From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757716AbYBTKPV (ORCPT ); Wed, 20 Feb 2008 05:15:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751254AbYBTKPI (ORCPT ); Wed, 20 Feb 2008 05:15:08 -0500 Received: from E23SMTP03.au.ibm.com ([202.81.18.172]:33219 "EHLO e23smtp03.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751091AbYBTKPG (ORCPT ); Wed, 20 Feb 2008 05:15:06 -0500 From: Srinivasa Ds Organization: IBM To: Andrew Morton , ananth@in.ibm.com, Jim Keniston , linux-kernel@vger.kernel.org, srikar@linux.vnet.ibm.com Subject: [RFC] [PATCH] Refuse kprobe insertion on add/sub_preempt_counter() Date: Wed, 20 Feb 2008 15:45:17 +0530 User-Agent: KMail/1.9.6 (enterprise 0.20070907.709405) MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200802201545.17986.srinivasa@in.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Kprobes makes use of preempt_disable(),preempt_enable_noresched() and these functions inturn call add/sub_preempt_count(). So we need to refuse user from inserting probe in to these functions. This patch disallows user from probing add/sub_preempt_count(). Signed-off-by: Srinivasa DS --- kernel/sched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Index: linux-2.6.25-rc2/kernel/sched.c =================================================================== --- linux-2.6.25-rc2.orig/kernel/sched.c +++ linux-2.6.25-rc2/kernel/sched.c @@ -3766,7 +3766,7 @@ void scheduler_tick(void) #if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT) -void add_preempt_count(int val) +void __kprobes add_preempt_count(int val) { /* * Underflow? @@ -3782,7 +3782,7 @@ void add_preempt_count(int val) } EXPORT_SYMBOL(add_preempt_count); -void sub_preempt_count(int val) +void __kprobes sub_preempt_count(int val) { /* * Underflow?