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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4D83C00145 for ; Mon, 12 Dec 2022 13:16:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231929AbiLLNQH (ORCPT ); Mon, 12 Dec 2022 08:16:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232586AbiLLNPo (ORCPT ); Mon, 12 Dec 2022 08:15:44 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2E6313D56 for ; Mon, 12 Dec 2022 05:15:13 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 87CBD60FF4 for ; Mon, 12 Dec 2022 13:15:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 336D6C433D2; Mon, 12 Dec 2022 13:15:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670850912; bh=fhs5fA57J/p4a3PHpy7bxrxXOmg/jUtb2bVxw7E3S1I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LK+FjtXMk0gkp+jbqKTD6I0NzL2KTvurmWNcVWJ5kX0D5VKeZHsHfD41EfJ1bjeTz w5J2girHUtuZTKhyeefs85wFIK5/4+QjjIK1ND0UWqsm1hwpGp2WBymvQOK0glnHIy Siy29aEPiErDwzotZC8YaSuJd7SWVNEjXg5DecUc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Mateusz=20Jo=C5=84czyk?= , Alessandro Zummo , Alexandre Belloni , Thomas Gleixner , Sasha Levin Subject: [PATCH 5.10 062/106] rtc: mc146818-lib: fix locking in mc146818_set_time Date: Mon, 12 Dec 2022 14:10:05 +0100 Message-Id: <20221212130927.589482356@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221212130924.863767275@linuxfoundation.org> References: <20221212130924.863767275@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mateusz Jończyk [ Upstream commit 811f5559270f25c34c338d6eaa2ece2544c3d3bd ] In mc146818_set_time(), CMOS_READ(RTC_CONTROL) was performed without the rtc_lock taken, which is required for CMOS accesses. Fix this. Nothing in kernel modifies RTC_DM_BINARY, so a separate critical section is allowed here. Fixes: dcf257e92622 ("rtc: mc146818: Reduce spinlock section in mc146818_set_time()") Signed-off-by: Mateusz Jończyk Cc: Alessandro Zummo Cc: Alexandre Belloni Cc: Thomas Gleixner Cc: stable@vger.kernel.org Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/20220220090403.153928-1-mat.jonczyk@o2.pl Signed-off-by: Sasha Levin --- drivers/rtc/rtc-mc146818-lib.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c index 1ca866461d10..3783aaf9dd5a 100644 --- a/drivers/rtc/rtc-mc146818-lib.c +++ b/drivers/rtc/rtc-mc146818-lib.c @@ -283,8 +283,10 @@ int mc146818_set_time(struct rtc_time *time) if (yrs >= 100) yrs -= 100; - if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) - || RTC_ALWAYS_BCD) { + spin_lock_irqsave(&rtc_lock, flags); + save_control = CMOS_READ(RTC_CONTROL); + spin_unlock_irqrestore(&rtc_lock, flags); + if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { sec = bin2bcd(sec); min = bin2bcd(min); hrs = bin2bcd(hrs); -- 2.35.1