6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx> [ Upstream commit c22502cb84d4c963f754e6d943d3133cfa80ba97 ] wait_event_interruptible() returns if the condition evaluates to true it receives a signal. However, the current code always assume that the wait_event_interruptible() returns only when the event is fired. This should not be the case as wait_event_interruptible() can return on receiving a signal (with -ERESTARTSYS as return value). We should consider this and bubble up the return value of wait_event_interruptible() to exactly know if the wait has failed and error out. This will also help to properly stop kthreads in the subsequent patch. Meanwhile at it, remote_wait_event() is modified to return 0 on success, and an error code (from wait_event_interruptible()) on failure. The return value is now checked for remote_wait_event() calls. Signed-off-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx> Tested-by: Stefan Wahren <wahrenst@xxxxxxx> Link: https://lore.kernel.org/r/20240703131052.597443-2-umang.jain@xxxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- .../interface/vchiq_arm/vchiq_core.c | 31 ++++++++++++++----- 1 file changed, 24 insertions(+), 7 deletions(-) diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c index df3af821f218..fb1907414cc1 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c @@ -501,16 +501,21 @@ remote_event_create(wait_queue_head_t *wq, struct remote_event *event) * routines where switched to the "interruptible" family of functions, as the * former was deemed unjustified and the use "killable" set all VCHIQ's * threads in D state. + * + * Returns: 0 on success, a negative error code on failure */ static inline int remote_event_wait(wait_queue_head_t *wq, struct remote_event *event) { + int ret = 0; + if (!event->fired) { event->armed = 1; dsb(sy); - if (wait_event_interruptible(*wq, event->fired)) { + ret = wait_event_interruptible(*wq, event->fired); + if (ret) { event->armed = 0; - return 0; + return ret; } event->armed = 0; /* Ensure that the peer sees that we are not waiting (armed == 0). */ @@ -518,7 +523,7 @@ remote_event_wait(wait_queue_head_t *wq, struct remote_event *event) } event->fired = 0; - return 1; + return ret; } /* @@ -1140,6 +1145,7 @@ queue_message_sync(struct vchiq_state *state, struct vchiq_service *service, struct vchiq_header *header; ssize_t callback_result; int svc_fourcc; + int ret; local = state->local; @@ -1147,7 +1153,9 @@ queue_message_sync(struct vchiq_state *state, struct vchiq_service *service, mutex_lock_killable(&state->sync_mutex)) return -EAGAIN; - remote_event_wait(&state->sync_release_event, &local->sync_release); + ret = remote_event_wait(&state->sync_release_event, &local->sync_release); + if (ret) + return ret; /* Ensure that reads don't overtake the remote_event_wait. */ rmb(); @@ -1929,13 +1937,16 @@ slot_handler_func(void *v) { struct vchiq_state *state = v; struct vchiq_shared_state *local = state->local; + int ret; DEBUG_INITIALISE(local); while (1) { DEBUG_COUNT(SLOT_HANDLER_COUNT); DEBUG_TRACE(SLOT_HANDLER_LINE); - remote_event_wait(&state->trigger_event, &local->trigger); + ret = remote_event_wait(&state->trigger_event, &local->trigger); + if (ret) + return ret; /* Ensure that reads don't overtake the remote_event_wait. */ rmb(); @@ -1966,6 +1977,7 @@ recycle_func(void *v) struct vchiq_shared_state *local = state->local; u32 *found; size_t length; + int ret; length = sizeof(*found) * BITSET_SIZE(VCHIQ_MAX_SERVICES); @@ -1975,7 +1987,9 @@ recycle_func(void *v) return -ENOMEM; while (1) { - remote_event_wait(&state->recycle_event, &local->recycle); + ret = remote_event_wait(&state->recycle_event, &local->recycle); + if (ret) + return ret; process_free_queue(state, found, length); } @@ -1992,6 +2006,7 @@ sync_func(void *v) (struct vchiq_header *)SLOT_DATA_FROM_INDEX(state, state->remote->slot_sync); int svc_fourcc; + int ret; while (1) { struct vchiq_service *service; @@ -1999,7 +2014,9 @@ sync_func(void *v) int type; unsigned int localport, remoteport; - remote_event_wait(&state->sync_trigger_event, &local->sync_trigger); + ret = remote_event_wait(&state->sync_trigger_event, &local->sync_trigger); + if (ret) + return ret; /* Ensure that reads don't overtake the remote_event_wait. */ rmb(); -- 2.43.0
