From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-250.mta1.migadu.com [95.215.58.250]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D3E4143B4BF for ; Sun, 18 Oct 2026 08:08:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.250 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792310889; cv=none; b=gEuNavaFpbxgpvrMGbsmdpnH+nw3p/3yNcQ5FFwMEJZuaIIaqcIbFkTPYjS9bp1cRGu61vv4zwEXk3uO2ScWKAZJSfapGA1aeTO2iUtEZQDa7Igdmod3bo+avZBoRdQ2KcC7NqL7QrUjXoh9UC8Ht+itbUDkZvOuFyLH6ZA7Dag= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792310889; c=relaxed/simple; bh=XbcCGqXm08UD+4MN89FaxhWYXmB/b4iOm5BY4cHWO+0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=n5nyhUNn0CKAZpCYnnSB2eJW97X1iz248yHEutDE6QKjC7P6XQYOjobCU8qyUWH5DXxUaEGBs0PoYWdhuxPAiwBYOmaaCudeIbtHZcQGzTlqqQq9dpkEi16KRiFfD24gLpjAO2g80p6YnPveh6sxRgpeDnVRWfdYi8AUlo1fvx4= 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=p7jnQJDx; arc=none smtp.client-ip=95.215.58.250 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="p7jnQJDx" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=XbcCGqXm08UD+4MN89FaxhWYXmB/b4iOm5BY4cHWO+0=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792310885; v=1; x=1792915685; b=p7jnQJDxQMGX25AeFA7oM+lhn6PaZkuGuFKMJ28uIQrj5oGa14bN9VPLVMltoQNSZ3xMxHJ4 MBwro4frvjNLi0qW4g74zXI+af9EHawmu1+cfcriWwvf+r4RygGT8ITaYfTpmMiYivez2iKfuca bTLLBgBV9PA8Dzjeg0ZTLouY= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 56d35b3a46d02963; Sun, 18 Oct 2026 08:08:04 +0000 X-Mizu-Trace-ID: 56d35b3a46d02963 X-Migadu-Flow: FLOW_OUT From: Lance Yang To: david@kernel.org Cc: akpm@linux-foundation.org, liam@infradead.org, ljs@kernel.org, vbabka@kernel.org, jannh@google.com, pfalcato@suse.de, muchun.song@linux.dev, osalvador@suse.de, linmiaohe@huawei.com, nao.horiguchi@gmail.com, agl@us.ibm.com, mel@csn.ul.ie, riel@surriel.com, peterx@redhat.com, kas@kernel.org, rppt@kernel.org, josef@toxicpanda.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 08/10] mm/hugetlb: tolerate UFFD_WP markers outside uffd-wp VMAs Date: Sun, 18 Oct 2026 16:07:59 +0800 Message-ID: <20261018080759.4295-1-lance.yang@linux.dev> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20261015-urgent_fixes-v1-8-42796911043b@kernel.org> References: <20261015-urgent_fixes-v1-8-42796911043b@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Thu, Oct 15, 2026 at 06:07:14PM +0200, David Hildenbrand (Arm) wrote: >UFFD PTE bit handling is a bit like swiss cheese, in particular with >recently added RWP mode. Having uffd-wp markers outside uffd-wp VMAs >already confused this code in the past and resulted in uffd-pte bits >confusing other code later. > >Let's play safe and just ignore these markers in hugetlb_no_page(), not >silently propagating the uffd-wp PTE bit. > >Fixes: 2d427bb01639 ("mm/userfaultfd: add RWP fault delivery and expose UFFDIO_REGISTER_MODE_RWP") >Cc: stable@vger.kernel.org >Signed-off-by: David Hildenbrand (Arm) >--- LGTM! Reviewed-by: Lance Yang