From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B054C433E3 for ; Fri, 21 Aug 2020 18:33:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2CEC420724 for ; Fri, 21 Aug 2020 18:33:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="oXevgdg2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726639AbgHUSd1 (ORCPT ); Fri, 21 Aug 2020 14:33:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53882 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726414AbgHUSdN (ORCPT ); Fri, 21 Aug 2020 14:33:13 -0400 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 051CCC061573; Fri, 21 Aug 2020 11:33:12 -0700 (PDT) Received: by mail-pf1-x443.google.com with SMTP id u20so1498299pfn.0; Fri, 21 Aug 2020 11:33:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=c0IYmtPlTYdcWM4v9Z24Y/LKv93Em9VatSn2LIsOk08=; b=oXevgdg2uRH/KC9bvFkJU7+ztru1Li73wtw4bjDpVTVu832bWDlGsSMsHUtVySWSvg NHjSlazuS4RCnTkMPbGvc8R5RStBnszAumbGrkCqb5zNQD9zICLGm2V3cTtxyRivsCUs oeUF03Y0fyO5F86DReTXkoNNoFewpW4rDwZFMTaXyLFMjqU/b2cveXwNzn5q/3ZEk5u+ RtVrd7lJlRGFNdzvuk/0B1fh2DYVMGzpNT9LSxhQUSGC0G/GaZr/4yws8e3PwpGLg6L5 VjUKV0G9sGs/30k7wxfefeLkzsMRBAUBRY2J4ohdqI506EECno6Xuz8NxB1G0HP6Z0Vi WvMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=c0IYmtPlTYdcWM4v9Z24Y/LKv93Em9VatSn2LIsOk08=; b=nmeFz+2ju76qar5/nzwgzAYUU+13ZhBpJll+wQJh6smZNNA4ItVoL5i/1ZD64feNNu rb/vN12ttblm9YwM3sKpTU+3LK5rjQKKPPgWbNvw94ipdfVtNgrybdR7wKSetY+OjgTc JpO2zmVmKmobquLaMWxNqQ7Lg6r37CwzYAat8+OjgMdykmBrp8qrqDMzEMF423QP1eiV pkSY+BzHTItEtfJC6wmOjk2d5+AisQBx4FboGg5Gq1x4TtCQLCyNlq+aFWmJUK0wgEqD W2f6ZfX0LxtKYSKVeSg0AFBZpAaeRaZHYfwcP64mtkHnS4rDNi1LIdhOUJ7QzGQ5cxJA 8qkw== X-Gm-Message-State: AOAM530y2axrKkDi150itPyzzWB+vzvupOXvZuWYC5F2u8gNp6mzKZrp IL0IVDAZjyYT1WPQEM+dV2U= X-Google-Smtp-Source: ABdhPJxlIumpirHMvSBxiTfmK6kO1Kw8bTcK0sfHdwMsy7+kyET/4vjtzvAjkZ8nobd1eZ+1+y+P1w== X-Received: by 2002:aa7:93ad:: with SMTP id x13mr3359105pff.33.1598034792345; Fri, 21 Aug 2020 11:33:12 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id f17sm3368582pfq.67.2020.08.21.11.33.11 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Fri, 21 Aug 2020 11:33:11 -0700 (PDT) Date: Fri, 21 Aug 2020 11:33:11 -0700 From: Guenter Roeck To: trix@redhat.com Cc: rydberg@bitmath.org, jdelvare@suse.com, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] hwmon: applesmc: check status earlier. Message-ID: <20200821183311.GA138863@roeck-us.net> References: <20200820131932.10590-1-trix@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200820131932.10590-1-trix@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 20, 2020 at 06:19:32AM -0700, trix@redhat.com wrote: > From: Tom Rix > > clang static analysis reports this representative problem > > applesmc.c:758:10: warning: 1st function call argument is an > uninitialized value > left = be16_to_cpu(*(__be16 *)(buffer + 6)) >> 2; > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > buffer is filled by the earlier call > > ret = applesmc_read_key(LIGHT_SENSOR_LEFT_KEY, ... > > This problem is reported because a goto skips the status check. > Other similar problems use data from applesmc_read_key before checking > the status. So move the checks to before the use. > > Signed-off-by: Tom Rix Applied. Thanks, Guenter > --- > drivers/hwmon/applesmc.c | 31 ++++++++++++++++--------------- > 1 file changed, 16 insertions(+), 15 deletions(-) > > diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c > index 316618409315..a18887990f4a 100644 > --- a/drivers/hwmon/applesmc.c > +++ b/drivers/hwmon/applesmc.c > @@ -753,15 +753,18 @@ static ssize_t applesmc_light_show(struct device *dev, > } > > ret = applesmc_read_key(LIGHT_SENSOR_LEFT_KEY, buffer, data_length); > + if (ret) > + goto out; > /* newer macbooks report a single 10-bit bigendian value */ > if (data_length == 10) { > left = be16_to_cpu(*(__be16 *)(buffer + 6)) >> 2; > goto out; > } > left = buffer[2]; > + > + ret = applesmc_read_key(LIGHT_SENSOR_RIGHT_KEY, buffer, data_length); > if (ret) > goto out; > - ret = applesmc_read_key(LIGHT_SENSOR_RIGHT_KEY, buffer, data_length); > right = buffer[2]; > > out: > @@ -810,12 +813,11 @@ static ssize_t applesmc_show_fan_speed(struct device *dev, > to_index(attr)); > > ret = applesmc_read_key(newkey, buffer, 2); > - speed = ((buffer[0] << 8 | buffer[1]) >> 2); > - > if (ret) > return ret; > - else > - return snprintf(sysfsbuf, PAGE_SIZE, "%u\n", speed); > + > + speed = ((buffer[0] << 8 | buffer[1]) >> 2); > + return snprintf(sysfsbuf, PAGE_SIZE, "%u\n", speed); > } > > static ssize_t applesmc_store_fan_speed(struct device *dev, > @@ -851,12 +853,11 @@ static ssize_t applesmc_show_fan_manual(struct device *dev, > u8 buffer[2]; > > ret = applesmc_read_key(FANS_MANUAL, buffer, 2); > - manual = ((buffer[0] << 8 | buffer[1]) >> to_index(attr)) & 0x01; > - > if (ret) > return ret; > - else > - return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", manual); > + > + manual = ((buffer[0] << 8 | buffer[1]) >> to_index(attr)) & 0x01; > + return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", manual); > } > > static ssize_t applesmc_store_fan_manual(struct device *dev, > @@ -872,10 +873,11 @@ static ssize_t applesmc_store_fan_manual(struct device *dev, > return -EINVAL; > > ret = applesmc_read_key(FANS_MANUAL, buffer, 2); > - val = (buffer[0] << 8 | buffer[1]); > if (ret) > goto out; > > + val = (buffer[0] << 8 | buffer[1]); > + > if (input) > val = val | (0x01 << to_index(attr)); > else > @@ -951,13 +953,12 @@ static ssize_t applesmc_key_count_show(struct device *dev, > u32 count; > > ret = applesmc_read_key(KEY_COUNT_KEY, buffer, 4); > - count = ((u32)buffer[0]<<24) + ((u32)buffer[1]<<16) + > - ((u32)buffer[2]<<8) + buffer[3]; > - > if (ret) > return ret; > - else > - return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", count); > + > + count = ((u32)buffer[0]<<24) + ((u32)buffer[1]<<16) + > + ((u32)buffer[2]<<8) + buffer[3]; > + return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", count); > } > > static ssize_t applesmc_key_at_index_read_show(struct device *dev,