From 81a897937827a81107861d50c77b4d04ff8b43a2 Mon Sep 17 00:00:00 2001 From: Alex Elder <elder@dreamhost.com> Date: Thu, 2 Feb 2012 08:13:30 -0600 Subject: [PATCH] rbd: do a few checks at build time This is a bit gratuitous, but there are a few things that can be verified at build time rather than run time, so do that. Signed-off-by: Alex Elder <elder@dreamhost.com> --- drivers/block/rbd.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 085df6765d21..14d0a3c9f96a 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -53,7 +53,14 @@ #define RBD_SNAP_HEAD_NAME "-" +/* + * An RBD device name will be "rbd#", where the "rbd" comes from + * RBD_DRV_NAME above, and # is a unique integer identifier. + * MAX_INT_FORMAT_WIDTH is used in ensuring DEV_NAME_LEN is big + * enough to hold all possible device names. + */ #define DEV_NAME_LEN 32 +#define MAX_INT_FORMAT_WIDTH ((5 * sizeof (int)) / 2 + 1) #define RBD_NOTIFY_TIMEOUT_DEFAULT 10 @@ -2304,8 +2311,9 @@ static int rbd_add_parse_args(struct rbd_device *rbd_dev, rbd_dev->obj_len = len; - snprintf(rbd_dev->obj_md_name, sizeof(rbd_dev->obj_md_name), "%s%s", - rbd_dev->obj, RBD_SUFFIX); + BUILD_BUG_ON(RBD_MAX_MD_NAME_LEN + < RBD_MAX_OBJ_NAME_LEN + sizeof (RBD_SUFFIX)); + sprintf(rbd_dev->obj_md_name, "%s%s", rbd_dev->obj, RBD_SUFFIX); /* * The snapshot name is optional, but it's an error if it's @@ -2355,7 +2363,9 @@ static ssize_t rbd_add(struct bus_type *bus, rbd_id_get(rbd_dev); /* Fill in the device name, now that we have its id. */ - snprintf(rbd_dev->name, DEV_NAME_LEN, RBD_DRV_NAME "%d", rbd_dev->id); + BUILD_BUG_ON(DEV_NAME_LEN + < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH); + sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->id); /* parse add command */ rc = rbd_add_parse_args(rbd_dev, buf, mon_addrs, count, -- GitLab