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 */ From patchwork Thu Aug 16 18:45:37 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 10568043 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 1F20F921 for ; Thu, 16 Aug 2018 18:49:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1A9BC2B7A6 for ; Thu, 16 Aug 2018 18:49:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0E8B32B80A; Thu, 16 Aug 2018 18:49:04 +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 7C9212B806 for ; Thu, 16 Aug 2018 18:49:03 +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=zqFMDyW0GMs2ArX6AMxRV/JUX6vW9AEzBukk5AZbhYU=; b=P5AF2Bjh/Zjqsw erfn5R645//YOCLk32hNqHKktLRSO8w+HogX1AEEcGJXYB79htBa771yPovt8ew94VIhIeuiVILmj byuM9XBZm+VDm/aftAM7QLb75yac52/5UmlT6POw9SKmPT+45iWHV15h4hVSh3cQT8ikk4e+pWrd8 8H0/d6EWxlhz2uWULD9SrzT7cdf1nn7IZf3V3fCFrAFcZWogu0hL2ve7oCwGx+Qp3TA5GaCd8JCtw cK5KCg+w7H9U619P4JFvm/sPdIcYpnjpZKgbZOWSureHWM2lkWkkdwDhNDvIzdxKSaxxWQvbvz9NC QYpUyuqJBEDulc6AOTqw==; 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 1fqNKL-0002tD-6x; Thu, 16 Aug 2018 18:48:57 +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 1fqNK9-0002iV-SS for linux-arm-kernel@lists.infradead.org; Thu, 16 Aug 2018 18:48:47 +0000 Received: from localhost (unknown [194.244.16.108]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 1447DCC4; Thu, 16 Aug 2018 18:48:35 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Subject: [PATCH 4.18 21/22] ioremap: Update pgtable free interfaces with addr Date: Thu, 16 Aug 2018 20:45:37 +0200 Message-Id: <20180816171557.357424307@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_114845_956022_812938F7 X-CRM114-Status: GOOD ( 14.38 ) 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 , hpa@zytor.com, Will Deacon , stable@vger.kernel.org, linux-mm@kvack.org, Chintan Pandya , 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: Chintan Pandya commit 785a19f9d1dd8a4ab2d0633be4656653bd3de1fc upstream. The following kernel panic was observed on ARM64 platform due to a stale TLB entry. 1. ioremap with 4K size, a valid pte page table is set. 2. iounmap it, its pte entry is set to 0. 3. ioremap the same address with 2M size, update its pmd entry with a new value. 4. CPU may hit an exception because the old pmd entry is still in TLB, which leads to a kernel panic. Commit b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page table") has addressed this panic by falling to pte mappings in the above case on ARM64. To support pmd mappings in all cases, TLB purge needs to be performed in this case on ARM64. Add a new arg, 'addr', to pud_free_pmd_page() and pmd_free_pte_page() so that TLB purge can be added later in seprate patches. [toshi.kani@hpe.com: merge changes, rewrite patch description] Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces") Signed-off-by: Chintan Pandya Signed-off-by: Toshi Kani Signed-off-by: Thomas Gleixner Cc: mhocko@suse.com Cc: akpm@linux-foundation.org Cc: hpa@zytor.com Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: Will Deacon Cc: Joerg Roedel Cc: stable@vger.kernel.org Cc: Andrew Morton Cc: Michal Hocko Cc: "H. Peter Anvin" Cc: Link: https://lkml.kernel.org/r/20180627141348.21777-3-toshi.kani@hpe.com Signed-off-by: Greg Kroah-Hartman --- arch/arm64/mm/mmu.c | 4 ++-- arch/x86/mm/pgtable.c | 12 +++++++----- include/asm-generic/pgtable.h | 8 ++++---- lib/ioremap.c | 4 ++-- 4 files changed, 15 insertions(+), 13 deletions(-) --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -977,12 +977,12 @@ int pmd_clear_huge(pmd_t *pmdp) return 1; } -int pud_free_pmd_page(pud_t *pud) +int pud_free_pmd_page(pud_t *pud, unsigned long addr) { return pud_none(*pud); } -int pmd_free_pte_page(pmd_t *pmd) +int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) { return pmd_none(*pmd); } --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -723,11 +723,12 @@ int pmd_clear_huge(pmd_t *pmd) /** * pud_free_pmd_page - Clear pud entry and free pmd page. * @pud: Pointer to a PUD. + * @addr: Virtual address associated with pud. * * Context: The pud range has been unmaped and TLB purged. * Return: 1 if clearing the entry succeeded. 