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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D04FCC433F5 for ; Fri, 17 Dec 2021 18:30:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=iYnEm1XcvMffkh/P3M10e5VxQZdM4I5Gjl3bfpjVnnQ=; b=k2hHV8sCIP9g0N Y71m/EAQKhXDcccZo4k2CxHZxbg3fabcV5fweUk60PB8IpifQKXmRX26kSM/SP4LENOi3/jVtPhA7 JXKDlhaZ5Jks5OCavH9of0INrQQI6l2ZxwHBskxHWpQjLMs+5Zo24cz2F0RYOnbx7N4WLB7sbPBVx 2SMe+hFZ5RkVoBXhHRKF7wRZs9RLDiT4jcZ0PP18AHC3Lpro7rDRkdR8L/LFUtvEejkpUyC0lsOmD r4wFULgZevf7y55jLjcIsGSGYmP0bCeAJCwOqt5MV59mlF3E/Sz5YNasass/UH79GHOopubI7+w74 LnFSPBk+OzyEafhz2LFw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1myHyw-00BqQl-NE; Fri, 17 Dec 2021 18:29:27 +0000 Received: from galois.linutronix.de ([2a0a:51c0:0:12e:550::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1myHDa-00BWUK-5B for linux-arm-kernel@lists.infradead.org; Fri, 17 Dec 2021 17:40:31 +0000 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1639762825; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=m5F123U0colHSmCqnwjZ4Dods3aSHz4qLqVBNFM6i9o=; b=M97PsoR4BRUQhroZzpUh4+XBNNJnywoRxRxr/ok/TBeMJCY4ypdunZjJmvjRgr7CiA4Kl8 /A+W9VzU6ilQsKbMPWly2k4CoIEjHRgYUJTPn/VJ2bHibz6W0C2KwOOEMSg/5LKERXhdkc 6UJRHy7cDgMBjuQw3iayUS+9Zk5JMTVGIqPr+ftNoAm2+FMT3s94ht0G1xNgMlDdX85REm 85CyTdtqc/UYJu0uqFprzssjiY93CZMZPQdFvEvdfWHz6jLtFgC/gsBNCwFw0p1gFnXWJA b5c+v7x/zH3SNeuu5fWJZlkXxH96820Y2m1J/Qh8H6OVDXOuXNeSvl3iI4nbbw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1639762825; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=m5F123U0colHSmCqnwjZ4Dods3aSHz4qLqVBNFM6i9o=; b=YsHqhAgCpxaEn4cn8Hd06FNdbE4AGuRS+n5cp9pTKZR1X670LiOuiGNuLeruZlOwdwaClv DdOnfTIC/6sUK8Cg== To: Nicolas Saenz Julienne , mark.rutland@arm.com, paulmck@kernel.org Cc: rostedt@goodmis.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, rcu@vger.kernel.org, peterz@infradead.org, mtosatti@redhat.com, frederic@kernel.org, corbet@lwn.net, Nicolas Saenz Julienne Subject: Re: [PATCH v3 1/2] Documentation: Fill the gaps about entry/noinstr constraints In-Reply-To: <20211217105753.892855-1-nsaenzju@redhat.com> References: <20211217105753.892855-1-nsaenzju@redhat.com> Date: Fri, 17 Dec 2021 18:40:25 +0100 Message-ID: <87a6gzcepi.ffs@tglx> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211217_094030_417022_F37A4A04 X-CRM114-Status: UNSURE ( 8.66 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Nicolas, On Fri, Dec 17 2021 at 11:57, Nicolas Saenz Julienne wrote: > +Non-instrumentable code - noinstr > +--------------------------------- > + > +Most instrumentation facilities depend on RCU, so intrumentation is prohibited > +for entry code before RCU starts watching and exit code after RCU stops > +watching. In addition, many architectures must save and restore register state, > +which means that (for example) a breakpoint in the breakpoint entry code would > +overwrite the debug registers of the initial breakpoint. > + > +Such code must be marked with the 'noinstr' attribute, placing that code into a > +special section inaccessible to instrumentation and debug facilities. Some > +functions are partially instrumentable, which is handled by marking them nointr s/nointr/noinstr/ Thanks for polishing this! tglx _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel