On Tue, 2017-01-31 at 00:01 +0300, Dan Carpenter wrote:
> It's hard to review this because there are no callers and the hash
> you're talking about is an RPI hash... You have no idea how lazy I
> am.
>
> You're right, that code looks racy but it's almost certainly harmless
> depending on how it's called. It has to race at the very very
> beginning
> otherwise it's fine.
I wonder if out of caution it would make sense to start stripping out
some of these entry points that don't have an obvious caller in the
kernel tree?
Anyway, here is the change from the linux-next tree. The change
essentially converts a call to a custom function
mutex_lock_interruptible_killable to simply mutex_lock_killable.
commit b826d73b3024485677163253b59ef9bd187ff765
Author: Arnd Bergmann <arnd@xxxxxxxx>
Date: Wed Nov 16 16:39:05 2016 +0100
staging: vc04_services: remove duplicate mutex_lock_interruptible
The driver tries to redefine mutex_lock_interruptible as an open-
coded
mutex_lock_killable, but that definition clashes with the normal
mutex_lock_interruptible definition when CONFIG_DEBUG_LOCK_ALLOC
is set:
staging/vc04_services/interface/vchiq_arm/vchiq_killable.h:67:0:
error: "mutex_lock_interruptible" redefined [-Werror]
#define mutex_lock_interruptible mutex_lock_interruptible_killable
include/linux/mutex.h:161:0: note: this is the location of the
previous definition
This simply removes the private implementation and uses the
normal mutex_lock_killable directly.
We could do the same for the down_interruptible_killable here, but
it's better to just remove the semaphores entirely from the driver,
which also takes care of that.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
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 d0435a05ea35..0d987898b4f8 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -554,7 +554,7 @@ vchiq_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
ret = -EINVAL;
break;
}
- rc = mutex_lock_interruptible(&instance->state-
>mutex);
+ rc = mutex_lock_killable(&instance->state->mutex);
if (rc != 0) {
vchiq_log_error(vchiq_arm_log_level,
"vchiq: connect: could not lock mutex
for "
diff --git
a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_connected.c
b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_connected.c
index 5efc62ffb2f5..7ea29665bd0c 100644
---
a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_connected.c
+++
b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_connected.c
@@ -72,7 +72,7 @@ void
vchiq_add_connected_callback(VCHIQ_CONNECTED_CALLBACK_T callback)
{
connected_init();
- if (mutex_lock_interruptible(&g_connected_mutex) != 0)
+ if (mutex_lock_killable(&g_connected_mutex) != 0)
return;
if (g_connected)
@@ -107,7 +107,7 @@ void vchiq_call_connected_callbacks(void)
connected_init();
- if (mutex_lock_interruptible(&g_connected_mutex) != 0)
+ if (mutex_lock_killable(&g_connected_mutex) != 0)
return;
for (i = 0; i < g_num_deferred_callbacks; i++)
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 7440db2ce40b..028e90bc1cdc 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -794,7 +794,7 @@ queue_message(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T
*service,
WARN_ON(!(stride <= VCHIQ_SLOT_SIZE));
if (!(flags & QMFLAGS_NO_MUTEX_LOCK) &&
- (mutex_lock_interruptible(&state->slot_mutex) != 0))
+ (mutex_lock_killable(&state->slot_mutex) != 0))
return VCHIQ_RETRY;
if (type == VCHIQ_MSG_DATA) {
@@ -863,7 +863,7 @@ queue_message(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T
*service,
return VCHIQ_RETRY;
if (service->closing)
return VCHIQ_ERROR;
- if (mutex_lock_interruptible(&state-
>slot_mutex) != 0)
+ if (mutex_lock_killable(&state->slot_mutex) !=
0)
return VCHIQ_RETRY;
if (service->srvstate != VCHIQ_SRVSTATE_OPEN)
{
/* The service has been closed */
@@ -1033,7 +1033,7 @@ queue_message_sync(VCHIQ_STATE_T *state,
VCHIQ_SERVICE_T *service,
local = state->local;
if ((VCHIQ_MSG_TYPE(msgid) != VCHIQ_MSG_RESUME) &&
- (mutex_lock_interruptible(&state->sync_mutex) != 0))
+ (mutex_lock_killable(&state->sync_mutex) != 0))
return VCHIQ_RETRY;
remote_event_wait(state, &local->sync_release);
