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 7663B23EA94; Fri, 28 Nov 2025 17:35:04 +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=1764351308; cv=none; b=goZLQk6F+Q90dqSquThxGQC/+mRy+V712zvMz9qgsObrZjzeoaOB13pUKtdSA2bbUlI/61m/gqIOJ9toH/50IUcGketUv29Hta4/9Ar123qi3zeXDi8dlK1kjBWCYt1ToQBZ4Syu0z3Yr+ldiFGckhKYKiiNpWYwQh3i09M4cA0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764351308; c=relaxed/simple; bh=qOdNMX0gZXn+LEkT91HW6xWrxtuex8638u2ALi+Eg7Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ESCEFa1B115eDo74D6o6FNmiCGycMiv22cI/MLPWbHTWprsHaomQ1WKmNsD32g7ewy5lj9doiShJq8+bLBKP5TFS0XUrFPGHCFwDNq2vTLDDbWzlsxo0o2r2MFAnqHCodw9zThJm6Sww99uxpzhIBcpQn7i/iiz0rgiwO5dc7Ns= 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=EL8Chp9j; 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="EL8Chp9j" 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=JwkxrOhf4MPsWdJ3TbYzFMXzZqwZrMM4caiEbRwaHlc=; b=EL8Chp9jEKRF7gKMPiwqVJMmUi 3sja2/y4vjeQ1ppshT3Y0Phtzb/uA0GK4rORcGycRI4NBjBEMRXoaSoIXCeS+SWJl032Ib++WYptL x0IYBkql8K00oiwm7UzwVXX3X/i2/sBjeGk2+j6vi8lnTIx0FlJNpxYizecjmRn1iFfwg8hxM0ip9 8p7k3NEwKfnQhmyhfYKrR+8rCrEUAn7CXRvAZO06nEmmL33gMsfTc5WHBJiUssojzWZUGL0x8BPYQ PhHgGkwqAaFhx/nnT54HgjdB7Zlsb5WvULLZ1VMGrYqeBfrUAuATDr+HUyD+sBc684L0Kt7gQdKgF aIHx+16g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:34828) 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 1vP2Me-0000000076f-1n11; Fri, 28 Nov 2025 17:34:36 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1vP2MZ-000000003nu-1jFT; Fri, 28 Nov 2025 17:34:31 +0000 Date: Fri, 28 Nov 2025 17:34:31 +0000 From: "Russell King (Oracle)" To: Sebastian Andrzej Siewior Cc: Xie Yuanbin , akpm@linux-foundation.org, arnd@arndb.de, brauner@kernel.org, david.laight@runbox.com, hch@lst.de, jack@suse.com, kuninori.morimoto.gx@renesas.com, liaohua4@huawei.com, lilinjie8@huawei.com, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, marc.zyngier@arm.com, nico@fluxnic.net, pangliyuan1@huawei.com, pfalcato@suse.de, punitagrawal@gmail.com, rjw@rjwysocki.net, rppt@kernel.org, tony@atomide.com, vbabka@suse.cz, viro@zeniv.linux.org.uk, wangkefeng.wang@huawei.com, will@kernel.org, wozizhi@huaweicloud.com Subject: Re: [RFC PATCH v2 1/2] ARM/mm/fault: always goto bad_area when handling with page faults of kernel address Message-ID: References: <20251127145127.qUXs_UAE@linutronix.de> <20251128022756.9973-1-xieyuanbin1@huawei.com> <20251128120359.Xc09qn1W@linutronix.de> <20251128172242.cCNBVf7H@linutronix.de> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251128172242.cCNBVf7H@linutronix.de> Sender: Russell King (Oracle) On Fri, Nov 28, 2025 at 06:22:42PM +0100, Sebastian Andrzej Siewior wrote: > On 2025-11-28 17:01:18 [+0000], Russell King (Oracle) wrote: > > > I hope Russell will add them once he gets to it. They got reviewed, I > > > added them to the patch system. > > > > I'm not sure which patches you're talking about, but discussion is > > still ongoing, so it would be greatly premature to merge anything. > > This thread > https://lore.kernel.org/all/20251110145555.2555055-1-bigeasy@linutronix.de/ > > and the patches are 9459/1 to 9463/1 in your patch system. They address > other issues, not this one. Oh, the branch predictor issue. Yea, I'm not keen on changing that because I'm not sure if it's correct (the knowledge for this has long since evaporated.) There have been multiple attempts at fixing this in the past, and I've previously pointed out problems with them when I _did_ have the knowledge. Have you looked back in the archives to see whether any of that feedback I've given in the past is relevant? > > https://lore.kernel.org/r/aSmUnZZATTn3JD7m@willie-the-truck > > > > There are now many threads each with their own discussion, which > > makes it more difficult to work out which is the implementation that > > should be merged. Clearly, not everyone knows about the other > > discussion threads. > > So Will suggested to let change the handler and handle this case. The > other patch is avoiding handling addr > TASK_SIZE. > Any preferences from your side? ... and now we have a new proposal from Linus. I'm not intending to do anything on this new problem until the discussion calms down and we stop getting new solutions. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!