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 84845CFD2F6 for ; Tue, 2 Dec 2025 15:46:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=B8lVeEewvobMOpR8lC3k8lo2AR9tpKYDSUjo/3iThWc=; b=NBXU4Vn6bch610i8LVWn2zvKOJ 0UdzEL06U1tynE81Jqq+Qqq58h1Ee+DIHotMYEVvJZKzfE2ou0y/ywcwU3D7RsBqEPyhHlwL+N7zT XwvgEGMXswJW+ZlX3Z2WoEtzzBcFh1hyq++7YzPbBGIUtnonE8+a9kxKFPZXQRVX2rZk2TKfzguZs Vs5YGPik90INCMc6qXqATyg2lDV3gWcyHcbUeMfqESaMbKWISU3RLvyFpr8QbE4fomvMzDscmpuWB 50dgbkLWHUFkOmJfmvWIWQKISsFDFyvhE3MaYB8m86DtVxpToK5vBLCe1pnuTbs1hA2wmoN3jWM/O jTuBWc5g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vQSaO-00000005Zjf-1TAn; Tue, 02 Dec 2025 15:46:41 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vQSaL-00000005Zj9-2FSs for linux-arm-kernel@lists.infradead.org; Tue, 02 Dec 2025 15:46:39 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=B8lVeEewvobMOpR8lC3k8lo2AR9tpKYDSUjo/3iThWc=; b=pGW1wQMDB4gpVcAKDhhrvOYIMF S+z2LpAbMdBAY5XqI1fKjg3P8u2iCOqMO4V4QEPppqxcuKT0/3m+J/t1w4LeF8OAbRzSZuemnp8BH lGdUigCNtpumHjdEYQZ9a2vtwZTMHMvBplbgfIGWsB3C9nGptZHiDxtwPuQZ4mEhiyzSbZfaaOYIc 27qdV3AxAeC+BJeAFNdPbC2zJWBKK1hkxbaBkzlLJylXr4moCUnz8wJK3sag6v/qc9px+7BSKVNWi ZI8yjuBc78wbyBMg70rqFMSMGxuVzF/31CbQi2nbiOMgt4DqsWa+IaI3C7wofwyrU5mXMFpowX/JU jmWpMz2g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:59058) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1vQSaC-000000001pg-3HUd; Tue, 02 Dec 2025 15:46:28 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1vQSa9-000000007Zj-1Cyb; Tue, 02 Dec 2025 15:46:25 +0000 Date: Tue, 2 Dec 2025 15:46:25 +0000 From: "Russell King (Oracle)" To: Sebastian Andrzej Siewior Cc: linux-arm-kernel@lists.infradead.org, linux-rt-devel@lists.linux.dev, Xie Yuanbin , Arnd Bergmann , Linus Walleij , "Yadi.hu" Subject: Re: [PATCH v3 2/5] ARM: mm: fault: Enable interrupts before invoking __do_user_fault() Message-ID: References: <20251110145555.2555055-1-bigeasy@linutronix.de> <20251110145555.2555055-3-bigeasy@linutronix.de> <20251202141816.wfHNUMFK@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251202141816.wfHNUMFK@linutronix.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251202_074637_850505_B56B5E39 X-CRM114-Status: GOOD ( 15.43 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Dec 02, 2025 at 03:18:16PM +0100, Sebastian Andrzej Siewior wrote: > On 2025-11-10 15:55:52 [+0100], To linux-arm-kernel@lists.infradead.org wrote: > | > | https://www.armlinux.org.uk/developer/patches/viewpatch.php?id=9460/1 > | > | Moved to Discarded. > | > | This makes the issues with the branch predictor hardening worse if this > | patch is merged on its own - since this adds another path where > | interrupts are enabled before calling harden_branch_predictor() in > | __do_user_fault(). It would be sensible to move the interrupt enable > | into __do_user_fault(). > | > | *** PLEASE DO NOT REPLY TO THIS MESSAGE *** > > I thought that we apply both. > In 9462/1 I am moving harden_branch_predictor() out of __do_user_fault() > because do_page_fault() needs the hardening before the interrupts are > enabled. Do mean something like If I apply 9460/1 without 9462/1 first, then it makes the problems with the branch predictor hardening worse. I'm not prepared to do that. However, 9462/1 is tied up in the discussions that are ongoing, and I'm not going to short-circuit the still-ongoing discussions that touch this area by applying this patch - which would screw up everyone's proposals to fix the various many problems that are being discovered in the 32-bit ARM fault handling. This means I can't apply 9462/1 nor 9460/1. Since 9463/1 likely requires these, I can't apply that one either. Sorry. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!