From patchwork Thu Jul 23 01:59:40 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 499047 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id BA75714090B; Thu, 23 Jul 2015 12:05:00 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZI5sW-0002VR-Te; Thu, 23 Jul 2015 02:04:56 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZI5pT-0000An-Ev for kernel-team@lists.ubuntu.com; Thu, 23 Jul 2015 02:01:47 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1ZI5pT-0005gT-12; Thu, 23 Jul 2015 02:01:47 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1ZI5pQ-0006Ax-OS; Wed, 22 Jul 2015 19:01:44 -0700 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.13.y-ckt 062/132] regmap: Fix possible shift overflow in regmap_field_init() Date: Wed, 22 Jul 2015 18:59:40 -0700 Message-Id: <1437616850-23266-63-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1437616850-23266-1-git-send-email-kamal@canonical.com> References: <1437616850-23266-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Cc: Kamal Mostafa , Mark Brown , Maxime Coquelin X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.13.11-ckt24 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Maxime Coquelin commit 921cc29473a0d7c109105c1876ddb432f4a4be7d upstream. The way the mask is generated in regmap_field_init() is wrong. Indeed, a field initialized with msb = 31 and lsb = 0 provokes a shift overflow while calculating the mask field. On some 32 bits architectures, such as x86, the generated mask is 0, instead of the expected 0xffffffff. This patch uses GENMASK() to fix the problem, as this macro is already safe regarding shift overflow. Signed-off-by: Maxime Coquelin Signed-off-by: Mark Brown Signed-off-by: Kamal Mostafa --- drivers/base/regmap/regmap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 7183d1d..c1d343e 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -808,11 +808,10 @@ EXPORT_SYMBOL_GPL(devm_regmap_init); static void regmap_field_init(struct regmap_field *rm_field, struct regmap *regmap, struct reg_field reg_field) { - int field_bits = reg_field.msb - reg_field.lsb + 1; rm_field->regmap = regmap; rm_field->reg = reg_field.reg; rm_field->shift = reg_field.lsb; - rm_field->mask = ((BIT(field_bits) - 1) << reg_field.lsb); + rm_field->mask = GENMASK(reg_field.msb, reg_field.lsb); rm_field->id_size = reg_field.id_size; rm_field->id_offset = reg_field.id_offset; }