diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c index 4023147c803c..d3bd73eae5a5 100644 --- a/sys/kern/kern_fork.c +++ b/sys/kern/kern_fork.c @@ -1,4 +1,4 @@ -/* $NetBSD: kern_fork.c,v 1.75 2000/11/07 12:41:52 jdolecek Exp $ */ +/* $NetBSD: kern_fork.c,v 1.76 2000/11/08 05:16:23 chs Exp $ */ /* * Copyright (c) 1982, 1986, 1989, 1991, 1993 @@ -106,9 +106,8 @@ fork1(struct proc *p1, int flags, int exitsig, void *stack, size_t stacksize, void (*func)(void *), void *arg, register_t *retval, struct proc **rnewprocp) { - struct proc *p2; + struct proc *p2, *tp; uid_t uid; - struct proc *newproc; int count, s; vaddr_t uaddr; static int nextpid, pidchecked = 0; @@ -126,6 +125,7 @@ fork1(struct proc *p1, int flags, int exitsig, void *stack, size_t stacksize, tablefull("proc", "increase kern.maxproc or NPROC"); return (EAGAIN); } + nprocs++; /* * Increment the count of procs running with this uid. Don't allow @@ -135,6 +135,7 @@ fork1(struct proc *p1, int flags, int exitsig, void *stack, size_t stacksize, if (__predict_false(uid != 0 && count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur)) { (void)chgproccnt(uid, -1); + nprocs--; return (EAGAIN); } @@ -147,6 +148,7 @@ fork1(struct proc *p1, int flags, int exitsig, void *stack, size_t stacksize, uaddr = uvm_km_valloc(kernel_map, USPACE); if (__predict_false(uaddr == 0)) { (void)chgproccnt(uid, -1); + nprocs--; return (ENOMEM); } @@ -156,94 +158,7 @@ fork1(struct proc *p1, int flags, int exitsig, void *stack, size_t stacksize, */ /* Allocate new proc. */ - newproc = pool_get(&proc_pool, PR_WAITOK); - - /* - * BEGIN PID ALLOCATION. - */ - s = proclist_lock_write(); - - /* - * Find an unused process ID. We remember a range of unused IDs - * ready to use (from nextpid+1 through pidchecked-1). - */ - nextpid++; -retry: - /* - * If the process ID prototype has wrapped around, - * restart somewhat above 0, as the low-numbered procs - * tend to include daemons that don't exit. - */ - if (nextpid >= PID_MAX) { - nextpid = 100; - pidchecked = 0; - } - if (nextpid >= pidchecked) { - const struct proclist_desc *pd; - - pidchecked = PID_MAX; - /* - * Scan the process lists to check whether this pid - * is in use. Remember the lowest pid that's greater - * than nextpid, so we can avoid checking for a while. - */ - pd = proclists; -again: - for (p2 = LIST_FIRST(pd->pd_list); p2 != 0; - p2 = LIST_NEXT(p2, p_list)) { - while (p2->p_pid == nextpid || - p2->p_pgrp->pg_id == nextpid || - p2->p_session->s_sid == nextpid) { - nextpid++; - if (nextpid >= pidchecked) - goto retry; - } - if (p2->p_pid > nextpid && pidchecked > p2->p_pid) - pidchecked = p2->p_pid; - - if (p2->p_pgrp->pg_id > nextpid && - pidchecked > p2->p_pgrp->pg_id) - pidchecked = p2->p_pgrp->pg_id; - - if (p2->p_session->s_sid > nextpid && - pidchecked > p2->p_session->s_sid) - pidchecked = p2->p_session->s_sid; - } - - /* - * If there's another list, scan it. If we have checked - * them all, we've found one! - */ - pd++; - if (pd->pd_list != NULL) - goto again; - } - - nprocs++; - p2 = newproc; - - /* Record the pid we've allocated. */ - p2->p_pid = nextpid; - - /* Record the signal to be delivered to the parent on exit. */ - p2->p_exitsig = exitsig; - - /* - * Put the proc on allproc before unlocking PID allocation - * so that waiters won't grab it as soon as we unlock. - */ - - p2->p_stat = SIDL; /* protect against others */ - p2->p_forw = p2->p_back = NULL; /* shouldn't be necessary */ - - LIST_INSERT_HEAD(&allproc, p2, p_list); - - LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash); - - /* - * END PID ALLOCATION. - */ - proclist_unlock_write(s); + p2 = pool_get(&proc_pool, PR_WAITOK); /* * Make a proc table entry for the new process. @@ -274,7 +189,7 @@ again: /* * Duplicate sub-structures as needed. * Increase reference counts on shared objects. - * The p_stats and p_sigacts substructs are set in vm_fork. + * The p_stats and p_sigacts substructs are set in uvm_fork(). */ p2->p_flag = P_INMEM | (p1->p_flag & P_SUGID); p2->p_emul = p1->p_emul; @@ -368,6 +283,89 @@ again: (func != NULL) ? func : child_return, (arg != NULL) ? arg : p2); + /* + * BEGIN PID ALLOCATION. + */ + s = proclist_lock_write(); + + /* + * Find an unused process ID. We remember a range of unused IDs + * ready to use (from nextpid+1 through pidchecked-1). + */ + nextpid++; +retry: + /* + * If the process ID prototype has wrapped around, + * restart somewhat above 0, as the low-numbered procs + * tend to include daemons that don't exit. + */ + if (nextpid >= PID_MAX) { + nextpid = 100; + pidchecked = 0; + } + if (nextpid >= pidchecked) { + const struct proclist_desc *pd; + + pidchecked = PID_MAX; + /* + * Scan the process lists to check whether this pid + * is in use. Remember the lowest pid that's greater + * than nextpid, so we can avoid checking for a while. + */ + pd = proclists; +again: + LIST_FOREACH(tp, pd->pd_list, p_list) { + while (tp->p_pid == nextpid || + tp->p_pgrp->pg_id == nextpid || + tp->p_session->s_sid == nextpid) { + nextpid++; + if (nextpid >= pidchecked) + goto retry; + } + if (tp->p_pid > nextpid && pidchecked > tp->p_pid) + pidchecked = tp->p_pid; + + if (tp->p_pgrp->pg_id > nextpid && + pidchecked > tp->p_pgrp->pg_id) + pidchecked = tp->p_pgrp->pg_id; + + if (tp->p_session->s_sid > nextpid && + pidchecked > tp->p_session->s_sid) + pidchecked = tp->p_session->s_sid; + } + + /* + * If there's another list, scan it. If we have checked + * them all, we've found one! + */ + pd++; + if (pd->pd_list != NULL) + goto again; + } + + /* Record the pid we've allocated. */ + p2->p_pid = nextpid; + + /* Record the signal to be delivered to the parent on exit. */ + p2->p_exitsig = exitsig; + + /* + * Put the proc on allproc before unlocking PID allocation + * so that waiters won't grab it as soon as we unlock. + */ + + p2->p_stat = SIDL; /* protect against others */ + p2->p_forw = p2->p_back = NULL; /* shouldn't be necessary */ + + LIST_INSERT_HEAD(&allproc, p2, p_list); + + LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash); + + /* + * END PID ALLOCATION. + */ + proclist_unlock_write(s); + /* * Make child runnable, set start time, and add to run queue. */