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 17BDCE7717D for ; Fri, 13 Dec 2024 09:17:45 +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:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=uRExllKY+4DGs0s+ZiFvrFQk9Bb6GpDeZ36Y1/rPLyI=; b=AsS3JWMQrUPMYe8+mIlyDDNi9W CrI4+lEOpcBZDEjQaAVzwcGkuoFYrhYmDhzSvCa8fokb9n1YID9hYTPzurGy/Is90eDiNjDtbPwJy t1402M2vusFqNecfXUY/cQhiUM1R+IOg4+TAqs/jp3hGufksNEogOtpCPjCDrWoMpFDStuLS6uREn UWlsrOVsOe6TfHFmF75xo41VateZZmHo2yLcE57LXsTQtEt0fsQU0RvM+gb6jKDcOT/uCVYUZS/93 TUbklWEXMZkCi6N1whySNKkPQ6+m3vVSwq6QEKNEnIDvx+v+o7/gq0x2r2CktqNqlAm6GNXrdJ4vm dSgJTfXA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tM1ng-00000003DXZ-3vjO; Fri, 13 Dec 2024 09:17:32 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tM1la-00000003D7v-2Kma for linux-arm-kernel@lists.infradead.org; Fri, 13 Dec 2024 09:15:24 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 85BD51595; Fri, 13 Dec 2024 01:15:47 -0800 (PST) Received: from [10.57.71.4] (unknown [10.57.71.4]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 515E63F5A1; Fri, 13 Dec 2024 01:15:17 -0800 (PST) Message-ID: Date: Fri, 13 Dec 2024 10:15:15 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] arm64: signal: Ensure signal delivery failure is recoverable To: Catalin Marinas , Mark Brown Cc: linux-arm-kernel@lists.infradead.org, Dave.Martin@arm.com, will@kernel.org References: <20241210160940.2031997-1-kevin.brodsky@arm.com> <5db7f7a0-1d3c-4bbd-ad2b-124bf54f49ef@sirena.org.uk> Content-Language: en-GB From: Kevin Brodsky In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241213_011522_655776_3B93468A X-CRM114-Status: GOOD ( 12.52 ) 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 12/12/2024 18:51, Catalin Marinas wrote: > On Thu, Dec 12, 2024 at 05:26:47PM +0000, Mark Brown wrote: >> On Thu, Dec 12, 2024 at 05:10:14PM +0000, Catalin Marinas wrote: >>> On Thu, Dec 12, 2024 at 04:47:46PM +0000, Mark Brown wrote: >>>>> Fixes: eaf62ce1563b ("arm64/signal: Set up and restore the GCS context for signal handlers") >>>> Presumably we also need a Fixes for whatever introduced the above copy. >>> Hmm, it was like this from the beginning. If we are to do a cc stable to >>> the oldest maintained LTS, I'd rather have a separate patch for >>> copy_siginfo_to_user(), it doesn't make much sense to backport a GCS >>> patch to early kernels. >> Hrm, good point about it triggering backports. I'm not sure it's worth >> doing that TBH. > I had the same thoughts. I think this was mostly triggered by the > POR_EL0 changes when Will raised the point that the kernel might return > with a more privileged value in this sysreg. I don't think backporting would be worth it either, referencing the original commit implementing signal support felt like overkill. The copy_siginfo_to_user() issue is such a corner case that I doubt anyone ever ran into it. - Kevin