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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 913BFC4332F for ; Tue, 20 Dec 2022 07:27:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233446AbiLTH1S (ORCPT ); Tue, 20 Dec 2022 02:27:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233041AbiLTH0P (ORCPT ); Tue, 20 Dec 2022 02:26:15 -0500 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 354D31277D for ; Mon, 19 Dec 2022 23:26:13 -0800 (PST) Received: by mail-pf1-x42a.google.com with SMTP id c13so7926033pfp.5 for ; Mon, 19 Dec 2022 23:26:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; 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=Do3acUsDb4bseCZZAAdCXOeb3zH5cpjKCNiCZshpYgw=; b=Jbm+ZDETl/xq5MthImH8BHHm9GBXQRsQVT3uhHj94LaQ8kg9xI0a4zaGCVg+cefzXk D5EG8JXUc/rT2JguGIYDN8cOKuwJv0wmeQi/ty+upc1PhBOmLL1OAFiJmY4QIEr3FV+u vkQIFqHEDKKxAt6NsvFG4EgYacTY5Kj73Kwv2ZtPwUgZQ+kat+enQ+Byyx4iHWoBBgQq lEBuUXzYINS4qMKwlgv7tZLpRkvuEoM9LlnJJp3/9ckZy1AN0k3HxjzcvUXMV91kEWB2 h8WeyuZsX4oE7ylWWH1LyNtoUaYvUmkYlnxbVpO/i5rxyaGkS28mf01HC/XLRtY7UuUs ZTLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=Do3acUsDb4bseCZZAAdCXOeb3zH5cpjKCNiCZshpYgw=; b=tC04kCc9hvHsf4h34hBKTqu9xNL+TougYhzRpRni+syB8xqqJ5OsRy2RYml0HQaSs9 raO6+4nf4ONgjKiqziJmwTdAlYqTGjK+NTnLQYyAY4csO+j70yu+M60gqJ9CIQs/5+oY Usmu8CCvZEVCPMnZmeXPNFsBzb8hS80vDJGQYNO0bYO5z1mEXLaTlsSaFGhVdmJ6kB0J wMjEo5A6NIEAcTFFU5Wyh0hcbintwToxMVPY9Bzvu3Tqk7G87qpMOIXD5E5FnGPqlMEe suflmDFxjyVrtgRd349olXm5RLHCUhES+ceIgaakI2QICsK18P6/Yzr7rV6uUmpLiWHT /xgQ== X-Gm-Message-State: ANoB5plyY1pSYH6BMK4S5A23rY5sj4nnwfDmz1n4khT146M/TyMXX6OA dLJcnFLJP+2kiTRXtmAbBTo= X-Google-Smtp-Source: AA0mqf4sXbpc959lO3xaruJ/7JwWbqHNxobqwVmkT0oSHM0O93U4eYrT6K7YtNCEihfb5iqOzV5xyA== X-Received: by 2002:aa7:8190:0:b0:575:62f8:be3 with SMTP id g16-20020aa78190000000b0057562f80be3mr45051940pfi.23.1671521172728; Mon, 19 Dec 2022 23:26:12 -0800 (PST) Received: from archlinux.localdomain ([140.121.198.213]) by smtp.googlemail.com with ESMTPSA id q15-20020aa7982f000000b00576f9773c80sm7865544pfl.206.2022.12.19.23.26.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Dec 2022 23:26:11 -0800 (PST) From: Chih-En Lin To: Andrew Morton , Qi Zheng , David Hildenbrand , Matthew Wilcox , Christophe Leroy , John Hubbard , Nadav Amit Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Steven Rostedt , Masami Hiramatsu , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Yang Shi , Peter Xu , Zach O'Keefe , "Liam R . Howlett" , Alex Sierra , Xianting Tian , Colin Cross , Suren Baghdasaryan , Barry Song , Pasha Tatashin , Suleiman Souhlal , Brian Geffon , Yu Zhao , Tong Tiangen , Liu Shixin , Li kunyu , Anshuman Khandual , Vlastimil Babka , Hugh Dickins , Minchan Kim , Miaohe Lin , Gautam Menghani , Catalin Marinas , Mark Brown , Will Deacon , "Eric W . Biederman" , Thomas Gleixner , Sebastian Andrzej Siewior , Andy Lutomirski , Fenghua Yu , Barret Rhoden , Davidlohr Bueso , "Jason A . Donenfeld" , Dinglan Peng , Pedro Fonseca , Jim Huang , Huichun Feng , Chih-En Lin Subject: [PATCH v3 08/14] mm/gup: Break COW PTE in follow_pfn_pte() Date: Tue, 20 Dec 2022 15:27:37 +0800 Message-Id: <20221220072743.3039060-9-shiyn.lin@gmail.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221220072743.3039060-1-shiyn.lin@gmail.com> References: <20221220072743.3039060-1-shiyn.lin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In most of cases, GUP will not modify the page table, excluding follow_pfn_pte(). To deal with COW PTE, break COW PTE in follow_pfn_pte(). Signed-off-by: Chih-En Lin --- mm/gup.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index fe195d47de74a..cd72010ba0e6d 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -476,6 +476,8 @@ static int follow_pfn_pte(struct vm_area_struct *vma, unsigned long address, entry = pte_mkyoung(entry); if (!pte_same(*pte, entry)) { + if (break_cow_pte(vma, NULL, address) < 0) + return -ENOMEM; set_pte_at(vma->vm_mm, address, pte, entry); update_mmu_cache(vma, address, pte); } -- 2.37.3