Merge "msm: kgsl: Avoid race condition in ioctl_syncsource_destroy" (6d2137a0) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/gpu/msm/kgsl_sync.c

+17 −19

Original line number	Diff line number	Diff line
		/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
		/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		@@ -474,23 +474,23 @@ long kgsl_ioctl_syncsource_create(struct kgsl_device_private *dev_priv,
		goto out;
		}

		kref_init(&syncsource->refcount);
		syncsource->private = private;

		idr_preload(GFP_KERNEL);
		spin_lock(&private->syncsource_lock);
		id = idr_alloc(&private->syncsource_idr, syncsource, 1, 0, GFP_NOWAIT);
		spin_unlock(&private->syncsource_lock);
		idr_preload_end();

		if (id > 0) {
		kref_init(&syncsource->refcount);
		syncsource->id = id;
		syncsource->private = private;

		param->id = id;
		ret = 0;
		} else {
		ret = id;
		}

		spin_unlock(&private->syncsource_lock);
		idr_preload_end();

		out:
		if (ret) {
		if (syncsource && syncsource->oneshot)
		@@ -548,25 +548,23 @@ long kgsl_ioctl_syncsource_destroy(struct kgsl_device_private *dev_priv,
		{
		struct kgsl_syncsource_destroy *param = data;
		struct kgsl_syncsource *syncsource = NULL;
		struct kgsl_process_private *private;

		syncsource = kgsl_syncsource_get(dev_priv->process_priv,
		param->id);

		if (syncsource == NULL)
		return -EINVAL;

		private = syncsource->private;
		struct kgsl_process_private *private = dev_priv->process_priv;

		spin_lock(&private->syncsource_lock);
		syncsource = idr_find(&private->syncsource_idr, param->id);

		if (syncsource) {
		idr_remove(&private->syncsource_idr, param->id);
		syncsource->id = 0;
		}

		spin_unlock(&private->syncsource_lock);

		if (syncsource == NULL)
		return -EINVAL;

		/* put reference from syncsource creation */
		kgsl_syncsource_put(syncsource);
		/* put reference from getting the syncsource above */
		kgsl_syncsource_put(syncsource);
		return 0;
		}