From: Ryota Ozaki <ozaki.ryota@gmail.com>
Date: Thu, 3 May 2012 05:43:44 +0000 (+1000)
Subject: mm: fix off-by-one bug in print_nodes_state()
X-Git-Tag: next-20120503~2^2~208
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e7f53dbcb23b4c8c67d415fa5d4bd2a3d22dfbcb;p=karo-tx-linux.git

mm: fix off-by-one bug in print_nodes_state()

/sys/devices/system/node/{online,possible} outputs a garbage byte because
print_nodes_state() returns content size + 1.  To fix the bug, the patch
changes the use of cpuset_sprintf_cpulist to follow the use at other
places, which is clearer and safer.

This bug was introduced since v2.6.24 (bde631a51876f23e9).

Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 90aa2a11a933..af1a177216f1 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -592,11 +592,9 @@ static ssize_t print_nodes_state(enum node_states state, char *buf)
 {
 	int n;
 
-	n = nodelist_scnprintf(buf, PAGE_SIZE, node_states[state]);
-	if (n > 0 && PAGE_SIZE > n + 1) {
-		*(buf + n++) = '\n';
-		*(buf + n++) = '\0';
-	}
+	n = nodelist_scnprintf(buf, PAGE_SIZE-2, node_states[state]);
+	buf[n++] = '\n';
+	buf[n] = '\0';
 	return n;
 }