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 DE9B9C43458 for ; Mon, 29 Jun 2026 12:24:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DAC896B00BE; Mon, 29 Jun 2026 08:24:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D112C6B00BF; Mon, 29 Jun 2026 08:24:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B61036B00C0; Mon, 29 Jun 2026 08:24:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 744D66B00BE for ; Mon, 29 Jun 2026 08:24:37 -0400 (EDT) Received: from smtpin06.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id E669A1A0509 for ; Mon, 29 Jun 2026 12:24:36 +0000 (UTC) X-FDA: 84932868552.06.60A244C Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf20.hostedemail.com (Postfix) with ESMTP id 37DF61C0009 for ; Mon, 29 Jun 2026 12:24:35 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=RgZY26GF; spf=pass (imf20.hostedemail.com: domain of ljs@kernel.org designates 172.234.252.31 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=1782735875; b=UFFgVeWcwuXgaPZw4nBIHwQX/E5G/QgtvGB57PxHl8hSba6396MBaDvvxJ4e89zEqG5XLO K7viYviI1pcF1eDOv+f7jpOxEmZbu5xjO/2SIiI6f2R3JCYJZiMRm47SG4Q4tozd8YfNV6 KS0h5P6tE9CsV4sUpYALDY68QSAHOzg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1782735875; 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=g8hFMC27gURJNhB6p0eY8jCsWeWrDR4QrXmiBvTta7E=; b=QNonCsF27wzKK1DxcX9O5eC2byGCmZK/APMZUt6DfE9LHzXOIn5tGqZWnemNO+n63wj7qO 5yEZzQSNNMgOkBDuPL9SXwaBIR7qVRT6lgdIZ451J41eH1NwhHfqqtH4s97olOnOZklcHq pLOJhVsFW7KHzDFlpVN2Ucyfc92pYbI= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=RgZY26GF; spf=pass (imf20.hostedemail.com: domain of ljs@kernel.org designates 172.234.252.31 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 sea.source.kernel.org (Postfix) with ESMTP id 7AAB041A2F; Mon, 29 Jun 2026 12:24:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90B261F000E9; Mon, 29 Jun 2026 12:24:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782735874; bh=g8hFMC27gURJNhB6p0eY8jCsWeWrDR4QrXmiBvTta7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=RgZY26GFPwRTB1pZ7k8Hjrkht1yhlMQPpzLMXpSHyJE/iJGDN7j65pJ81hC/gtgLX TIXGR9Pmq2Hxctix/kWtNogsZ/VpxS9rEtLqkjyg+2gCc64vbLA1kjiihuPpSGgVqn 5JE/+voej08NE9+VTMp/13Hp/4FeI8UWueVZot/5DzUfLHtSYw42SyKNlH2Be9bcXj S5L9pNn+ueyRVBev/leVYE6cKXlQlFTi7KLCH/hDrN51Ijk2orVDyg60yHbU+yCkn0 GD8zPsNv+frXWvkaGHFxjbjgZFYsSeY3aqb2c33rePaO6yVCRySC9q7kmsMnG53f98 8frGbDucBM2cA== 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 13/30] mm/vma: refactor vmg_adjust_set_range() for clarity Date: Mon, 29 Jun 2026 13:23:24 +0100 Message-ID: X-Mailer: git-send-email 2.54.