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 X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CDE6C636CB for ; Thu, 15 Jul 2021 19:05:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86B5A610C7 for ; Thu, 15 Jul 2021 19:05:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241929AbhGOTHz (ORCPT ); Thu, 15 Jul 2021 15:07:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:34230 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242248AbhGOS5O (ORCPT ); Thu, 15 Jul 2021 14:57:14 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 598E2613DC; Thu, 15 Jul 2021 18:54:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626375258; bh=swNqVe0z99ZqvzGEdEapp55al/zXzvnmMw+OPrrGzhc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MpVJePY5kl82pcfUtOPbJYi4KBbeJblxN303uLcMWpfB8qW9CCAflu7aJ4AAYwpvD 04ZNeyvqt9G9kaVuXurhTnpeRtYIHR8xcY1i5VnEd3LqogqT2wB+TgRLA2CPC7Oxv2 xuZsV0GcdgTl3NxpXJlsMlID8bDfHd6uUePoPuH0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bibo Mao , Thomas Bogendoerfer , Sasha Levin Subject: [PATCH 5.12 012/242] hugetlb: clear huge pte during flush function on mips platform Date: Thu, 15 Jul 2021 20:36:14 +0200 Message-Id: <20210715182553.931931387@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210715182551.731989182@linuxfoundation.org> References: <20210715182551.731989182@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bibo Mao [ Upstream commit 33ae8f801ad8bec48e886d368739feb2816478f2 ] If multiple threads are accessing the same huge page at the same time, hugetlb_cow will be called if one thread write the COW huge page. And function huge_ptep_clear_flush is called to notify other threads to clear the huge pte tlb entry. The other threads clear the huge pte tlb entry and reload it from page table, the reload huge pte entry may be old. This patch fixes this issue on mips platform, and it clears huge pte entry before notifying other threads to flush current huge page entry, it is similar with other architectures. Signed-off-by: Bibo Mao Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin --- arch/mips/include/asm/hugetlb.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/mips/include/asm/hugetlb.h b/arch/mips/include/asm/hugetlb.h index 10e3be870df7..c2144409c0c4 100644 --- a/arch/mips/include/asm/hugetlb.h +++ b/arch/mips/include/asm/hugetlb.h @@ -46,7 +46,13 @@ static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm, static inline void huge_ptep_clear_flush(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { - flush_tlb_page(vma, addr & huge_page_mask(hstate_vma(vma))); + /* + * clear the huge pte entry firstly, so that the other smp threads will + * not get old pte entry after finishing flush_tlb_page and before + * setting new huge pte entry + */ + huge_ptep_get_and_clear(vma->vm_mm, addr, ptep); + flush_tlb_page(vma, addr); } #define __HAVE_ARCH_HUGE_PTE_NONE -- 2.30.2