io_uring/kbuf: Allow the full buffer id space for provided buffers

[ Upstream commit f74c746e476b9dad51448b9a9421aae72b60e25f ]

nbufs tracks the number of buffers and not the last bgid. In 16-bit, we
have 2^16 valid buffers, but the check mistakenly rejects the last
bid. Let's fix it to make the interface consistent with the
documentation.

Fixes: ddf0322db7 ("io_uring: add IORING_OP_PROVIDE_BUFFERS")
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20231005000531.30800-3-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Gabriel Krisman Bertazi 2023-10-04 20:05:30 -04:00 committed by Greg Kroah-Hartman
parent 60db638be5
commit 32b15fef33
1 changed files with 7 additions and 4 deletions

View File

@ -19,12 +19,15 @@
#define BGID_ARRAY 64
/* BIDs are addressed by a 16-bit field in a CQE */
#define MAX_BIDS_PER_BGID (1 << 16)
struct io_provide_buf {
struct file *file;
__u64 addr;
__u32 len;
__u32 bgid;
__u16 nbufs;
__u32 nbufs;
__u16 bid;
};
@ -281,7 +284,7 @@ int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return -EINVAL;
tmp = READ_ONCE(sqe->fd);
if (!tmp || tmp > USHRT_MAX)
if (!tmp || tmp > MAX_BIDS_PER_BGID)
return -EINVAL;
memset(p, 0, sizeof(*p));
@ -327,7 +330,7 @@ int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe
return -EINVAL;
tmp = READ_ONCE(sqe->fd);
if (!tmp || tmp > USHRT_MAX)
if (!tmp || tmp > MAX_BIDS_PER_BGID)
return -E2BIG;
p->nbufs = tmp;
p->addr = READ_ONCE(sqe->addr);
@ -347,7 +350,7 @@ int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe
tmp = READ_ONCE(sqe->off);
if (tmp > USHRT_MAX)
return -E2BIG;
if (tmp + p->nbufs > USHRT_MAX)
if (tmp + p->nbufs > MAX_BIDS_PER_BGID)
return -EINVAL;
p->bid = tmp;
return 0;