| Message ID | 20220930062749.152261-3-anuj20.g@samsung.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Fixed-buffer for uring-cmd/passthru | expand |
On 9/30/22 12:27 AM, Anuj Gupta wrote: > 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> > --- > include/linux/io_uring.h | 2 +- > include/uapi/linux/io_uring.h | 9 +++++++++ > io_uring/uring_cmd.c | 18 +++++++++++++++++- > 3 files changed, 27 insertions(+), 2 deletions(-) > > diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h > index 1dbf51115c30..e10c5cc81082 100644 > --- a/include/linux/io_uring.h > +++ b/include/linux/io_uring.h > @@ -28,7 +28,7 @@ struct io_uring_cmd { > void *cookie; > }; > u32 cmd_op; > - u32 pad; > + u32 flags; > u8 pdu[32]; /* available inline for free use */ > }; > > diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h > index 92f29d9505a6..ab7458033ee3 100644 > --- a/include/uapi/linux/io_uring.h > +++ b/include/uapi/linux/io_uring.h > @@ -56,6 +56,7 @@ struct io_uring_sqe { > __u32 hardlink_flags; > __u32 xattr_flags; > __u32 msg_ring_flags; > + __u32 uring_cmd_flags; > }; > __u64 user_data; /* data to be passed back at completion time */ > /* pack this to avoid bogus arm OABI complaints */ > @@ -219,6 +220,14 @@ enum io_uring_op { > IORING_OP_LAST, > }; > > +/* > + * sqe->uring_cmd_flags > + * IORING_URING_CMD_FIXED use registered buffer; pass thig flag > + * along with setting sqe->buf_index. > + */ > +#define IORING_URING_CMD_FIXED (1U << 0) > + > + > /* > * sqe->fsync_flags > */ > diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c > index 6a6d69523d75..05e8ad8cef87 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> > > @@ -77,7 +78,22 @@ 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) { > + 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); > + } > + if (ioucmd->flags & ~IORING_URING_CMD_FIXED) > return -EINVAL; Not that it _really_ matters, but why isn't this check the first thing that is done after reading the flags? No need to respin, I can just move it myself.
On Fri, Sep 30, 2022 at 7:28 PM Jens Axboe <axboe@kernel.dk> wrote: > > On 9/30/22 12:27 AM, Anuj Gupta wrote: > > 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> > > --- > > include/linux/io_uring.h | 2 +- > > include/uapi/linux/io_uring.h | 9 +++++++++ > > io_uring/uring_cmd.c | 18 +++++++++++++++++- > > 3 files changed, 27 insertions(+), 2 deletions(-) > > > > diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h > > index 1dbf51115c30..e10c5cc81082 100644 > > --- a/include/linux/io_uring.h > > +++ b/include/linux/io_uring.h > > @@ -28,7 +28,7 @@ struct io_uring_cmd { > > void *cookie; > > }; > > u32 cmd_op; > > - u32 pad; > > + u32 flags; > > u8 pdu[32]; /* available inline for free use */ > > }; > > > > diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h > > index 92f29d9505a6..ab7458033ee3 100644 > > --- a/include/uapi/linux/io_uring.h > > +++ b/include/uapi/linux/io_uring.h > > @@ -56,6 +56,7 @@ struct io_uring_sqe { > > __u32 hardlink_flags; > > __u32 xattr_flags; > > __u32 msg_ring_flags; > > + __u32 uring_cmd_flags; > > }; > > __u64 user_data; /* data to be passed back at completion time */ > > /* pack this to avoid bogus arm OABI complaints */ > > @@ -219,6 +220,14 @@ enum io_uring_op { > > IORING_OP_LAST, > > }; > > > > +/* > > + * sqe->uring_cmd_flags > > + * IORING_URING_CMD_FIXED use registered buffer; pass thig flag > > + * along with setting sqe->buf_index. > > + */ > > +#define IORING_URING_CMD_FIXED (1U << 0) > > + > > + > > /* > > * sqe->fsync_flags > > */ > > diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c > > index 6a6d69523d75..05e8ad8cef87 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> > > > > @@ -77,7 +78,22 @@ 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) { > > + 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); > > + } > > + if (ioucmd->flags & ~IORING_URING_CMD_FIXED) > > return -EINVAL; > > Not that it _really_ matters, but why isn't this check the first thing > that is done after reading the flags? No need to respin, I can just move > it myself. > Right, checking this condition should have been the first thing to do after reading the flags. Thanks for taking care of it. > -- > Jens Axboe -- Anuj Gupta
diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h index 1dbf51115c30..e10c5cc81082 100644 --- a/include/linux/io_uring.h +++ b/include/linux/io_uring.h @@ -28,7 +28,7 @@ struct io_uring_cmd { void *cookie; }; u32 cmd_op; - u32 pad; + u32 flags; u8 pdu[32]; /* available inline for free use */ }; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 92f29d9505a6..ab7458033ee3 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -56,6 +56,7 @@ struct io_uring_sqe { __u32 hardlink_flags; __u32 xattr_flags; __u32 msg_ring_flags; + __u32 uring_cmd_flags; }; __u64 user_data; /* data to be passed back at completion time */ /* pack this to avoid bogus arm OABI complaints */ @@ -219,6 +220,14 @@ enum io_uring_op { IORING_OP_LAST, }; +/* + * sqe->uring_cmd_flags + * IORING_URING_CMD_FIXED use registered buffer; pass thig flag + * along with setting sqe->buf_index. + */ +#define IORING_URING_CMD_FIXED (1U << 0) + + /* * sqe->fsync_flags */ diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 6a6d69523d75..05e8ad8cef87 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> @@ -77,7 +78,22 @@ 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) { + 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); + } + if (ioucmd->flags & ~IORING_URING_CMD_FIXED) return -EINVAL; ioucmd->cmd = sqe->cmd; ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);