From rientjes@google.com Tue Mar 16 13:26:23 2010 From: David Rientjes Date: Wed, 10 Mar 2010 14:50:21 -0800 (PST) Subject: driver core: numa: fix BUILD_BUG_ON for node_read_distance To: Greg Kroah-Hartman Message-ID: node_read_distance() has a BUILD_BUG_ON() to prevent buffer overruns when the number of nodes printed will exceed the buffer length. Each node only needs four chars: three for distance (maximum distance is 255) and one for a seperating space or a trailing newline. Signed-off-by: David Rientjes Cc: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- drivers/base/node.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -165,8 +165,11 @@ static ssize_t node_read_distance(struct int len = 0; int i; - /* buf currently PAGE_SIZE, need ~4 chars per node */ - BUILD_BUG_ON(MAX_NUMNODES*4 > PAGE_SIZE/2); + /* + * buf is currently PAGE_SIZE in length and each node needs 4 chars + * at the most (distance + space or newline). + */ + BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE); for_each_online_node(i) len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));