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 A0CEC399CFD; Fri, 10 Jul 2026 20:23:42 +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=1783715023; cv=none; b=T7PQhiJ7kFjT9wRmWUeHIngpEW3AAFEIMzCMXdEkgpE7vsJuQHu3smXH+b66+v2xwFzz4tORNgtvJq4WVUXitxwNFEBuPrW0UOnEWoI9fd+72kVfShoBJhWNOPOZiGjqWqJnedqr4FFzGIkO+NyZ1p0CwVIm0KQGDZ3kzBTVgrU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783715023; c=relaxed/simple; bh=fynty0cOXQIbsI8Im1dMU82VMgwlvpXxQo8CNb014Ng=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=gFd97vgE2HaLZqKCL9xhiRYzJovhY3RTzCYjWy/Prga1YNYpvcZ8H+9Ta93wfXw/M6uemA3/luzSW8T88JcDnTqtAAksd62eC8TCOUqTUo+PcDGn0tObq/+6W1SsNvKrBnzR1jcJ+XXYpI303lUWNah4S5fMlALkyjVEswJzO4o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=d3dTLtbw; 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="d3dTLtbw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A19E1F000E9; Fri, 10 Jul 2026 20:23:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783715022; bh=2aND6ZTrK5aCnF0vB/hvCQzWPNkI/PGqvLHzAGyQuss=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=d3dTLtbwHpud6iwAczcr/G9qOssm4UAuvj4AITz+zWpoo3DzOVp4gv/8j/t3INWRl h2iqumoE+G4TsrZXl0JhrXm1DZwp+Xg3/+wksbc2t0H/PLF/RGB/5vKhFzP677NytU q6MV3RVJSQRNxvQnBeZzwMXbXmKkia3AIRewaLGVCnf5X62tPiyvXhyTzEoOmXSEGC 7JJiwAJmtNQpNHVWkspiwndBidkwdss3Ra2oN97KJrOwhYLngF5H0St0YiV3hmYCXT mfa+HnPzm/yNr4CqvgKrXrsT0Jsexbb8zALJKBx2Z3Z8c8MYQaM3JxOThN0dU2Lcc2 ZnfBU5TdzppUw== From: Lorenzo Stoakes Date: Fri, 10 Jul 2026 21:16:57 +0100 Subject: [PATCH v2 16/33] mm/vma: minor cleanup of expand_[upwards, downwards]() 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: <20260710-b4-pre-scalable-cow-v2-16-2a5aa403d977@kernel.org> References: <20260710-b4-pre-scalable-cow-v2-0-2a5aa403d977@kernel.org> In-Reply-To: <20260710-b4-pre-scalable-cow-v2-0-2a5aa403d977@kernel.org> To: Andrew Morton , David Hildenbrand , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Rik van Riel , Harry Yoo , Jann Horn , Lance Yang , Pedro Falcato , Russell King , Dinh Nguyen , Simon Schuster , "James E.J. Bottomley" , Helge Deller , Alexander Viro , Christian Brauner , Jan Kara , Dan Williams , Matthew Wilcox , Muchun Song , Oscar Salvador , Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Miaohe Lin , Naoya Horiguchi , Xu Xin , Chengming Zhou , SJ Park , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Hugh Dickins , Peter Xu , Kees Cook , Marek Szyprowski , Robin Murphy , Andrey Konovalov , Alexander Potapenko , Dmitry Vyukov , Steven Rostedt , Mathieu Desnoyers , Jarkko Sakkinen , Dave Hansen , Thomas Gleixner , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Ian Abbott , H Hartley Sweeten , Lucas Stach , Christian Gmeiner , David Airlie , Simona Vetter , Patrik Jakobsson , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Rob Clark , Dmitry Baryshkov , Abhinav Kumar , Jessica Zhang , Sean Paul , Marijn Suijten , Tomi Valkeinen , Thierry Reding , Mikko Perttunen , Jonathan Hunter , Christian Koenig , Huang Rui , Matthew Auld , Jason Gunthorpe , Yishai Hadas , Shameer Kolothum , Kevin Tian , Ankit Agrawal , Alex Williamson , Paolo Bonzini , Shakeel Butt , Usama Arif Cc: Lorenzo Stoakes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, damon@lists.linux.dev, iommu@lists.linux.dev, kasan-dev@googlegroups.com, linux-sgx@vger.kernel.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, linux-tegra@vger.kernel.org, kvm@vger.kernel.org, Russell King X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=2119; i=ljs@kernel.org; h=from:subject:message-id; bh=fynty0cOXQIbsI8Im1dMU82VMgwlvpXxQo8CNb014Ng=; b=kA0DAAoWz53NioHifxQByyZiAGpRUzzIuaLaCaR4CfWWXA/TVMCwmdk5sAWWI2+fuF7yBKZGo 4h1BAAWCgAdFiEE5/QXv1IUVp6J0E9Gz53NioHifxQFAmpRUzwACgkQz53NioHifxSSHwEA7mlE x52NRnGbJn2diesM85ALQpE3tCi1SqD0qgxp4fkBAMrSm0IQy3xvIXv/5PUxUHYQwVkEyzhhVNm YRBxFnqAF X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 Adjust the stack expansion functions expand_upwards() and expand_downwards() such that they are expressed in terms of named constant values, and make use of vma_start_pgoff(). This clearly documents that we are referencing the page offset of the start of the VMA. Additionally this cleans up the overflow check in expand_upwards(). No functional change intended. Reviewed-by: Pedro Falcato Reviewed-by: Gregory Price Signed-off-by: Lorenzo Stoakes --- mm/vma.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/mm/vma.c b/mm/vma.c index 7265a054cfa3..5d5e60ea8a25 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -3216,13 +3216,12 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) /* Somebody else might have raced and expanded it already */ if (address > vma->vm_end) { - unsigned long size, grow; - - size = address - vma->vm_start; - grow = (address - vma->vm_end) >> PAGE_SHIFT; + const unsigned long size = address - vma->vm_start; + const unsigned long grow = (address - vma->vm_end) >> PAGE_SHIFT; + const pgoff_t pgoff = vma_start_pgoff(vma); error = -ENOMEM; - if (vma->vm_pgoff + (size >> PAGE_SHIFT) >= vma->vm_pgoff) { + if (pgoff + (size >> PAGE_SHIFT) >= pgoff) { error = acct_stack_growth(vma, size, grow); if (!error) { if (vma_test(vma, VMA_LOCKED_BIT)) @@ -3295,13 +3294,11 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address) /* Somebody else might have raced and expanded it already */ if (address < vma->vm_start) { - unsigned long size, grow; - - size = vma->vm_end - address; - grow = (vma->vm_start - address) >> PAGE_SHIFT; + const unsigned long size = vma->vm_end - address; + const unsigned long grow = (vma->vm_start - address) >> PAGE_SHIFT; error = -ENOMEM; - if (grow <= vma->vm_pgoff) { + if (grow <= vma_start_pgoff(vma)) { error = acct_stack_growth(vma, size, grow); if (!error) { if (vma_test(vma, VMA_LOCKED_BIT)) -- 2.55.0