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 37DF61C0009 X-Rspam-User: X-Stat-Signature: xxcbodw4gif6niygcn3x5awzw6tydtem X-HE-Tag: 1782735875-759661 X-HE-Meta: U2FsdGVkX18cAGWMV9zkqv8t3YEVGcO6LowSEl6i7DXZYePBtpLz2ffIv0wQlX0bWqjg/Ur2xKcBgUToPKDQh6NpmoemzjugVy2xDGBkUoTc7dZME0XfiLUuNuFdu4cIsUKaylOSCAapzlyYQC870tmsMH7DnjoR+eS9n6rjIjDe9k6Vq6iE3VtTMA2FJ5+QmxYhzJz47Jcp2cRJsFfadeVGcdNPFDrq6v70bYywmZ93/8UN2MHTLYPNh86G76O4/6Gscm7PDVRc0dv0dnPFUsrbMfPQWsjuDsef4jWR+6nB7qEz1Q8U4lK/ja9q8N1M0mWEuDgSNtmWW7kbZHaNupZCl4sctu5hadCsKQ0/GwkA9hmGLg3ZAR/SoFEXjcYrCDvqGu3sL4EX3NLPnlnkJHrXZIoTtI+hfH2D1Ab7iDD+ALfDoF51aH9WPwBj45EJlVMCxd0j8aCz56HeVA8Zm7CVjbTuiE4rsihlflzdgNjAaV9VW0lUvGqqZE99MZsOljKQwfO9s9lr/YVkngJKJCgXr32U1toJIibloIaYeBY3x/bBhH2D6AHhuJQE5DVvxG1qkGKhN0AX98FKirqXFLdyCDSwhbguywhFhgxHmo888jOvxGpHF1iHfBeY/QzoDySQr2L1GMclVxQkOJdxC9NQihsZBCxsGt2X7w57cXjtwzw6pEuDHTAI90RlVaClRgmdSUuoPdeRNCZ1HpF6+VG1FqcBGjPVMpO4N+8wBgEG7X9ejJuaDKkJuKowhZTMjWUuc2r4+FxHNbKatINqDp/MIlg7G0YmX0DKp9DYd+Ay1lULWROb7J+axuJQHJilPmDB1FLhOqRBGhv83aScrnkaGFOAPEcnBKbNYmvaELrJJo+otME6bUpL/MZMWX4Q9sAmYWuq8nkDCg924ft/r0vUZvZtrn65huCRplAPbwmNeQ+IHfoxIpu9+kHld35fpYJvnCahKstayHT44a7 l7c/Cvr2 rEXBrM3yQgdjoNmxGB0Pzq+Ftzr7gAhdROzhkQAjA7hDarca4xo+ecvjq9REi2BvR67pErOUuNXSVGl+9Od4dw4ahPyh4iydiNfjlWJTKi560Gbah1s/y5Hud9nYIbs6BqvLQqwf0ljUBaXyMMkMll28Qk5CMuKSatqdTBFlVLoadTuY8ovW9neNeKPCAsvQ++AYES/r91pdZeorbZXwFvoH5gGYdgL+1QXrdQurlnZevf+jx6zbgP6XmJY7IePw+fIYiBwcF8oK3uDrWoqSY3xKO4K2rthP8Djb1tt5NDcOoPxYeXVwZzJRAAZOUOmdOF1QGbp5vfiUyp4JU/CIIRfu9DZ/cBzHBdbrB Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Add comments with ASCII diagrams to describe what we're doing, avoid dubious use of PHYS_PFN(), and use vma_start_pgoff(). The most complicated scenario represented here is vmg->__adjust_next_start - when this is set, vmg->[start, end] actually indicate the range to be retained, so take special care to describe this accurately. No functional change intended. Signed-off-by: Lorenzo Stoakes --- mm/vma.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 47 insertions(+), 4 deletions(-) diff --git a/mm/vma.c b/mm/vma.c index 6296acecf3b7..1e99fe8aa6ef 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -704,11 +704,54 @@ static void vmg_adjust_set_range(struct vma_merge_struct *vmg) pgoff_t pgoff; if (vmg->__adjust_middle_start) { - adjust = vmg->middle; - pgoff = adjust->vm_pgoff + PHYS_PFN(vmg->end - adjust->vm_start); + /* + * vmg->start vmg->end + * | | + * v merge v + * <-------------> + * delta + * <------> + * |------|----------------| + * | prev | middle | + * |------|----------------| + * ^ + * | + * middle->vm_start + */ + struct vm_area_struct *middle = vmg->middle; + const unsigned long delta = vmg->end - middle->vm_start; + + pgoff = vma_start_pgoff(middle) + (delta >> PAGE_SHIFT); + adjust = middle; } else if (vmg->__adjust_next_start) { - adjust = vmg->next; - pgoff = adjust->vm_pgoff - PHYS_PFN(adjust->vm_start - vmg->end); + /* + * Originally: + * + * vmg->start vmg->end + * | | + * v merge v + * <------------> + * . . + * merge_existing_range() updates to: + * . . + * vmg->start vmg->end . + * | | . + * v retain v . + * <----------> . + * delta . + * <-----> . + * |----------------|------| + * | middle | next | + * |----------------|------| + * ^ + * | + * next->vm_start + */ + struct vm_area_struct *next = vmg->next; + const unsigned long delta = next->vm_start - vmg->end; + + pgoff = vma_start_pgoff(next) - (delta >> PAGE_SHIFT); + adjust = next; } else { return; } -- 2.54.0