Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 12/12] driver core: numa: fix BUILD_BUG_ON for node_read_distance | Date | Fri, 19 Mar 2010 08:18:55 -0700 |
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From: David Rientjes <rientjes@google.com>
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 <rientjes@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- drivers/base/node.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/base/node.c b/drivers/base/node.c index ad43185..93b3ac6 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -165,8 +165,11 @@ static ssize_t node_read_distance(struct sys_device * dev, 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)); -- 1.7.0.2
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