From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1163066Ab2GMQvX (ORCPT ); Fri, 13 Jul 2012 12:51:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:27471 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932288Ab2GMQtG (ORCPT ); Fri, 13 Jul 2012 12:49:06 -0400 Date: Fri, 13 Jul 2012 18:46:27 +0200 From: Oleg Nesterov To: Ingo Molnar Cc: Anton Arapov , Peter Zijlstra , Srikar Dronamraju , linux-kernel@vger.kernel.org Subject: [PATCH 3/9] uprobes: kill write_opcode()->lock_page(new_page) Message-ID: <20120713164627.GA23545@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120713164552.GA23509@redhat.com> 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 write_opcode() does lock_page(new_page) for no reason. Nobody can see this page until __replace_page() exposes it under ptl lock, and we do nothing with this page after pte_unmap_unlock(). If nothing else, the similar code in do_wp_page() doesn't lock the new page for page_add_new_anon_rmap/set_pte_at_notify. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju --- kernel/events/uprobes.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index fbb4188..dff8da2 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -239,9 +239,7 @@ retry: if (ret) goto unlock_out; - lock_page(new_page); ret = __replace_page(vma, vaddr, old_page, new_page); - unlock_page(new_page); unlock_out: unlock_page(old_page); -- 1.5.5.1