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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 6BCE8C43603 for ; Tue, 10 Dec 2019 21:10:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4158824697 for ; Tue, 10 Dec 2019 21:10:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576012237; bh=qoWIB+0WSAHa/3SwzS6I1z52KR/Wh/ZPFYeXYzN9PqQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mMYokBAhaixzMhFcZxQM6Oef3cX0UixuMKYq2VxsegGaD9GKDUElhdE/c75+L+d0A aY22ks+Z0oyI+JjX3gKRONBD7ogg51/bypvcgk2wnRHxJQ4ZYNYVMWaWYJfFHDFbU+ sDWQaqjhvXjjL83UmaXFXLuuost9aSuTgYTxrO3s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728549AbfLJVKg (ORCPT ); Tue, 10 Dec 2019 16:10:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:60598 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728531AbfLJVKd (ORCPT ); Tue, 10 Dec 2019 16:10:33 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6F228246C4; Tue, 10 Dec 2019 21:10:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576012233; bh=qoWIB+0WSAHa/3SwzS6I1z52KR/Wh/ZPFYeXYzN9PqQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ftwrQ6ccbopfaYCsCYq4OVICDtXHKYkm3focToIOSF0BVMjaoC75D4cQJqGUsLy3X 1qe0lERg5TU1PDWMoxku12/SPpk5i6m0P/GBjBs4+sE6trBALv9OVotW73LjtKW1px SckpQsmkthGyKOWFHsUkJz5uyi+OrZYPmuBkvdgg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Heiko Carstens , Vasily Gorbik , Sasha Levin , linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 182/350] s390/time: ensure get_clock_monotonic() returns monotonic values Date: Tue, 10 Dec 2019 16:04:47 -0500 Message-Id: <20191210210735.9077-143-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191210210735.9077-1-sashal@kernel.org> References: <20191210210735.9077-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Heiko Carstens [ Upstream commit 011620688a71f2f1fe9901dbc2479a7c01053196 ] The current implementation of get_clock_monotonic() leaves it up to the caller to call the function with preemption disabled. The only core kernel caller (sched_clock) however does not disable preemption. In order to make sure that all callers of this function see monotonic values handle disabling preemption within the function itself. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin --- arch/s390/include/asm/timex.h | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h index 64539c221672b..0f12a3f912820 100644 --- a/arch/s390/include/asm/timex.h +++ b/arch/s390/include/asm/timex.h @@ -10,8 +10,9 @@ #ifndef _ASM_S390_TIMEX_H #define _ASM_S390_TIMEX_H -#include +#include #include +#include /* The value of the TOD clock for 1.1.1970. */ #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL @@ -186,15 +187,18 @@ extern unsigned char tod_clock_base[16] __aligned(8); /** * get_clock_monotonic - returns current time in clock rate units * - * The caller must ensure that preemption is disabled. * The clock and tod_clock_base get changed via stop_machine. - * Therefore preemption must be disabled when calling this - * function, otherwise the returned value is not guaranteed to - * be monotonic. + * Therefore preemption must be disabled, otherwise the returned + * value is not guaranteed to be monotonic. */ static inline unsigned long long get_tod_clock_monotonic(void) { - return get_tod_clock() - *(unsigned long long *) &tod_clock_base[1]; + unsigned long long tod; + + preempt_disable(); + tod = get_tod_clock() - *(unsigned long long *) &tod_clock_base[1]; + preempt_enable(); + return tod; } /** -- 2.20.1