change all callers of enterpgrp() to pre-allocate a pgrp or session if

it might be needed later -- before calling pfind(), so that enterpgrp()
can operate without sleeping
ok tedu

4 files changed, 77 insertions, 36 deletions

diff --git a/sys/compat/hpux/hpux_compat.c b/sys/compat/hpux/hpux_compat.c
index a1c2e0f65b9..73193038c6f 100644
--- a/sys/compat/hpux/hpux_compat.c
+++ b/sys/compat/hpux/hpux_compat.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hpux_compat.c,v 1.29 2007/09/22 09:57:40 martin Exp $	*/
+/*	$OpenBSD: hpux_compat.c,v 1.30 2008/11/01 05:59:21 deraadt Exp $	*/
 /*	$NetBSD: hpux_compat.c,v 1.35 1997/05/08 16:19:48 mycroft Exp $	*/
 
 /*
@@ -63,6 +63,7 @@
 #include <sys/stat.h>
 #include <sys/syslog.h>
 #include <sys/malloc.h>
+#include <sys/pool.h>
 #include <sys/mount.h>
 #include <sys/ipc.h>
 #include <sys/user.h>
@@ -1163,9 +1164,12 @@ hpux_sys_setpgrp_6x(p, v, retval)
 	void *v;
 	register_t *retval;
 {
+	struct pgrp *npgrp;
+
+	npgrp = pool_get(&pgrp_pool, PR_WAITOK);
 
 	if (p->p_pid != p->p_pgid)
-		enterpgrp(p, p->p_pid, 0);
+		enterpgrp(p, p->p_pid, npgrp, NULL);
 	*retval = p->p_pgid;
 	return (0);
 }
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index e97e929255d..9bbe506f971 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_proc.c,v 1.38 2008/10/31 17:17:03 deraadt Exp $	*/
+/*	$OpenBSD: kern_proc.c,v 1.39 2008/11/01 05:59:21 deraadt Exp $	*/
 /*	$NetBSD: kern_proc.c,v 1.14 1996/02/09 18:59:41 christos Exp $	*/
 
 /*
@@ -193,20 +193,22 @@ pgfind(pid_t pgid)
 
 /*
  * Move p to a new or existing process group (and session)
+ * Caller provides a pre-allocated pgrp and session that should
+ * be freed if they are not used.
  */
 int
-enterpgrp(struct proc *p, pid_t pgid, int mksess)
+enterpgrp(struct proc *p, pid_t pgid, struct pgrp *newpgrp,
+    struct session *newsess)
 {
 	struct pgrp *pgrp = pgfind(pgid);
 
 #ifdef DIAGNOSTIC
-	if (pgrp != NULL && mksess)	/* firewalls */
+	if (pgrp != NULL && newsess)	/* 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
@@ -215,24 +217,27 @@ enterpgrp(struct proc *p, pid_t pgid, int mksess)
 		if (p->p_pid != pgid)
 			panic("enterpgrp: new pgrp and pid != pgid");
 #endif
-		if ((np = pfind(savepid)) == NULL || np != p)
+
+		if ((np = pfind(p->p_pid)) == NULL || np != p) {
+			pool_put(&pgrp_pool, newpgrp);
+			if (newsess)
+				pool_put(&session_pool, newsess);
 			return (ESRCH);
-		pgrp = pool_get(&pgrp_pool, PR_WAITOK);
-		if (mksess) {
-			struct session *sess;
+		}
 
+		pgrp = newpgrp;
+		if (newsess) {
 			/*
 			 * new session
 			 */
-			sess = pool_get(&session_pool, PR_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));
+			newsess->s_leader = p;
+			newsess->s_count = 1;
+			newsess->s_ttyvp = NULL;
+			newsess->s_ttyp = NULL;
+			bcopy(p->p_session->s_login, newsess->s_login,
+			    sizeof(newsess->s_login));
 			atomic_clearbits_int(&p->p_flag, P_CONTROLT);
-			pgrp->pg_session = sess;
+			pgrp->pg_session = newsess;
 #ifdef DIAGNOSTIC
 			if (p != curproc)
 				panic("enterpgrp: mksession and p != curproc");
@@ -245,8 +250,16 @@ enterpgrp(struct proc *p, pid_t pgid, int mksess)
 		LIST_INIT(&pgrp->pg_members);
 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
 		pgrp->pg_jobc = 0;
-	} else if (pgrp == p->p_pgrp)
+	} else if (pgrp == p->p_pgrp) {
+		if (newsess)
+			pool_put(&session_pool, newsess);
+		pool_put(&pgrp_pool, newpgrp);
 		return (0);
+	} else {
+		if (newsess)
+			pool_put(&session_pool, newsess);
+		pool_put(&pgrp_pool, newpgrp);
+	}
 
