Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932684AbbGJQxM (ORCPT ); Fri, 10 Jul 2015 12:53:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53024 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932534AbbGJQw7 (ORCPT ); Fri, 10 Jul 2015 12:52:59 -0400 Date: Fri, 10 Jul 2015 18:51:21 +0200 From: Oleg Nesterov To: Andrew Morton Cc: Andy Lutomirski , Hugh Dickins , Kirill Shutemov , Linus Torvalds , Pavel Emelyanov , linux-kernel@vger.kernel.org Subject: [PATCH v2 0/3] special_mapping_fault() is broken Message-ID: <20150710165121.GA10341@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1022 Lines: 28 Hello, special_mapping_fault() is absolutely broken. It seems it was always wrong, but this didn't matter until vdso/vvar started to use more than one page. The patches are the same, just 1/3 was re-diffed on top of the recent 6b7339f4c31ad "mm: avoid setting up anonymous pages into file mapping" from Kirill. And after this change vma_is_anonymous() becomes really trivial, it simply checks vm_ops == NULL. However, I do think the helper makes sense. There are a lot of ->vm_ops != NULL checks, the helper makes the caller's code more understandable (self-documented) and this is more grep-friendly. Oleg. include/linux/mm.h | 5 +++++ mm/memory.c | 8 ++++---- mm/mmap.c | 14 +++----------- 3 files changed, 12 insertions(+), 15 deletions(-) -- 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/