From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 356F6196C7C for ; Wed, 4 Mar 2026 01:42:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772588548; cv=none; b=m2CmJC0B6eeaVpc565AQ1J2m99YDAd/6s6S8dwWVGTwWutDZ6mTgWaz7EWjw6BGXCkFNUZ127qkNnPosQ6BeTLYg/zYpAN6ijsA9z+6/XKE3Q/WOuboDCRBWmm70bGZhxXK7zfASbnQrCW3EY1jvyDt4ok9e5YEiA6FQ6ApvktU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772588548; c=relaxed/simple; bh=HtUcXngqU2WZtmvYiLqh/Lz8u8AzPsTyZFzC+kUR67c=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=CYspLLinMBHeIbMXM0oY/SZTfFpZksUQA5eM4eKEwm2Y6+Iv39EERbzw3nFoe9zKT1wkIbEgMN8pAkliqMzg6bY3XmhtqUurqA8bW+/1UF1YQItkJLYo2UAU/zqMYBPzyvYgh5wB9uDDx0cTGMRGJQiE1YLOk1T68WuvvENkF+g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=sMxFd0PK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="sMxFd0PK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F366C116C6; Wed, 4 Mar 2026 01:42:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1772588547; bh=HtUcXngqU2WZtmvYiLqh/Lz8u8AzPsTyZFzC+kUR67c=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=sMxFd0PKpApfPEmkkUs99569yVWTUbSLlU2F9oWXQ8jOwRn5sV/HCZ3itm5+hPiLS lCCrK9DTViXSrd+xCd4yHMLOHJiHAjvL5aR99MamoD4RVHKcEGcSc69VxSwxFtxTwa ccJzlyXgALGUYK0cAZ/YbmDvqavbwXErIhX1ROfw= Date: Tue, 3 Mar 2026 17:42:26 -0800 From: Andrew Morton To: Lorenzo Stoakes Cc: "David Hildenbrand (Arm)" , Zi Yan , Baolin Wang , "Liam R . Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Matthew Wilcox , Chris Down , Suren Baghdasaryan , Mike Rapoport , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH mm-hotfixes] mm/huge_memory: fix memory corruption on huge zero page move Message-Id: <20260303174226.1b9079ccd60164fe0b28a3e1@linux-foundation.org> In-Reply-To: References: <20260302170619.867056-1-lorenzo.stoakes@oracle.com> <901fec30-c5c2-46c5-b48d-f9a8f5e5c928@kernel.org> <20260302125032.313797b0ec908cd133f3ed82@linux-foundation.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 3 Mar 2026 07:25:32 +0000 Lorenzo Stoakes wrote: > On Mon, Mar 02, 2026 at 12:50:32PM -0800, Andrew Morton wrote: > > On Mon, 2 Mar 2026 17:19:15 +0000 Lorenzo Stoakes wrote: > > > > > On Mon, Mar 02, 2026 at 06:10:06PM +0100, David Hildenbrand (Arm) wrote: > > > > There are already patches in flight: > > > > > > > > https://lore.kernel.org/r/aaBVaHs8rIkNcwM0@chrisdown.name > > > > > > Yup, if people would actually cc the right people I'd not have wasted my > > > afternoon. > > > > > > Replying there. > > > > > > > I'm not sure where this is headed but I'll queue this patch for now, to > > get it some testing, to lessen duplicated bug reports and to generally track things. > > Hi Andrew - Who is a confused person! > We should drop my patch and take Chris's. "my patch" being "mm/huge_memory: fix memory corruption on huge zero page move", I assume. > However, life isn't so simple :) as there's been some confusion with his series > since his email client seemed to mess up somehow and a couple patches need to be > squashed on one another. > > So to make life easier, I enclose a squashed patch (combining the commit > message from both), with my R-b, T-b tags attached, please replace my patch > with this one. OK. I added your signed-off-by also. > Also, could you make this into a 2 patch series with > https://lore.kernel.org/linux-mm/aaBWG4fajXXbjpVN@chrisdown.name/ _after_ this > one? Well, "mm/huge_memory: Fix use of NULL folio in move_pages_huge_pmd()" is a cc:stable mm-hotfix and I don't think "selftests/mm: Add UFFDIO_MOVE huge zeropage PMD regression test" is to be treated that way? If correct, I'd keep "selftests/mm: Add UFFDIO_MOVE huge zeropage PMD regression test" as a standalone singleton in mmm-unstable. > mm-unstable (I'm not sure why we're rushing changes there so quick...) had > _only_ this regression test patch in it, so we were left with a kernel that > splatted on running mm selftests, which is not what we want. But the regression fix "mm/huge_memory: fix memory corruption on huge zero page move" was in mm-hotfixes, cc:stable? > (It seems to me this is what mm-new is for, and it seems we have some holes in > our testing still since this got thorugh). > > Please drop the patch you have for this already in mm-unstable and make sure we > only have it _after_ the fix is applied :) I think you mean to drop "mm/huge_memory: fix memory corruption on huge zero page move" from mm-hotfixes. So we now have "mm/huge_memory: fix use of NULL folio in move_pages_huge_pmd()" in mm-hotfixes, cc:stable "selftests/mm: add UFFDIO_MOVE huge zeropage PMD regression test" in mm-unstable, not cc:stable. btw, "selftests/mm: add UFFDIO_MOVE huge zeropage PMD regression test" still has a bunch of unaddressed review comments from David.