From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A01D6CA601E for ; Fri, 9 Oct 2026 16:56:36 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4j1Y0y6F4Gz2yr0; Sat, 10 Oct 2026 03:56:34 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=172.105.4.254 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1791564994; cv=none; b=lNzCQRuXb98NxwfGw3UQHdFFsHOv5jrobq4ZuA8ZvxXcXzCpf9uYgnQjnu7Ci+CeDLLg0lp4EgvKpnDH1olmLQHld+iuul7J8EJi5AlO/EU3JqVL+POOwnpRTV5ZagnG5LLGlfgaH39MibpEq9/hqFWOp3TrjWvqJiYWtZlPqmRcpVwboHEVIIcbDhoDKoR9ha+TAePRAXtcW+u5Pb4/HiHmsG3QrcS3Ti6QdvKrTnPtfchCwMuYvavBOeAEudEc2VBFI6PXUUfYv/CjRcokUykCuEzBedZvp6Rxm5aJUfsQ+dAwcXe6uXeBnTrhx2iPmMdSrOH75pIFsbr0K4oksA== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1791564994; c=relaxed/relaxed; bh=fE0OAfD+VvZZQlsp7SZETT3KsGTWZ99jT3uHHIgYDkQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DV7NH6gz6HpKKVnDnz/9/MvSRUDqOp9bMEsZTZRFJBYvAALRDG4MsU8h4ZvgCS0crvaZbL/F2moMxccruCMIVGjwhJwyTHy1jTSihBcwrLpHiIHyX5gKBhga0KvwVxY/XQcjGnQ7Te6uD0+eslApx/8b5jWLqOiN00DY1OfvOSf1aw4P24rOIn6dwTQ0nsS0D/wmvpj8OXO0XHUatAf5g1DlVyI5CXM7uRTkUGtf1YZc3XyWfCEoqkO/DP0BotXzX0DucZwBwi5ZvjV9IahyT0mm6KIEhDV6ocoKJgRLSpxYgzuhsGPiVaoMlImhhGEHRRGr5/89BbUp8ZE7f76UeA== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=RUsl9XnU; dkim-atps=neutral; spf=pass (client-ip=172.105.4.254; helo=tor.source.kernel.org; envelope-from=ljs@kernel.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.org Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=RUsl9XnU; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=172.105.4.254; helo=tor.source.kernel.org; envelope-from=ljs@kernel.org; receiver=lists.ozlabs.org) Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4j1Y0x71x5z2y8d for ; Sat, 10 Oct 2026 03:56:33 +1100 (AEDT) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 646786053E; Fri, 9 Oct 2026 16:56:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA2421F000FF; Fri, 9 Oct 2026 16:56:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791564991; bh=fE0OAfD+VvZZQlsp7SZETT3KsGTWZ99jT3uHHIgYDkQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=RUsl9XnUQdex4hYDI/nvqZumtgOTjlWiX0N56fVGal9ZXTElbzreII28hFeRkApJB NHo6FTkv1s0R1SKHMxFh2yoyGgEj94FI2YTZ5R2m7lwDx9O3N5/dtVzHCZ7rRFHg+b AtSEfYi+n++t5xP6H8VImwwnXKYhoLn2R1W0Koa99MOWI+o8HHqK2kIurxPlAU0Yri ygANXuDjupNkgl+uor72EiN8FZ3fmo02D0/KSu5wQ2x84hwaNSlHgKIyyR/PugD/c9 1rQuaM8k2AyO9mDtnEOKbWctVlZ0WY0IhSQdg1dl1SdQIKXtdsg79DgnHAMkLcGLF5 UTDY8ujTUNlMg== Date: Fri, 9 Oct 2026 17:56:08 +0100 From: "Lorenzo Stoakes (ARM)" To: Suren Baghdasaryan Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , David Hildenbrand , Mike Rapoport , 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 Subject: Re: [PATCH v4 07/38] mm: add mmap action for discontiguous kernel page mapping Message-ID: References: <20261003-b4-mmap-prepare-vma-flag-sanify-v4-0-a1f052500fd7@kernel.org> <20261003-b4-mmap-prepare-vma-flag-sanify-v4-7-a1f052500fd7@kernel.org> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Sun, Oct 04, 2026 at 10:11:18AM -0700, Suren Baghdasaryan wrote: > On Sat, Oct 3, 2026 at 6:35 PM Lorenzo Stoakes (ARM) wrote: > > diff --git a/mm/memory.c b/mm/memory.c > > index 448342883e9d..45b21bb04a18 100644 > > --- a/mm/memory.c > > +++ b/mm/memory.c > > +static void __map_kernel_pages_prepare(struct vm_area_desc *desc) > > +{ > > + if (vma_desc_test(desc, VMA_MIXEDMAP_BIT)) > > + return; > > + > > + VM_WARN_ON_ONCE(mmap_read_trylock(desc->mm)); > > Sorry I missed this before and it is pre-existing code but is this a > weird way of asserting that mmap_lock is write-locked? If so, why not > just use mmap_assert_write_locked()? Ah yeah, this weirdness is duplicated from the existing code. Will fix up on resin! -- Cheers, Lorenzo