Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
drivers/media/v4l2-core/v4l2-async.c:238:1: warning:
'v4l2_async_notifier_unregister' uses dynamic stack allocation [enabled by
default]
Instead, let's enforce a limit for the buffer.
In this specific case, there's a hard limit imposed by V4L2_MAX_SUBDEVS,
with is currently 128. That means that the buffer size can be up to
128x8 = 1024 bytes (on a 64bits kernel), with is too big for stack.
Worse than that, someone could increase it and cause real troubles.
So, let's use dynamically allocated data, instead.
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Cc: Guennadi Liakhovetski <[email protected]>
---
drivers/media/v4l2-core/v4l2-async.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/v4l2-async.c
b/drivers/media/v4l2-core/v4l2-async.c
index c85d69da35bd..071596869036 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -189,12 +189,14 @@ void v4l2_async_notifier_unregister(struct
v4l2_async_notifier *notifier)
struct v4l2_subdev *sd, *tmp;
unsigned int notif_n_subdev = notifier->num_subdevs;
unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
- struct device *dev[n_subdev];
+ struct device **dev;
int i = 0;
if (!notifier->v4l2_dev)
return;
+ dev = kmalloc(sizeof(*dev) * n_subdev, GFP_KERNEL);
+
mutex_lock(&list_lock);
list_del(¬ifier->list);
@@ -228,6 +230,7 @@ void v4l2_async_notifier_unregister(struct
v4l2_async_notifier *notifier)
}
put_device(d);
}
+ kfree(dev);
notifier->v4l2_dev = NULL;
--
1.8.3.1
--
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