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=-20.2 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,SPF_PASS, 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 EB2D0C63798 for ; Mon, 19 Jul 2021 16:18:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3C2F61289 for ; Mon, 19 Jul 2021 16:18:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236368AbhGSPhM (ORCPT ); Mon, 19 Jul 2021 11:37:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:53516 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343839AbhGSO7W (ORCPT ); Mon, 19 Jul 2021 10:59:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6EF20611F2; Mon, 19 Jul 2021 15:37:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626709044; bh=Nj0Udr4R71nGxE+aMr8O49t+TEjcRM2tKiepHUjqTXA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xit3BPZtniQ8KarQ3ofcApd3PRd3k7VqwcIeI3aPqs1AOMC/VHmsawKl92FKaa15I gFj4ZRZ1mwvHJXleYHRfXGzoSDtuNnA3y0V6zZVp5XyOwFR+9vQrKtnJZNgnVthsv0 2yOlfNFF+Ic63yR4+TNUMviuq+Q2Nn6YQ+lOG6Vg= 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 4.19 232/421] hugetlb: clear huge pte during flush function on mips platform Date: Mon, 19 Jul 2021 16:50:43 +0200 Message-Id: <20210719144954.462802772@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144946.310399455@linuxfoundation.org> References: <20210719144946.310399455@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 982bc0685330..4747a4694669 100644 --- a/arch/mips/include/asm/hugetlb.h +++ b/arch/mips/include/asm/hugetlb.h @@ -67,7 +67,13 @@ 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); } static inline int huge_pte_none(pte_t pte) -- 2.30.2