From patchwork Wed Aug 23 13:13:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 13362349 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 1CD3EEE49B2 for ; Wed, 23 Aug 2023 13:16:50 +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:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=J1l4yWXHqvHIvOFQom/ilY8kfo9x9XWUxhifIaOAQY0=; b=1ru1nt25i0IsFy fwLtArxhFFXms9Gk4tgr8UYD0VXXPfwgOzLS8czHwGvrrzGyHD9IFQt0b88RcOy/vEe07h8kTkhzt WHk8rpkEcxywsldjlcI6qkB1XsTwiw/IxrSGepANYuH1FAqyo423wuXeaRqWdt458UGauQXszD5ak NI5MlNTMI0NsgHy8MNT1VcEsw/jkLeeZNqMRknmy9TJrqRrv50M62SyxpBtNIrL8aCZClZYWwmFtG EW68Ib9tMUWSBr2F5eK9WVDmJ1/wN2Xah/E7dbfct95xbEq0pHH3L7nZTdpiK4B21m6p+5MJAjzEZ nSjMKEi6LQQ5/howNaRg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qYnib-000dKB-15; Wed, 23 Aug 2023 13:16:17 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qYniH-000d76-1o for linux-arm-kernel@lists.infradead.org; Wed, 23 Aug 2023 13:15:59 +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 ECD8715BF; Wed, 23 Aug 2023 06:16:36 -0700 (PDT) Received: from e121798.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8BF703F740; Wed, 23 Aug 2023 06:15:50 -0700 (PDT) From: Alexandru Elisei To: 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 Cc: pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.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: [PATCH RFC 17/37] arm64: mte: Disable dynamic tag storage management if HW KASAN is enabled Date: Wed, 23 Aug 2023 14:13:30 +0100 Message-Id: <20230823131350.114942-18-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230823131350.114942-1-alexandru.elisei@arm.com> References: <20230823131350.114942-1-alexandru.elisei@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230823_061557_648972_7E55AB88 X-CRM114-Status: GOOD ( 13.77 ) 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 Reserving the tag storage associated with a tagged page requires the ability to migrate existing data if the tag storage is in use for data. The kernel allocates pages, which are now tagged because of HW KASAN, in non-preemptible contexts, which can make reserving the associate tag storage impossible. Don't expose the tag storage pages to the memory allocator if HW KASAN is enabled. Signed-off-by: Alexandru Elisei --- arch/arm64/kernel/mte_tag_storage.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm64/kernel/mte_tag_storage.c b/arch/arm64/kernel/mte_tag_storage.c index 4a6bfdf88458..f45128d0244e 100644 --- a/arch/arm64/kernel/mte_tag_storage.c +++ b/arch/arm64/kernel/mte_tag_storage.c @@ -314,6 +314,18 @@ static int __init mte_tag_storage_activate_regions(void) return 0; } + /* + * The kernel allocates memory in non-preemptible contexts, which makes + * migration impossible when reserving the associated tag storage. + * + * The check is safe to make because KASAN HW tags are enabled before + * the rest of the init functions are called, in smp_prepare_boot_cpu(). + */ + if (kasan_hw_tags_enabled()) { + pr_info("KASAN HW tags enabled, disabling tag storage"); + return 0; + } + for (i = 0; i < num_tag_regions; i++) { tag_range = &tag_regions[i].tag_range; for (pfn = tag_range->start; pfn <= tag_range->end; pfn += pageblock_nr_pages) {