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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E4564C43458 for ; Mon, 29 Jun 2026 12:24:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B89216B00B3; Mon, 29 Jun 2026 08:24:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B625A6B00B4; Mon, 29 Jun 2026 08:24:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A28AC6B00B5; Mon, 29 Jun 2026 08:24:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 719266B00B3 for ; Mon, 29 Jun 2026 08:24:34 -0400 (EDT) Received: from smtpin21.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id DAF851C3782 for ; Mon, 29 Jun 2026 12:24:33 +0000 (UTC) X-FDA: 84932868426.21.69C1579 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf16.hostedemail.com (Postfix) with ESMTP id 3DF63180003 for ; Mon, 29 Jun 2026 12:24:32 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=gbRlBt02; spf=pass (imf16.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1782735872; b=NDD7bcbaVHgX5buD2ABPPr78OB4CoY52gKy+b1HBdF2I7TvSv/4KeAgHUxf5AMHDe0EOeL 2BeOnUYihC85P1HWEOQUJ3j/3yB40tGVqVmRAZjaeT8XbpbkgOxp2Zq3osONAtbeeuWHs/ qIrtYyvOPirJEvrBysKpROuFHPjv4bU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1782735872; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=lDqHHLYLI8SULeQcrQbbmm1Xqv4SbCojm3yMjIkoYS4=; b=SysTzKtooQ9B8JM2CC96mb3KX8i0SnJmjyF8kKtGc1DlTGNxps9fxPNFj+MOB0bIDhwtLN otir1h1AlRcqlC3kSQGYSLjMql3iMGCqtQpphFKYJdvMCkXRk47PjRQka+ttWP7OiY+CUh /UpMvgFXIMT7y9Hu65DUE2qPPAJgumA= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=gbRlBt02; spf=pass (imf16.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id C3636600AA; Mon, 29 Jun 2026 12:24:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B55091F00A3A; Mon, 29 Jun 2026 12:24:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782735871; bh=lDqHHLYLI8SULeQcrQbbmm1Xqv4SbCojm3yMjIkoYS4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gbRlBt02eZV32vXAx1N9ysOeq0S6bwI9Ce2BPgKuRfpVZlRZdgJ+Rc9bshTzbaA/Y W14Sww3HyjEdedsUcYMcpQ9oUG/ausaLK7qwWO/ObfDuCVFHpJi681zlmHI1oY44qw JuYWfnS14KRRMRCqN6X7rVTIgwoB+b+Q7CFljrLUmX4CHXFe+lXtsfDfiR+NpSZg/6 VFAgvA186XL/RNO5OBNYDw+9qoiTSPd1SJA4VjVv6xPifTqqwKvmIhr/L00cadwwD/ Av7DzDW/ixy/Z1oRx3ExXlGkJB1de3WNQx1EoGzP7SZH1bGKaVpj5CUFZ1WpGLIrVF Z+35Yut2os7Xw== From: Lorenzo Stoakes To: Andrew Morton Cc: Russell King , Dinh Nguyen , Simon Schuster , "James E . J . Bottomley" , Helge Deller , Jarkko Sakkinen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Ian Abbott , H Hartley Sweeten , Lucas Stach , David Airlie , Simona Vetter , Patrik Jakobsson , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Rob Clark , Dmitry Baryshkov , Tomi Valkeinen , Thierry Reding , Mikko Perttunen , Jonathan Hunter , Christian Koenig , Huang Rui , Ankit Agrawal , Alex Williamson , Alexander Viro , Christian Brauner , Dan Williams , Muchun Song , Oscar Salvador , David Hildenbrand , Suren Baghdasaryan , "Liam R . Howlett" , Matthew Wilcox , Marek Szyprowski , Peter Zijlstra , Arnaldo Carvalho de Melo , Namhyung Kim , Masami Hiramatsu , Oleg Nesterov , Steven Rostedt , SeongJae Park , Miaohe Lin , Hugh Dickins , Mike Rapoport , Kees Cook , Paolo Bonzini , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, 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, linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev, linux-mm@kvack.org, iommu@lists.linux.dev, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, kasan-dev@googlegroups.com, damon@lists.linux.dev, Pedro Falcato , Rik van Riel , Harry Yoo , Jann Horn Subject: [PATCH 12/30] mm/vma: clean up anon_vma_compatible() Date: Mon, 29 Jun 2026 13:23:23 +0100 Message-ID: <5a7a07bd2a774989849b0fea84f758059ed914df.1782735110.git.ljs@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 3DF63180003 X-Stat-Signature: ix1n8twixtqo1qs534xt9gmipphgxx4h X-HE-Tag: 1782735872-265830 X-HE-Meta: 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 wx8SOctb V++gJBqwoTpERp+Caa0v/hx8CjJ+KTQdM18XnYBivB9BJ9WyNBG/1AUvXJkW+s6blnXecJWLmMO30QrwTeTP7uaLgotzEbWhvB6+MshAmjcUtwyt66EQNEXX+FVpS9NYbuPdh9jUgis+GKBzvmpJhaB+oxCZXqsbsK/6cfSxJ8u+2etSzYQ9BUZt181BW7pVC1CjTQXP55d9HmYtJg+Yru/AnK5BUuHEqx3WBrhMivWezG0rIP9xeoX5dAr78DN5XKV1v4OO3d/pg13fd1SGTxxucVPBgo9ziFMiZBmIvptgfGAxr55RZyFRE6mfW6ewGUeIBQb06zpn/3fk5g7M4VFkBAyqQl4Jl9QeO Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Break up the existing very large conditional, add comments and use vma_[start/end]_pgoff() to make clearer what we're doing here. No functional change intended. Signed-off-by: Lorenzo Stoakes --- mm/vma.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/mm/vma.c b/mm/vma.c index b60375c6c5c3..6296acecf3b7 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -1967,14 +1967,25 @@ static int anon_vma_compatible(struct vm_area_struct *a, struct vm_area_struct * { vma_flags_t diff = vma_flags_diff_pair(&a->flags, &b->flags); + /* Ignore flags that mprotect() can change. */ vma_flags_clear_mask(&diff, VMA_ACCESS_FLAGS); + /* Ignore flags that do not impact merging. */ vma_flags_clear_mask(&diff, VMA_IGNORE_MERGE_FLAGS); - return a->vm_end == b->vm_start && - mpol_equal(vma_policy(a), vma_policy(b)) && - a->vm_file == b->vm_file && - vma_flags_empty(&diff) && - b->vm_pgoff == a->vm_pgoff + ((b->vm_start - a->vm_start) >> PAGE_SHIFT); + /* Must be adjacent. */ + if (a->vm_end != b->vm_start) + return false; + /* Must have matching policy. */ + if (!mpol_equal(vma_policy(a), vma_policy(b))) + return false; + /* Must both be anon or map the same file (MAP_PRIVATE case). */ + if (a->vm_file != b->vm_file) + return false; + /* Flags must be equivalent modulo mprotect(). */ + if (!vma_flags_empty(&diff)) + return false; + /* Page offset must align. */ + return vma_end_pgoff(a) == vma_start_pgoff(b); } /* -- 2.54.0