From fac253e52fda73b6610f39716abe04dd2d919fb8 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Thu, 20 Sep 2018 13:17:36 -0600 Subject: [PATCH] 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 Cc: Arvind Yadav Signed-off-by: Suzuki K Poulose Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 3e07fd335f8c..9fd0c387e678 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -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); -- 2.11.0