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 7532A2D8378; Fri, 9 Oct 2026 16:56:31 +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=1791564992; cv=none; b=elEOgTtEHsPhwjmcjbQep2msLS/L+KTzU4uVeWecuz+Tk7AQU+E93GTQoGXA2kxAzKKaXIRA/afUyQlA/o9NrXFYpDsz3lesUcs/X9hNHR+XQ+RQyY3WwIXHDpoI3OsgutVqDFWaZ6SDVXBQTlTHW4RFvGYejBq0bDnkL+12WJM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791564992; c=relaxed/simple; bh=Gsc13vUDcqHhR9WqLn+uEOJ3bL2AXkQlfX0gpVkBRts=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MkvG/1pLRqmKNPgkDjWOd+M2g2fz3TDtk49oOlUHUdVn96aty4ScJ6PblUBstN+NcMwmtEoa0RfWT9hpXFio6RF0m7tWe5JTU1O2J0NJII8pn0waq0LXE0axgTItNb+SkByVBBnslwEb28h/8Nenj6UzPP8um5c4a0lx/WhTP7U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RUsl9XnU; 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="RUsl9XnU" 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> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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