@@ -1365,7 +1365,7 @@ resolve_bulks(VCHIQ_SERVICE_T *service,
VCHIQ_BULK_QUEUE_T *queue)
WARN_ON(!((int)(queue->local_insert - queue->process)
> 0));
WARN_ON(!((int)(queue->remote_insert - queue->process)
> 0));
- rc = mutex_lock_interruptible(&state-
>bulk_transfer_mutex);
+ rc = mutex_lock_killable(&state->bulk_transfer_mutex);
if (rc != 0)
break;
@@ -1839,7 +1839,7 @@ parse_rx_slots(VCHIQ_STATE_T *state)
int resolved = 0;
DEBUG_TRACE(PARSE_LINE);
- if (mutex_lock_interruptible(
+ if (mutex_lock_killable(
&service->bulk_mutex) != 0) {
DEBUG_TRACE(PARSE_LINE);
goto bail_not_ready;
@@ -1903,7 +1903,7 @@ parse_rx_slots(VCHIQ_STATE_T *state)
&service->bulk_rx : &service-
>bulk_tx;
DEBUG_TRACE(PARSE_LINE);
- if (mutex_lock_interruptible(
+ if (mutex_lock_killable(
&service->bulk_mutex) != 0) {
DEBUG_TRACE(PARSE_LINE);
goto bail_not_ready;
@@ -2780,7 +2780,7 @@ do_abort_bulks(VCHIQ_SERVICE_T *service)
VCHIQ_STATUS_T status;
/* Abort any outstanding bulk transfers */
- if (mutex_lock_interruptible(&service->bulk_mutex) != 0)
+ if (mutex_lock_killable(&service->bulk_mutex) != 0)
return 0;
abort_outstanding_bulks(service, &service->bulk_tx);
abort_outstanding_bulks(service, &service->bulk_rx);
@@ -3300,7 +3300,7 @@ vchiq_bulk_transfer(VCHIQ_SERVICE_HANDLE_T
handle,
queue = (dir == VCHIQ_BULK_TRANSMIT) ?
&service->bulk_tx : &service->bulk_rx;
- if (mutex_lock_interruptible(&service->bulk_mutex) != 0) {
+ if (mutex_lock_killable(&service->bulk_mutex) != 0) {
status = VCHIQ_RETRY;
goto error_exit;
}
@@ -3314,7 +3314,7 @@ vchiq_bulk_transfer(VCHIQ_SERVICE_HANDLE_T
handle,
status = VCHIQ_RETRY;
goto error_exit;
}
- if (mutex_lock_interruptible(&service-
>bulk_mutex)
+ if (mutex_lock_killable(&service->bulk_mutex)
!= 0) {
status = VCHIQ_RETRY;
goto error_exit;
@@ -3344,7 +3344,7 @@ vchiq_bulk_transfer(VCHIQ_SERVICE_HANDLE_T
handle,
/* The slot mutex must be held when the service is being
closed, so
claim it here to ensure that isn't happening */
- if (mutex_lock_interruptible(&state->slot_mutex) != 0) {
+ if (mutex_lock_killable(&state->slot_mutex) != 0) {
status = VCHIQ_RETRY;
goto cancel_bulk_error_exit;
}
diff --git
a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_kern_lib.c
b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_kern_lib.c
index 14bd2857e462..e93922a87263 100644
---
a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_kern_lib.c
+++
b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_kern_lib.c
@@ -134,7 +134,7 @@ VCHIQ_STATUS_T vchiq_shutdown(VCHIQ_INSTANCE_T
instance)
vchiq_log_trace(vchiq_core_log_level,
"%s(%p) called", __func__, instance);
- if (mutex_lock_interruptible(&state->mutex) != 0)
+ if (mutex_lock_killable(&state->mutex) != 0)
return VCHIQ_RETRY;
/* Remove all services */
@@ -191,7 +191,7 @@ VCHIQ_STATUS_T vchiq_connect(VCHIQ_INSTANCE_T
instance)
vchiq_log_trace(vchiq_core_log_level,
"%s(%p) called", __func__, instance);
- if (mutex_lock_interruptible(&state->mutex) != 0) {
+ if (mutex_lock_killable(&state->mutex) != 0) {
vchiq_log_trace(vchiq_core_log_level,
"%s: call to mutex_lock failed", __func__);
status = VCHIQ_RETRY;
diff --git
a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_killable.h
b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_killable.h
index 335446e05476..778063ba312a 100644
---
a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_killable.h
+++
b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_killable.h
@@ -52,18 +52,4 @@ static inline int __must_check
down_interruptible_killable(struct semaphore *sem
}
#define down_interruptible down_interruptible_killable
-
-static inline int __must_check
mutex_lock_interruptible_killable(struct mutex *lock)
-{
- /* Allow interception of killable signals only. We don't want
to be interrupted by harmless signals like SIGALRM */
- int ret;
- sigset_t blocked, oldset;
- siginitsetinv(&blocked, SHUTDOWN_SIGS);
- sigprocmask(SIG_SETMASK, &blocked, &oldset);
- ret = mutex_lock_interruptible(lock);
- sigprocmask(SIG_SETMASK, &oldset, NULL);
- return ret;
-}
-#define mutex_lock_interruptible mutex_lock_interruptible_killable
-
#endif
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