linux-kernel - [PATCH v3 08/14] mm/gup: Break COW PTE in follow_pfn

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20221220072743.3039060-9-shiyn.lin@gmail.com>
Date:   Tue, 20 Dec 2022 15:27:37 +0800
From:   Chih-En Lin <shiyn.lin@...il.com>
To:     Andrew Morton <akpm@...ux-foundation.org>,
        Qi Zheng <zhengqi.arch@...edance.com>,
        David Hildenbrand <david@...hat.com>,
        Matthew Wilcox <willy@...radead.org>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        John Hubbard <jhubbard@...dia.com>,
        Nadav Amit <namit@...are.com>
Cc:     linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Steven Rostedt <rostedt@...dmis.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Yang Shi <shy828301@...il.com>, Peter Xu <peterx@...hat.com>,
        Zach O'Keefe <zokeefe@...gle.com>,
        "Liam R . Howlett" <Liam.Howlett@...cle.com>,
        Alex Sierra <alex.sierra@....com>,
        Xianting Tian <xianting.tian@...ux.alibaba.com>,
        Colin Cross <ccross@...gle.com>,
        Suren Baghdasaryan <surenb@...gle.com>,
        Barry Song <baohua@...nel.org>,
        Pasha Tatashin <pasha.tatashin@...een.com>,
        Suleiman Souhlal <suleiman@...gle.com>,
        Brian Geffon <bgeffon@...gle.com>, Yu Zhao <yuzhao@...gle.com>,
        Tong Tiangen <tongtiangen@...wei.com>,
        Liu Shixin <liushixin2@...wei.com>,
        Li kunyu <kunyu@...china.com>,
        Anshuman Khandual <anshuman.khandual@....com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Hugh Dickins <hughd@...gle.com>,
        Minchan Kim <minchan@...nel.org>,
        Miaohe Lin <linmiaohe@...wei.com>,
        Gautam Menghani <gautammenghani201@...il.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Mark Brown <broonie@...nel.org>, Will Deacon <will@...nel.org>,
        "Eric W . Biederman" <ebiederm@...ssion.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        Andy Lutomirski <luto@...nel.org>,
        Fenghua Yu <fenghua.yu@...el.com>,
        Barret Rhoden <brho@...gle.com>,
        Davidlohr Bueso <dave@...olabs.net>,
        "Jason A . Donenfeld" <Jason@...c4.com>,
        Dinglan Peng <peng301@...due.edu>,
        Pedro Fonseca <pfonseca@...due.edu>,
        Jim Huang <jserv@...s.ncku.edu.tw>,
        Huichun Feng <foxhoundsk.tw@...il.com>,
        Chih-En Lin <shiyn.lin@...il.com>
Subject: [PATCH v3 08/14] mm/gup: Break COW PTE in follow_pfn_pte()

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 <shiyn.lin@...il.com>
---
 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