From patchwork Sat Jun 25 02:47:07 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guenter Roeck X-Patchwork-Id: 9198333 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6435A60754 for ; Sat, 25 Jun 2016 02:47:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4C06F284B1 for ; Sat, 25 Jun 2016 02:47:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3E337284DD; Sat, 25 Jun 2016 02:47:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 93878284B1 for ; Sat, 25 Jun 2016 02:47:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751938AbcFYCr1 (ORCPT ); Fri, 24 Jun 2016 22:47:27 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:57302 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751922AbcFYCrV (ORCPT ); Fri, 24 Jun 2016 22:47:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=roeck-us.net; s=default; h=Message-Id:Date:Subject:Cc:To:From; bh=h5llodDLakcADHfCK13l9bAogHbohyl8rd2PrWl/P1o=; b=cTzvnmJu6e3m9FTHVrq4v7HtXL hHjJFuqCPa1cYtHGQAmuo9DFp0gNbQqr0vnKMgFuxFCBpAMssKPESfZftNDqPoasKRsWcl6o6EdqZ 8q61YL4o3W1/reO829kMpXD58S9r12xVgBYgba6zuvyM0XtzBNt8G0IZJfOx/YcCQ8M858Ipgcn3W IvsnJcup5kzr3w0ZY9/jiRejBKfFDPlNZwjWSgCmfLZ9zjKTxi/soB6XTw0AXW//Hm4OrAdGHv4nY jgWIaOt0ECkln3EmxTGY6OAMVkDRNTuSHurO8QuniSpZN8bcKbAkcLdLWH1MK/qNlhuRkKyWKqKK/ A1M3N7Ew==; Received: from 108-223-40-66.lightspeed.sntcca.sbcglobal.net ([108.223.40.66]:40844 helo=localhost) by bh-25.webhostbox.net with esmtpa (Exim 4.86_1) (envelope-from ) id 1bGdcn-001qcs-Na; Sat, 25 Jun 2016 02:47:14 +0000 From: Guenter Roeck To: Hardware Monitoring Cc: Jean Delvare , Guenter Roeck , "Andrew F. Davis" Subject: [PATCH] hwmon: (ina3221) Fix negative limits Date: Fri, 24 Jun 2016 19:47:07 -0700 Message-Id: <1466822827-31231-1-git-send-email-linux@roeck-us.net> X-Mailer: git-send-email 2.5.0 X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The result of an integer divide by an unsigned is undefined. This causes unexpected results when writing negative values into the limit registers. Maintain the shunt_resistors variables as signed integer to avoid the problem. Also, for simplicity and ease of use, clamp shunt resistor value on writes instead of rejecting bad values. Cc: Andrew F. Davis Signed-off-by: Guenter Roeck Acked-by: Andrew F. Davis --- drivers/hwmon/ina3221.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c index d055b6a2266b..e6b49500c52a 100644 --- a/drivers/hwmon/ina3221.c +++ b/drivers/hwmon/ina3221.c @@ -95,7 +95,7 @@ static const unsigned int register_channel[] = { struct ina3221_data { struct regmap *regmap; struct regmap_field *fields[F_MAX_FIELDS]; - unsigned int shunt_resistors[INA3221_NUM_CHANNELS]; + int shunt_resistors[INA3221_NUM_CHANNELS]; }; static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg, @@ -155,7 +155,7 @@ static ssize_t ina3221_show_current(struct device *dev, struct ina3221_data *ina = dev_get_drvdata(dev); unsigned int reg = sd_attr->index; unsigned int channel = register_channel[reg]; - unsigned int resistance_uo = ina->shunt_resistors[channel]; + int resistance_uo = ina->shunt_resistors[channel]; int val, current_ma, voltage_nv, ret; ret = ina3221_read_value(ina, reg, &val); @@ -176,7 +176,7 @@ static ssize_t ina3221_set_current(struct device *dev, struct ina3221_data *ina = dev_get_drvdata(dev); unsigned int reg = sd_attr->index; unsigned int channel = register_channel[reg]; - unsigned int resistance_uo = ina->shunt_resistors[channel]; + int resistance_uo = ina->shunt_resistors[channel]; int val, current_ma, voltage_uv, ret; ret = kstrtoint(buf, 0, ¤t_ma); @@ -223,15 +223,14 @@ static ssize_t ina3221_set_shunt(struct device *dev, struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr); struct ina3221_data *ina = dev_get_drvdata(dev); unsigned int channel = sd_attr->index; - unsigned int val; + int val; int ret; - ret = kstrtouint(buf, 0, &val); + ret = kstrtoint(buf, 0, &val); if (ret) return ret; - if (val == 0) - return -EINVAL; + val = clamp_val(val, 1, INT_MAX); ina->shunt_resistors[channel] = val;