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 DF8D81E8826; Fri, 2 Oct 2026 12:27:07 +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=1790944029; cv=none; b=erBqfgXGHsd1jVjLho7CugjYYYc55AleATwFlExXA1i1u7aZnMxJMylZf64qcSzNiY0/mDbVG4Z3pS3+8fvCZCn93ZZll1UKXZxjDy7KoqdQsNM5QKZy2HdnCtFX4ULDWwsJs8SRJNKC6r+id5cbcp8FYc5V4hStAHRLpUs7E8k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790944029; c=relaxed/simple; bh=Rz6XYStyWFzN0ZjvCDWKB7fThH12QCzItZ/47IqIX1M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nVGwnXLyY6g12xgkmUUko/v5dErWQpE6JuDyhfLd4cJzhHA0iqbUjJlyNYpOcpiO5CDoM5+lRMJlkNbCZAe4mWVflZKrX9YTc2remEg8chNRtKmJPEoGB1/p03XySvVDjntmpw4dLxN5NqpaRHZodhYMZzIMXBkb+mAUXwFS3SU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cxL+MpzC; 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="cxL+MpzC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C8FE1F000FF; Fri, 2 Oct 2026 12:26:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790944027; bh=hHcwGbw/dTLavCD1q0Wz915FUcvfzunoMb3D7u+JUi8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=cxL+MpzC1cfSdjAOczoG1wPIbWTQrpCLMvzVBXSmnKiDFYDBMn64LTPj/OWtWuFXw gMS4it0MZsivPy8icpf5Socvb5mYV2Im4m2dtIO0izWysvPZaaVznKHHE8BUgxTm84 r9D0MJpBzqhVcI1wDRYzLV3kd3Y/HTsDcWwM/QeLKcJvTZvL+5LlcKmc0a0aAwrQ2U ZYFaZjVC0hCZ6nCAC8I0h5O90ago1k3NGUIsPkt6VWSJG/PggFTuZRQsBvT4/V6tEj +1USCOD4kbv5ptO7N71o+f+lwiUaQKKZEz6kENcKDRXDz8XMOg2VDIFttVx9pefZu/ Fg8q/hmZlpmxg== Date: Fri, 2 Oct 2026 13:26:38 +0100 From: "Lorenzo Stoakes (ARM)" To: Zi Yan Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , David Hildenbrand , 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 , 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" , Jaya Kumar , 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 Subject: Re: [PATCH v3 23/40] mm/mlock: clear VMA_LOCKED_MASK over mmap callback Message-ID: References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> <20260917-b4-mmap-prepare-vma-flag-sanify-v3-23-4583d8a23bca@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=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Oct 01, 2026 at 11:20:17AM -0400, Zi Yan wrote: > On Thu Sep 17, 2026 at 12:22 PM EDT, Lorenzo Stoakes (ARM) wrote: > > Currently there's a confusing mess around VMA_LOCKED_BIT and > > VMA_LOCKONFAULT_BIT. > > > > It is permitted for drivers to set any flags they like, with the VMA > > already possessing lock flags. > > > > This results in the absurd situation of a VMA possessing both > > VMA_SPECIAL_FLAGS and VMA_LOCKED_MASK flags, which is not permitted. > > > > This has resulted in mlock_vma_folio() having a very silly check for this > > scenario to work around it. > > > > There is no need for this - just clear the flags before invoking the hook > > and reinstate them afterwards if they are required. > > > > Nothing relies upon this being set during the mmap operation. > > > > mmap_prepare is unaffected by this so requires no fix. > > > > Signed-off-by: Lorenzo Stoakes (ARM) > > --- > > mm/internal.h | 9 +-------- > > mm/vma.c | 14 ++++++++++++++ > > 2 files changed, 15 insertions(+), 8 deletions(-) > > > > > > + /* If VMA flags still valid for locked mask, reinstate. */ > > + if (vma_supports_mlock(vma)) { > > + const vma_flags_t mask = > > + vma_flags_and_mask(&map->vma_flags, > > + VMA_LOCKED_MASK); > > + > > + vma_set_flags_mask(vma, mask); > > It took me a while to figure out vma_set_flags_mask() is an OR > operation. Yeah naming is hard :) Let me add a comment here though because it's kinda a bit unusual. > > > + } > > + > > map->vma_flags = vma->flags; > > > > return 0; > > Otherwise, LGTM. > > Reviewed-by: Zi Yan Thanks! > > > > -- > Best Regards, > Yan, Zi > -- Cheers, Lorenzo