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authorAnuj Gupta <anuj20.g@samsung.com>2022-09-30 11:57:39 +0530
committerJens Axboe <axboe@kernel.dk>2022-09-30 07:50:59 -0600
commit9cda70f622cdcf049521a9c2886e5fd8a90a0591 (patch)
tree4b56fa2929bfb24a0211c20e561a55453c041878 /io_uring
parenta9216fac3ed8819cbbda5d39dd5fcaa43dfd35d8 (diff)
io_uring: introduce fixed buffer support for io_uring_cmd
Add IORING_URING_CMD_FIXED flag that is to be used for sending io_uring command with previously registered buffers. User-space passes the buffer index in sqe->buf_index, same as done in read/write variants that uses fixed buffers. Signed-off-by: Anuj Gupta <anuj20.g@samsung.com> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20220930062749.152261-3-anuj20.g@samsung.com [axboe: shuffle valid flags check before acting on it] Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
-rw-r--r--io_uring/uring_cmd.c19
1 files changed, 18 insertions, 1 deletions
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 6a6d69523d75..e50de0b6b9f8 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -4,6 +4,7 @@
#include <linux/file.h>
#include <linux/io_uring.h>
#include <linux/security.h>
+#include <linux/nospec.h>
#include <uapi/linux/io_uring.h>
@@ -77,8 +78,24 @@ int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
- if (sqe->rw_flags || sqe->__pad1)
+ if (sqe->__pad1)
return -EINVAL;
+
+ ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
+ if (ioucmd->flags & ~IORING_URING_CMD_FIXED)
+ return -EINVAL;
+
+ if (ioucmd->flags & IORING_URING_CMD_FIXED) {
+ struct io_ring_ctx *ctx = req->ctx;
+ u16 index;
+
+ req->buf_index = READ_ONCE(sqe->buf_index);
+ if (unlikely(req->buf_index >= ctx->nr_user_bufs))
+ return -EFAULT;
+ index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
+ req->imu = ctx->user_bufs[index];
+ io_req_set_rsrc_node(req, ctx, 0);
+ }
ioucmd->cmd = sqe->cmd;
ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
return 0;