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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 AA112C49EAF for ; Thu, 24 Jun 2021 14:14:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 895D3613EB for ; Thu, 24 Jun 2021 14:14:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231809AbhFXORN (ORCPT ); Thu, 24 Jun 2021 10:17:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231157AbhFXORM (ORCPT ); Thu, 24 Jun 2021 10:17:12 -0400 Received: from mail-ot1-x335.google.com (mail-ot1-x335.google.com [IPv6:2607:f8b0:4864:20::335]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3ADDEC061756; Thu, 24 Jun 2021 07:14:52 -0700 (PDT) Received: by mail-ot1-x335.google.com with SMTP id i12-20020a05683033ecb02903346fa0f74dso5682419otu.10; Thu, 24 Jun 2021 07:14:52 -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; bh=PltV1dDZIj1E5BryefLYmXslgsXDB9xPKP51qS/jnz0=; b=W1OLsto6Gj045hEpKGYZ0B2mTHZyojCO2CvrzyXAd2VTPRHlmjK0RIKAmp1n0GWdFi F27aJKcv5qLYdCQeMUPj4T4fgP6raZOmlGIfwZkCs6CREEQjjjg5+CSCGQSSoAEuilGX w9AKS4fG6Z+s70h4jVnRo+vL9ivfmpEHHDw6Ti2Jk72Y5kb18IZtGHmy6pRYhHKwk73d 2PvRtKRC0xr4TWH8JTYlWcTEMvylIN0Z7Vkjv4DgnCI839YAWr1i2fxPZdLcQHKWWhU7 sGXah0t2b5K7prqA1yX4MWpGQ/7D83E89Qh+dH98m4zG7AFVMxA48NdIH+THlukNtYLb 0P6g== 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; bh=PltV1dDZIj1E5BryefLYmXslgsXDB9xPKP51qS/jnz0=; b=CVo07bAU5ItWeETC8iePWp7QdQF4VqWHbksauYWPLhRZD0G9zROV9LV3v5pan22qMn C7cs3dAWiNnc71WGXnpw+ntC7/cUDeHndWco6BK+X6glTwxt3rBzUXSfKONHRFKXQhJ4 KqLj+6ZBFOdKeNkZYc3wyGRd9tzobb9PDU+x5q7dVvFF3PZrFIILJsVPNd1duR15+kAG psc7J7FFubugvHNjC6Uh+nbsffCdF9s56/BIiQN6EFQbSxZCEIsDJ0CWGZXOxvtv6Zim BxoLIqj1zjQ6QPPmdVqjR0uqbhewYaYixOFIQ7X85J+raR38MJzVwW5Ne9390owWHFVa pLGA== X-Gm-Message-State: AOAM531KuPb1fxGK4GXsMJO+ivnWh9atc1XdQQQHyVDzZSy4jjBpH7e9 Q9TWp/wu8ocXHSXgu3mUeg8= X-Google-Smtp-Source: ABdhPJwnNTR1KnX36TMCG0aIp4+cm+Rtg5S0BASEQG7634PuHiwjrqG+KJdgAXE/5mfLd/aQL8vYwg== X-Received: by 2002:a9d:6a83:: with SMTP id l3mr4845954otq.189.1624544090563; Thu, 24 Jun 2021 07:14:50 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id s2sm611897ooa.39.2021.06.24.07.14.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Jun 2021 07:14:49 -0700 (PDT) Sender: Guenter Roeck Date: Thu, 24 Jun 2021 07:14:48 -0700 From: Guenter Roeck To: Dmitry Osipenko Cc: Zhang Rui , Daniel Lezcano , Amit Kucheria , Jean Delvare , linux-hwmon@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org Subject: Re: [PATCH v5 1/2] hwmon: (lm90) Prevent integer underflows of temperature calculations Message-ID: <20210624141448.GA3691705@roeck-us.net> References: <20210623042231.16008-1-digetx@gmail.com> <20210623042231.16008-2-digetx@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210623042231.16008-2-digetx@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 23, 2021 at 07:22:30AM +0300, Dmitry Osipenko wrote: > The min/max/crit and all other temperature values that are passed to > the driver are unlimited and value that is close to INT_MIN results in > integer underflow of the temperature calculations made by the driver > for LM99 sensor. Temperature hysteresis is among those values that need > to be limited, but limiting of hysteresis is independent from the sensor > version. Add the missing limits. > > Signed-off-by: Dmitry Osipenko Applied. Thanks, Guenter > --- > drivers/hwmon/lm90.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c > index b53f17511b05..567b7c521f38 100644 > --- a/drivers/hwmon/lm90.c > +++ b/drivers/hwmon/lm90.c > @@ -1029,8 +1029,11 @@ static int lm90_set_temp11(struct lm90_data *data, int index, long val) > int err; > > /* +16 degrees offset for temp2 for the LM99 */ > - if (data->kind == lm99 && index <= 2) > + if (data->kind == lm99 && index <= 2) { > + /* prevent integer underflow */ > + val = max(val, -128000l); > val -= 16000; > + } > > if (data->kind == adt7461 || data->kind == tmp451) > data->temp11[index] = temp_to_u16_adt7461(data, val); > @@ -1089,8 +1092,11 @@ static int lm90_set_temp8(struct lm90_data *data, int index, long val) > int err; > > /* +16 degrees offset for temp2 for the LM99 */ > - if (data->kind == lm99 && index == 3) > + if (data->kind == lm99 && index == 3) { > + /* prevent integer underflow */ > + val = max(val, -128000l); > val -= 16000; > + } > > if (data->kind == adt7461 || data->kind == tmp451) > data->temp8[index] = temp_to_u8_adt7461(data, val); > @@ -1137,6 +1143,9 @@ static int lm90_set_temphyst(struct lm90_data *data, long val) > else > temp = temp_from_s8(data->temp8[LOCAL_CRIT]); > > + /* prevent integer underflow */ > + val = max(val, -128000l); > + > data->temp_hyst = hyst_to_reg(temp - val); > err = i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST, > data->temp_hyst);