From patchwork Mon Apr 30 17:59:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kani, Toshi" X-Patchwork-Id: 10372199 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 5B3096032A for ; Mon, 30 Apr 2018 18:03:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8624727FB3 for ; Mon, 30 Apr 2018 18:03:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7AD7E28429; Mon, 30 Apr 2018 18:03:07 +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 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 B1D2D27FB3 for ; Mon, 30 Apr 2018 18:03:06 +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:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: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=SyTuHqjXcT2ZApUlqx6riuivRthPH0+xc2ZUI3zRGrE=; b=srS5NIYazwy+HTQ+sDhOlPwwXf /5wNX5Dw7GxaUpwk0cyOQHAUqWsXWZ/COZBsO8oZBSmkw6mbNucDl72AReGa0FO51ssEH4/5nTJTz QYrPeNezaW7idmzS7Y46dAj3pUjC7xGz43cUwqKmuUXpEFvgBL2Ml+5FrYJCu6Iam2lu+Bbseu2+d 7dG2vxAo5+AgHq2DPoa2RdUpNlkfyJ6SkDvVP6aqaMq/MOurKdx2dLiVQmEYG9stZQ/eGkx9ET62H zwyBwX4Y2lybQg1gISfo5O02TrDHwDvFuoDGDigdpB6flOwi7lZmifcqs1Il5DEtI3jUDI2BauGVh h2D1c/mw==; 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 1fDD8Y-0007B9-GT; Mon, 30 Apr 2018 18:02:54 +0000 Received: from g9t5009.houston.hpe.com ([15.241.48.73]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fDD6J-0006Ae-IJ for linux-arm-kernel@lists.infradead.org; Mon, 30 Apr 2018 18:00:43 +0000 Received: from g9t2301.houston.hpecorp.net (g9t2301.houston.hpecorp.net [16.220.97.129]) by g9t5009.houston.hpe.com (Postfix) with ESMTP id 25CE694; Mon, 30 Apr 2018 18:00:25 +0000 (UTC) Received: from misato.americas.hpqcorp.net (misato.americas.hpqcorp.net [10.34.81.122]) by g9t2301.houston.hpecorp.net (Postfix) with ESMTP id E18FB76E; Mon, 30 Apr 2018 18:00:23 +0000 (UTC) From: Toshi Kani To: mhocko@suse.com, akpm@linux-foundation.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Subject: [PATCH 2/3] x86/mm: add TLB purge to free pmd/pte page interfaces Date: Mon, 30 Apr 2018 11:59:24 -0600 Message-Id: <20180430175925.2657-3-toshi.kani@hpe.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180430175925.2657-1-toshi.kani@hpe.com> References: <20180430175925.2657-1-toshi.kani@hpe.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180430_110035_730636_67CFA6CE X-CRM114-Status: GOOD ( 13.07 ) 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: Toshi Kani , Joerg Roedel , x86@kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-mm@kvack.org, cpandya@codeaurora.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 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 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 Cc: Andrew Morton Cc: Michal Hocko Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Joerg Roedel Cc: --- arch/x86/mm/pgtable.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 37e3cbac59b9..816fd41ee854 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -720,24 +720,40 @@ 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. */ 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); + pmd_sv = (pmd_t *)__get_free_page(GFP_KERNEL); - for (i = 0; i < PTRS_PER_PMD; i++) - if (!pmd_free_pte_page(&pmd[i], addr + (i * PMD_SIZE))) - 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; @@ -748,7 +764,7 @@ int pud_free_pmd_page(pud_t *pud, unsigned long addr) * @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) @@ -760,6 +776,10 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) 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;