Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933193AbcDBA54 (ORCPT ); Fri, 1 Apr 2016 20:57:56 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54762 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933063AbcDBA5u (ORCPT ); Fri, 1 Apr 2016 20:57:50 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Arnd Bergmann , Mark Brown , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 163/170] regulator: s5m8767: fix get_register() error handling Date: Fri, 1 Apr 2016 17:54:09 -0700 Message-Id: <1459558456-24452-164-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1459558456-24452-1-git-send-email-kamal@canonical.com> References: <1459558456-24452-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2691 Lines: 70 3.19.8-ckt18 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Arnd Bergmann commit e07ff9434167981c993a26d2edbbcb8e13801dbb upstream. The s5m8767_pmic_probe() function calls s5m8767_get_register() to read data without checking the return code, which produces a compile-time warning when that data is accessed: drivers/regulator/s5m8767.c: In function 's5m8767_pmic_probe': drivers/regulator/s5m8767.c:924:7: error: 'enable_reg' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/regulator/s5m8767.c:944:30: error: 'enable_val' may be used uninitialized in this function [-Werror=maybe-uninitialized] This changes the s5m8767_get_register() function to return a -EINVAL not just for an invalid register number but also for an invalid regulator number, as both would result in returning uninitialized data. The s5m8767_pmic_probe() function is then changed accordingly to fail on a read error, as all the other callers of s5m8767_get_register() already do. In practice this probably cannot happen, as we don't call s5m8767_get_register() with invalid arguments, but the gcc warning seems valid in principle, in terms writing safe error checking. Signed-off-by: Arnd Bergmann Fixes: 9c4c60554acf ("regulator: s5m8767: Convert to use regulator_[enable|disable|is_enabled]_regmap") Signed-off-by: Mark Brown Signed-off-by: Kamal Mostafa --- drivers/regulator/s5m8767.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c index 58f5d3b..27343e1 100644 --- a/drivers/regulator/s5m8767.c +++ b/drivers/regulator/s5m8767.c @@ -202,9 +202,10 @@ static int s5m8767_get_register(struct s5m8767_info *s5m8767, int reg_id, } } - if (i < s5m8767->num_regulators) - *enable_ctrl = - s5m8767_opmode_reg[reg_id][mode] << S5M8767_ENCTRL_SHIFT; + if (i >= s5m8767->num_regulators) + return -EINVAL; + + *enable_ctrl = s5m8767_opmode_reg[reg_id][mode] << S5M8767_ENCTRL_SHIFT; return 0; } @@ -937,8 +938,12 @@ static int s5m8767_pmic_probe(struct platform_device *pdev) else regulators[id].vsel_mask = 0xff; - s5m8767_get_register(s5m8767, id, &enable_reg, + ret = s5m8767_get_register(s5m8767, id, &enable_reg, &enable_val); + if (ret) { + dev_err(s5m8767->dev, "error reading registers\n"); + return ret; + } regulators[id].enable_reg = enable_reg; regulators[id].enable_mask = S5M8767_ENCTRL_MASK; regulators[id].enable_val = enable_val; -- 2.7.4