Commit 2c41fab1 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'io_uring-5.12-2021-03-21' of git://git.kernel.dk/linux-block 

Pull io_uring followup fixes from Jens Axboe:

 - The SIGSTOP change from Eric, so we properly ignore that for
   PF_IO_WORKER threads.

 - Disallow sending signals to PF_IO_WORKER threads in general, we're
   not interested in having them funnel back to the io_uring owning
   task.

 - Stable fix from Stefan, ensuring we properly break links for short
   send/sendmsg recv/recvmsg if MSG_WAITALL is set.

 - Catch and loop when needing to run task_work before a PF_IO_WORKER
   threads goes to sleep.

* tag 'io_uring-5.12-2021-03-21' of git://git.kernel.dk/linux-block:
  io_uring: call req_set_fail_links() on short send[msg]()/recv[msg]() with MSG_WAITALL
  io-wq: ensure task is running before processing task_work
  signal: don't allow STOP on PF_IO_WORKER threads
  signal: don't allow sending any signals to PF_IO_WORKER threads
parents 1d4345eb 0031275d

fs/io-wq.c

+6 −2
Original line number Diff line number Diff line
@@ -386,13 +386,16 @@ static struct io_wq_work *io_get_next_work(struct io_wqe *wqe) 
	return NULL;

}



static void io_flush_signals(void)

static bool io_flush_signals(void)

{

	if (unlikely(test_tsk_thread_flag(current, TIF_NOTIFY_SIGNAL))) {

		__set_current_state(TASK_RUNNING);

		if (current->task_works)

			task_work_run();

		clear_tsk_thread_flag(current, TIF_NOTIFY_SIGNAL);

		return true;

	}

	return false;

}



static void io_assign_current_work(struct io_worker *worker,
@@ -499,7 +502,8 @@ static int io_wqe_worker(void *data) 
		}

		__io_worker_idle(wqe, worker);

		raw_spin_unlock_irq(&wqe->lock);

		io_flush_signals();

		if (io_flush_signals())

			continue;

		ret = schedule_timeout(WORKER_IDLE_TIMEOUT);

		if (try_to_freeze() || ret)

			continue;

fs/io_uring.c

+20 −4
Original line number Diff line number Diff line
@@ -4386,6 +4386,7 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_async_msghdr iomsg, *kmsg;

	struct socket *sock;

	unsigned flags;

	int min_ret = 0;

	int ret;



	sock = sock_from_file(req->file);
@@ -4406,6 +4407,9 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) 
	else if (issue_flags & IO_URING_F_NONBLOCK)

		flags |= MSG_DONTWAIT;



	if (flags & MSG_WAITALL)

		min_ret = iov_iter_count(&kmsg->msg.msg_iter);



	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);

	if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN)

		return io_setup_async_msg(req, kmsg);
@@ -4416,7 +4420,7 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) 
	if (kmsg->free_iov)

		kfree(kmsg->free_iov);

	req->flags &= ~REQ_F_NEED_CLEANUP;

	if (ret < 0)

	if (ret < min_ret)

		req_set_fail_links(req);

	__io_req_complete(req, issue_flags, ret, 0);

	return 0;
@@ -4429,6 +4433,7 @@ static int io_send(struct io_kiocb *req, unsigned int issue_flags) 
	struct iovec iov;

	struct socket *sock;

	unsigned flags;

	int min_ret = 0;

	int ret;



	sock = sock_from_file(req->file);
@@ -4450,6 +4455,9 @@ static int io_send(struct io_kiocb *req, unsigned int issue_flags) 
	else if (issue_flags & IO_URING_F_NONBLOCK)

		flags |= MSG_DONTWAIT;



	if (flags & MSG_WAITALL)

		min_ret = iov_iter_count(&msg.msg_iter);



	msg.msg_flags = flags;

	ret = sock_sendmsg(sock, &msg);

	if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN)
@@ -4457,7 +4465,7 @@ static int io_send(struct io_kiocb *req, unsigned int issue_flags) 
	if (ret == -ERESTARTSYS)

		ret = -EINTR;



	if (ret < 0)

	if (ret < min_ret)

		req_set_fail_links(req);

	__io_req_complete(req, issue_flags, ret, 0);

	return 0;
@@ -4609,6 +4617,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) 
	struct socket *sock;

	struct io_buffer *kbuf;

	unsigned flags;

	int min_ret = 0;

	int ret, cflags = 0;

	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
@@ -4640,6 +4649,9 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) 
	else if (force_nonblock)

		flags |= MSG_DONTWAIT;



	if (flags & MSG_WAITALL)

		min_ret = iov_iter_count(&kmsg->msg.msg_iter);



	ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,

					kmsg->uaddr, flags);

	if (force_nonblock && ret == -EAGAIN)
@@ -4653,7 +4665,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) 
	if (kmsg->free_iov)

		kfree(kmsg->free_iov);

	req->flags &= ~REQ_F_NEED_CLEANUP;

	if (ret < 0)

	if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))

		req_set_fail_links(req);

	__io_req_complete(req, issue_flags, ret, cflags);

	return 0;
@@ -4668,6 +4680,7 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) 
	struct socket *sock;

	struct iovec iov;

	unsigned flags;

	int min_ret = 0;

	int ret, cflags = 0;

	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
@@ -4699,6 +4712,9 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) 
	else if (force_nonblock)

		flags |= MSG_DONTWAIT;



	if (flags & MSG_WAITALL)

		min_ret = iov_iter_count(&msg.msg_iter);



	ret = sock_recvmsg(sock, &msg, flags);

	if (force_nonblock && ret == -EAGAIN)

		return -EAGAIN;
@@ -4707,7 +4723,7 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) 
out_free:

	if (req->flags & REQ_F_BUFFER_SELECTED)

		cflags = io_put_recv_kbuf(req);

	if (ret < 0)

	if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))

		req_set_fail_links(req);

	__io_req_complete(req, issue_flags, ret, cflags);

	return 0;

kernel/signal.c

+5 −1
Original line number Diff line number Diff line
@@ -288,7 +288,8 @@ bool task_set_jobctl_pending(struct task_struct *task, unsigned long mask) 
			JOBCTL_STOP_SIGMASK | JOBCTL_TRAPPING));

	BUG_ON((mask & JOBCTL_TRAPPING) && !(mask & JOBCTL_PENDING_MASK));



	if (unlikely(fatal_signal_pending(task) || (task->flags & PF_EXITING)))

	if (unlikely(fatal_signal_pending(task) ||

		     (task->flags & (PF_EXITING | PF_IO_WORKER))))

		return false;



	if (mask & JOBCTL_STOP_SIGMASK)
@@ -833,6 +834,9 @@ static int check_kill_permission(int sig, struct kernel_siginfo *info, 


	if (!valid_signal(sig))

		return -EINVAL;

	/* PF_IO_WORKER threads don't take any signals */

	if (t->flags & PF_IO_WORKER)

		return -ESRCH;



	if (!si_fromuser(info))

		return 0;