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 05182F8A145 for ; Thu, 16 Apr 2026 08:55:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4A1FC6B0005; Thu, 16 Apr 2026 04:55:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 452036B008A; Thu, 16 Apr 2026 04:55:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 319F06B008C; Thu, 16 Apr 2026 04:55:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 1B8C86B0005 for ; Thu, 16 Apr 2026 04:55:55 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id A2D2D140798 for ; Thu, 16 Apr 2026 08:55:54 +0000 (UTC) X-FDA: 84663811428.08.876817C Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf15.hostedemail.com (Postfix) with ESMTP id C9793A0006 for ; Thu, 16 Apr 2026 08:55:52 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="M/EWIteG"; spf=pass (imf15.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1776329753; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=cOD5tX59IXhHCZv1zWXdKyfw26oghRJfbQqFR6LoD44=; b=fZxD+qZ4VWEsYJRrBzsgA2ZFLw4RODxQD47DeLvgS8SzOkAZMrvIKMvQSx0mlyXNWVF9Vh Wg4xnlb1u/+PUNmuoJQt63edNCQUfJYX260mJqA2bjuc69dz702UxqeAwp3adjJMXqfPb1 phyZOjBrrBdAmKw7FoZJ8EVX3ThJ9aQ= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="M/EWIteG"; spf=pass (imf15.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1776329753; a=rsa-sha256; cv=none; b=EpkyFaI/LKg/ZJI9A955B0PV8ixGuwKk0G5y0qskvtiiFiiPevkiWHJTSCMC2nxhk4Zrgj IryPhHGSWlpyjkQiL1sR4PfAxiM3fLpXS4zh6AP2Z4EjqCYO70tWUCOtL+DkEAW0tJ+zSJ KKfZc2/hWMWwKvLGfbLP+fdxZuLPb/o= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id D28A443B04; Thu, 16 Apr 2026 08:55:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CDE49C2BCAF; Thu, 16 Apr 2026 08:55:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776329751; bh=GSP0xdpLtfh+ShVRtbdWDherB8PF5rGv+/SkLctS+dw=; h=Date:Subject:To:References:From:In-Reply-To:From; b=M/EWIteGqXP5eb7n5mzxBJhl/Ai0b73YCo5rfNnCY03nyTfrxuAeTUTM5pBSEVsT7 CfcufnXOlw2FSLEY9VgiuIPW6Y99MEM86HFy70QPFYCSq4CV9qAInEmAGf+Gf2cd3R MgJ1NNoiESY7ko1uVxE615YSbTykElKNz4Zz1bN22Ur7DuR80nKcUu2C3/5987JYfm dHABSGAxTzsPURXVZJ/88oe1N3Mnv28uJzBQwBQrzKwFc8MRsNymvEgFE7EVBN6Ih4 lE84TpbkaP1EPcM9H+aWSN8C+pAKXPkCwqh40Z1DN7a/azpIBJXr1hVMXUzkDXOeq2 ossBLrJ7WQBJg== Message-ID: Date: Thu, 16 Apr 2026 10:55:38 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 3/3] mm: skip KASAN tagging for page-allocated page tables To: Muhammad Usama Anjum , Arnd Bergmann , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Kees Cook , Andrew Morton , 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 References: <20260324132631.482520-1-usama.anjum@arm.com> <20260324132631.482520-4-usama.anjum@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20260324132631.482520-4-usama.anjum@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: C9793A0006 X-Stat-Signature: ztp5mikcsbxe1n5e6paaoqfg6iay5i7u X-Rspam-User: X-HE-Tag: 1776329752-688853 X-HE-Meta: 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 mE4iIkVJ SAWbQCO1m2N63hX4fUSkGcNyfLuqyrAOTb7RvEdlUYg8ofuIYPA+GPke30GqHeBl/c5g6LLq9mXa5S5rwWHWV/SM+8qWZCmnF0MMVzIjVzFXAVS/nu4kOtSsDLy2m9cQQpOD0FC+/ao+ggalBKnQH5cv5HCke+zCId+CLMk4j0AM+rjKjUD07C9/5gokkR0wY5HcDzmg2zyCXcBNqOC8bSGuf5NfolKHdM+O+RJ3XdDEn2JoPcOJ1rI3hywrJOzDToNybBEDg9D9jIYK68WtGp8vMq/oAC+e5sgwcbp6s6zQF44DJjSBDZk0H5tu+icFJ6U/oi29kK3PZVlKdLIUPjkVUFw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 3/24/26 14:26, Muhammad Usama Anjum wrote: > Page tables are always accessed via the linear mapping with a match-all > tag, so HW-tag KASAN never checks them. For page-allocated tables (PTEs > and PGDs etc), avoid the tag setup and poisoning overhead by using > __GFP_SKIP_KASAN. SLUB-backed page tables are unchanged for now. (They > aren't widely used and require more SLUB related skip logic. Leave it > later.) > > Reviewed-by: Ryan Roberts > Signed-off-by: Muhammad Usama Anjum > --- > Changes since v1: > - Update description to mention SLUB-backed page tables are unchanged > --- > 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) Acked-by: David Hildenbrand (Arm) -- Cheers, David