io_uring: add build check for buf_index overflows

req->buf_index is u16 and so we rely on registered buffers indexes
fitting into it. Add a build check, so when the upper limit for the
number of buffers is lifted we get a compliation fail but not lurking
problems.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/787e8e1a17cea51ca6301426b1c4c4887b8bd676.1629920396.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-08-25 20:51:40 +01:00 committed by Jens Axboe
parent b18a1a4574
commit 90499ad00c

View File

@ -10493,6 +10493,10 @@ static int __init io_uring_init(void)
sizeof(struct io_uring_rsrc_update));
BUILD_BUG_ON(sizeof(struct io_uring_rsrc_update) >
sizeof(struct io_uring_rsrc_update2));
/* ->buf_index is u16 */
BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16));
/* should fit into one byte */
BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8));