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 31DFC39E19A; Tue, 8 Sep 2026 20:02:56 +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=1788897778; cv=none; b=uqLuFRzG3yy5mPZxTSFL4TPoT7coKU4hVEtiltkwF2tYCTi45C2bJ31PLo5QVr+vDB5A46PxBgDkxT9l06q98+JdzZ4iVlLOggMy9pRm0YlE5VEx1qsC5kxCAhbbJ+ahjbmJTLv8eB9czd4xIx+KkEAUQn6GYGkabLL/EjmaIro= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788897778; c=relaxed/simple; bh=cTBSc+RhBb8P2CssJn069Zx2TN5+EwkhNO+s8E1YjR4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=evAq+OaWn5F1IF+jjA+BDkPYlyV0N2q+6qgk7T0wj0/rwKCQ5BHxJ8OgAJiwxh4ERrjUX7lQxALHJvMox3rFSU+8oYi1lOB0kFiDUaR+udsp7R2XzlxP763wH6jj0Wb8sManCYq8hAvPo9lSKvLmOuNYffX/BEgx3uERfz0jIdc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nH5WJi2u; 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="nH5WJi2u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 694551F00A3A; Tue, 8 Sep 2026 20:02:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788897776; bh=xAuHiG3VMiz41sfgAPoYgyzk8Zb9pZjO5QbNMONAAQ8=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=nH5WJi2ugUWEAlQwpJVZAN0YVWc7hEFypbO61f8EjYuAl1M80qXUAZD7uFk7h0zkJ 8yjlvVbZ3xrWqvX/TM9nlcB7m+h9xxZTBrsD760l/7wNfRlT0SovNp/2ddOhMkYtrL hvlomkDI1JxVIJQmUjVCnBP1bv1XHQ5PgUD4ZzGsI05M9x05hJzi8vmSRGv+L2C9R6 1B5pEiiz0eDsew2lR8qWczJvT5TqYiKBFknmTZTrozYhQylQJQP4XMvHPq94/vSoQQ 1i5FcUC29OnFtAONlRCLU5+4r5Wiv6+et0rCVLMNPJ6qTAErKxw+aZ2dvopqhehLb7 xfpLNaEIHKvdQ== From: "Lorenzo Stoakes (ARM)" Date: Tue, 08 Sep 2026 21:01:05 +0100 Subject: [PATCH 01/39] mm/vma: predicate setting mmap_prepare VMA fields on new vma alloc Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-1-dacf19cce22b@kernel.org> References: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org> In-Reply-To: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org> To: 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 , 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" , 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 , Xu Xin , Chengming Zhou , Michal Hocko , Miklos Szeredi Cc: 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, "Lorenzo Stoakes (ARM)" X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1712; i=ljs@kernel.org; h=from:subject:message-id; bh=cTBSc+RhBb8P2CssJn069Zx2TN5+EwkhNO+s8E1YjR4=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLIWZG74aWYupM5yl3PeBd4LVxN+h72/tztZ2qeUqSLn+ sEpnscUOkpZGMS4GGTFFFmefxHfHyQSNq/zgr8bzBxWJpAhDFycAjARzi0M/7OUbgb9m+N1uVtP Z46t0bTz9gnaLWxhpTVT1nhc0iqOFGf4xaSpXcErfddQIkJ7A9es5OklgvNiOv/V3xVsu7h2LYc /KwA= X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 It only makes sense to manipulate VMA fields if we allocated a new VMA, rather than merged it. VMA merging does not compare vm_ops or vm_private_data, so a merged VMA keeps its own, which is also what the legacy f_op->mmap path does since it never touches an existing VMA. Previously set_vma_user_defined_fields() overwrote the merged VMA's fields with those set for the new mapping. In practice these are the same values, with rare exceptions such as shmem selecting vm_ops based on whether the file has been unlinked, so no user-visible change is expected. Make this dependency explicit, and additionally constify have_mmap_prepare while we're here. Signed-off-by: Lorenzo Stoakes (ARM) --- mm/vma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/vma.c b/mm/vma.c index 97567fb7ef33..2a90c509bb31 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -2866,7 +2866,7 @@ static unsigned long __mmap_region(struct file *file, unsigned long addr, { struct mm_struct *mm = current->mm; struct vm_area_struct *vma = NULL; - bool have_mmap_prepare = file && file->f_op->mmap_prepare; + const bool have_mmap_prepare = file && file->f_op->mmap_prepare; VMA_ITERATOR(vmi, mm, addr); const pgoff_t anon_pgoff = addr >> PAGE_SHIFT; MMAP_STATE(map, mm, &vmi, addr, len, pgoff, anon_pgoff, vma_flags, file); @@ -2909,7 +2909,7 @@ static unsigned long __mmap_region(struct file *file, unsigned long addr, allocated_new = true; } - if (have_mmap_prepare && !map_is_anon(&map)) + if (have_mmap_prepare && allocated_new && !map_is_anon(&map)) set_vma_user_defined_fields(vma, &map); __mmap_complete(&map, vma); -- 2.55.0