/* $NetBSD: kern_proc.c,v 1.66 2003/09/16 12:05:49 christos 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. 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 1.66 2003/09/16 12:05:49 christos Exp $"); #include "opt_kstack.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static void pg_delete(pid_t); /* * 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 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 * pid_table */ struct lock proclist_lock; /* * List of processes that has called exit, but need to be reaped. * 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. */ struct simplelock deadproc_slock; struct deadprocs deadprocs = SLIST_HEAD_INITIALIZER(deadprocs); /* * pid to proc lookup is done by indexing the pid_table array. * Since pid numbers are only allocated when an empty slot * has been found, there is no need to search any lists ever. * (an orphaned pgrp will lock the slot, a session will lock * the pgrp with the same number.) * If the table is too small it is reallocated with twice the * previous size and the entries 'unzipped' into the two halves. * A linked list of free entries is passed through the pt_proc * field of 'free' items - set odd to be an invalid ptr. */ struct pid_table { struct proc *pt_proc; struct pgrp *pt_pgrp; }; #if 1 /* strongly typed cast - should be a noop */ static __inline uint p2u(struct proc *p) { return (uint)(uintptr_t)p; }; #else #define p2u(p) ((uint)p) #endif #define P_VALID(p) (!(p2u(p) & 1)) #define P_NEXT(p) (p2u(p) >> 1) #define P_FREE(pid) ((struct proc *)(uintptr_t)((pid) << 1 | 1)) #define INITIAL_PID_TABLE_SIZE (1 << 5) static struct pid_table *pid_table; static uint pid_tbl_mask = INITIAL_PID_TABLE_SIZE - 1; static uint pid_alloc_lim; /* max we allocate before growing table */ static uint pid_alloc_cnt; /* number of allocated pids */ /* links through free slots - never empty! */ static uint next_free_pt, last_free_pt; static pid_t pid_max = PID_MAX; /* largest value we allocate */ struct pool proc_pool; struct pool lwp_pool; struct pool lwp_uc_pool; struct pool pcred_pool; struct pool plimit_pool; struct pool pstats_pool; struct pool pgrp_pool; struct pool rusage_pool; struct pool ras_pool; struct pool sadata_pool; struct pool saupcall_pool; struct pool ptimer_pool; MALLOC_DEFINE(M_EMULDATA, "emuldata", "Per-process emulation data"); MALLOC_DEFINE(M_PROC, "proc", "Proc structures"); MALLOC_DEFINE(M_SESSION, "session", "session header"); MALLOC_DEFINE(M_SUBPROC, "subproc", "Proc sub-structures"); /* * 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(void) { const struct proclist_desc *pd; int i; #define LINK_EMPTY ((PID_MAX + INITIAL_PID_TABLE_SIZE) & ~(INITIAL_PID_TABLE_SIZE - 1)) for (pd = proclists; pd->pd_list != NULL; pd++) LIST_INIT(pd->pd_list); spinlockinit(&proclist_lock, "proclk", 0); simple_lock_init(&deadproc_slock); pid_table = malloc(INITIAL_PID_TABLE_SIZE * sizeof *pid_table, M_PROC, M_WAITOK); /* Set free list running through table... Preset 'use count' above PID_MAX so we allocate pid 1 next. */ for (i = 0; i <= pid_tbl_mask; i++) { pid_table[i].pt_proc = P_FREE(LINK_EMPTY + i + 1); pid_table[i].pt_pgrp = 0; } /* slot 0 is just grabbed */ next_free_pt = 1; /* Need to fix last entry. */ last_free_pt = pid_tbl_mask; pid_table[last_free_pt].pt_proc = P_FREE(LINK_EMPTY); /* point at which we grow table - to avoid reusing pids too often */ pid_alloc_lim = pid_tbl_mask - 1; #undef LINK_EMPTY LIST_INIT(&alllwp); LIST_INIT(&deadlwp); LIST_INIT(&zomblwp); 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(&lwp_pool, sizeof(struct lwp), 0, 0, 0, "lwppl", &pool_allocator_nointr); pool_init(&lwp_uc_pool, sizeof(ucontext_t), 0, 0, 0, "lwpucpl", &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(&pstats_pool, sizeof(struct pstats), 0, 0, 0, "pstatspl", &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); pool_init(&sadata_pool, sizeof(struct sadata), 0, 0, 0, "sadatapl", &pool_allocator_nointr); pool_init(&saupcall_pool, sizeof(struct sadata_upcall), 0, 0, 0, "saupcpl", &pool_allocator_nointr); pool_init(&ptimer_pool, sizeof(struct ptimer), 0, 0, 0, "ptimerpl", &pool_allocator_nointr); } /* * Acquire a read lock on the proclist. */ void proclist_lock_read(void) { 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) { (void) spinlockmgr(&proclist_lock, LK_RELEASE, NULL); } /* * Acquire a write lock on the proclist. */ int proclist_lock_write(void) { 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(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_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); } /* * Check that the specifies process group in in the session of the * specified process. * Treats -ve ids as process ids. * Used to validate TIOCSPGRP requests. */ int pgid_in_session(struct proc *p, pid_t pg_id) { struct pgrp *pgrp; if (pg_id < 0) { struct proc *p1 = pfind(-pg_id); if (p1 == NULL) return EINVAL; pgrp = p1->p_pgrp; } else { pgrp = pgfind(pg_id); if (pgrp == NULL) return EINVAL; } if (pgrp->pg_session != p->p_pgrp->pg_session) return EPERM; return 0; } /* * Is p an inferior of q? */ int inferior(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_t pid) { struct proc *p; proclist_lock_read(); p = pid_table[pid & pid_tbl_mask].pt_proc; /* Only allow live processes to be found by pid. */ if (!P_VALID(p) || p->p_pid != pid || !((1 << SACTIVE | 1 << SSTOP) & 1 << p->p_stat)) p = 0; /* XXX MP - need to have a reference count... */ proclist_unlock_read(); return p; } /* * Locate a process group by number */ struct pgrp * pgfind(pid_t pgid) { struct pgrp *pgrp; proclist_lock_read(); pgrp = pid_table[pgid & pid_tbl_mask].pt_pgrp; /* * Can't look up a pgrp that only exists because the session * hasn't died yet (traditional) */ if (pgrp == NULL || pgrp->pg_id != pgid || LIST_EMPTY(&pgrp->pg_members)) pgrp = 0; /* XXX MP - need to have a reference count... */ proclist_unlock_read(); return pgrp; } /* * Set entry for process 0 */ void proc0_insert(struct proc *p, struct lwp *l, struct pgrp *pgrp, struct session *sess) { int s; simple_lock_init(&p->p_lwplock); LIST_INIT(&p->p_lwps); LIST_INSERT_HEAD(&p->p_lwps, l, l_sibling); p->p_nlwps = 1; simple_lock_init(&p->p_sigctx.ps_silock); CIRCLEQ_INIT(&p->p_sigctx.ps_siginfo); s = proclist_lock_write(); pid_table[0].pt_proc = p; LIST_INSERT_HEAD(&allproc, p, p_list); LIST_INSERT_HEAD(&alllwp, l, l_list); p->p_pgrp = pgrp; pid_table[0].pt_pgrp = pgrp; LIST_INIT(&pgrp->pg_members); LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist); pgrp->pg_session = sess; sess->s_count = 1; sess->s_sid = 0; sess->s_leader = p; proclist_unlock_write(s); } static void expand_pid_table(void) { uint pt_size = pid_tbl_mask + 1; struct pid_table *n_pt, *new_pt; struct proc *proc; struct pgrp *pgrp; int i; int s; pid_t pid; new_pt = malloc(pt_size * 2 * sizeof *new_pt, M_PROC, M_WAITOK); s = proclist_lock_write(); if (pt_size != pid_tbl_mask + 1) { /* Another process beat us to it... */ proclist_unlock_write(s); FREE(new_pt, M_PROC); return; } /* * Copy entries from old table into new one. * If 'pid' is 'odd' we need to place in the upper half, * even pid's to the lower half. * Free items stay in the low half so we don't have to * fixup the reference to them. * We stuff free items on the front of the freelist * because we can't write to unmodified entries. * Processing the table backwards maintians a semblance * of issueing pid numbers that increase with time. */ i = pt_size - 1; n_pt = new_pt + i; for (; ; i--, n_pt--) { proc = pid_table[i].pt_proc; pgrp = pid_table[i].pt_pgrp; if (!P_VALID(proc)) { /* Up 'use count' so that link is valid */ pid = (P_NEXT(proc) + pt_size) & ~pt_size; proc = P_FREE(pid); if (pgrp) pid = pgrp->pg_id; } else pid = proc->p_pid; /* Save entry in appropriate half of table */ n_pt[pid & pt_size].pt_proc = proc; n_pt[pid & pt_size].pt_pgrp = pgrp; /* Put other piece on start of free list */ pid = (pid ^ pt_size) & ~pid_tbl_mask; n_pt[pid & pt_size].pt_proc = P_FREE((pid & ~pt_size) | next_free_pt); n_pt[pid & pt_size].pt_pgrp = 0; next_free_pt = i | (pid & pt_size); if (i == 0) break; } /* Switch tables */ n_pt = pid_table; pid_table = new_pt; pid_tbl_mask = pt_size * 2 - 1; /* * pid_max starts as PID_MAX (= 30000), once we have 16384 * allocated pids we need it to be larger! */ if (pid_tbl_mask > PID_MAX) { pid_max = pid_tbl_mask * 2 + 1; pid_alloc_lim |= pid_alloc_lim << 1; } else pid_alloc_lim <<= 1; /* doubles number of free slots... */ proclist_unlock_write(s); FREE(n_pt, M_PROC); } struct proc * proc_alloc(void) { struct proc *p; int s; int nxt; pid_t pid; struct pid_table *pt; p = pool_get(&proc_pool, PR_WAITOK); p->p_stat = SIDL; /* protect against others */ /* allocate next free pid */ for (;;expand_pid_table()) { if (__predict_false(pid_alloc_cnt >= pid_alloc_lim)) /* ensure pids cycle through 2000+ values */ continue; s = proclist_lock_write(); pt = &pid_table[next_free_pt]; #ifdef DIAGNOSTIC if (__predict_false(P_VALID(pt->pt_proc) || pt->pt_pgrp)) panic("proc_alloc: slot busy"); #endif nxt = P_NEXT(pt->pt_proc); if (nxt & pid_tbl_mask) break; /* Table full - expand (NB last entry not used....) */ proclist_unlock_write(s); } /* pid is 'saved use count' + 'size' + entry */ pid = (nxt & ~pid_tbl_mask) + pid_tbl_mask + 1 + next_free_pt; if ((uint)pid > (uint)pid_max) pid &= pid_tbl_mask; p->p_pid = pid; next_free_pt = nxt & pid_tbl_mask; /* Grab table slot */ pt->pt_proc = p; pid_alloc_cnt++; proclist_unlock_write(s); return p; } /* * Free last resources of a process - called from proc_free (in kern_exit.c) */ void proc_free_mem(struct