block: Improve bio_set_op_attrs() robustness (3e1de31b) · Commits · 戴 / test

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>

include/linux/blk_types.h

+12 −5

Original line number	Original line	Diff line number	Diff line
	@@ -94,10 +94,17 @@ struct bio {
	#define bio_op(bio) ((bio)->bi_opf >> BIO_OP_SHIFT)		#define bio_op(bio) ((bio)->bi_opf >> BIO_OP_SHIFT)

	#define bio_set_op_attrs(bio, op, op_flags) do { \		#define bio_set_op_attrs(bio, op, op_flags) do { \
	WARN_ON(op >= (1 << REQ_OP_BITS)); \		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 = bio_flags(bio); \
	(bio)->bi_opf \|= ((unsigned int) (op) << BIO_OP_SHIFT); \		(bio)->bi_opf \|= (((op) + 0U) << BIO_OP_SHIFT); \
	(bio)->bi_opf \|= op_flags; \		(bio)->bi_opf \|= (op_flags); \
	} while (0)		} while (0)

	#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)		#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)

Admin message