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[209.132.180.67]) by mx.google.com with ESMTP id t62si6088277pfa.49.2018.01.26.01.25.19; Fri, 26 Jan 2018 01:25:33 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@gmail.com header.s=20161025 header.b=MUsiOTRI; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752666AbeAZJYt (ORCPT + 99 others); Fri, 26 Jan 2018 04:24:49 -0500 Received: from mail-ot0-f194.google.com ([74.125.82.194]:36909 "EHLO mail-ot0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752242AbeAZJYr (ORCPT ); Fri, 26 Jan 2018 04:24:47 -0500 Received: by mail-ot0-f194.google.com with SMTP id a24so9586672otd.4; Fri, 26 Jan 2018 01:24:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=fxfwHUfOagojezwxkytIq9lQLhpSmGzBXhGYRLTDxY8=; b=MUsiOTRI+6bdXpplJNmSFyWi/Cf+0dgS/++JhpmInJdQsyOFAG5KDLsJbNS6JrFfVX XPbtuRODEwvnMSVL65W+BDrdMyoMeuUWZilL+XizfT0xTCOJnhABRyPpexmOPrb0z53z /bdGhk1jS70xwj5LUTDiTJZcrtc7E+/DoNI7zZWK5KL4O6SgTDv7oVyhLGjzrkLj/YDU izL9HXsWy72hMlNNdvS6qqDo3YnlPl36w+HmrkQ2X2UEoPHFAuQhB2S7rtzSP+i6cG82 s7RztN3SSxGj7PwYHYRWo2IrnlymeNT1rbGVc6XtRJlmc6bG/9c1yaJykHNhXa9NG6FX dkbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=fxfwHUfOagojezwxkytIq9lQLhpSmGzBXhGYRLTDxY8=; b=MdKocG4FEeO4iW2IHMqndegDQR7O4j507aSSoIIit3xT+Ot+/+8g+4lttVDa0A0pGe cpMrvrQ3Dk8zhF7bMpWPpUf0inTuHrIkaSosv5i9A3rbVZL6S34ABATiZqKnGOUSMqN/ Btt9qdJ1Gsy60I2M9RgsmMv9UTyf6hljQBV8FZsqhkigXtpnHKRaaggIiIdciE1q3pOP Y+rrouap8X9PX1WZ4zlBI47zEdXZYRg8U6O/a0aXEiLjI0u8EG5yFN3TCmLNykvkv3m1 bnB7AEZ9x7ek0xcT/l566Uvj8HtJOlLhL7+oRq2yUAPV187ZGEnApsH7vKNHmA/D4peD xjKw== X-Gm-Message-State: AKwxytdfCjyzBG2JvtcWW1IvmWYBu2Danqzg7/WaTnasMuSNG8OlukPC sDyZTQxkRPq/t6OKDrUnnJbWQvV3Lt+Q0iKNQVXJuQ== X-Received: by 10.157.114.221 with SMTP id d29mr13343105otk.104.1516958686896; Fri, 26 Jan 2018 01:24:46 -0800 (PST) MIME-Version: 1.0 Received: by 10.157.68.119 with HTTP; Fri, 26 Jan 2018 01:24:46 -0800 (PST) In-Reply-To: References: From: Arnd Bergmann Date: Fri, 26 Jan 2018 10:24:46 +0100 X-Google-Sender-Auth: cwXvjRhdtwzhPcN-3tx0Nj1WYzM Message-ID: Subject: Re: [RESEND PATCH] rtc: Fix overflow when converting time64_t to rtc_time To: Baolin Wang Cc: Alessandro Zummo , Alexandre Belloni , Mark Brown , linux-rtc@vger.kernel.org, Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 26, 2018 at 6:06 AM, Baolin Wang wrote: > If we convert one large time values to rtc_time, in the original formula > 'days * 86400' can be overflowed in 'unsigned int' type to make the formula > get one incorrect remain seconds value. Thus we can use div_s64_rem() > function to avoid this situation. > > Signed-off-by: Baolin Wang Acked-by: Arnd Bergmann