lkml.org 
[lkml]   [2010]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[patch] numa: fix BUILD_BUG_ON for node_read_distance
    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>
    ---
    drivers/base/node.c | 7 +++++--
    1 files changed, 5 insertions(+), 2 deletions(-)

    diff --git a/drivers/base/node.c b/drivers/base/node.c
    --- 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));

    \
     
     \ /
      Last update: 2010-03-10 23:53    [W:0.021 / U:31.844 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site