From patchwork Sat Sep 24 00:17:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Zhong X-Patchwork-Id: 12987297 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5929DC04A95 for ; Sat, 24 Sep 2022 00:18:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232959AbiIXASG (ORCPT ); Fri, 23 Sep 2022 20:18:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233009AbiIXASG (ORCPT ); Fri, 23 Sep 2022 20:18:06 -0400 Received: from mail-pg1-x52f.google.com (mail-pg1-x52f.google.com [IPv6:2607:f8b0:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25D6812416A for ; Fri, 23 Sep 2022 17:18:05 -0700 (PDT) Received: by mail-pg1-x52f.google.com with SMTP id 129so202108pgc.5 for ; Fri, 23 Sep 2022 17:18:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date; bh=dNmY41FSeHwLWx9pzDWHLuLrAuxRIW3iZmu5xCh/RKE=; b=M5fw44HT7EXQ6hQak8g8VtBkG8YsUs3vlUmg6tfmCp3NzRmMpndGWZNQHglrzEtWBO ccwku72LwSzGkm7MwcnFY5BFelvGHl/P03Bamkum5b6ac5dng7GLHe8MVPCdgBt2xMa4 iYF/uiGXio4zU4bGbE/KfptX4pYmcKqAi+j0qHjcH29+UrsiuGl+KxBRqyiykkhmjWTk clCXWOc0RGPIEwvDk/F0sg4N8M04ysiSLV3m0NROFfedc2o1moktJaKGToln+Aej4Dka ozRdsFEURehWq6FmMgAKCzMCpAziHjzDt8ut0kJHhMEn/r4plbzDSZ3MCAVcp6Sx3m8A f15w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date; bh=dNmY41FSeHwLWx9pzDWHLuLrAuxRIW3iZmu5xCh/RKE=; b=k+zP1HmhVZrRsYBfGr//aBrXU3c2OsHkk8je8HNuCqPza5q/sIuekTQEgxmwObGh9g 2q8lv3cjKs//Yd7r1F6oQetkHWkL6tDNtjh83BiYX2wpmpIedvhJQ84WO+paxPxtHA8a cTaYrThb5GccJhDMF81tQZzp3568ipw703sw8AD5rByqVuhrgWPGv9Qgp2Y8SLIpz5I0 /2cWWf08XbB3t+Rw4RhURixJHt/GvJrOTsORdFGb+lhzeUDhTlTsPp5SM/IewjQ/ia2P Dl01nzUjbfA6PRS6IKbRoIqH875610FMFuhclk5NYew+qFbMd/+QUVUm5Pnwwm2LkEdB IQFg== X-Gm-Message-State: ACrzQf2jzAInF5FyT0Mg6G/w3h6CrSEg7PzjAx8017aohfwRAnmzjBiv Fz9C54gLVEaddXWgBsxSP04xuJBx/70= X-Google-Smtp-Source: AMsMyM6ZE/1iZTbaKo+4KuZR9/e2eBSnl8ba+77GnJHjefS1YZ3OPLIwEiKpugG3zsvsbA/UjbtdVg== X-Received: by 2002:a63:7984:0:b0:439:57e4:97a2 with SMTP id u126-20020a637984000000b0043957e497a2mr9970210pgc.191.1663978684211; Fri, 23 Sep 2022 17:18:04 -0700 (PDT) Received: from localhost.localdomain (lily-optiplex-3070.dynamic.ucsd.edu. [2607:f720:1300:3033::1:4dd]) by smtp.googlemail.com with ESMTPSA id om12-20020a17090b3a8c00b0020263b7177csm11495864pjb.3.2022.09.23.17.18.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Sep 2022 17:18:03 -0700 (PDT) From: Li Zhong To: linux-hwmon@vger.kernel.org Cc: linux@roeck-us.net, jdelvare@suse.com, Li Zhong Subject: [PATCH v3] drivers/hwmon/adm9240: fix data race in adm9240_fan_read Date: Fri, 23 Sep 2022 17:17:51 -0700 Message-Id: <20220924001751.1726369-1-floridsleeves@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org In adm9240_read() adm9240_fan_read() adm9240_write_fan_div(), it assumes that the caller of adm9240_write_fan_div() must hold data->update_lock. Otherwise, it may cause data races when data is updated by other threads. Signed-off-by: Li Zhong --- drivers/hwmon/adm9240.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/adm9240.c b/drivers/hwmon/adm9240.c index 483cd757abd3..40e3558d3709 100644 --- a/drivers/hwmon/adm9240.c +++ b/drivers/hwmon/adm9240.c @@ -501,17 +501,23 @@ static int adm9240_fan_read(struct device *dev, u32 attr, int channel, long *val switch (attr) { case hwmon_fan_input: + mutex_lock(&data->update_lock); err = regmap_read(data->regmap, ADM9240_REG_FAN(channel), ®val); - if (err < 0) + if (err < 0) { + mutex_unlock(&data->update_lock); return err; + } if (regval == 255 && data->fan_div[channel] < 3) { /* adjust fan clock divider on overflow */ err = adm9240_write_fan_div(data, channel, ++data->fan_div[channel]); - if (err) + if (err) { + mutex_unlock(&data->update_lock); return err; + } } *val = FAN_FROM_REG(regval, BIT(data->fan_div[channel])); + mutex_unlock(&data->update_lock); break; case hwmon_fan_div: *val = BIT(data->fan_div[channel]);