From patchwork Sat Aug 1 21:58:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cengiz Can X-Patchwork-Id: 11696241 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4B3A3138C for ; Sat, 1 Aug 2020 21:59:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C9C72071E for ; Sat, 1 Aug 2020 21:59:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727817AbgHAV7e (ORCPT ); Sat, 1 Aug 2020 17:59:34 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:9221 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726477AbgHAV7e (ORCPT ); Sat, 1 Aug 2020 17:59:34 -0400 X-Originating-IP: 178.240.22.159 Received: from localhost.localdomain (unknown [178.240.22.159]) (Authenticated sender: cengiz@kernel.wtf) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 3482B240004; Sat, 1 Aug 2020 21:59:27 +0000 (UTC) From: Cengiz Can To: andy.shevchenko@gmail.com Cc: cengiz@kernel.wtf, dan.carpenter@oracle.com, devel@driverdev.osuosl.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org, sakari.ailus@linux.intel.com Subject: [PATCH v5] staging: atomisp: move null check to earlier point Date: Sun, 2 Aug 2020 00:58:07 +0300 Message-Id: <20200801215806.2659-1-cengiz@kernel.wtf> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200731083856.GF3703480@smile.fi.intel.com> References: <20200731083856.GF3703480@smile.fi.intel.com> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org `find_gmin_subdev()` that returns a pointer to `struct gmin_subdev` can return NULL. In `gmin_v2p8_ctrl()` there's a call to this function but the possibility of a NULL was not checked before its being dereferenced, i.e.: /* Acquired here --------v */ struct gmin_subdev *gs = find_gmin_subdev(subdev); /* v------Dereferenced here */ if (gs->v2p8_gpio >= 0) { ... } With this change we're null checking `find_gmin_subdev()` result and we return an error if that's the case. We also WARN() for the sake of debugging. Signed-off-by: Cengiz Can Reported-by: Coverity Static Analyzer CID 1465536 Suggested-by: Mauro Carvalho Chehab Signed-off-by: Cengiz Can --- Please do note that this change introduces a new return value to `gmin_v2p8_ctrl()`. [NEW] - raise a WARN and return -ENODEV if there are no subdevices. - return result of `gpio_request` or `gpio_direction_output`. - return 0 if GPIO is ON. - return results of `regulator_enable` or `regulator_disable`. - according to PMIC type, return result of `axp_regulator_set` or `gmin_i2c_write`. - return -EINVAL if unknown PMIC type. Patch Changelog: v4: Fix minor typo in commit message v5: Remove typo from email subject drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c index 0df46a1af5f0..1ad0246764a6 100644 --- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c +++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c @@ -871,6 +871,9 @@ static int gmin_v2p8_ctrl(struct v4l2_subdev *subdev, int on) int ret; int value; + if (WARN_ON(!gs)) + return -ENODEV; + if (gs->v2p8_gpio >= 0) { pr_info("atomisp_gmin_platform: 2.8v power on GPIO %d\n", gs->v2p8_gpio); @@ -881,7 +884,7 @@ static int gmin_v2p8_ctrl(struct v4l2_subdev *subdev, int on) pr_err("V2P8 GPIO initialization failed\n"); } - if (!gs || gs->v2p8_on == on) + if (gs->v2p8_on == on) return 0; gs->v2p8_on = on;