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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,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 8F7A1C43381 for ; Fri, 22 Mar 2019 14:34:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 67EDC218D3 for ; Fri, 22 Mar 2019 14:34:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729093AbfCVOeZ (ORCPT ); Fri, 22 Mar 2019 10:34:25 -0400 Received: from mout.kundenserver.de ([212.227.126.133]:42545 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729067AbfCVOeY (ORCPT ); Fri, 22 Mar 2019 10:34:24 -0400 Received: from wuerfel.lan ([149.172.19.189]) by mrelayeu.kundenserver.de (mreue009 [212.227.15.129]) with ESMTPA (Nemesis) id 1MPXpS-1hL0DB0LKc-00Ma3I; Fri, 22 Mar 2019 15:33:47 +0100 From: Arnd Bergmann To: Lee Jones Cc: clang-built-linux@googlegroups.com, Nick Desaulniers , Nathan Chancellor , Arnd Bergmann , Charles Keepax , Linus Walleij , Sapthagiri Baratam , Colin Ian King , patches@opensource.cirrus.com, linux-kernel@vger.kernel.org Subject: [PATCH] mfd: arizona: fix undefined behavior Date: Fri, 22 Mar 2019 15:33:37 +0100 Message-Id: <20190322143345.1208144-1-arnd@arndb.de> X-Mailer: git-send-email 2.20.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Provags-ID: V03:K1:xIa628kaEnjxRdbZtVTepxGCiZqr9F/xHj3Bl6rG4r9O/ufNc3k rfcAqo4uT3Q0sl+2SvhyhUf7rimuKFJa+zasw/NYhG/yVWAkF4hEAMbQCaT111cEB7eL/U+ tXxl/zfWba0aeClXAkNk/6oq3LdL7jGRSe6ltKI16+nZ59l8dOHQIGbDtKcI8rMNAAe1Y2R 4vib9SaiQnxLEMXJtT8IQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:PzEbtT9jSxA=:NxTZ9ZfLS8xWvzxLZ82av0 sGiY7Yn/Ry7ePxEXa/CfUZp9rGnkJZyTV39wjYwQHCTwPubzfC+fig/ZkMfEqLzj5OjIK614s 0Fw0I7eYK5L+g5wLMecGTKyPEibq+62iK2ing2VZI+45fnBoHV81lG7OPjIwHgJfkIKVl3h6F tD8el8YYbooMlYdalnHvVwZc8u3XDP63XwRawIR3UyWFWR0MydchCXJIOdnGLL05oPKBxj6zs 1HMYliN0pHleHYv7XqHIeEW9bvZ7W8iZsVNDOjHYnaSDQqJyJYwejYfOm8Db9ND7rJbAk8akH vCQpt+xSIxAAnJJviM619ii/kMHNl1ruGYBL2wYXSxvAQEutTm1IgvC9VuASfi+JycFHJQ+OB q2YVugI15K/JeZ8SM77EUBdufhnmfRriehI/zl7GMFqXtv9MlQw+apv9EDFUwXs4ZXxk25FIJ 1F/BgoEvlfEk6n+XfDq9VU48IpU2kTMkCDCE/DEVQY5iXw/PcoW5lzuPx3OOa0lGoT33w9bj7 G4s51Dc+emTYHGlF0u2Ur3dOIFkqJR43Dkj+Am160aKzDnMFBE8EiPoc/X4tVwtOgp7h8N7T3 6wez0KVKmRNGVR7z6UyZvqMfxyXpHhnwYosf2UK8keicJPO46NEpb6OTlV9w1JidVTBE3sKVb 1/yHGwBNw9nJ/lIjAUZOvGdHE+pPPLWT3eVuioH2ZqN0YfudbOSgDJV4/ubj3HKv8Jh0neDRE WaO6Go6KMamAPLugWT8/1qw4ZrUeIb4r060nnA== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the driver is used with a subdevice that is disabled in the kernel configuration, clang gets a little confused about the control flow and fails to notice that n_subdevs is only uninitialized when subdevs is NULL, and we check for that, leading to a false-positive warning: drivers/mfd/arizona-core.c:1423:19: error: variable 'n_subdevs' is uninitialized when used here [-Werror,-Wuninitialized] subdevs, n_subdevs, NULL, 0, NULL); ^~~~~~~~~ drivers/mfd/arizona-core.c:999:15: note: initialize the variable 'n_subdevs' to silence this warning int n_subdevs, ret, i; ^ = 0 Ideally, we would rearrange the code to avoid all those early initializations and have an explicit exit in each disabled case, but it's much easier to chicken out and add one more initialization here to shut up the warning. Signed-off-by: Arnd Bergmann --- drivers/mfd/arizona-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c index 27b61639cdc7..0ca0fc9a67fd 100644 --- a/drivers/mfd/arizona-core.c +++ b/drivers/mfd/arizona-core.c @@ -996,7 +996,7 @@ int arizona_dev_init(struct arizona *arizona) unsigned int reg, val; int (*apply_patch)(struct arizona *) = NULL; const struct mfd_cell *subdevs = NULL; - int n_subdevs, ret, i; + int n_subdevs = 0, ret, i; dev_set_drvdata(arizona->dev, arizona); mutex_init(&arizona->clk_lock); -- 2.20.0