Commit 56d8e318 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe

io_uring/msg_ring: fix flagging remote execution

There is a couple of problems with queueing a tw in io_msg_ring_data()
for remote execution. First, once we queue it the target ring can
go away and so setting IORING_SQ_TASKRUN there is not safe. Secondly,
the userspace might not expect IORING_SQ_TASKRUN.

Extract a helper and uniformly use TWA_SIGNAL without TWA_SIGNAL_NO_IPI
tricks for now, just as it was done in the original patch.

Cc: stable@vger.kernel.org
Fixes: 6d043ee1 ("io_uring: do msg_ring in target task via tw")
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e12d7a46
...@@ -58,6 +58,25 @@ void io_msg_ring_cleanup(struct io_kiocb *req) ...@@ -58,6 +58,25 @@ void io_msg_ring_cleanup(struct io_kiocb *req)
msg->src_file = NULL; msg->src_file = NULL;
} }
static inline bool io_msg_need_remote(struct io_ring_ctx *target_ctx)
{
if (!target_ctx->task_complete)
return false;
return current != target_ctx->submitter_task;
}
static int io_msg_exec_remote(struct io_kiocb *req, task_work_func_t func)
{
struct io_ring_ctx *ctx = req->file->private_data;
struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);
init_task_work(&msg->tw, func);
if (task_work_add(ctx->submitter_task, &msg->tw, TWA_SIGNAL))
return -EOWNERDEAD;
return IOU_ISSUE_SKIP_COMPLETE;
}
static void io_msg_tw_complete(struct callback_head *head) static void io_msg_tw_complete(struct callback_head *head)
{ {
struct io_msg *msg = container_of(head, struct io_msg, tw); struct io_msg *msg = container_of(head, struct io_msg, tw);
...@@ -96,15 +115,8 @@ static int io_msg_ring_data(struct io_kiocb *req, unsigned int issue_flags) ...@@ -96,15 +115,8 @@ static int io_msg_ring_data(struct io_kiocb *req, unsigned int issue_flags)
if (msg->src_fd || msg->dst_fd || msg->flags) if (msg->src_fd || msg->dst_fd || msg->flags)
return -EINVAL; return -EINVAL;
if (target_ctx->task_complete && current != target_ctx->submitter_task) { if (io_msg_need_remote(target_ctx))
init_task_work(&msg->tw, io_msg_tw_complete); return io_msg_exec_remote(req, io_msg_tw_complete);
if (task_work_add(target_ctx->submitter_task, &msg->tw,
TWA_SIGNAL_NO_IPI))
return -EOWNERDEAD;
atomic_or(IORING_SQ_TASKRUN, &target_ctx->rings->sq_flags);
return IOU_ISSUE_SKIP_COMPLETE;
}
ret = -EOVERFLOW; ret = -EOVERFLOW;
if (target_ctx->flags & IORING_SETUP_IOPOLL) { if (target_ctx->flags & IORING_SETUP_IOPOLL) {
...@@ -202,14 +214,8 @@ static int io_msg_send_fd(struct io_kiocb *req, unsigned int issue_flags) ...@@ -202,14 +214,8 @@ static int io_msg_send_fd(struct io_kiocb *req, unsigned int issue_flags)
req->flags |= REQ_F_NEED_CLEANUP; req->flags |= REQ_F_NEED_CLEANUP;
} }
if (target_ctx->task_complete && current != target_ctx->submitter_task) { if (io_msg_need_remote(target_ctx))
init_task_work(&msg->tw, io_msg_tw_fd_complete); return io_msg_exec_remote(req, io_msg_tw_fd_complete);
if (task_work_add(target_ctx->submitter_task, &msg->tw,
TWA_SIGNAL))
return -EOWNERDEAD;
return IOU_ISSUE_SKIP_COMPLETE;
}
return io_msg_install_complete(req, issue_flags); return io_msg_install_complete(req, issue_flags);
} }
......
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