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Commit a8590633 authored by Lynus Vaz's avatar Lynus Vaz
Browse files

msm: kgsl: Fix the process sysfs refcounting 



The kobject used for the process's sysfs node did not provide a
release function, so it did not correctly implement the refcounting.
Add a release callback so that we keep the process structure valid
as long as the kobject is alive.

Change-Id: I6db54092ed29ecd4d2f157188a4f1a5fc70f1edf
Signed-off-by: default avatarLynus Vaz <lvaz@codeaurora.org>
parent c9876a6f

drivers/gpu/msm/kgsl_sharedmem.c

+14 −8
Original line number Diff line number Diff line
@@ -126,12 +126,10 @@ static ssize_t mem_entry_sysfs_show(struct kobject *kobj, 
	ssize_t ret;



	/*

	 * 1. sysfs_remove_file waits for reads to complete before the node

	 *    is deleted.

	 * 2. kgsl_process_init_sysfs takes a refcount to the process_private,

	 *    which is put at the end of kgsl_process_uninit_sysfs.

	 * These two conditions imply that priv will not be freed until this

	 * function completes, and no further locking is needed.

	 * kgsl_process_init_sysfs takes a refcount to the process_private,

	 * which is put when the kobj is released. This implies that priv will

	 * not be freed until this function completes, and no further locking

	 * is needed.

	 */

	priv = kobj ? container_of(kobj, struct kgsl_process_private, kobj) :

			NULL;
@@ -144,12 +142,22 @@ static ssize_t mem_entry_sysfs_show(struct kobject *kobj, 
	return ret;

}



static void mem_entry_release(struct kobject *kobj)

{

	struct kgsl_process_private *priv;



	priv = container_of(kobj, struct kgsl_process_private, kobj);

	/* Put the refcount we got in kgsl_process_init_sysfs */

	kgsl_process_private_put(priv);

}



static const struct sysfs_ops mem_entry_sysfs_ops = {

	.show = mem_entry_sysfs_show,

};



static struct kobj_type ktype_mem_entry = {

	.sysfs_ops = &mem_entry_sysfs_ops,

	.release = &mem_entry_release,

};



static struct mem_entry_stats mem_stats[] = {
@@ -172,8 +180,6 @@ kgsl_process_uninit_sysfs(struct kgsl_process_private *private) 
	}



	kobject_put(&private->kobj);

	/* Put the refcount we got in kgsl_process_init_sysfs */

	kgsl_process_private_put(private);

}



/**