Commit fac253e5 authored by Suzuki K Poulose's avatar Suzuki K Poulose Committed by Greg Kroah-Hartman
Browse files

coresight: Document error handling in coresight_register 



commit 6403587a930c ("coresight: use put_device() instead of kfree()")
fixes the double freeing of resources and ensures that the device
refcount is dropped properly. Add a comment to explain this to
help the readers and prevent people trying to "unfix" it again.

While at it, rename the labels for better readability.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b31bd669

drivers/hwtracing/coresight/coresight.c

+11 −7
Original line number Diff line number Diff line
@@ -1006,7 +1006,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) 
	csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);

	if (!csdev) {

		ret = -ENOMEM;

		goto err_kzalloc_csdev;

		goto err_out;

	}



	if (desc->type == CORESIGHT_DEV_TYPE_LINK ||
@@ -1022,7 +1022,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) 
	refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);

	if (!refcnts) {

		ret = -ENOMEM;

		goto err_kzalloc_refcnts;

		goto err_free_csdev;

	}



	csdev->refcnt = refcnts;
@@ -1035,7 +1035,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) 
		conns = kcalloc(csdev->nr_outport, sizeof(*conns), GFP_KERNEL);

		if (!conns) {

			ret = -ENOMEM;

			goto err_kzalloc_conns;

			goto err_free_refcnts;

		}



		for (i = 0; i < csdev->nr_outport; i++) {
@@ -1062,7 +1062,11 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) 
	ret = device_register(&csdev->dev);

	if (ret) {

		put_device(&csdev->dev);

		goto err_kzalloc_csdev;

		/*

		 * All resources are free'd explicitly via

		 * coresight_device_release(), triggered from put_device().

		 */

		goto err_out;

	}



	mutex_lock(&coresight_mutex);
@@ -1074,11 +1078,11 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) 


	return csdev;



err_kzalloc_conns:

err_free_refcnts:

	kfree(refcnts);

err_kzalloc_refcnts:

err_free_csdev:

	kfree(csdev);

err_kzalloc_csdev:

err_out:

	return ERR_PTR(ret);

}

EXPORT_SYMBOL_GPL(coresight_register);

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