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Commit d6a49f7b authored by Deepak Kumar's avatar Deepak Kumar Committed by Gerrit - the friendly Code Review server
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msm: kgsl: Avoid racing against context delete while releasing contexts 



While releasing contexts take a reference to context inside read rcu
lock to avoid racing against context deletion. This will avoid using
dangling context pointer in device_release_contexts.

Change-Id: I76e787f6dde5a324fec23e81829174bd28134c6c
Signed-off-by: default avatarDeepak Kumar <dkumar@codeaurora.org>
parent 53d1dd96

drivers/gpu/msm/kgsl.c

+11 −8
Original line number Diff line number Diff line
@@ -1072,25 +1072,28 @@ static void device_release_contexts(struct kgsl_device_private *dev_priv) 
	struct kgsl_device *device = dev_priv->device;

	struct kgsl_context *context;

	int next = 0;

	int result = 0;



	while (1) {

		read_lock(&device->context_lock);

		context = idr_get_next(&device->context_idr, &next);

		read_unlock(&device->context_lock);



		if (context == NULL)

		if (context == NULL) {

			read_unlock(&device->context_lock);

			break;



		if (context->dev_priv == dev_priv) {

		} else if (context->dev_priv == dev_priv) {

			/*

			 * Hold a reference to the context in case somebody

			 * tries to put it while we are detaching

			 */

			result = _kgsl_context_get(context);

		}

		read_unlock(&device->context_lock);



			if (_kgsl_context_get(context)) {

		if (result) {

			kgsl_context_detach(context);

			kgsl_context_put(context);

			}

			result = 0;

		}



		next = next + 1;