From patchwork Thu Aug 16 18:45:23 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 10568053 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F037D921 for ; Thu, 16 Aug 2018 18:55:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E741D2B47A for ; Thu, 16 Aug 2018 18:55:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DAC772B7FF; Thu, 16 Aug 2018 18:55:10 +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=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 643662B47A for ; Thu, 16 Aug 2018 18:55:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Cpy3SUiHDXGK3Kqmje2JmZRxWHo3PToe7moKFtWtf/4=; b=aJM4oRsDGbbMpo RsF+4CAa3JlvWNoMeNfzf2oqThL8pDI2vrqlOZfm3muuOYFUSOZFC6vTRjPYOMH0MvGJFmjaJLDLq oIB1sO9YPRPVJ1brN+lOp/dozuyK/lWuBZvyJaI9wu5W1aMz4xi0TVk+PIbZNxG8uIjzKnaj/Wow7 MgYOfZRZPzuiGjUcYU34Ho/hLkhPtpBuDeYuMHDontEK639gleqABeUg0i+WbQ2onUg+aF0xl4J87 xydP/UsB05yjWrv9cIGOlZqsbfXQmUcOeT3LOjqLsxSLQJEYWE7BaOuWAQd0UlVItphmsQeF5CwrQ IqYAbjkMBT/ETzj/Nn7w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fqNQL-0005dD-13; Thu, 16 Aug 2018 18:55:09 +0000 Received: from mail.linuxfoundation.org ([140.211.169.12]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fqNKS-0002pk-MM for linux-arm-kernel@lists.infradead.org; Thu, 16 Aug 2018 18:49:11 +0000 Received: from localhost (unknown [194.244.16.108]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id C0CAFCB7; Thu, 16 Aug 2018 18:48:53 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Subject: [PATCH 4.18 07/22] x86/mm: Disable ioremap free page handling on x86-PAE Date: Thu, 16 Aug 2018 20:45:23 +0200 Message-Id: <20180816171556.786084738@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180816171556.502583508@linuxfoundation.org> References: <20180816171556.502583508@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180816_114905_411008_A32596CE X-CRM114-Status: UNSURE ( 9.09 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mhocko@suse.com, Toshi Kani , Greg Kroah-Hartman , Joerg Roedel , cpandya@codeaurora.org, stable@vger.kernel.org, linux-mm@kvack.org, hpa@zytor.com, Thomas Gleixner , akpm@linux-foundation.org, linux-arm-kernel@lists.infradead.org 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 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Toshi Kani commit f967db0b9ed44ec3057a28f3b28efc51df51b835 upstream. ioremap() supports pmd mappings on x86-PAE. However, kernel's pmd tables are not shared among processes on x86-PAE. Therefore, any update to sync'd pmd entries need re-syncing. Freeing a pte page also leads to a vmalloc fault and hits the BUG_ON in vmalloc_sync_one(). Disable free page handling on x86-PAE. pud_free_pmd_page() and pmd_free_pte_page() simply return 0 if a given pud/pmd entry is present. This assures that ioremap() does not update sync'd pmd entries at the cost of falling back to pte mappings. Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces") Reported-by: Joerg Roedel Signed-off-by: Toshi Kani Signed-off-by: Thomas Gleixner Cc: mhocko@suse.com Cc: akpm@linux-foundation.org Cc: hpa@zytor.com Cc: cpandya@codeaurora.org Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: stable@vger.kernel.org Cc: Andrew Morton Cc: Michal Hocko Cc: "H. Peter Anvin" Cc: Link: https://lkml.kernel.org/r/20180627141348.21777-2-toshi.kani@hpe.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/pgtable.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -719,6 +719,7 @@ int pmd_clear_huge(pmd_t *pmd) return 0; } +#ifdef CONFIG_X86_64 /** * pud_free_pmd_page - Clear pud entry and free pmd page. * @pud: Pointer to a PUD. @@ -766,4 +767,22 @@ int pmd_free_pte_page(pmd_t *pmd) return 1; } + +#else /* !CONFIG_X86_64 */ + +int pud_free_pmd_page(pud_t *pud) +{ + return pud_none(*pud); +} + +/* + * Disable free page handling on x86-PAE. This assures that ioremap() + * does not update sync'd pmd entries. See vmalloc_sync_one(). + */ +int pmd_free_pte_page(pmd_t *pmd) +{ + return pmd_none(*pmd); +} + +#endif /* CONFIG_X86_64 */ #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */