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 1C71AEE49A5 for ; Wed, 23 Aug 2023 02:57:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232353AbjHWC57 (ORCPT ); Tue, 22 Aug 2023 22:57:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230231AbjHWC55 (ORCPT ); Tue, 22 Aug 2023 22:57:57 -0400 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A51701BE for ; Tue, 22 Aug 2023 19:57:55 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id d2e1a72fcca58-68bbd45d0d5so153242b3a.1 for ; Tue, 22 Aug 2023 19:57:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google2022; t=1692759475; x=1693364275; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=SME2DvVs9blfVZ8zp0UdPxu1cIq3MKtc4ha5tK0NIgE=; b=Dc43MJfwdq/zHsEqQTPdiV5xt3yUy+e3JQfRi5iw1Vw+aVJTTv7wDZ4vU9Ob58TgvO g0DQCqkPLPbhj7EloC8/TgyjQNchqYGZmNg15sfi97uZBXK5SF/C0kB6GWOTnLNtS5Rd SYlBQW5YUI7Y6PlI7atNU/FrK7x97CT3yYT8K9pf+inhfJDqxMMlR8pQ00k6cBL536UP 6A/+QwA/q7Z6LK+4BJq/m88KgWto5WellkAaurFPclmsmSWG+LasupQMQcipdeloYnJF AXgKgoswHqndKxC2nLvKeqxGNLh26cCO5rWDy1NUEw92+TZESe97+D3lZhz7YVZZkY8A smHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692759475; x=1693364275; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=SME2DvVs9blfVZ8zp0UdPxu1cIq3MKtc4ha5tK0NIgE=; b=T+zc01fwGdaDY1KAJqoIUJKVDRkB8+3EAZnI+TD+A+gIM6qgYmFR2GuFipCFxiE6GQ /9Y9XCdy0Ou5KdscBNaeEUwMWK4yN5OyGTzqk1KTiv3GxdZcJM4ejWb5FxCCuJMHHLOv ybpVnvxxUR+ppZ5EfwXpi9RJvKbjWNLtQe/MdU5V9V5zIrXKlEOkrLDjf7/8dA+ACCY2 KqMXC0PhVxxVdtPVFhXMauHq3GzooSegWBYHZlbgV+HDKqNru1XjKp7nqneHURtm09Wc 7THGK23LWTzHaCVWJ6YeNWwge/MV4WLJmW2aVdowI63JA6yTp46ViU+fLnl3tehzoDm+ Hv+g== X-Gm-Message-State: AOJu0YxISSWEn7Q8rhc8TEfEDOIcbqG2siqyBgjBwuJGKilScCq08TQU /vPkMUldIV/qM7fyF2akZt1edA== X-Google-Smtp-Source: AGHT+IETEsIrTDXLxEiI/YnaIkMEbWdsL7+oyfU8ciOMH2G5fA1n2mxqzx4MukdySCJwnBdfmv8lYQ== X-Received: by 2002:a17:90a:2d8b:b0:26d:414d:a98a with SMTP id p11-20020a17090a2d8b00b0026d414da98amr10374180pjd.1.1692759475083; Tue, 22 Aug 2023 19:57:55 -0700 (PDT) Received: from cork (c-73-158-249-15.hsd1.ca.comcast.net. [73.158.249.15]) by smtp.gmail.com with ESMTPSA id 3-20020a17090a198300b0025023726fc4sm5448007pji.26.2023.08.22.19.57.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Aug 2023 19:57:54 -0700 (PDT) Date: Tue, 22 Aug 2023 19:57:52 -0700 From: =?iso-8859-1?Q?J=F6rn?= Engel To: "Huang, Ying" Cc: Uday Shankar , Kees Cook , Tony Luck , "Guilherme G. Piccoli" , "Rafael J. Wysocki" , Len Brown , James Morse , Borislav Petkov , Len Brown , linux-hardening@vger.kernel.org, linux-acpi@vger.kernel.org, Qiuxu Zhuo Subject: Re: [PATCH] Revert "ACPI, APEI, use raw spinlock in ERST" Message-ID: References: <20230822010933.2247671-1-ushankar@purestorage.com> <87y1i3c015.fsf@yhuang6-desk2.ccr.corp.intel.com> <20230822234522.GA2590891@dev-ushankar.dev.purestorage.com> <87cyzebi00.fsf@yhuang6-desk2.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87cyzebi00.fsf@yhuang6-desk2.ccr.corp.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Wed, Aug 23, 2023 at 10:38:23AM +0800, Huang, Ying wrote: > > Thanks for reminding! That's a good point. > > Checked the implementation of rt_mutex version of spin_trylock(). One > possible code path is, > > spin_trylock() > rt_spin_trylock() > __rt_spin_trylock() > rt_mutex_slowtrylock() > raw_spin_lock_irqsave() You are right. I'm actually quite surprised how we turn a trylock into a spinning lock. Now I know, thank you! Jörn -- "Security vulnerabilities are here to stay." -- Scott Culp, Manager of the Microsoft Security Response Center, 2001