mm, percpu: Make sure percpu_alloc early parameter has an argument

Otherwise we are getting a nil dereference if percpu_alloc kernel boot argument is specified without value. | [ 0.000000] BUG: unable to handle kernel NULL pointer dereference at (null) | [ 0.000000] IP: [<ffffffff81391360>] strcmp+0x10/0x30 Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Tejun Heo <tj@kernel.org>
AhmedMostafa16 · Dec 2, 2012 · 5479c78 · 5479c78
1 parent b4916cb
commit 5479c78
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/mm/percpu.c b/mm/percpu.c
@@ -1380,6 +1380,9 @@ enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO;
 
 static int __init percpu_alloc_setup(char *str)
 {
+	if (!str)
+		return -EINVAL;
+
 	if (0)
 		/* nada */;
 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK