openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
Bart Van Assche 2016-09-14 10:46:22 +02:00 committed by Jens Axboe
parent 4382e33ad3
commit 3e1de31b9b
1 changed files with 12 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
include/linux/blk_types.h
View File

@ -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)