From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 743CB4E36C9; Tue, 13 Oct 2026 11:29:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791890990; cv=none; b=erqx2cpp9La55wYKGLF9SsJixAQa5DSBJUtUAr7zYdcQSbDmNA3XyXIDALPjiGSZKEeME2b17uTyLaqd2AkEfmjFi7kGQVPuQ/Hg9LyUaHjUWAlyF3mgo1rBHu9jGhjBYa26YzAOQH0SRRlD7FXxZs4xXEr0o2JDcfEV5uB4in4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791890990; c=relaxed/simple; bh=hcGq33lvY9rVtSOYs+BB1JK/Pze/KCvmsRz+ajmuwnw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hgwhhjKkRZloQzMyGCP5hfJuFovuK7Fc2EdZhSGgyn+PfYT7pKbXcRnCO68jZAEa60PHV7ebqlTg04BAKpjoFr+5aoe/71xJaY5UHFlhxNxOpONlVZVXwaXUrFJbxZqQguQcreTnLX85MwG9o/37rbmoYWLrIpzx/AgevloQm+I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Q5XSCDOi; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Q5XSCDOi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 908C11F000FF; Tue, 13 Oct 2026 11:29:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791890989; bh=6XqjA/BTi0UimOJRXPoyDY9jgW+xNcOyj9nBVG0M9QA=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Q5XSCDOiMCkxmNBt3Wahjw3f3gX93ZDCSa9CdYxuU9X0hN6bEVTNB4IELta63m0QB dEMhDlXbRQUfz3Ev8UIUCG0TeY/DE8JmQVCgJ1HlzvrcE0UJhAAPV4W0EvcgheF2lB j6DYhxROXPlPjm+pidXFCm8wvv8jdGcSC7oNJZLDlhqrlBEsbRerhPIg47miiV6xt6 1smY9LeY4AAu8C5wf0CqHWMfUWbyMAjGj9pGtHRbexb2hn9pCr3gWJ0CI7ByXeA/VU b2CZVSAsoNG/Lq++tK5RDQ5VuXnlI4jkuiBgwHsD8MmEsVf5mMFDl6K+DSaVvOmynM jiz20RE12a6sw== Date: Tue, 13 Oct 2026 12:29:16 +0100 From: "Lorenzo Stoakes (ARM)" To: "David Hildenbrand (Arm)" Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Greg Kroah-Hartman , Dennis Dalessandro , Jason Gunthorpe , Leon Romanovsky , Paul Moore , Stephen Smalley , Jaroslav Kysela , Takashi Iwai , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Doug Gilbert , "James E.J. Bottomley" , "Martin K. Petersen" , Simona Vetter , Helge Deller , Sebastian Reichel , John Hubbard , Peter Xu , Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Rik van Riel , Harry Yoo , Juri Lelli , Vincent Guittot , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Arnd Bergmann , Muchun Song , Oscar Salvador , "Matthew Wilcox (Oracle)" , Jan Kara , Marc Zyngier , Oliver Upton , Catalin Marinas , Madhavan Srinivasan , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , "David S. Miller" , Andreas Larsson , Alexander Viro , Christian Brauner , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Youngjun Park , Johannes Weiner , Qi Zheng , Shakeel Butt , Axel Rasmussen , Yuanchu Xie , Wei Xu , Chengming Zhou , Michal Hocko , Miklos Szeredi , Xu Xin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-usb@vger.kernel.org, linux-rdma@vger.kernel.org, selinux@vger.kernel.org, linux-sound@vger.kernel.org, bpf@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, fuse-devel@lists.linux.dev, Ihor Solodrai , Bert Karwatzki Subject: Re: [PATCH v5 31/38] mm/uffd: use predicates for userfaultfd checks Message-ID: References: <20261009-b4-mmap-prepare-vma-flag-sanify-v5-0-923b70125b1e@kernel.org> <20261009-b4-mmap-prepare-vma-flag-sanify-v5-31-923b70125b1e@kernel.org> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Oct 12, 2026 at 08:48:04PM +0200, David Hildenbrand (Arm) wrote: > On 10/9/26 20:04, Lorenzo Stoakes (ARM) wrote: > > diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c > > index 949017e60608..f33b04700838 100644 > > --- a/mm/userfaultfd.c > > +++ b/mm/userfaultfd.c > > @@ -2146,10 +2152,11 @@ static bool vma_can_userfault(struct vm_area_struct *vma, vm_flags_t vm_flags, > > { > > const struct vm_uffd_ops *ops = vma_uffd_ops(vma); > > > > - if (vma->vm_flags & (VM_DROPPABLE | VM_SHADOW_STACK)) > > + /* Only mm-backed memory can have its faults handled by userspace. */ > > + if (!vma_is_mm_backed(vma)) > > return false; > > Again, for both I would prefer keeping the droppable check separate. Ack as per discussion on other thread, will separate out for v6! > Acked-by: David Hildenbrand (Arm) Thanks! -- Cheers, Lorenzo