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 1AA12C982E0 for ; Fri, 16 Jan 2026 17:34:12 +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=XYA1/PW/0yIH+JE9voV2k0usAZeLlOr7n78hGG9p8IA=; b=inlf8cEX817Z8UFvBTDbaXOvbM 8rtqSPg+wGWTV28bEO6JCttRZnGMyf7+SHSq3CS5q66H1E4h066Zij6HqQUrQdg2AToP1m+5TBDe1 P5+apDDN3HtP9/q5QX6H8E+X1JV8PI6rBkCcGm8k8bv2kkWpHteeAyDVq0u+m3UT/LBUlpjDw+80k uFrO8bvZ1H7vwY8RaIl3DB4fyGnCU7XxrlNeJwf0qkXd9QMo4jAboH0tWUcKxBQXzZD60emPmcEdn ngO3SYqmUVw3GsYpG+BCNdVUYCiL/3nkH9gV6+TmaTKOMPlMHH4Rg9f/MxAOd1tuFOfnwSHKXJlWH 3YoAIgGA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vgnhy-0000000EaVs-3lAr; Fri, 16 Jan 2026 17:34:02 +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 1vgnhv-0000000EaUq-3tIM for linux-arm-kernel@lists.infradead.org; Fri, 16 Jan 2026 17:34:01 +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=XYA1/PW/0yIH+JE9voV2k0usAZeLlOr7n78hGG9p8IA=; b=QFQLb4DtnGGuGfg6tzYpMSXF/W ue4Jp5++XNHkR2KYLvgIRT7dbompth+qQ+kdEHlX3RYEmuv3XkPzJ19DPeN29oLEl10ve92Sb/rnj Y/GZhWvxaOGeNQW0YF8yBcKLMCEId2mlPlhi1ghGMfixcRWCdW/gWI5ZmuApKMF0fHhDtr+Z/QO6/ 7yI77qfOwnAu2iaboZeksr9zTCwGy4PUCuxB7yxvWwfl+NZN/Kphh8kF2poxmSjhe1lMbTrH4nJco gZv49PoDsMKt5V3MJ3h0ThE2gsd8pD6nzgE4IEXVC/2PR8uDwXxUsXiQTrx5vpRsW7v58TglFEb5g KAPt3GhA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:53306) 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 1vgnhn-000000002YA-3e5e; Fri, 16 Jan 2026 17:33:52 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1vgnhk-000000003mL-3E2k; Fri, 16 Jan 2026 17:33:48 +0000 Date: Fri, 16 Jan 2026 17:33:48 +0000 From: "Russell King (Oracle)" To: Sebastian Andrzej Siewior Cc: linux-arm-kernel@lists.infradead.org, linux-rt-devel@lists.linux.dev, Arnd Bergmann , Linus Walleij , "Yadi.hu" , Bryan Brattlof Subject: Re: [PATCH v4 1/2] ARM: mm: fault: Enable interrupts before invoking __do_user_fault() Message-ID: References: <20260116170041.1059997-1-bigeasy@linutronix.de> <20260116170041.1059997-2-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260116170041.1059997-2-bigeasy@linutronix.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260116_093359_968483_84F0A095 X-CRM114-Status: GOOD ( 11.98 ) 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 Fri, Jan 16, 2026 at 06:00:40PM +0100, Sebastian Andrzej Siewior wrote: > From: "Yadi.hu" > > A page fault from userland for a kernel address originates from from > do_sect_fault() (!LPAE) or do_page_fault() and ends in __do_user_fault() > by sending a signal. > > Sending a signal requires to acquire sighand_struct::siglock which is a > spinlock_t. On PREEMPT_RT spinlock_t becomes a sleeping spin lock which > requires interrupts to be enabled. Since the calling context is user > land, interrupts must have been enabled so it is fine to enable them in > this case. > > Enable interrupts in do_kernel_address_page_fault() unconditional in the > user_mode case(). > Enable interrupts in do_sect_fault() if they were previously enabled. Do you need any of this? __do_user_fault() now calls local_irq_enable() as almost the first thing it does. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!