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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 04BC6C432C2 for ; Wed, 25 Sep 2019 20:32:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C711321D79 for ; Wed, 25 Sep 2019 20:32:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="iKTW5eGm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393235AbfIYUcY (ORCPT ); Wed, 25 Sep 2019 16:32:24 -0400 Received: from mail-io1-f67.google.com ([209.85.166.67]:36933 "EHLO mail-io1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393204AbfIYUcW (ORCPT ); Wed, 25 Sep 2019 16:32:22 -0400 Received: by mail-io1-f67.google.com with SMTP id b19so421052iob.4 for ; Wed, 25 Sep 2019 13:32:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Joen6PgN4Ppb107hjPSYd8q2loeVTGPWBeR8yaoJJfc=; b=iKTW5eGmeo7sl0Q4HF9ZqwfjLbHPh77cZyWr36n8dzNdMbT+HJemF9vuYIeQp42jxo Qacg5Pz2zsOsDg/o/arm+Ck81IAphdlBANecSt6LiqOvq9WAOZlKhtqxEJAO4BWKsFmr qDJICSw4ZPcg1YZeuD4zDxTZD0XFTlD27h63s= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Joen6PgN4Ppb107hjPSYd8q2loeVTGPWBeR8yaoJJfc=; b=Ik+RPFdpNS0JUtz3ZGLXYJtBFd3pDCXgfskcHZLmQ8kBmSquJ6StsR+TbrswX7D1kf ecNzxDli2uixFw5gWVxY7cvM8t3bTmwdwmFL0l4OBhkY6icBEpVb+bDxqZlGnPO+nEZV 8+m9XFR5BNXESWpQUWFaMWgsWmOLm9DuaQO/PmA3Ji2hQsb/JnXTfzkmVZSLzNn2NgQ0 iUD4goXP8pUzOwnzylKLmZHlkU02f+zR/wD6J+bhq9kCFbbEvkjW2MI0dLEdAVnQtaf0 m/IUTaltMX8rXCyAZ3MffbJtKB91eQKFJmPXbwE2In68fYFT2xCPnlJr3UIpjDu54gVl Hd4w== X-Gm-Message-State: APjAAAX1NzGBW25tFBWfpYLm2phIDSynicK8VjBUR5HQsM/h9RJgflB6 Ki1Ri0ne87BAqvMLmysx8Mathw== X-Google-Smtp-Source: APXvYqwP6ll3AAaHm5zA/bZMtHo3VackpD0kbI9u/xv9rtajmPg9oQEH0fjV0awqQtIwDacR9W4tiA== X-Received: by 2002:a6b:b704:: with SMTP id h4mr1413903iof.218.1569443541534; Wed, 25 Sep 2019 13:32:21 -0700 (PDT) Received: from ncrews2.bld.corp.google.com ([2620:15c:183:200:cb43:2cd4:65f5:5c84]) by smtp.gmail.com with ESMTPSA id 80sm449790iou.13.2019.09.25.13.32.20 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 25 Sep 2019 13:32:21 -0700 (PDT) From: Nick Crews To: Alexandre Belloni , Alessandro Zummo Cc: linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, Pavel Machek , enric.balletbo@collabora.com, bleung@chromium.org, dlaurie@chromium.org, djkurtz@chromium.org, dtor@google.com, Nick Crews Subject: [PATCH v3] rtc: wilco-ec: Handle reading invalid times Date: Wed, 25 Sep 2019 14:32:09 -0600 Message-Id: <20190925203209.79941-1-ncrews@chromium.org> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If the RTC HW returns an invalid time, the rtc_year_days() call would crash. This patch adds error logging in this situation, and removes the tm_yday and tm_wday calculations. These fields should not be relied upon by userspace according to man rtc, and thus we don't need to calculate them. Signed-off-by: Nick Crews --- drivers/rtc/rtc-wilco-ec.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/rtc/rtc-wilco-ec.c b/drivers/rtc/rtc-wilco-ec.c index 8ad4c4e6d557..53da355d996a 100644 --- a/drivers/rtc/rtc-wilco-ec.c +++ b/drivers/rtc/rtc-wilco-ec.c @@ -110,10 +110,15 @@ static int wilco_ec_rtc_read(struct device *dev, struct rtc_time *tm) tm->tm_mday = rtc.day; tm->tm_mon = rtc.month - 1; tm->tm_year = rtc.year + (rtc.century * 100) - 1900; - tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); - - /* Don't compute day of week, we don't need it. */ - tm->tm_wday = -1; + /* Ignore other tm fields, man rtc says userspace shouldn't use them. */ + + if (rtc_valid_tm(tm)) { + dev_err(dev, + "Time from RTC is invalid: second=%u, minute=%u, hour=%u, day=%u, month=%u, year=%u, century=%u", + rtc.second, rtc.minute, rtc.hour, rtc.day, rtc.month, + rtc.year, rtc.century); + return -EIO; + } return 0; } -- 2.21.0