From: Josh Triplett <josht@us.ibm.com>
Date: Wed, 4 Oct 2006 09:17:11 +0000 (-0700)
Subject: [PATCH] rcu: Avoid kthread_stop on invalid pointer if rcutorture reader startup fails
X-Git-Tag: v2.6.19-rc1~51
X-Git-Url: http://git.rot13.org/?a=commitdiff_plain;h=2860aaba4dc87fa43c08724434b87a8650f3bff5;p=powerpc.git

[PATCH] rcu: Avoid kthread_stop on invalid pointer if rcutorture reader startup fails

rcu_torture_init kmallocs the array of reader threads, then creates each
one with kthread_run, cleaning up with rcu_torture_cleanup if this fails.
rcu_torture_cleanup calls kthread_stop on any non-NULL pointer in the
array; however, any readers after the one that failed to start up will have
invalid pointers, not null pointers.  Avoid this by using kzalloc instead.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 021d3108bb..42e7f01e80 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -780,7 +780,7 @@ rcu_torture_init(void)
 		writer_task = NULL;
 		goto unwind;
 	}
-	reader_tasks = kmalloc(nrealreaders * sizeof(reader_tasks[0]),
+	reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
 			       GFP_KERNEL);
 	if (reader_tasks == NULL) {
 		VERBOSE_PRINTK_ERRSTRING("out of memory");