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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C826C77B72 for ; Fri, 14 Apr 2023 14:25:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E189B6B0078; Fri, 14 Apr 2023 10:25:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DC86A900004; Fri, 14 Apr 2023 10:25:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C69B3900003; Fri, 14 Apr 2023 10:25:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id B8A726B0078 for ; Fri, 14 Apr 2023 10:25:56 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 7B7A180329 for ; Fri, 14 Apr 2023 14:25:56 +0000 (UTC) X-FDA: 80680220712.17.22E3BDE Received: from mail-pj1-f42.google.com (mail-pj1-f42.google.com [209.85.216.42]) by imf07.hostedemail.com (Postfix) with ESMTP id A395D40011 for ; Fri, 14 Apr 2023 14:25:54 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=gmail.com header.s=20221208 header.b="V/L9mGM5"; spf=pass (imf07.hostedemail.com: domain of shiyn.lin@gmail.com designates 209.85.216.42 as permitted sender) smtp.mailfrom=shiyn.lin@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1681482354; 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=/tVFETdIXCOfqp++FbGXI8ZTRFNtRU4kz7mKWpQ0TKQ=; b=N6b4y9UM3xjOSFs7P6yX958otURwEFDZKAQGOe+bPGXYB2fh1T3v5wKv21es4YQGzfRTdG 1H9a3kBMgkhytvrlskMfyVhmk+viKlR7NKJC+nGs4rNLMA2fatOZYA2a37+lhG3YYf5boo kpokuEvFOowK+rCAbDMn0vSXCUoCTPQ= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=gmail.com header.s=20221208 header.b="V/L9mGM5"; spf=pass (imf07.hostedemail.com: domain of shiyn.lin@gmail.com designates 209.85.216.42 as permitted sender) smtp.mailfrom=shiyn.lin@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1681482354; a=rsa-sha256; cv=none; b=jh/Rg9eoK31SzydUyjqfck4zJVUNsYV7WPEitHO1Zca/JXPSSqeYX90SwUIz5IDbkf6fgv hS6g57mGZMh2B8fyRJE2EcNZlUXgwjpQXQFpEQrZIyQIZQfy6LMYOW7mqF/rHgO+/TnfH9 hBhJjkrg/V5xUdtd1OZZBnutHTTq4Lg= Received: by mail-pj1-f42.google.com with SMTP id k65-20020a17090a3ec700b00247131783f7so4265711pjc.0 for ; Fri, 14 Apr 2023 07:25:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1681482353; x=1684074353; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=/tVFETdIXCOfqp++FbGXI8ZTRFNtRU4kz7mKWpQ0TKQ=; b=V/L9mGM5vRCilsgFuug2qDo+tf+mz8X3NMe4ExWTkIzgp5PoriAleb9ABHiqBVuzoB llo+kuyF6EvctKAWOk7/AgctLIF5nzoIZG8o22MemV1Trqr4GMU4SWQjs7lk4AFfxWZs fEFh+J5+1k4h11tgMkVGCwcojSc3VhOk+jlEQkXDF+LG7ADIDJS5DzduuXdI5BA3XzGA o5xxBjrwCkRjOkZx09CVQJsh7Y3tKhqCo7zRr9YQVNfXI9o2wXUwtf+xHKgwJyn/eUFx DbBL8+08eqWZGvXOjPhYZPEEOFvmlvTmXp2I+hQAV+uqiFqt7yhXiTpblR0eG92ZfVyg zMBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681482353; x=1684074353; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/tVFETdIXCOfqp++FbGXI8ZTRFNtRU4kz7mKWpQ0TKQ=; b=Ja31Znrif/CgiiYZIKTZinadeBQhPe0YhNrz9ajyNBruajgZCCLVLzdFPjqQ/kOaAo w/H8RFBppmUGNrhEy02WuICMQyJlfE//h94pRFeJDTZrmX/nwnbyFv1MCgKHIkQc9Kf+ pgt6Qf7VoN9sF3siv5R3pY8pwqXMOOgV838tOvXdSKzdIf5b9/Nwvk4NaCHbBZrWIjgT 8uCcOX6OSXB9HwkChxzRrlbUOZxPw3bosoUwzvJXthaXJIV8PNVpVDeREmWpfM/GVnWg Bb1hESTldSXKqwb+9csLhFKa6A9t4emLmHpm6LJAQ9bssrstJUgJjh842ATKsdlHeztW 5PQw== X-Gm-Message-State: AAQBX9dNYs7jVxEunBRWFL2y7fdlBfE+fqqtcobkvlaWH+5DXu8lMf2O M9XtnsYbwobXvWx0NXtqVeY= X-Google-Smtp-Source: AKy350bY4APGkMEn5jnT3hrPcgD0IFpWnxPux4TPQ74b4zdNFtZk3bMgcaFkmd5oasXe2ggPZ2CL0Q== X-Received: by 2002:a17:903:22ce:b0:1a5:f:a7c7 with SMTP id y14-20020a17090322ce00b001a5000fa7c7mr3342685plg.0.1681482353510; Fri, 14 Apr 2023 07:25:53 -0700 (PDT) Received: from strix-laptop.. (2001-b011-20e0-1499-8303-7502-d3d7-e13b.dynamic-ip6.hinet.net. [2001:b011:20e0:1499:8303:7502:d3d7:e13b]) by smtp.googlemail.com with ESMTPSA id h7-20020a17090ac38700b0022335f1dae2sm2952386pjt.22.2023.04.14.07.25.