| Message ID | 1520873548-26667-1-git-send-email-nborisov@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Mar 12, 2018 at 06:52:28PM +0200, Nikolay Borisov wrote: > The kernel would like to have all stack VLA usage removed[1]. > Unfortunately using an integer constant variable as the size of an > array is still considered a VLA. Instead let's use directly sizeof(var) > which removes the VLA usage. Use the occasion to remove csum_size > altogether and use sizeof() also for the size passed to memcmp The point of csum_size here is to define once, use everywhere, so we don't have to opencode sizeof. To avoid the 'not really a VLA', we can rewrite that. > > [1]: https://lkml.org/lkml/2018/3/7/621 > > Signed-off-by: Nikolay Borisov <nborisov@suse.com> > --- > fs/btrfs/disk-io.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index 3809d6d66f6a..6247162e334a 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -403,8 +403,7 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info, > > if (csum_type == BTRFS_CSUM_TYPE_CRC32) { > u32 crc = ~(u32)0; > - const int csum_size = sizeof(crc); > - char result[csum_size]; > + char result[sizeof(crc)]; > > /* > * The super_block structure does not span the whole > @@ -415,7 +414,7 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info, > crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); > btrfs_csum_final(crc, result); > > - if (memcmp(raw_disk_sb, result, csum_size)) > + if (memcmp(raw_disk_sb, result, sizeof(crc))) sizeof(result) would be better here as it's clear what we're going to memcpy, while 'crc' is define somewhere above. > ret = 1; > } > > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 3809d6d66f6a..6247162e334a 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -403,8 +403,7 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info, if (csum_type == BTRFS_CSUM_TYPE_CRC32) { u32 crc = ~(u32)0; - const int csum_size = sizeof(crc); - char result[csum_size]; + char result[sizeof(crc)]; /* * The super_block structure does not span the whole @@ -415,7 +414,7 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info, crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); btrfs_csum_final(crc, result); - if (memcmp(raw_disk_sb, result, csum_size)) + if (memcmp(raw_disk_sb, result, sizeof(crc))) ret = 1; }
The kernel would like to have all stack VLA usage removed[1]. Unfortunately using an integer constant variable as the size of an array is still considered a VLA. Instead let's use directly sizeof(var) which removes the VLA usage. Use the occasion to remove csum_size altogether and use sizeof() also for the size passed to memcmp [1]: https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Nikolay Borisov <nborisov@suse.com> --- fs/btrfs/disk-io.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)