0 otherwise. */ -int pud_free_pmd_page(pud_t *pud) +int pud_free_pmd_page(pud_t *pud, unsigned long addr) { pmd_t *pmd; int i; @@ -738,7 +739,7 @@ int pud_free_pmd_page(pud_t *pud) pmd = (pmd_t *)pud_page_vaddr(*pud); for (i = 0; i < PTRS_PER_PMD; i++) - if (!pmd_free_pte_page(&pmd[i])) + if (!pmd_free_pte_page(&pmd[i], addr + (i * PMD_SIZE))) return 0; pud_clear(pud); @@ -750,11 +751,12 @@ int pud_free_pmd_page(pud_t *pud) /** * pmd_free_pte_page - Clear pmd entry and free pte page. * @pmd: Pointer to a PMD. + * @addr: Virtual address associated with pmd. * * Context: The pmd range has been unmaped and TLB purged. * Return: 1 if clearing the entry succeeded. 0 otherwise. */ -int pmd_free_pte_page(pmd_t *pmd) +int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) { pte_t *pte; @@ -770,7 +772,7 @@ int pmd_free_pte_page(pmd_t *pmd) #else /* !CONFIG_X86_64 */ -int pud_free_pmd_page(pud_t *pud) +int pud_free_pmd_page(pud_t *pud, unsigned long addr) { return pud_none(*pud); } @@ -779,7 +781,7 @@ int pud_free_pmd_page(pud_t *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) +int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) { return pmd_none(*pmd); } --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -1019,8 +1019,8 @@ int pud_set_huge(pud_t *pud, phys_addr_t int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot); int pud_clear_huge(pud_t *pud); int pmd_clear_huge(pmd_t *pmd); -int pud_free_pmd_page(pud_t *pud); -int pmd_free_pte_page(pmd_t *pmd); +int pud_free_pmd_page(pud_t *pud, unsigned long addr); +int pmd_free_pte_page(pmd_t *pmd, unsigned long addr); #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */ static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot) { @@ -1046,11 +1046,11 @@ static inline int pmd_clear_huge(pmd_t * { return 0; } -static inline int pud_free_pmd_page(pud_t *pud) +static inline int pud_free_pmd_page(pud_t *pud, unsigned long addr) { return 0; } -static inline int pmd_free_pte_page(pmd_t *pmd) +static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) { return 0; } --- a/lib/ioremap.c +++ b/lib/ioremap.c @@ -92,7 +92,7 @@ static inline int ioremap_pmd_range(pud_ if (ioremap_pmd_enabled() && ((next - addr) == PMD_SIZE) && IS_ALIGNED(phys_addr + addr, PMD_SIZE) && - pmd_free_pte_page(pmd)) { + pmd_free_pte_page(pmd, addr)) { if (pmd_set_huge(pmd, phys_addr + addr, prot)) continue; } @@ -119,7 +119,7 @@ static inline int ioremap_pud_range(p4d_ if (ioremap_pud_enabled() && ((next - addr) == PUD_SIZE) && IS_ALIGNED(phys_addr + addr, PUD_SIZE) && - pud_free_pmd_page(pud)) { + pud_free_pmd_page(pud, addr)) { if (pud_set_huge(pud, phys_addr + addr, prot)) continue; } From patchwork Thu Aug 16 18:45:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 10568039 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 474E85A4 for ; Thu, 16 Aug 2018 18:48:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 40BE52B7A6 for ; 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bh=XZS0kyPviHr4xY5MQiCwyv9kZE7WaH0r7hfsbJIUYMY=; b=X10t7xB55zjEBs BSyZU2HAsBvpJinAdjnarjEob1WF9mynhTwJI6Mjthql+wXkQ1vC5Chx29ZbdgJG+uFr5s0dJFUbd 5xoj2nHNVO5s8X33XhPdl349cv7vscjxqT9ZXBgHfOoAa82ZkQ1V4uJ+fepLP01S/VmzacgMvCmF0 wO6gr9DbSxkK8SVNXk5u9tETzVHY72xSUVEChdfyL2LUovIwPdJnVpAGRCsnUlJu5atZjwGhAXQKH B2zaMbdV1zr6YsJpCyYGn0Ax4R5vecE+DZp0wTqSvUC30rubWqd2ORODeFcJCM5hEyZJszswUO6CE kN7keqyw86MIYkthvcSQ==; 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 1fqNKE-0002kS-1i; Thu, 16 Aug 2018 18:48:50 +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 1fqNK9-0002ib-SU for linux-arm-kernel@lists.infradead.org; Thu, 16 Aug 2018 18:48:47 +0000 Received: from localhost (unknown [194.244.16.108]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id A0D01CE8; Thu, 16 Aug 2018 18:48:38 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Subject: [PATCH 4.18 22/22] x86/mm: Add TLB purge to free pmd/pte page interfaces Date: Thu, 16 Aug 2018 20:45:38 +0200 Message-Id: <20180816171557.396691632@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_114845_954801_C2D64660 X-CRM114-Status: GOOD ( 13.86 ) 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, akpm@linux-foundation.org, Thomas Gleixner , 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 5e0fb5df2ee871b841f96f9cb6a7f2784e96aa4e upstream. ioremap() calls pud_free_pmd_page() / pmd_free_pte_page() when it creates a pud / pmd map. The following preconditions are met at their entry. - All pte entries for a target pud/pmd address range have been cleared. - System-wide TLB purges have been peformed for a target pud/pmd address range. The preconditions assure that there is no stale TLB entry for the range. Speculation may not cache TLB entries since it requires all levels of page entries, including ptes, to have P & A-bits set for an associated address. However, speculation may cache pud/pmd entries (paging-structure caches) when they have P-bit set. Add a system-wide TLB purge (INVLPG) to a single page after clearing pud/pmd entry's P-bit. SDM 4.10.4.1, Operation that Invalidate TLBs and Paging-Structure Caches, states that: INVLPG invalidates all paging-structure caches associated with the current PCID regardless of the liner addresses to which they correspond. Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces") 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: Joerg Roedel Cc: stable@vger.kernel.org Cc: Andrew Morton Cc: Michal Hocko Cc: "H. Peter Anvin" Cc: Link: https://lkml.kernel.org/r/20180627141348.21777-4-toshi.kani@hpe.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/pgtable.c | 38 +++++++++++++++++++++++++++++++------- 1 file changed, 31 insertions(+), 7 deletions(-) --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -725,24 +725,44 @@ int pmd_clear_huge(pmd_t *pmd) * @pud: Pointer to a PUD. * @addr: Virtual address associated with pud. * - * Context: The pud range has been unmaped and TLB purged. + * Context: The pud range has been unmapped and TLB purged. * Return: 1 if clearing the entry succeeded. 0 otherwise. + * + * NOTE: Callers must allow a single page allocation. */ int pud_free_pmd_page(pud_t *pud, unsigned long addr) { - pmd_t *pmd; + pmd_t *pmd, *pmd_sv; + pte_t *pte; int i; if (pud_none(*pud)) return 1; pmd = (pmd_t *)pud_page_vaddr(*pud); - - for (i = 0; i < PTRS_PER_PMD; i++) - if (!pmd_free_pte_page(&pmd[i], addr + (i * PMD_SIZE))) - return 0; + pmd_sv = (pmd_t *)__get_free_page(GFP_KERNEL); + if (!pmd_sv) + return 0; + + for (i = 0; i < PTRS_PER_PMD; i++) { + pmd_sv[i] = pmd[i]; + if (!pmd_none(pmd[i])) + pmd_clear(&pmd[i]); + } pud_clear(pud); + + /* INVLPG to clear all paging-structure caches */ + flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1); + + for (i = 0; i < PTRS_PER_PMD; i++) { + if (!pmd_none(pmd_sv[i])) { + pte = (pte_t *)pmd_page_vaddr(pmd_sv[i]); + free_page((unsigned long)pte); + } + } + + free_page((unsigned long)pmd_sv); free_page((unsigned long)pmd); return 1; @@ -753,7 +773,7 @@ int pud_free_pmd_page(pud_t *pud, unsign * @pmd: Pointer to a PMD. * @addr: Virtual address associated with pmd. * - * Context: The pmd range has been unmaped and TLB purged. + * Context: The pmd range has been unmapped and TLB purged. * Return: 1 if clearing the entry succeeded. 0 otherwise. */ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) @@ -765,6 +785,10 @@ int pmd_free_pte_page(pmd_t *pmd, unsign pte = (pte_t *)pmd_page_vaddr(*pmd); pmd_clear(pmd); + + /* INVLPG to clear all paging-structure caches */ + flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1); + free_page((unsigned long)pte); return 1;