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 67A24FCE068 for ; Thu, 26 Feb 2026 12:30:07 +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=pr+8ExyOhFxW/Uz4btSXrzEhPFdn+MVB6LdMQibRYoc=; b=J2JQCnWPimcyaVgvHacNj3HjsV 9DvWBp07PZzvLwO213EqlJmN+btL/3wJdKTMKpAzrXDterthv7NrN4V6VNkLgTaytxIlBFd878xHw ZfRnfUhDpZQiNjpTvI08HlR7HVPHRFkK2Rmy/AIF+Fnimxe63K5rI9peykEOVfUvkoRSnQIrR52N4 ODD1FlnBHVz8Ly6HbKQJH06LQWMr+PTdgw4YO8Bzkwh19uKYbUqAGoFNd3eLK/1sEl6yOWow+WtRe V/WQpwhMErTmNFBjcRINWdQKLlpiPe5h05XnEcqFGlVGZ2dV4M7JK+Y48BfnCN53rnSTtG2WWARqP yhWg3AZA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vvaVE-000000067Sb-1T1j; Thu, 26 Feb 2026 12:30:00 +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 1vvaVA-000000067S5-3t0D for linux-arm-kernel@lists.infradead.org; Thu, 26 Feb 2026 12:29:58 +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=pr+8ExyOhFxW/Uz4btSXrzEhPFdn+MVB6LdMQibRYoc=; b=HGpZuHzGxjaKNDkGGJJid5glay 5hMT/4g7xmwuGLThWi9lbZaCDMCu+rYp3wijiDQtm601uNutXM7BiANvKLcd6IbfN0AQiwftMFfbk 9e0B9QAB5WzNX6ZxQEmeql5WIrVaVgMHtChctKYJCS080QG5xg3fNYFPI3SXJCXkbfOwLFaueiggL uriyBEZ3ulpESGQhbJGh9uJDKqfbb8zCIDMwdxr3hA7aHMXFl9AuiyL2BfumcpiC9pNp9ILK4qprS CcFSAL/PU5VJFvy78IgS2dxjpXNY+wja/U983SX+6Fd491N2lLoR00kfj6SSTxHuqZ3JZ1F02FGCm SxkV6OEQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:52834) 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 1vvaV3-000000007v5-1PAl; Thu, 26 Feb 2026 12:29:49 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1vvaUz-000000001xL-31zo; Thu, 26 Feb 2026 12:29:45 +0000 Date: Thu, 26 Feb 2026 12:29:45 +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" Subject: Re: [PATCH v5 1/2] ARM: mm: fault: Enable interrupts before invoking __do_user_fault() Message-ID: References: <20260226111742.3598421-1-bigeasy@linutronix.de> <20260226111742.3598421-2-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260226111742.3598421-2-bigeasy@linutronix.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260226_042957_255193_BC2A16B0 X-CRM114-Status: GOOD ( 15.75 ) 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 Thu, Feb 26, 2026 at 12:17:41PM +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. > > [bigeasy: Initial patch/ report by Yadi. Maintained the patch and redid > the patch description since] > > Signed-off-by: Yadi.hu > Acked-by: Linus Walleij > Reviewed-by: Arnd Bergmann > Signed-off-by: Sebastian Andrzej Siewior Sorry, I've been swamped with stmmac for ages, which has become a millstone. I need to push out these patches: ARM: provide individual is_translation_fault() and is_permission_fault() ARM: move FSR fault status definitions before fsr_fs() ARM: use BIT() and GENMASK() for fault status register fields ARM: move is_permission_fault() and is_translation_fault() to fault.h ARM: move vmalloc() lazy-page table population ARM: ensure interrupts are enabled in __do_user_fault() which will address some of your issues, and clean up the fault handling code. These patches all date from 5th December. :/ -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!