From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id CBE7C390C9F; Wed, 29 Apr 2026 10:28:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777458501; cv=none; b=LMS8T9AYDHAu7XnaINfeGUjQfoAUSA9YWP/gtaBW8gWh+MkbExDfXSPwDoueAyfwva6ii4NGolDXbP6RMe/EhJglRQX7lX4bdixTW6UiebhxDA4X9xt5C0Q3arai7MU+JNwJF3eSen6sLslL1JmyQs9gB0QfHIaW+fRRs/17CZ8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777458501; c=relaxed/simple; bh=Wk7w9lhH1k+YWbLTG0ALVUDnoHIRsitzS6tZ9UC4swc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=aH+eASBsObfsp98Kzl6L8j66Z4h5Kx9o9zuzRw4A96/gW1hOsqBayd65/sMf5gFACw3YRbPCQ8e1vIjDE11V1jJ03qEgwR8qyFE9GpZJSzWjdJkGfHcUg17oS9qFIPRi15s4XuE8XnBrt2cOTJOUkesy8FzOQmk+obYxGAxG/kU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=T6QBMkrR; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="T6QBMkrR" 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 CBD562A68; Wed, 29 Apr 2026 03:28:13 -0700 (PDT) Received: from a080796.blr.arm.com (a080796.arm.com [10.164.21.51]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id EA4B63F763; Wed, 29 Apr 2026 03:28:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1777458499; bh=Wk7w9lhH1k+YWbLTG0ALVUDnoHIRsitzS6tZ9UC4swc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T6QBMkrRy4jK7cyGHC88StfkMlvC7TKCLOf4uKVKSxH0q5oOE7SFbPc/FukftUdc5 s1nYC8B8aMvQLMUmQTHVG4LAktohXf0VpI1n02HmiFkLc7jEpu6EsiGLIfUCkWBrPh ya7TyfdwFxyc1myoadrkLjQOXFWQkf9o6I9zkBfU= From: Dev Jain To: akpm@linux-foundation.org, david@kernel.org, urezki@gmail.com, kees@kernel.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, arnd@arndb.de Cc: Muhammad Usama Anjum , ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, kprateek.nayak@amd.com, tglx@kernel.org, mathieu.desnoyers@efficios.com, linux-arch@vger.kernel.org, ryan.roberts@arm.com, catalin.marinas@arm.com, Dev Jain Subject: [PATCH v4 3/3] mm: skip KASAN tagging for page-allocated page tables Date: Wed, 29 Apr 2026 15:57:04 +0530 Message-Id: <20260429102704.680174-4-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260429102704.680174-1-dev.jain@arm.com> References: <20260429102704.680174-1-dev.jain@arm.com> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Muhammad Usama Anjum 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 Reviewed-by: Catalin Marinas Acked-by: David Hildenbrand (Arm) Signed-off-by: Muhammad Usama Anjum Signed-off-by: Dev Jain --- 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) /** -- 2.34.1