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staging: vchiq_core: Bubble up wait_event_interruptible() return value

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BugLink: https://bugs.launchpad.net/bugs/2085849

[ 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@ideasonboard.com>
Tested-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240703131052.597443-2-umang.jain@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
This commit is contained in:
Umang Jain
2024-07-03 18:40:51 +05:30
committed by Mehmet Basaran
parent 69811809b0
commit 635fad3da5
1 changed files with 24 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+24 -7
View File
@@ -503,16 +503,21 @@ 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). */
@@ -520,7 +525,7 @@ remote_event_wait(wait_queue_head_t *wq, struct remote_event *event)
}
event->fired = 0;
return 1;
return ret;
}
/*
@@ -1141,6 +1146,7 @@ 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;
@@ -1148,7 +1154,9 @@ 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();
@@ -1933,13 +1941,16 @@ 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();
@@ -1970,6 +1981,7 @@ 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);
@@ -1979,7 +1991,9 @@ 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);
}
@@ -1996,6 +2010,7 @@ 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;
@@ -2003,7 +2018,9 @@ 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();