diff options
| author | Bart Van Assche | 2016-09-14 10:46:22 +0200 |
|---|---|---|
| committer | Jens Axboe | 2016-09-14 08:48:29 -0600 |
| commit | 3e1de31b9bf608c5b35e2d0d134eb87f2a9ba4ae (patch) | |
| tree | b06d27e90f22588d73d1b969dab7f26fc6e82319 | |
| parent | 4382e33ad374862eacf62003bb02c750391ada05 (diff) | |
block: Improve bio_set_op_attrs() robustness
Since REQ_OP_BITS == 3 and __REQ_NR_BITS == 30 it is not that hard
to pass an op_flags argument to bio_set_op_attrs() that is larger
than the number of bits reserved for the op_flags argument. Complain
if this happens. Additionally, ensure that negative arguments trigger
a complaint (1 << ... is signed while 1U << ... is unsigned; adding
0U to an integer expression causes it to be promoted to an unsigned
type).
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | include/linux/blk_types.h | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 311fa2f478b8..53ee1a2acd4f 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -93,11 +93,18 @@ struct bio { #define bio_flags(bio) ((bio)->bi_opf & ((1 << BIO_OP_SHIFT) - 1)) #define bio_op(bio) ((bio)->bi_opf >> BIO_OP_SHIFT) -#define bio_set_op_attrs(bio, op, op_flags) do { \ - WARN_ON(op >= (1 << REQ_OP_BITS)); \ - (bio)->bi_opf = bio_flags(bio); \ - (bio)->bi_opf |= ((unsigned int) (op) << BIO_OP_SHIFT); \ - (bio)->bi_opf |= op_flags; \ +#define bio_set_op_attrs(bio, op, op_flags) do { \ + if (__builtin_constant_p(op)) \ + BUILD_BUG_ON((op) + 0U >= (1U << REQ_OP_BITS)); \ + else \ + WARN_ON_ONCE((op) + 0U >= (1U << REQ_OP_BITS)); \ + if (__builtin_constant_p(op_flags)) \ + BUILD_BUG_ON((op_flags) + 0U >= (1U << BIO_OP_SHIFT)); \ + else \ + WARN_ON_ONCE((op_flags) + 0U >= (1U << BIO_OP_SHIFT)); \ + (bio)->bi_opf = bio_flags(bio); \ + (bio)->bi_opf |= (((op) + 0U) << BIO_OP_SHIFT); \ + (bio)->bi_opf |= (op_flags); \ } while (0) #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs) |