proc *p) { int s; pid_t pid = p->p_pid; struct pid_table *pt; s = proclist_lock_write(); pt = &pid_table[pid & pid_tbl_mask]; #ifdef DIAGNOSTIC if (__predict_false(pt->pt_proc != p)) panic("proc_free: pid_table mismatch, pid %x, proc %p", pid, p); #endif /* save pid use count in slot */ pt->pt_proc = P_FREE(pid & ~pid_tbl_mask); if (pt->pt_pgrp == NULL) { /* link last freed entry onto ours */ pid &= pid_tbl_mask; pt = &pid_table[last_free_pt]; pt->pt_proc = P_FREE(P_NEXT(pt->pt_proc) | pid); last_free_pt = pid; pid_alloc_cnt--; } nprocs--; proclist_unlock_write(s); pool_put(&proc_pool, p); } /* * Move p to a new or existing process group (and session) * * If we are creating a new pgrp, the pgid should equal * the calling processes pid. * If is only valid to enter a process group that is in the session * of the process. * Also mksess should only be set if we are creating a process group * * Only called from sys_setsid, sys_setpgid/sys_setprp and the * SYSV setpgrp support for hpux == enterpgrp(curproc, curproc->p_pid) */ int enterpgrp(struct proc *p, pid_t pgid, int mksess) { struct pgrp *new_pgrp, *pgrp; struct session *sess; struct proc *curp = curproc; pid_t pid = p->p_pid; int rval; int s; pid_t pg_id = NO_PGID; /* Allocate data areas we might need before doing any validity checks */ proclist_lock_read(); /* Because pid_table might change */ if (pid_table[pgid & pid_tbl_mask].pt_pgrp == 0) { proclist_unlock_read(); new_pgrp = pool_get(&pgrp_pool, PR_WAITOK); } else { proclist_unlock_read(); new_pgrp = NULL; } if (mksess) MALLOC(sess, struct session *, sizeof(struct session), M_SESSION, M_WAITOK); else sess = NULL; s = proclist_lock_write(); rval = EPERM; /* most common error (to save typing) */ /* Check pgrp exists or can be created */ pgrp = pid_table[pgid & pid_tbl_mask].pt_pgrp; if (pgrp != NULL && pgrp->pg_id != pgid) goto done; /* Can only set another process under restricted circumstances. */ if (p != curp) { /* must exist and be one of our children... */ if (p != pid_table[pid & pid_tbl_mask].pt_proc || !inferior(p, curp)) { rval = ESRCH; goto done; } /* ... in the same session... */ if (sess != NULL || p->p_session != curp->p_session) goto done; /* ... existing pgid must be in same session ... */ if (pgrp != NULL && pgrp->pg_session != p->p_session) goto done; /* ... and not done an exec. */ if (p->p_flag & P_EXEC) { rval = EACCES; goto done; } } /* Changing the process group/session of a session leader is definitely off limits. */ if (SESS_LEADER(p)) { if (sess == NULL && p->p_pgrp == pgrp) /* unless it's a definite noop */ rval = 0; goto done; } /* Can only create a process group with id of process */ if (pgrp == NULL && pgid != pid) goto done; /* Can only create a session if creating pgrp */ if (sess != NULL && pgrp != NULL) goto done; /* Check we allocated memory for a pgrp... */ if (pgrp == NULL && new_pgrp == NULL) goto done; /* Don't attach to 'zombie' pgrp */ if (pgrp != NULL && LIST_EMPTY(&pgrp->pg_members)) goto done; /* Expect to succeed now */ rval = 0; if (pgrp == p->p_pgrp) /* nothing to do */ goto done; /* Ok all setup, link up required structures */ if (pgrp == NULL) { pgrp = new_pgrp; new_pgrp = 