From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753992AbYHLDQd (ORCPT ); Mon, 11 Aug 2008 23:16:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752984AbYHLDOm (ORCPT ); Mon, 11 Aug 2008 23:14:42 -0400 Received: from mga02.intel.com ([134.134.136.20]:3597 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752924AbYHLDOl (ORCPT ); Mon, 11 Aug 2008 23:14:41 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.32,192,1217833200"; d="scan'208";a="428377147" Subject: [PATCH -v3 6/7] kexec jump: __ftrace_enabled_save/restore From: Huang Ying To: Steven Rostedt , "Eric W. Biederman" , Pavel Machek , nigel@nigel.suspend2.net, "Rafael J. Wysocki" , Andrew Morton , Vivek Goyal , mingo@elte.hu, Linus Torvalds Cc: linux-kernel@vger.kernel.org, Kexec Mailing List Content-Type: text/plain Date: Tue, 12 Aug 2008 11:14:36 +0800 Message-Id: <1218510876.24951.45.camel@caritas-dev.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add __ftrace_enabled_save/restore, used to disable ftrace for a while. Now, this is used by kexec jump, which need a version without lock, for general situation, a locked version should be used. Signed-off-by: Huang Ying --- include/linux/ftrace.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -98,6 +98,27 @@ static inline void tracer_disable(void) #endif } +/* Ftrace disable/restore without lock. Some synchronization mechanism + * must be used to prevent ftrace_enabled to be changed between + * disable/restore. */ +static inline int __ftrace_enabled_save(void) +{ +#ifdef CONFIG_FTRACE + int saved_ftrace_enabled = ftrace_enabled; + ftrace_enabled = 0; + return saved_ftrace_enabled; +#else + return 0; +#endif +} + +static inline void __ftrace_enabled_restore(int enabled) +{ +#ifdef CONFIG_FTRACE + ftrace_enabled = enabled; +#endif +} + #ifdef CONFIG_FRAME_POINTER /* TODO: need to fix this for ARM */ # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))