Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758098Ab3CYBjf (ORCPT ); Sun, 24 Mar 2013 21:39:35 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33762 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755017Ab3CYBPA (ORCPT ); Sun, 24 Mar 2013 21:15:00 -0400 Message-Id: <20130325010526.341185526@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 25 Mar 2013 01:05:44 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, Heiko Carstens , Martin Schwidefsky Subject: [ 020/104] s390/mm: fix flush_tlb_kernel_range() Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In-Reply-To: <20130325010524.240972766@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:f137:78a:b654:affb X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1751 Lines: 49 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Heiko Carstens commit f6a70a07079518280022286a1dceb797d12e1edf upstream. Our flush_tlb_kernel_range() implementation calls __tlb_flush_mm() with &init_mm as argument. __tlb_flush_mm() however will only flush tlbs for the passed in mm if its mm_cpumask is not empty. For the init_mm however its mm_cpumask has never any bits set. Which in turn means that our flush_tlb_kernel_range() implementation doesn't work at all. This can be easily verified with a vmalloc/vfree loop which allocates a page, writes to it and then frees the page again. A crash will follow almost instantly. To fix this remove the cpumask_empty() check in __tlb_flush_mm() since there shouldn't be too many mms with a zero mm_cpumask, besides the init_mm of course. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Ben Hutchings --- arch/s390/include/asm/tlbflush.h | 2 -- 1 file changed, 2 deletions(-) --- a/arch/s390/include/asm/tlbflush.h +++ b/arch/s390/include/asm/tlbflush.h @@ -74,8 +74,6 @@ static inline void __tlb_flush_idte(unsi static inline void __tlb_flush_mm(struct mm_struct * mm) { - if (unlikely(cpumask_empty(mm_cpumask(mm)))) - return; /* * If the machine has IDTE we prefer to do a per mm flush * on all cpus instead of doing a local flush if the mm -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/