From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755271Ab2GJANS (ORCPT ); Mon, 9 Jul 2012 20:13:18 -0400 Received: from mail-gg0-f174.google.com ([209.85.161.174]:58908 "EHLO mail-gg0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755239Ab2GJANO (ORCPT ); Mon, 9 Jul 2012 20:13:14 -0400 From: Anton Vorontsov To: Greg Kroah-Hartman , Kees Cook , Colin Cross , Tony Luck , Steven Rostedt , Frederic Weisbecker , Ingo Molnar Cc: Arnd Bergmann , John Stultz , Shuah Khan , arve@android.com, Rebecca Schultz Zavin , Jesper Juhl , Randy Dunlap , Stephen Boyd , Thomas Meyer , Andrew Morton , Marco Stornelli , WANG Cong , linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org, linaro-kernel@lists.linaro.org, patches@linaro.org, kernel-team@android.com Subject: [PATCH 4/8] tracing/function: Introduce persistent trace option Date: Mon, 9 Jul 2012 17:10:42 -0700 Message-Id: <1341879046-5197-4-git-send-email-anton.vorontsov@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <20120710001004.GA22744@lizard> References: <20120710001004.GA22744@lizard> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch introduces 'func_ptrace' option, now available in /sys/kernel/debug/tracing/options when function tracer is selected. The patch also adds some tiny code that calls back to pstore to record the trace. The callback is no-op when PSTORE=n. Signed-off-by: Anton Vorontsov --- kernel/trace/trace_functions.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index c7b0c6a..13770ab 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include "trace.h" @@ -74,6 +75,14 @@ function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip) preempt_enable_notrace(); } +/* Our two options */ +enum { + TRACE_FUNC_OPT_STACK = 0x1, + TRACE_FUNC_OPT_PSTORE = 0x2, +}; + +static struct tracer_flags func_flags; + static void function_trace_call(unsigned long ip, unsigned long parent_ip) { @@ -97,6 +106,12 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { + /* + * So far tracing doesn't support multiple buffers, so + * we make an explicit call for now. + */ + if (unlikely(func_flags.val & TRACE_FUNC_OPT_PSTORE)) + pstore_ftrace_call(ip, parent_ip); pc = preempt_count(); trace_function(tr, ip, parent_ip, flags, pc); } @@ -158,15 +173,13 @@ static struct ftrace_ops trace_stack_ops __read_mostly = .flags = FTRACE_OPS_FL_GLOBAL, }; -/* Our two options */ -enum { - TRACE_FUNC_OPT_STACK = 0x1, -}; - static struct tracer_opt func_opts[] = { #ifdef CONFIG_STACKTRACE { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) }, #endif +#ifdef CONFIG_PSTORE_FTRACE + { TRACER_OPT(func_pstore, TRACE_FUNC_OPT_PSTORE) }, +#endif { } /* Always set a last empty entry */ }; @@ -218,6 +231,8 @@ static int func_set_flag(u32 old_flags, u32 bit, int set) } return 0; + } else if (bit == TRACE_FUNC_OPT_PSTORE) { + return 0; } return -EINVAL; -- 1.7.10.4