From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-177.mta0.migadu.com (out-177.mta0.migadu.com [91.218.175.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BF1E242849E for ; Thu, 2 Jul 2026 08:33:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782981241; cv=none; b=RnpwfKEwgtFtIq1SYX3eP02/mDAx7itAklTKSd8SSPhLaj0Rbely8olglX7uf5SHD+jPVTcNwhzXvDKmEIWGt3Ip/i0L93dY+qgkbsPUfLFQMnk4Z+Z4izED4K+VidxI+EU1Sn8tApbqG0Ky8xxf13Zp7evGcbof7aObjJ123eY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782981241; c=relaxed/simple; bh=B8tJJylgSzwicd4/Ou8KHfoy0REk1bTZoXh89fMGD30=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=ofZ0QoxFbN+T6maXH8iDri+uZ/ODaGIyCX8jp/QsBPout6YdmQONeKcmbOl1f3sCMM6K2BQzR2sRwGGPNoQkhhbX/VtYst+oMJHCuzdflcvi9ouIeOVYc0XbPT7W3Oo6G0i5lXdgb8ZJLfprMkA257CuqBJLynERJ2WOcdn2T7Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=SJ0Y0Aqy; arc=none smtp.client-ip=91.218.175.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="SJ0Y0Aqy" Content-Type: text/plain; charset=us-ascii DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1782981227; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SyxPIQyiRY94UmnatdvvXHm0PH6iQcFy569ksBi+Ngk=; b=SJ0Y0AqyMS9M2n2QZLRzV1CPGIMZPLVfRQEKWNUmoYjG8lKgVlBsK23Sq7KAs/mmzgEz+r yA/YQ+R4wSRzWGwmuCE7yTqfBDSlerC0fAv8AtZef1qE5HYDgFwTX2JGVoxG7O1hdV5b/4 JZKbHPW3AKseFmIiWCmAGoK0KJTfGys= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3864.600.51.1.1\)) Subject: Re: [PATCH v2 5/6] mm/page_vma_mapped: use huge_ptep_get() for hugetlb X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Muchun Song In-Reply-To: <20260702051341.126509-6-dev.jain@arm.com> Date: Thu, 2 Jul 2026 16:33:06 +0800 Cc: osalvador@suse.de, akpm@linux-foundation.org, ljs@kernel.org, david@kernel.org, liam@infradead.org, riel@surriel.com, vbabka@kernel.org, harry@kernel.org, jannh@google.com, lance.yang@linux.dev, kas@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, rcampbell@nvidia.com, apopple@nvidia.com, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com, j-nomura@ce.jp.nec.com, nao.horiguchi@gmail.com, ak@linux.intel.com, mel@csn.ul.ie, pfalcato@suse.de, jpoimboe@kernel.org, dave.hansen@intel.com, tglx@kernel.org, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, ryan.roberts@arm.com, anshuman.khandual@arm.com, stable@vger.kernel.org Content-Transfer-Encoding: 7bit Message-Id: <6518FA25-16CB-4BC3-B724-B075B0D1B425@linux.dev> References: <20260702051341.126509-1-dev.jain@arm.com> <20260702051341.126509-6-dev.jain@arm.com> To: Dev Jain X-Migadu-Flow: FLOW_OUT > On Jul 2, 2026, at 13:13, Dev Jain wrote: > > check_pte() is the final validation step in page_vma_mapped_walk(). > It reads pvmw->pte with ptep_get() to decide whether the entry maps > the PFN range being walked. For hugetlb VMAs, that pointer refers > to a hugetlb entry. > > On arches which provide their own huge_ptep_get() to dereference a huge > pte pointer, accessing via ptep_get() would cause pte_pfn(), > pte_present() etc to misbehave. > > It is not clear whether this has a trivially visible effect to userspace. > > Use huge_ptep_get() to dereference a huge pte pointer. > > Fixes: ace71a19cec5 ("mm: introduce page_vma_mapped_walk()") > Cc: stable@vger.kernel.org > Signed-off-by: Dev Jain Reviewed-by: Muchun Song Thanks.