Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751504Ab2HHEfQ (ORCPT ); Wed, 8 Aug 2012 00:35:16 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:46050 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751358Ab2HHEez (ORCPT ); Wed, 8 Aug 2012 00:34:55 -0400 X-AuditID: b753bd60-928c4ba0000047ca-2c-5021ec6bb12b X-AuditID: b753bd60-928c4ba0000047ca-2c-5021ec6bb12b Message-ID: <5021EC6B.7020605@hitachi.com> Date: Wed, 08 Aug 2012 13:34:51 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 5.2; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Thomas Gleixner , Frederic Weisbecker , Linus Torvalds , Andi Kleen Subject: Re: [RFC PATCH 3/4] ftrace: Do not test frame pointers if -mfentry is used References: <20120807193845.146666357@goodmis.org> <20120807194059.773895870@goodmis.org> In-Reply-To: <20120807194059.773895870@goodmis.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1552 Lines: 43 (2012/08/08 4:38), Steven Rostedt wrote: > From: Steven Rostedt > > The function graph has a test to check if the frame pointer is > corrupted, which can happen with various options of gcc with mcount. > But this is not an issue with -mfentry as -mfentry does not need nor use > frame pointers for function graph tracing. > > Cc: Andi Kleen > Signed-off-by: Steven Rostedt > --- > kernel/trace/trace_functions_graph.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c > index ce27c8b..99b4378 100644 > --- a/kernel/trace/trace_functions_graph.c > +++ b/kernel/trace/trace_functions_graph.c > @@ -143,7 +143,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, > return; > } > > -#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST > +#if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY) I think CONFIG_HAVE_FENTRY would better unselect CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST in arch/x86/Kconfig explicitly. Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/