0; if (sess != NULL) { sess->s_sid = p->p_pid; sess->s_leader = p; sess->s_count = 1; sess->s_ttyvp = NULL; sess->s_ttyp = NULL; sess->s_flags = p->p_session->s_flags & ~S_LOGIN_SET; memcpy(sess->s_login, p->p_session->s_login, sizeof(sess->s_login)); p->p_flag &= ~P_CONTROLT; } else { sess = p->p_pgrp->pg_session; SESSHOLD(sess); } pgrp->pg_session = sess; sess = 0; pgrp->pg_id = pgid; LIST_INIT(&pgrp->pg_members); #ifdef DIAGNOSTIC if (__predict_false(pid_table[pgid & pid_tbl_mask].pt_pgrp)) panic("enterpgrp: pgrp table slot in use"); if (__predict_false(mksess && p != curp)) panic("enterpgrp: mksession and p != curproc"); #endif pid_table[pgid & pid_tbl_mask].pt_pgrp = pgrp; pgrp->pg_jobc = 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); /* Move process to requested group */ LIST_REMOVE(p, p_pglist); if (LIST_EMPTY(&p->p_pgrp->pg_members)) /* defer delete until we've dumped the lock */ pg_id = p->p_pgrp->pg_id; p->p_pgrp = pgrp; LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist); done: proclist_unlock_write(s); if (sess != NULL) free(sess, M_SESSION); if (new_pgrp != NULL) pool_put(&pgrp_pool, new_pgrp); if (pg_id != NO_PGID) pg_delete(pg_id); #ifdef DEBUG_PGRP if (__predict_false(rval)) printf("enterpgrp(%d,%d,%d), curproc %d, rval %d\n", pid, pgid, mksess, curp->p_pid, rval); #endif return rval; } /* * remove process from process group */ int leavepgrp(struct proc *p) { int s = proclist_lock_write(); struct pgrp *pgrp; pid_t pg_id; pgrp = p->p_pgrp; LIST_REMOVE(p, p_pglist); p->p_pgrp = 0; pg_id = LIST_EMPTY(&pgrp->pg_members) ? pgrp->pg_id : NO_PGID; proclist_unlock_write(s); if (pg_id != NO_PGID) pg_delete(pg_id); return 0; } static void pg_free(pid_t pg_id) { struct pgrp *pgrp; struct pid_table *pt; int s; s = proclist_lock_write(); pt = &pid_table[pg_id & pid_tbl_mask]; pgrp = pt->pt_pgrp; #ifdef DIAGNOSTIC if (__predict_false(!pgrp || pgrp->pg_id != pg_id || !LIST_EMPTY(&pgrp->pg_members))) panic("pg_free: process group absent or has members"); #endif pt->pt_pgrp = 0; if (!P_VALID(pt->pt_proc)) { /* orphaned pgrp, put slot onto free list */ #ifdef DIAGNOSTIC if (__predict_false(P_NEXT(pt->pt_proc) & pid_tbl_mask)) panic("pg_free: process slot on free list"); #endif pg_id &= pid_tbl_mask; pt = &pid_table[last_free_pt]; pt->pt_proc = P_FREE(P_NEXT(pt->pt_proc) | pg_id); last_free_pt = pg_id; pid_alloc_cnt--; } proclist_unlock_write(s); pool_put(&pgrp_pool, pgrp); } /* * delete a process group */ static void pg_delete(pid_t pg_id) { struct pgrp *pgrp; struct tty *ttyp; struct session *ss; int s; s = proclist_lock_write(); pgrp = pid_table[pg_id & pid_tbl_mask].pt_pgrp; if (pgrp == NULL || pgrp->pg_id != pg_id || !LIST_EMPTY(&pgrp->pg_members)) { proclist_unlock_write(s); return; } /* Remove reference (if any) from tty to this process group */ ttyp = pgrp->pg_session->s_ttyp; if (ttyp != NULL && ttyp->t_pgrp == pgrp) ttyp->t_pgrp = NULL; ss = pgrp->pg_session; if (ss->s_sid == pgrp->pg_id) { proclist_unlock_write(s); SESSRELE(ss); /* pgrp freed by sessdelete() if last reference */ return; } proclist_unlock_write(s); SESSRELE(ss); pg_free(pg_id); } /* * Delete session - called from SESSRELE when s_count becomes zero. */ void sessdelete(struct session *ss) { /* * We keep the pgrp with the same id as the session in * order to stop a process being given the same pid. * Since the pgrp holds a reference to the session, it * must be a 'zombie' pgrp by now. */ pg_free(ss->s_sid); FREE(ss, M_SESSION); } /* * 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(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(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 to defaults */ void p_sugid(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 DDB #include void pidtbl_dump(void); void pidtbl_dump(void) { struct pid_table *pt; struct proc *p; struct pgrp *pgrp; int id; db_printf("pid table %p size %x, next %x, last %x\n", pid_table, pid_tbl_mask+1, next_free_pt, last_free_pt); for (pt = pid_table, id = 0; id <= pid_tbl_mask; id++, pt++) { p = pt->pt_proc; if (!P_VALID(p) && !pt->pt_pgrp) continue; db_printf(" id %x: ", id); if (P_VALID(p)) db_printf("proc %p id %d (0x%x) %s\n", p, p->p_pid, p->p_pid, p->p_comm); else db_printf("next %x use %x\n", P_NEXT(p) & pid_tbl_mask, P_NEXT(p) & ~pid_tbl_mask); if ((pgrp = pt->pt_pgrp)) { db_printf("\tsession %p, sid %d, count %d, login %s\n", pgrp->pg_session, pgrp->pg_session->s_sid, pgrp->pg_session->s_count, pgrp->pg_session->s_login); db_printf("\tpgrp %p, pg_id %d, pg_jobc %d, members %p\n", pgrp, pgrp->pg_id, pgrp->pg_jobc, pgrp->pg_members.lh_first); for (p = pgrp->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) { db_printf("\t\tpid %d addr %p pgrp %p %s\n", p->p_pid, p, p->p_pgrp, p->p_comm); } } } } #endif /* DDB */ #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 lwp *l) { u_int32_t *ip; u_int32_t const *end; KASSERT(l != NULL); KASSERT(l != &lwp0); /* * fill all the stack with magic number * so that later modification on it can be detected. */ ip = (u_int32_t *)KSTACK_LOWEST_ADDR(l); end = (u_int32_t *)((caddr_t)KSTACK_LOWEST_ADDR(l) + KSTACK_SIZE); for (; ip < end; ip++) { *ip = KSTACK_MAGIC; } } void kstack_check_magic(const struct lwp *l) { u_int32_t const *ip, *end; int stackleft; KASSERT(l != NULL); /* don't check proc0 */ /*XXX*/ if (l == &lwp0) return; #ifdef __MACHINE_STACK_GROWS_UP /* stack grows upwards (eg. hppa) */ ip = (u_int32_t *)((caddr_t)KSTACK_LOWEST_ADDR(l) + KSTACK_SIZE); end = (u_int32_t *)KSTACK_LOWEST_ADDR(l); for (ip--; ip >= end; ip--) if (*ip != KSTACK_MAGIC) break; stackleft = (caddr_t)KSTACK_LOWEST_ADDR(l) + KSTACK_SIZE - (caddr_t)ip; #else /* __MACHINE_STACK_GROWS_UP */ /* stack grows downwards (eg. i386) */ ip = (u_int32_t *)KSTACK_LOWEST_ADDR(l); end = (u_int32_t *)((caddr_t)KSTACK_LOWEST_ADDR(l) + KSTACK_SIZE); for (; ip < end; ip++) if (*ip != KSTACK_MAGIC) break; stackleft = (caddr_t)ip - KSTACK_LOWEST_ADDR(l); #endif /* __MACHINE_STACK_GROWS_UP */ if (kstackleftmin > stackleft) { kstackleftmin = stackleft; if (stackleft < kstackleftthres) printf("warning: kernel stack left %d bytes" "(pid %u:lid %u)\n", stackleft, (u_int)l->l_proc->p_pid, (u_int)l->l_lid); } if (stackleft <= 0) { panic("magic on the top of kernel stack changed for " "pid %u, lid %u: maybe kernel stack overflow", (u_int)l->l_proc->p_pid, (u_int)l->l_lid); } } #endif /* KSTACK_CHECK_MAGIC */