From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754858Ab1BIUKh (ORCPT ); Wed, 9 Feb 2011 15:10:37 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:56145 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753515Ab1BIUKc (ORCPT ); Wed, 9 Feb 2011 15:10:32 -0500 X-Authority-Analysis: v=1.1 cv=+c36koQ5Dcj/1qolKHjtkYAGXvrVJRRiKMp+84F5sLg= c=1 sm=0 a=KPctdiwS7pgA:10 a=bbbx4UPp9XUA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=20KFwNOVAAAA:8 a=WfulkdPnAAAA:8 a=meVymXHHAAAA:8 a=z92ZAsfz5gGZNyKBvmQA:9 a=OBcuedXyxaaXIjAvHoquoKGr1ukA:4 a=jEp0ucaQiEUA:10 a=l29vjEC0CZ8A:10 a=jeBq3FmKZ4MA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Message-Id: <20110209201030.063742553@goodmis.org> User-Agent: quilt/0.48-1 Date: Wed, 09 Feb 2011 15:02:52 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Thomas Gleixner , Frederic Weisbecker , "H. Peter Anvin" , Mathieu Desnoyers , Andi Kleen , Masami Hiramatsu Subject: [RFC][PATCH 3/4] ftrace: Do not test frame pointers if -mfentry is used References: <20110209200249.111932716@goodmis.org> Content-Disposition: inline; filename=0003-ftrace-Do-not-test-frame-pointers-if-mfentry-is-used.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 files changed, 4 insertions(+), 1 deletions(-) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 76b0598..e7bc48b 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -129,7 +129,7 @@ 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_HAS_FENTRY) /* * The arch may choose to record the frame pointer used * and check it here to make sure that it is what we expect it @@ -140,6 +140,9 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, * * Currently, x86_32 with optimize for size (-Os) makes the latest * gcc do the above. + * + * Note, -mfentry does not use frame pointers, and this test + * is not needed if CC_HAS_FENTRY is set. */ if (unlikely(current->ret_stack[index].fp != frame_pointer)) { ftrace_graph_stop(); -- 1.7.2.3