From 2ea51a70232b4bd59dc6059ffd1585fd81f5b25c Mon Sep 17 00:00:00 2001
From: guenther <guenther@openbsd.org>
Date: Sun, 11 Dec 2011 19:42:28 +0000
Subject: Suspend other rthreads before dumping core or execing; make them exit
 when exec succeeds.

ok jsing@
---
 sys/kern/kern_exec.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

(limited to 'sys/kern/kern_exec.c')

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 1c5380c40f9..ff53d3feb9a 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_exec.c,v 1.120 2011/10/16 05:29:51 guenther Exp $	*/
+/*	$OpenBSD: kern_exec.c,v 1.121 2011/12/11 19:42:28 guenther Exp $	*/
 /*	$NetBSD: kern_exec.c,v 1.75 1996/02/09 18:59:28 christos Exp $	*/
 
 /*-
@@ -267,6 +267,10 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 #endif
 	char *pathbuf = NULL;
 
+	/* get other threads to stop */
+	if ((error = single_thread_set(p, SINGLE_UNWIND, 1)))
+		goto bad;
+
 	/*
 	 * Cheap solution to complicated problems.
 	 * Mark this process as "leave me alone, I'm execing".
@@ -409,6 +413,13 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 	/* adjust "active stack depth" for process VSZ */
 	pack.ep_ssize = len;	/* maybe should go elsewhere, but... */
 
+	/*
+	 * we're committed: any further errors will kill the process, so
+	 * kill the other threads now.
+	 * XXX wait until threads are reaped to make uvmspace_exec() cheaper?
+	 */
+	single_thread_set(p, SINGLE_EXIT, 0);
+
 	/*
 	 * Prepare vmspace for remapping. Note that uvmspace_exec can replace
 	 * p_vmspace!
@@ -667,6 +678,7 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 #endif
 
 	atomic_clearbits_int(&p->p_flag, P_INEXEC);
+	single_thread_clear(p);
 
 #if NSYSTRACE > 0
 	if (ISSET(p->p_flag, P_SYSTRACE) &&
@@ -702,6 +714,7 @@ bad:
  clrflag:
 #endif
 	atomic_clearbits_int(&p->p_flag, P_INEXEC);
+	single_thread_clear(p);
 
 	if (pathbuf != NULL)
 		pool_put(&namei_pool, pathbuf);
-- 
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