From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 86B162248A8 for ; Tue, 2 Dec 2025 15:46:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764690398; cv=none; b=dUXwD/dwqMo6dtANy19uwOK5nCauDlPqzETfXY56vCpFuNzbPM5oXymy83nCIhu8fiVQ43mpc/v1tj2oj4owrXnZU05R6W0zRhUiT27lcZGatOLoJomUAZ5uZYsvID61N0UhGnTOKA7k5DxyZe/66vk+e3hLPahcnBPsOicXhlg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764690398; c=relaxed/simple; bh=KjtMcdo1q07YLEnKSETnsu9YPtnqxwGw5nK+k/AAiN4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DoJGp8twAxUm6zU6WBfR8nFfsYGrSM5gCynCsImeuw0RUH/dInrJ57e2eCg6iiDKdJinaIBzNCfJA0fEQToDWS1fhfvrrVDzQcMCFD/1zEQNKeo596WxnBziVOIC/3N9Rvd+apt+aGzoPnzORuuvtCQO2kK24Z8WxnFZmLjuRh4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=pGW1wQMD; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="pGW1wQMD" 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> Precedence: bulk X-Mailing-List: linux-rt-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251202141816.wfHNUMFK@linutronix.de> Sender: Russell King (Oracle) 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!