Commit 72925dec authored by Umang Jain's avatar Umang Jain Committed by Greg Kroah-Hartman
Browse files

staging: vchiq_core: Return -EINTR in queue_message() on interrupt 



queue_message() uses mutex_lock_killable() and
wait_for_completion_killable() variations of locking and wait event
completions respectively. These functions return either 0 (on success)
or -EINTR, if interrupted by a fatal signal (as documented in the
kernel).

However, queue_message() is currently returning -EAGAIN if these
killable functions are interrupted by fatal signals. Bubbling up
-EAGAIN might give a sense to the caller, that the code path can
be re-tried however, in actual sense, a fatal signal has been
received by the process and the process is going away.

Hence, we should align the return value with what these killable
versions will return i.e. -EINTR (Interrupted system call).

Signed-off-by: default avatarUmang Jain <umang.jain@ideasonboard.com>
Link: https://lore.kernel.org/r/20240918163100.870596-4-umang.jain@ideasonboard.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fbd06c75

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c

+11 −11
Original line number Diff line number Diff line
@@ -922,7 +922,7 @@ queue_message(struct vchiq_state *state, struct vchiq_service *service, 


	if (!(flags & QMFLAGS_NO_MUTEX_LOCK) &&

	    mutex_lock_killable(&state->slot_mutex))

		return -EAGAIN;

		return -EINTR;



	if (type == VCHIQ_MSG_DATA) {

		int tx_end_index;
@@ -963,7 +963,7 @@ queue_message(struct vchiq_state *state, struct vchiq_service *service, 
			mutex_unlock(&state->slot_mutex);



			if (wait_for_completion_killable(&state->data_quota_event))

				return -EAGAIN;

				return -EINTR;



			mutex_lock(&state->slot_mutex);

			spin_lock(&state->quota_spinlock);
@@ -987,11 +987,11 @@ queue_message(struct vchiq_state *state, struct vchiq_service *service, 
			VCHIQ_SERVICE_STATS_INC(service, quota_stalls);

			mutex_unlock(&state->slot_mutex);

			if (wait_for_completion_killable(&quota->quota_event))

				return -EAGAIN;

				return -EINTR;

			if (service->closing)

				return -EHOSTDOWN;

			if (mutex_lock_killable(&state->slot_mutex))

				return -EAGAIN;

				return -EINTR;

			if (service->srvstate != VCHIQ_SRVSTATE_OPEN) {

				/* The service has been closed */

				mutex_unlock(&state->slot_mutex);
@@ -1524,7 +1524,7 @@ parse_open(struct vchiq_state *state, struct vchiq_header *header) 
			set_service_state(service, VCHIQ_SRVSTATE_OPENSYNC);

		} else {

			if (queue_message(state, NULL, openack_id, memcpy_copy_callback,

					  &ack_payload, sizeof(ack_payload), 0) == -EAGAIN)

					  &ack_payload, sizeof(ack_payload), 0) == -EINTR)

				goto bail_not_ready;



			/* The service is now open */
@@ -1539,7 +1539,7 @@ parse_open(struct vchiq_state *state, struct vchiq_header *header) 
fail_open:

	/* No available service, or an invalid request - send a CLOSE */

	if (queue_message(state, NULL, MAKE_CLOSE(0, VCHIQ_MSG_SRCPORT(msgid)),

			  NULL, NULL, 0, 0) == -EAGAIN)

			  NULL, NULL, 0, 0) == -EINTR)

		goto bail_not_ready;



	return 1;
@@ -1786,7 +1786,7 @@ parse_message(struct vchiq_state *state, struct vchiq_header *header) 
		if (state->conn_state != VCHIQ_CONNSTATE_PAUSE_SENT) {

			/* Send a PAUSE in response */

			if (queue_message(state, NULL, MAKE_PAUSE, NULL, NULL, 0,

					  QMFLAGS_NO_MUTEX_UNLOCK) == -EAGAIN)

					  QMFLAGS_NO_MUTEX_UNLOCK) == -EINTR)

				goto bail_not_ready;

		}

		/* At this point slot_mutex is held */
@@ -1903,7 +1903,7 @@ handle_poll(struct vchiq_state *state) 


	case VCHIQ_CONNSTATE_PAUSING:

		if (queue_message(state, NULL, MAKE_PAUSE, NULL, NULL, 0,

				  QMFLAGS_NO_MUTEX_UNLOCK) != -EAGAIN) {

				  QMFLAGS_NO_MUTEX_UNLOCK) != -EINTR) {

			vchiq_set_conn_state(state, VCHIQ_CONNSTATE_PAUSE_SENT);

		} else {

			/* Retry later */
@@ -1913,7 +1913,7 @@ handle_poll(struct vchiq_state *state) 


	case VCHIQ_CONNSTATE_RESUMING:

		if (queue_message(state, NULL, MAKE_RESUME, NULL, NULL, 0,

				  QMFLAGS_NO_MUTEX_LOCK) != -EAGAIN) {

				  QMFLAGS_NO_MUTEX_LOCK) != -EINTR) {

			vchiq_set_conn_state(state, VCHIQ_CONNSTATE_CONNECTED);

		} else {

			/*
@@ -3276,11 +3276,11 @@ int vchiq_queue_kernel_message(struct vchiq_instance *instance, unsigned int han 
					     data, size);



		/*

		 * vchiq_queue_message() may return -EAGAIN, so we need to

		 * vchiq_queue_message() may return -EINTR, so we need to

		 * implement a retry mechanism since this function is supposed

		 * to block until queued

		 */

		if (status != -EAGAIN)

		if (status != -EINTR)

			break;



		msleep(1);