 	/*
 	 * Adjust eligibility of affected pgrps to participate in job control.
diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c
index 7379a924540..4b0185952e2 100644
--- a/sys/kern/kern_prot.c
+++ b/sys/kern/kern_prot.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_prot.c,v 1.36 2008/10/31 17:17:04 deraadt Exp $	*/
+/*	$OpenBSD: kern_prot.c,v 1.37 2008/11/01 05:59:21 deraadt Exp $	*/
 /*	$NetBSD: kern_prot.c,v 1.33 1996/02/09 18:59:42 christos Exp $	*/
 
 /*
@@ -233,11 +233,18 @@ sys_getgroups(struct proc *p, void *v, register_t *retval)
 int
 sys_setsid(struct proc *p, void *v, register_t *retval)
 {
+	struct session *newsess;
+	struct pgrp *newpgrp;
+
+	newsess = pool_get(&session_pool, PR_WAITOK);
+	newpgrp = pool_get(&pgrp_pool, PR_WAITOK);
 
 	if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) {
+		pool_put(&pgrp_pool, newpgrp);
+		pool_put(&session_pool, newsess);
 		return (EPERM);
 	} else {
-		(void)enterpgrp(p, p->p_pid, 1);
+		(void) enterpgrp(p, p->p_pid, newpgrp, newsess);
 		*retval = p->p_pid;
 		return (0);
 	}
@@ -265,9 +272,9 @@ sys_setpgid(struct proc *curp, void *v, register_t *retval)
 		syscallarg(int) pgid;
 	} */ *uap = v;
 	struct proc *targp;		/* target process */
-	struct pgrp *pgrp;		/* target pgrp */
+	struct pgrp *pgrp, *newpgrp;	/* target pgrp */
 	pid_t pid;
-	int pgid;
+	int pgid, error;
 
 	pid = SCARG(uap, pid);
 	pgid = SCARG(uap, pgid);
@@ -275,24 +282,39 @@ sys_setpgid(struct proc *curp, void *v, register_t *retval)
 	if (pgid < 0)
 		return (EINVAL);
 
+	newpgrp = pool_get(&pgrp_pool, PR_WAITOK);
+
 	if (pid != 0 && pid != curp->p_pid) {
-		if ((targp = pfind(pid)) == 0 || !inferior(targp))
-			return (ESRCH);
-		if (targp->p_session != curp->p_session)
-			return (EPERM);
-		if (targp->p_flag & P_EXEC)
-			return (EACCES);
+		if ((targp = pfind(pid)) == 0 || !inferior(targp)) {
+			error = ESRCH;
+			goto out;
+		}
+		if (targp->p_session != curp->p_session) {
+			error = EPERM;
+			goto out;
+		}
+		if (targp->p_flag & P_EXEC) {
+			error = EACCES;
+			goto out;
+		}
 	} else
 		targp = curp;
-	if (SESS_LEADER(targp))
-		return (EPERM);
+	if (SESS_LEADER(targp)) {
+		error = EPERM;
+		goto out;
+	}
 	if (pgid == 0)
 		pgid = targp->p_pid;
 	else if (pgid != targp->p_pid)
 		if ((pgrp = pgfind(pgid)) == 0 ||
-		    pgrp->pg_session != curp->p_session)
-			return (EPERM);
-	return (enterpgrp(targp, pgid, 0));
+		    pgrp->pg_session != curp->p_session) {
+			error = EPERM;
+			goto out;
+		}
+	return (enterpgrp(targp, pgid, newpgrp, NULL));
+out:
+	pool_put(&pgrp_pool, newpgrp);
+	return (error);
 }
 
 /* ARGSUSED */
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index a52b35b528f..cbea6649d1c 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.h,v 1.108 2008/10/14 18:27:29 guenther Exp $	*/
+/*	$OpenBSD: proc.h,v 1.109 2008/11/01 05:59:20 deraadt Exp $	*/
 /*	$NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $	*/
 
 /*-
@@ -400,6 +400,7 @@ extern struct pool proc_pool;		/* memory pool for procs */
 extern struct pool rusage_pool;		/* memory pool for zombies */
 extern struct pool ucred_pool;		/* memory pool for ucreds */
 extern struct pool session_pool;	/* memory pool for sessions */
+extern struct pool pgrp_pool;		/* memory pool for pgrps */
 extern struct pool pcred_pool;		/* memory pool for pcreds */
 
 struct simplelock;
@@ -410,7 +411,8 @@ void	proc_printit(struct proc *p, const char *modif,
     int (*pr)(const char *, ...));
 
 int	chgproccnt(uid_t uid, int diff);
-int	enterpgrp(struct proc *p, pid_t pgid, int mksess);
+int	enterpgrp(struct proc *p, pid_t pgid, struct pgrp *newpgrp,
+	    struct session *newsess);
 void	fixjobc(struct proc *p, struct pgrp *pgrp, int entering);
 int	inferior(struct proc *p);
 int	leavepgrp(struct proc *p);