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Apr 2023 07:25:53 -0700 (PDT) From: Chih-En Lin To: Andrew Morton , Qi Zheng , David Hildenbrand , "Matthew Wilcox (Oracle)" , Christophe Leroy , John Hubbard , Nadav Amit , Barry Song , Pasha Tatashin Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Peter Zijlstra , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Yu Zhao , Steven Barrett , Juergen Gross , Peter Xu , Kefeng Wang , Tong Tiangen , Christoph Hellwig , "Liam R. Howlett" , Yang Shi , Vlastimil Babka , Alex Sierra , Vincent Whitchurch , Anshuman Khandual , Li kunyu , Liu Shixin , Hugh Dickins , Minchan Kim , Joey Gouly , Chih-En Lin , Michal Hocko , Suren Baghdasaryan , "Zach O'Keefe" , Gautam Menghani , Catalin Marinas , Mark Brown , "Eric W. Biederman" , Andrei Vagin , Shakeel Butt , Daniel Bristot de Oliveira , "Jason A. Donenfeld" , Greg Kroah-Hartman , Alexey Gladkov , x86@kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Dinglan Peng , Pedro Fonseca , Jim Huang , Huichun Feng Subject: [PATCH v5 10/17] mm/gup: Trigger break COW PTE before calling follow_pfn_pte() Date: Fri, 14 Apr 2023 22:23:34 +0800 Message-Id: <20230414142341.354556-11-shiyn.lin@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230414142341.354556-1-shiyn.lin@gmail.com> References: <20230414142341.354556-1-shiyn.lin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: u9rjtwz39z8fheydehgg98ueepc3wm75 X-Rspam-User: X-Rspamd-Queue-Id: A395D40011 X-Rspamd-Server: rspam06 X-HE-Tag: 1681482354-220672 X-HE-Meta: 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 gwp47SeO Etnne5XObmS8k8euhwBMl7TnoiykjOIxj7bDe6A4ByOA6bvOlpIxJwlCfqIYsgP2m21GcJ4Luth+gsfXatbK7eBT2gGL5WDX1wTQUv9RRV/F7JLTskPft3LubuDABNgpNi5XgT9KMlXoDcS9SEJUUPzTNaRLYifmoseRYlZ33n0wEth/SkohwRPEAKmO6Yngxxg7+pg5WfKpMBeMNFTUegMP+jY+SAzSSze0bBzG5D0kJt7oX0XsEFc5q53eRDZXpHEMcqNw0IDJ03so5rSXodDta/DR3Ya7/QnMlftMqjCZj94Z20lpIMyQPTkwrgSkAI/w+ZouwCNRuqbIrHWI4fLrf+AsVQ/kg70bRMbUYe7PzK+rXYDTvf6jbXE2YdPichOJsCkjCHT0oAo6+7womLCnrbcSe4n+J5mVGHz1BCi0CZhblk1U6pIhG/CF3xx18wzEuT/afqOSA+wThmE7OTJjS3Tk7x5sCiwPMogXP1wM/darI2uWj05Jjr7S5zAh0hBpkA8rgrYRDiukphqjVYZyTZhiuJ8oWCWXFXFZGf6CnRFKX4Et9CL+WAdT+bKB/nQHa/2lEReWDUhPPMKMwxAI/Ng== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: In most of cases, GUP will not modify the page table, excluding follow_pfn_pte(). To deal with COW PTE, Trigger the break COW PTE fault before calling follow_pfn_pte(). Signed-off-by: Chih-En Lin --- mm/gup.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/mm/gup.c b/mm/gup.c index eab18ba045db..325424c02ca6 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -544,7 +544,8 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == (FOLL_PIN | FOLL_GET))) return ERR_PTR(-EINVAL); - if (unlikely(pmd_bad(*pmd))) + /* COW-ed PTE has write protection which can trigger pmd_bad(). */ + if (unlikely(pmd_write(*pmd) && pmd_bad(*pmd))) return no_page_table(vma, flags); ptep = pte_offset_map_lock(mm, pmd, address, &ptl); @@ -587,6 +588,11 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, if (is_zero_pfn(pte_pfn(pte))) { page = pte_page(pte); } else { + if (test_bit(MMF_COW_PTE, &mm->flags) && + !pmd_write(*pmd)) { + page = ERR_PTR(-EMLINK); + goto out; + } ret = follow_pfn_pte(vma, address, ptep, flags); page = ERR_PTR(ret); goto out; -- 2.34.1