From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752777AbZIIBQS (ORCPT ); Tue, 8 Sep 2009 21:16:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751989AbZIIBQR (ORCPT ); Tue, 8 Sep 2009 21:16:17 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:60298 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751015AbZIIBQR (ORCPT ); Tue, 8 Sep 2009 21:16:17 -0400 Message-ID: <4AA70198.9070500@cn.fujitsu.com> Date: Wed, 09 Sep 2009 09:15:04 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b3pre) Gecko/20090513 Fedora/3.0-2.3.beta2.fc11 Thunderbird/3.0b2 MIME-Version: 1.0 To: Ingo Molnar CC: Frederic Weisbecker , Steven Rostedt , LKML Subject: [PATCH 1/2] tracing: Add sysctl to enable/disable tracing on oops Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently we always disable tracing on oops, and this patch adds a sysctl so one can choose to enable it. Signed-off-by: Li Zefan --- include/linux/kernel.h | 2 ++ kernel/panic.c | 3 ++- kernel/sysctl.c | 10 ++++++++++ kernel/trace/ring_buffer.c | 2 ++ 4 files changed, 16 insertions(+), 1 deletions(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index f61039e..5c4528f 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -516,12 +516,14 @@ static inline char *pack_hex_byte(char *buf, u8 byte) * Most likely, you want to use tracing_on/tracing_off. */ #ifdef CONFIG_RING_BUFFER +extern int trace_on_oops; void tracing_on(void); void tracing_off(void); /* trace_off_permanent stops recording with no way to bring it back */ void tracing_off_permanent(void); int tracing_is_on(void); #else +#define trace_on_oops 0 static inline void tracing_on(void) { } static inline void tracing_off(void) { } static inline void tracing_off_permanent(void) { } diff --git a/kernel/panic.c b/kernel/panic.c index 512ab73..22ec502 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -301,7 +301,8 @@ int oops_may_print(void) */ void oops_enter(void) { - tracing_off(); + if (!trace_on_oops) + tracing_off(); /* can't trust the integrity of the kernel anymore: */ debug_locks_off(); do_oops_enter_exit(); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index cdbe8d0..a768c15 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -537,6 +537,16 @@ static struct ctl_table kern_table[] = { .proc_handler = &stack_trace_sysctl, }, #endif +#ifdef CONFIG_RING_BUFFER + { + .ctl_name = CTL_UNNUMBERED, + .procname = "trace_on_oops", + .data = &trace_on_oops, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, +#endif #ifdef CONFIG_TRACING { .ctl_name = CTL_UNNUMBERED, diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 454e74e..fc10962 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -155,6 +155,8 @@ static unsigned long ring_buffer_flags __read_mostly = RB_BUFFERS_ON; #define BUF_PAGE_HDR_SIZE offsetof(struct buffer_data_page, data) +int trace_on_oops; + /** * tracing_on - enable all tracing buffers * -- 1.6.3