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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 , Will Deacon , Ryan.Roberts@arm.com, david.hildenbrand@arm.com Subject: Re: [PATCH v2 3/3] mm: skip KASAN tagging for page-allocated page tables Message-ID: References: <20260324132631.482520-1-usama.anjum@arm.com> <20260324132631.482520-4-usama.anjum@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260324132631.482520-4-usama.anjum@arm.com> X-Rspamd-Queue-Id: 38B4540007 X-Stat-Signature: okamg7jtts536zwi6wem373mobap7diw X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1775845181-886253 X-HE-Meta: U2FsdGVkX1+3jJlIp+Z/H/72Ia29OnbcoCM4o3owm5sd1FkkpxlkzqPchWzGjOj1XmWC1uvu/ryuKiZBMplB7AEHm5PU2zQ8LAw0edwIi5ItSAtj6dRBfc8iwll23YgIZvSpJkmt2u+cc/O00ZzWuzmge/XcKAIeUUSY4RljwE8j6w1ulBlDjfdgV6P2pAEXIZdsuIG/YSsUEZudK+2lnYqjXxMfBwcRZ1R75XT1qqNUYvuvQ1W5T5EVEv5VCKUF1DP5h0cd3EAKAwVUojijAK/xQa7Yt2rl7/Z+ZHd+VWbKg0cOMixTz4pZLtbsU+apeTm02z60/K/RPHOV88gBxbsPxgnNyEWXQyeb79tDNllCh0xY1npbLiFcv0HYnU3OlicNm4x3ZFlR/+UKrHV8YFoPMfUsLGZutN+lhNiqxnXA72DvfqHBKdvjGW/bust9kCNsobsOBqqzKD+XC7rENCkiTR94C+wsIG48DDi26+QmCQmpjlwaOQXkPsOztEmhd1e76xP2U8gg3Ms8UddFdH9sXdLbNbMrE5zKCokvA5UqEE28E/MyySZfubB6kImOP4RfozJxitNhH3MFNzf8/N6TN22RU/LDDOmAJ27VwTz9/VAFOKuyKbesQQEMnGNMIbgpkYegZhZiu0VusaC+zlWU8GIrr5c0ZL47d7piZOJXqqzXkM030s0x+I9VOJkesFiTpWI89KlnqWTZiMqbr9Y9sq0I2IwB8GQLx7AODj6lHibWVgI02G6lBpFitRfmZOhmKU58f7g10GMQY9e1PiC6LfSCS3GAz7jYTozkzJ3D31ABoJ1HpOXSeKKzbeOQ66fSKYvNhe4IZxVlH+ksdU/vo6dY8YW388Mo1/Y4JwfuRIDBWuydgIl/K721QZ2EKaV/tgn2MdCtuttSsQnU4vD3Vd5z0UKstglkj1125D3qFTyKNbcGzZ9CitLvvXczUiFibrL2Drckk9ZG5Rp n9Wzdnmj zAjbLMDkUcw/J9dfE8wwN4mgtg0HiUniMxR/2Tg9U/RU3ONF71B+2chVGCvvhI0DrrHeywI8jKO14UIUYXKqyVKlQmTLbgbSWu8w6cTPMIVcnZ89lWEi7kxyZiuEmPZFSbhMJhWIM0F/w9l919dvRGHCjenUaMSQ9FcdIgMtkZSG6B4UpcTcN9KYcehORuAX5CBknuuH8U7WP72mpaOCkIjuHHcjeWDVrG+MHSY9ZAsZXPMjRPPL8zs+lJLPWDE2Kmf/xmH1O068nLorePttTpKgJ2MjLermdTwYPQ2zNXetPvl+17lZYtdq8ONTV7cKysm8L Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Mar 24, 2026 at 01:26:29PM +0000, 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 Reviewed-by: Catalin Marinas