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 B1B02C4167B for ; Mon, 27 Nov 2023 15:08:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=iulmnPDdmyK3qMmPj0wSyuSBUpebzLNwG3B4IfP8pmg=; b=Ikuab7Zgx09NH6 YhHnHFG0QYl01Iu7f0ysWBFvBYT1UOSr5k5Hf90YPBcw0kk5t8YPS9BxWPq50AEe3uYfUM5Tt83uz nnxd6tTTfTAQOueZRR4CnoffjEoa7tIPBKnAT5Q8w03hQMDT1aQqGBn6xRI4RBUXEhUZAWxtJJL9n UUVR6w0gpFi5QjXAJkiRIg/HQYUAKP5BWx2d7wqFgS7SeW1igmlXpp4wrVUpnJyeF9HnwZTsw39Vj QLjRyE+lbVkLH7APTHOzvWneqsYCxHF39/UhUtOT7em9520wfmqHSOWjPWKOmD20McoGVhIubJrg7 72dv1zydr1oS+fSIzMfA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r7dCz-002lsv-0Y; Mon, 27 Nov 2023 15:07:37 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r7dCw-002lsO-0J for linux-arm-kernel@lists.infradead.org; Mon, 27 Nov 2023 15:07:35 +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 288502F4; Mon, 27 Nov 2023 07:08:20 -0800 (PST) Received: from raptor (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4905E3F6C4; Mon, 27 Nov 2023 07:07:27 -0800 (PST) Date: Mon, 27 Nov 2023 15:07:24 +0000 From: Alexandru Elisei To: David Hildenbrand Cc: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com, pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH RFC v2 14/27] arm64: mte: Disable dynamic tag storage management if HW KASAN is enabled Message-ID: References: <20231119165721.9849-1-alexandru.elisei@arm.com> <20231119165721.9849-15-alexandru.elisei@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231127_070734_181157_CA3A1F68 X-CRM114-Status: GOOD ( 12.97 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, On Fri, Nov 24, 2023 at 08:54:12PM +0100, David Hildenbrand wrote: > On 19.11.23 17:57, Alexandru Elisei wrote: > > To be able to reserve the tag storage associated with a page requires that > > the tag storage page can be migrated. > > > > When HW KASAN is enabled, the kernel allocates pages, which are now tagged, > > in non-preemptible contexts, which can make reserving the associate tag > > storage impossible. > > I assume that it's the only in-kernel user that actually requires tagged > memory (besides for user space), correct? Indeed, this is the case. I'll expand the commit message to be more clear about it. Thanks, Alex > > -- > Cheers, > > David / dhildenb > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel