From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-79.mta0.migadu.com [91.218.175.79]) (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 C8F632EFD9B for ; Sat, 19 Sep 2026 05:04:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789794269; cv=none; b=CshzF8lJ7hyZMc/ndve7iXjq0rXR64lBDiIX05HZF53B7NkwT/re4eNc2TDGOruPjfOUdUS9+XrpJWjwAGQVcmMHs5yANkG/5w9w/BPfcg1KFgHm6sKkXf9YfCz5R001JeWzlMTdpzNqHjBQNfRhnHkFIPoVAY0wbScMvYxm0DI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789794269; c=relaxed/simple; bh=5I0cr23layOUUFrQCtUSsraWauuJu7Tb+3NGrSlqoQ4=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=BrYt4fqzqTfhOOONXc0BCdypHgoQoHOiLC6NOIF8gF/c6jlFj85kkpdp7s5zVhKD2GcbZLAP7FeBoqKfPY1G5CojoBvAw7QGwcu2fWViQw7dC3JUlX+pTeJvE6G9SVB28rbtMON11N4aZ04gcp/qXBksaUp/W9JlQ4TgQuEp1Tg= 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=QL4xWcL6; arc=none smtp.client-ip=91.218.175.79 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="QL4xWcL6" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=5I0cr23layOUUFrQCtUSsraWauuJu7Tb+3NGrSlqoQ4=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789794264; v=1; x=1790399064; b=QL4xWcL6F2qii5FZmJmVKX8TpVgdkWigIyWrKho7+LYKfJTjma+I3kKhumgngIdE9JgEa3eu dqRrJer8hfvon2QWaq02MciuosmH6ZufSQQnHOU5oAlWfq0KN/jJdHjUCO9ja3ae/azZLK1xHBj E2LeJP43jlg2iL9HIM68If+4= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta11.migadu.com with ESMTPS id 5dbd40a902d5780f; Sat, 19 Sep 2026 05:04:14 +0000 X-Mizu-Trace-ID: 5dbd40a902d5780f X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii 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 \(3864.700.51.1.1\)) Subject: Re: [PATCH 0/2] dax: Fix Device DAX range allocation validation From: Muchun Song In-Reply-To: Date: Sat, 19 Sep 2026 13:03:54 +0800 Cc: Muchun Song , Dan Williams , Vishal Verma , Alison Schofield , Andrew Morton , Joao Martins , nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <0F332745-D70F-4C51-A597-50C1CAE53CCB@linux.dev> References: <20260915095621.3744167-1-songmuchun@bytedance.com> To: Dave Jiang X-Mailer: Apple Mail (2.3864.700.51.1.1) > On Sep 19, 2026, at 01:02, Dave Jiang wrote: >=20 >=20 >=20 > On 9/15/26 2:56 AM, Muchun Song wrote: >> While working on the HugeTLB Vmemmap Optimization (HVO) = generalization, >> Sashiko reported that memmap_init_zone_device() could be asked to >> initialize struct pages with a large-page order for a physical range >> that was not naturally aligned to that order. >>=20 >> Following the Device DAX call path confirmed that the condition was >> reachable. Device DAX range validation checks the range size, but not >> its start address. An unaligned range can therefore reach >> memmap_init_zone_device() after the device binds, and a subsequent = write >> to a userspace mapping may trigger a kernel panic. With the help of = an >> LLM, I was able to reproduce the failure. >>=20 >> The automatic resize path has a related problem. It can split an = aligned >> size request across arbitrary free gaps, consume an unaligned = fragment, >> and leave the resize partially applied when a later allocation fails. >>=20 >> This series validates both the start and size of every Device DAX = range >> and makes automatic resize account only for usable aligned space. It >> also fixes the mapping sysfs attribute to propagate validation = failures >> instead of reporting success without allocating the requested range. >>=20 >> Muchun Song (2): >> dax/bus: fix Device DAX range alignment validation >> dax/bus: fix mapping attribute error reporting >>=20 >> drivers/dax/bus.c | 144 = +++++++++++++++++++++++++++++++++++----------- >> 1 file changed, 109 insertions(+), 35 deletions(-) >>=20 >>=20 >> base-commit: 1a1de54f7369cd2b5bac0f265910e60ad3a6b4c3 >=20 > This commit does not exist in Linus's tree. Can you please base the = series on top of the latest 7.3-rc tag so sashiko can look over it? = Thanks! Hi, The series is based on linux-next 20260914, and drivers/dax/bus.c is = identical between that branch and the latest 7.3-rc. Sashiko has also already = reviewed it here: [1]. Therefore, I didn't quite catch your point. Are you expecting Sashiko to = conduct another round of review based on the 7.3-rc code? (Are you concerned = about issues introduced by the additional commits in linux-next compared to 7.3-rc?) [1] = https://sashiko.dev/#/patchset/20260915095621.3744167-1-songmuchun%40byted= ance.com Thanks, Muchun