From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753670AbaHRJl2 (ORCPT ); Mon, 18 Aug 2014 05:41:28 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:43112 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753291AbaHRJgY (ORCPT ); Mon, 18 Aug 2014 05:36:24 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "David S. Miller" , Luis Henriques Subject: [PATCH 3.11 123/137] sparc64: Do not insert non-valid PTEs into the TSB hash table. Date: Mon, 18 Aug 2014 10:33:04 +0100 Message-Id: <1408354398-10226-124-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1408354398-10226-1-git-send-email-luis.henriques@canonical.com> References: <1408354398-10226-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.15 -stable review patch. If anyone has any objections, please let me know. ------------------ From: "David S. Miller" commit 18f38132528c3e603c66ea464727b29e9bbcb91b upstream. The assumption was that update_mmu_cache() (and the equivalent for PMDs) would only be called when the PTE being installed will be accessible by the user. This is not true for code paths originating from remove_migration_pte(). There are dire consequences for placing a non-valid PTE into the TSB. The TLB miss frramework assumes thatwhen a TSB entry matches we can just load it into the TLB and return from the TLB miss trap. So if a non-valid PTE is in there, we will deadlock taking the TLB miss over and over, never satisfying the miss. Just exit early from update_mmu_cache() and friends in this situation. Based upon a report and patch from Christopher Alexander Tobias Schulze. Signed-off-by: David S. Miller [ luis: backported to 3.11: used davem's backport to 3.10 and 3.12 ] Signed-off-by: Luis Henriques --- arch/sparc/mm/init_64.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index ed82edad1a39..774ba41dba4d 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -350,6 +350,10 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t * mm = vma->vm_mm; + /* Don't insert a non-valid PTE into the TSB, we'll deadlock. */ + if (!pte_accessible(mm, pte)) + return; + spin_lock_irqsave(&mm->context.lock, flags); #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE) -- 1.9.1