_init(&plimit_pool, sizeof(struct plimit), 0, 0, 0, "plimitpl", &pool_allocator_nointr); pool_init(&rusage_pool, sizeof(struct rusage), 0, 0, 0, "rusgepl", &pool_allocator_nointr); pool_init(&ras_pool, sizeof(struct ras), 0, 0, 0, "raspl", &pool_allocator_nointr); } /* * Acquire a read lock on the proclist. */ void proclist_lock_read() { int error; error = spinlockmgr(&proclist_lock, LK_SHARED, NULL); #ifdef DIAGNOSTIC if (__predict_false(error != 0)) panic("proclist_lock_read: failed to acquire lock"); #endif } /* * Release a read lock on the proclist. */ void proclist_unlock_read() { (void) spinlockmgr(&proclist_lock, LK_RELEASE, NULL); } /* * Acquire a write lock on the proclist. */ int proclist_lock_write() { int s, error; s = splclock(); error = spinlockmgr(&proclist_lock, LK_EXCLUSIVE, NULL); #ifdef DIAGNOSTIC if (__predict_false(error != 0)) panic("proclist_lock: failed to acquire lock"); #endif return (s); } /* * Release a write lock on the proclist. */ void proclist_unlock_write(s) int s; { (void) spinlockmgr(&proclist_lock, LK_RELEASE, NULL); splx(s); } /* * Change the count associated with number of processes * a given user is using. */ int chgproccnt(uid, diff) uid_t uid; int diff; { struct uidinfo *uip; struct uihashhead *uipp; uipp = UIHASH(uid); LIST_FOREACH(uip, uipp, ui_hash) 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 q? */ int inferior(p, q) struct proc *p; struct proc *q; { for (; p != q; p = p->p_pptr) if (p->p_pid == 0) return (0); return (1); } /* * Locate a process by number */ struct proc * pfind(pid) pid_t pid; { struct proc *p; proclist_lock_read(); LIST_FOREACH(p, PIDHASH(pid), p_hash) if (p->p_pid == pid) goto out; out: proclist_unlock_read(); return (p); } /* * Locate a process group by number */ struct pgrp * pgfind(pgid) pid_t pgid; { struct pgrp *pgrp; LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash) 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) struct proc *p; pid_t pgid; int mksess; { struct pgrp *pgrp = pgfind(pgid); #ifdef DIAGNOSTIC if (__predict_false(pgrp != NULL && mksess)) /* firewalls */ panic("enterpgrp: setsid into non-empty pgrp"); if (__predict_false(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 (__predict_false(p->p_pid != pgid)) panic("enterpgrp: new pgrp and pid != pgid"); #endif pgrp = pool_get(&pgrp_pool, PR_WAITOK); if ((np = pfind(savepid)) == NULL || np != p) { pool_put(&pgrp_pool, pgrp); return (ESRCH); } if (mksess) { struct session *sess; /* * new session */ MALLOC(sess, struct session *, sizeof(struct session), M_SESSION, M_WAITOK); if ((np = pfind(savepid)) == NULL || np != p) { FREE(sess, M_SESSION); pool_put(&pgrp_pool, pgrp); return (ESRCH); } sess->s_sid = p->p_pid; sess->s_leader = p; sess->s_count = 1; sess->s_ttyvp = NULL; sess->s_ttyp = NULL; memcpy(sess->s_login, p->p_session->s_login, sizeof(sess->s_login)); p->p_flag &= ~P_CONTROLT; pgrp->pg_session = sess; #ifdef DIAGNOSTIC if (__predict_false(p != curproc)) panic("enterpgrp: mksession and p != curproc"); #endif } else { SESSHOLD(p->p_session); pgrp->pg_session = p->p_session; } 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 (LIST_EMPTY(&p->p_pgrp->pg_members)) 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) struct proc *p; { LIST_REMOVE(p, p_pglist); if (LIST_EMPTY(&p->p_pgrp->pg_members)) pgdelete(p->p_pgrp); p->p_pgrp = 0; return (0); } /* * delete a process group */ void pgdelete(pgrp) struct pgrp *pgrp; { /* Remove reference (if any) from tty to this process group */ 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); SESSRELE(pgrp->pg_session); pool_put(&pgrp_pool, 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) struct proc *p; struct pgrp *pgrp; int entering; { struct pgrp *hispgrp; 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. */ LIST_FOREACH(p, &p->p_children, p_sibling) { 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; { struct proc *p; LIST_FOREACH(p, &pg->pg_members, p_pglist) { if (p->p_stat == SSTOP) { LIST_FOREACH(p, &pg->pg_members, p_pglist) { psignal(p, SIGHUP); psignal(p, SIGCONT); } return; } } } /* mark process as suid/sgid, reset some values do defaults */ void p_sugid(p) struct proc *p; { struct plimit *newlim; p->p_flag |= P_SUGID; /* reset what needs to be reset in plimit */ if (p->p_limit->pl_corename != defcorename) { if (p->p_limit->p_refcnt > 1 && (p->p_limit->p_lflags & PL_SHAREMOD) == 0) { newlim = limcopy(p->p_limit); limfree(p->p_limit); p->p_limit = newlim; } free(p->p_limit->pl_corename, M_TEMP); p->p_limit->pl_corename = defcorename; } } #ifdef DEBUG void pgrpdump() { struct pgrp *pgrp; struct proc *p; int i; for (i = 0; i <= pgrphash; i++) { if ((pgrp = LIST_FIRST(&pgrphashtbl[i])) != 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, LIST_FIRST(&pgrp->pg_members)); LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { printf("\t\tpid %d addr %p pgrp %p\n", p->p_pid, p, p->p_pgrp); } } } } } #endif /* DEBUG */ #ifdef KSTACK_CHECK_MAGIC #include #define KSTACK_MAGIC 0xdeadbeaf /* XXX should be per process basis? */ int kstackleftmin = KSTACK_SIZE; int kstackleftthres = KSTACK_SIZE / 8; /* warn if remaining stack is less than this */ void kstack_setup_magic(const struct proc *p) { u_int32_t *ip; u_int32_t const *end; KASSERT(p != 0); KASSERT(p != &proc0); /* * fill all the stack with magic number * so that later modification on it can be detected. */ ip = (u_int32_t *)KSTACK_LOWEST_ADDR(p); end = (u_int32_t *)((caddr_t)KSTACK_LOWEST_ADDR(p) + KSTACK_SIZE); for (; ip < end; ip++) { *ip = KSTACK_MAGIC; } } void kstack_check_magic(const struct proc *p) { u_int32_t const *ip, *end; int stackleft; KASSERT(p != 0); /* don't check proc0 */ /*XXX*/ if (p == &proc0) return; #ifdef __MACHINE_STACK_GROWS_UP /* stack grows upwards (eg. hppa) */ ip = (u_int32_t *)((caddr_t)KSTACK_LOWEST_ADDR(p) + KSTACK_SIZE); end = (u_int32_t *)KSTACK_LOWEST_ADDR(p); for (ip--; ip >= end; ip--) if (*ip != KSTACK_MAGIC) break; stackleft = (caddr_t)KSTACK_LOWEST_ADDR(p) + KSTACK_SIZE - (caddr_t)ip; #else /* __MACHINE_STACK_GROWS_UP */ /* stack grows downwards (eg. i386) */ ip = (u_int32_t *)KSTACK_LOWEST_ADDR(p); end = (u_int32_t *)((caddr_t)KSTACK_LOWEST_ADDR(p) + KSTACK_SIZE); for (; ip < end; ip++) if (*ip != KSTACK_MAGIC) break; stackleft = (caddr_t)ip - KSTACK_LOWEST_ADDR(p); #endif /* __MACHINE_STACK_GROWS_UP */ if (kstackleftmin > stackleft) { kstackleftmin = stackleft; if (stackleft < kstackleftthres) printf("warning: kernel stack left %d bytes(pid %u)\n", stackleft, p->p_pid); } if (stackleft <= 0) { panic("magic on the top of kernel stack changed for pid %u: " "maybe kernel stack overflow", p->p_pid); } } #endif /* KSTACK_CHECK_MAGIC */