From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C44C3C67790 for ; Fri, 27 Jul 2018 10:16:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 86159208A1 for ; Fri, 27 Jul 2018 10:16:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 86159208A1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387611AbeG0LhO (ORCPT ); Fri, 27 Jul 2018 07:37:14 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:40862 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729547AbeG0LhN (ORCPT ); Fri, 27 Jul 2018 07:37:13 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 847BF15BE; Fri, 27 Jul 2018 03:15:59 -0700 (PDT) Received: from en101.Emea.Arm.com (en101.Emea.Arm.com [10.4.13.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 08E343F575; Fri, 27 Jul 2018 03:15:56 -0700 (PDT) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, mathieu.poirier@linaro.org, mike.leach@linaro.org, robert.walker@arm.com, coresight@lists.linaro.org, robh@kernel.org, frowand.list@gmail.com, devicetree@vger.kernel.org, matt.sealey@arm.com, charles.garcia-tobin@arm.com, john.horley@arm.com, al.grant@arm.com, Suzuki K Poulose , Arvind Yadav Subject: [PATCH v3 1/9] coresight: Document error handling in coresight_register Date: Fri, 27 Jul 2018 11:15:29 +0100 Message-Id: <1532686537-12380-2-git-send-email-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1532686537-12380-1-git-send-email-suzuki.poulose@arm.com> References: <1532686537-12380-1-git-send-email-suzuki.poulose@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- Change since v1: - Document the error handling than trying to "unfix" the problem. --- 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 3e07fd3..9fd0c38 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); -- 2.7.4