On Fri, 27 Jul 2012 13:09:53 +0200, Stefan Behrens wrote: > On Fri, 27 Jul 2012 16:04:14 +0530, Nageswara R Sastry wrote: >> Check for the return value of 'open_ctree()' before dereferencing it. >> >> Signed-off-by: Nageswara R Sastry <nasastry@xxxxxxxxxx> >> --- >> btrfs-image.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/btrfs-image.c b/btrfs-image.c >> index f2bbcc8..2a33a55 100644 >> --- a/btrfs-image.c >> +++ b/btrfs-image.c >> @@ -491,6 +491,7 @@ static int create_metadump(const char *input, FILE *out, int num_threads, >> int ret; >> >> root = open_ctree(input, 0, 0); >> + BUG_ON(!root); >> BUG_ON(root->nodesize != root->leafsize); >> >> ret = metadump_init(&metadump, root, out, num_threads, >> > > In general, explicit BUG_ON() checks for a NULL pointer are not added to > the Linux kernel if the pointer is dereferenced afterwards. When the > NULL area is accessed, you get a general protection fault including the > call trace and a dump of all registers. Adding explicit BUG_ON(ptr != > NULL) adds overhead without bringing any additional information. Please ignore and excuse my noise from before. Your patch is for btrfs-progs, not for the kernel. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
