Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756630Ab0LQV7T (ORCPT ); Fri, 17 Dec 2010 16:59:19 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41653 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755899Ab0LQV7S (ORCPT ); Fri, 17 Dec 2010 16:59:18 -0500 From: Matthew Garrett To: guenter.roeck@ericsson.com Cc: rydberg@euromail.se, linux-kernel@vger.kernel.org, lm-sensors@lm-sensors.org, Matthew Garrett Subject: [PATCH 2/2] applesmc: Perform some more sanity checking on temperatures Date: Fri, 17 Dec 2010 16:58:26 -0500 Message-Id: <1292623106-31684-2-git-send-email-mjg@redhat.com> In-Reply-To: <20101216170018.GA8140@ericsson.com> References: <20101216170018.GA8140@ericsson.com> X-SA-Do-Not-Run: Yes X-SA-Exim-Connect-IP: 66.187.233.202 X-SA-Exim-Mail-From: mjg@redhat.com X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1199 Lines: 34 It seems that the two-byte temperature format is intended to be signed ("sp78" appears to mean "signed, decimal point, 7 bits before, 8 bits after") and it doesn't seem terribly plausible that we'll get any of these machines below freezing. It's probably more reasonable to assume that negative values indicate errors and drop them. Signed-off-by: Matthew Garrett --- drivers/hwmon/applesmc.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c index 6c98b60..c1eead4 100644 --- a/drivers/hwmon/applesmc.c +++ b/drivers/hwmon/applesmc.c @@ -744,6 +744,10 @@ static ssize_t applesmc_show_temperature(struct device *dev, return ret; if (entry->len == 2) { + if (buffer[0] >= 0x80) { + /* The two byte format is signed - ignore negative */ + return -EINVAL; + } temp = buffer[0] * 1000; temp += (buffer[1] >> 6) * 250; } else { -- 1.7.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/