From c6c7db5816d9061a769c46dda626f4da6220c682 Mon Sep 17 00:00:00 2001
From: Andrew Morton <akpm@linux-foundation.org>
Date: Wed, 27 Mar 2013 10:25:04 +1100
Subject: [PATCH] argv_split-teach-it-to-handle-mutable-strings-fix

Cc: Andi Kleen <andi@firstfloor.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 lib/argv_split.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/argv_split.c b/lib/argv_split.c
index fa7d30abd5d4..cac7ec49e149 100644
--- a/lib/argv_split.c
+++ b/lib/argv_split.c
@@ -51,6 +51,10 @@ EXPORT_SYMBOL(argv_free);
  * considered to be a single argument separator.  The returned array
  * is always NULL-terminated.  Returns NULL on memory allocation
  * failure.
+ *
+ * The source string at `str' may be undergoing concurrent alteration via
+ * userspace sysctl activity (at least).  The argv_split() implementation
+ * attempts to handle this gracefully by taking a local copy to work on.
  */
 char **argv_split(gfp_t gfp, const char *str, int *argcp)
 {
-- 
2.39.5