From patchwork Thu Jul 7 12:09:04 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen (ThunderTown)" X-Patchwork-Id: 9218851 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 825A160574 for ; Thu, 7 Jul 2016 12:14:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 72A9928698 for ; Thu, 7 Jul 2016 12:14:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6782A28726; Thu, 7 Jul 2016 12:14:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2A6EF28698 for ; Thu, 7 Jul 2016 12:14:36 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bL8BE-0008VV-6I; Thu, 07 Jul 2016 12:13:20 +0000 Received: from szxga01-in.huawei.com ([58.251.152.64]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bL8BA-0007wa-Rl for linux-arm-kernel@lists.infradead.org; Thu, 07 Jul 2016 12:13:18 +0000 Received: from 172.24.1.137 (EHLO szxeml433-hub.china.huawei.com) ([172.24.1.137]) by szxrg01-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id DNJ24683; Thu, 07 Jul 2016 20:12:00 +0800 (CST) Received: from localhost (10.177.23.164) by szxeml433-hub.china.huawei.com (10.82.67.210) with Microsoft SMTP Server id 14.3.235.1; Thu, 7 Jul 2016 20:11:51 +0800 From: Zhen Lei To: Catalin Marinas , Will Deacon , linux-arm-kernel , linux-kernel Subject: [PATCH 1/1] arm64/hugetlb: clear PG_dcache_clean if the page is dirty when munmap Date: Thu, 7 Jul 2016 20:09:04 +0800 Message-ID: <1467893344-8352-1-git-send-email-thunder.leizhen@huawei.com> X-Mailer: git-send-email 1.9.5.msysgit.1 MIME-Version: 1.0 X-Originating-IP: [10.177.23.164] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A0B0206.577E4711.0029, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 59c42e7c37e82fd024ab09013a0925d7 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160707_051317_381060_B7CFE9E3 X-CRM114-Status: GOOD ( 13.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Xinwei Hu , Zhen Lei , Zefan Li , Hanjun Guo , Tianhong Ding Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP At present, PG_dcache_clean is only cleared when the related huge page is about to be freed. But sometimes, there maybe a process is in charge to copy binary codes into a shared memory, and notifies other processes to execute base on that. For the first time, there is no problem, because the default value of page->flags is PG_dcache_clean cleared. So the cache will be maintained at the time of set_pte_at for other processes. But if the content of the shared memory have been updated again, there is no cache operations, because the PG_dcache_clean is still set. For example: Process A open a hugetlbfs file mmap it as a shared memory copy some binary codes into it munmap Process B open the hugetlbfs file mmap it as a shared memory, executable invoke the functions in the shared memory munmap repeat the above steps. Signed-off-by: Zhen Lei --- arch/arm64/mm/hugetlbpage.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) -- 2.5.0 diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 2e49bd2..547b158 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -201,6 +201,7 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { pte_t pte; + struct page *page; if (pte_cont(*ptep)) { int ncontig, i; @@ -222,12 +223,21 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, if (pte_dirty(ptep_get_and_clear(mm, addr, cpte))) is_dirty = true; } - if (is_dirty) - return pte_mkdirty(pte); - else - return pte; + if (is_dirty) { + pte = pte_mkdirty(pte); + page = pte_page(pte); + clear_bit(PG_dcache_clean, &page->flags); + } + + return pte; } else { - return ptep_get_and_clear(mm, addr, ptep); + pte = ptep_get_and_clear(mm, addr, ptep); + if (huge_pte_dirty(pte)) { + page = pte_page(pte); + clear_bit(PG_dcache_clean, &page->flags); + } + + return pte; } }