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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 77EC0108E1F7 for ; Thu, 19 Mar 2026 11:50:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E2B986B0492; Thu, 19 Mar 2026 07:50:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E01A76B0494; Thu, 19 Mar 2026 07:50:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D3ED66B0495; Thu, 19 Mar 2026 07:50:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id C5B1C6B0492 for ; Thu, 19 Mar 2026 07:50:20 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 82097593E3 for ; Thu, 19 Mar 2026 11:50:20 +0000 (UTC) X-FDA: 84562644600.26.28376F8 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf18.hostedemail.com (Postfix) with ESMTP id E21FE1C0011 for ; Thu, 19 Mar 2026 11:50:18 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf18.hostedemail.com: domain of usama.anjum@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=usama.anjum@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1773921019; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+cFTzhkZEuZGk5mdEmYKsgnsaUq2Bz1VYYLB6dpBYBk=; b=Vz0egKrE+EmXYO3r9Mlq3SZfTklQp+voQBc70CmgvxeQU+ZYwctNWl6DJQMaXg5Xl+ba9D lwMjFAKRM4a7M4hoIcRaFV2cmNMG+BJiwWVG9pKh11k7fvOfYiqXmsGl0A/1nFjjHIeAlc Jqz1v7g99u2zzDezBU80yxcNrWbRfU4= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf18.hostedemail.com: domain of usama.anjum@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=usama.anjum@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1773921019; a=rsa-sha256; cv=none; b=U4Dmo2FDGwxnI2R55Nv4V1SSqTEXmhTIvKJLQa4vRCOMNEAvgUaDBWyDtLKvUSnI5Nek1C yNIQBUw99muDGZ0jHNA1BhjxXiHD6w+BLRFauQIUxEjY5Evg+rsh+xSkCMpdL83V2GHlaz UnxpfoHhvw36QAF2okRBjGcKzkfDTwI= 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 05AEE20E3; Thu, 19 Mar 2026 04:50:12 -0700 (PDT) Received: from e142334-100.cambridge.arm.com (e142334-100.cambridge.arm.com [10.1.194.63]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C7B4A3F778; Thu, 19 Mar 2026 04:50:13 -0700 (PDT) From: Muhammad Usama Anjum To: Arnd Bergmann , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Kees Cook , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Uladzislau Rezki , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrey Konovalov , Marco Elver , Vincenzo Frascino , Peter Collingbourne , Catalin Marinas , Will Deacon , Ryan.Roberts@arm.com, david.hildenbrand@arm.com Cc: Muhammad Usama Anjum Subject: [PATCH 3/3] mm: SKIP KASAN for page table allocations Date: Thu, 19 Mar 2026 11:49:46 +0000 Message-ID: <20260319114952.3241359-4-usama.anjum@arm.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260319114952.3241359-1-usama.anjum@arm.com> References: <20260319114952.3241359-1-usama.anjum@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: E21FE1C0011 X-Stat-Signature: 884cdiqmy389aspbnfg3yqr6m5j3tcnb X-Rspam-User: X-HE-Tag: 1773921018-835929 X-HE-Meta: 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 CAV0zIx+ 0fubrNp/L2slR4uY2ld9uQJXseeqaep8tFr8GT8KnoInq3bnc/hHWHfVLKkIqLpy2xcUgKZNi4v9Jr4HiPcKizR1oRQRH3rCabstmiXcqpD+ZGdWW0j2vgqJ9fb7VDZhyXMrI0HgBrGjjMRdwLirLUH9JDszuNFw15W222Qo4J2SkzLHQ2xJ3sANDSg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Page tables are always accessed via __va(phys) / phys_to_virt(phys). With a match-all tag in the pointer, MTE never checks memory tags on access. Therefore: KASAN HW tags are set during page table allocation but never checked during use. KASAN poisoning on free provides no value for these pages as well. Its pure overhead - both at allocation time and free time. Hence, skip the tag setting for all page tables. Signed-off-by: Muhammad Usama Anjum --- include/asm-generic/pgalloc.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h index 57137d3ac1592..051aa1331051c 100644 --- a/include/asm-generic/pgalloc.h +++ b/include/asm-generic/pgalloc.h @@ -4,7 +4,7 @@ #ifdef CONFIG_MMU -#define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO) +#define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO | __GFP_SKIP_KASAN) #define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT) /** -- 2.47.3