diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c index 6759a6261500..3a2e4582db8e 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c @@ -1058,15 +1058,27 @@ service_callback(enum vchiq_reason reason, struct vchiq_header *header, DEBUG_TRACE(SERVICE_CALLBACK_LINE); + rcu_read_lock(); service = handle_to_service(handle); - if (WARN_ON(!service)) + if (WARN_ON(!service)) { + rcu_read_unlock(); return VCHIQ_SUCCESS; + } user_service = (struct user_service *)service->base.userdata; instance = user_service->instance; - if (!instance || instance->closing) + if (!instance || instance->closing) { + rcu_read_unlock(); return VCHIQ_SUCCESS; + } + + /* + * As hopping around different synchronization mechanism, + * taking an extra reference results in simpler implementation. + */ + vchiq_service_get(service); + rcu_read_unlock(); vchiq_log_trace(vchiq_arm_log_level, "%s - service %lx(%d,%p), reason %d, header %lx, instance %lx, bulk_userdata %lx", @@ -1097,6 +1109,7 @@ service_callback(enum vchiq_reason reason, struct vchiq_header *header, bulk_userdata); if (status != VCHIQ_SUCCESS) { DEBUG_TRACE(SERVICE_CALLBACK_LINE); + vchiq_service_put(service); return status; } } @@ -1105,10 +1118,12 @@ service_callback(enum vchiq_reason reason, struct vchiq_header *header, if (wait_for_completion_interruptible(&user_service->remove_event)) { vchiq_log_info(vchiq_arm_log_level, "%s interrupted", __func__); DEBUG_TRACE(SERVICE_CALLBACK_LINE); + vchiq_service_put(service); return VCHIQ_RETRY; } else if (instance->closing) { vchiq_log_info(vchiq_arm_log_level, "%s closing", __func__); DEBUG_TRACE(SERVICE_CALLBACK_LINE); + vchiq_service_put(service); return VCHIQ_ERROR; } DEBUG_TRACE(SERVICE_CALLBACK_LINE); @@ -1137,6 +1152,7 @@ service_callback(enum vchiq_reason reason, struct vchiq_header *header, header = NULL; } DEBUG_TRACE(SERVICE_CALLBACK_LINE); + vchiq_service_put(service); if (skip_completion) return VCHIQ_SUCCESS;