From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Frederic Weisbecker <fweisbec@gmail.com>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andi Kleen <andi@firstfloor.org>
Subject: [RFC PATCH 3/4] ftrace: Do not test frame pointers if -mfentry is used
Date: Tue, 07 Aug 2012 15:38:48 -0400 [thread overview]
Message-ID: <20120807194059.773895870@goodmis.org> (raw)
In-Reply-To: 20120807193845.146666357@goodmis.org
[-- Attachment #1: Type: text/plain, Size: 1511 bytes --]
From: Steven Rostedt <srostedt@redhat.com>
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 <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
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)
/*
* The arch may choose to record the frame pointer used
* and check it here to make sure that it is what we expect it
@@ -154,6 +154,9 @@ 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_USING_FENTRY is set.
*/
if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
ftrace_graph_stop();
--
1.7.10.4
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next prev parent reply other threads:[~2012-08-07 19:41 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-07 19:38 [RFC PATCH 0/4] ftrace: Add use of -mfentry for x86_64 Steven Rostedt
2012-08-07 19:38 ` [RFC PATCH 1/4] ftrace: Make recordmcount.c handle __fentry__ Steven Rostedt
2012-08-07 23:57 ` John Reiser
2012-08-08 0:05 ` Steven Rostedt
2012-08-27 17:03 ` [tip:perf/core] " tip-bot for Steven Rostedt
2012-08-07 19:38 ` [RFC PATCH 2/4] ftrace: Add -mfentry to Makefile on function tracer Steven Rostedt
2012-08-27 17:04 ` [tip:perf/core] " tip-bot for Steven Rostedt
2012-08-07 19:38 ` Steven Rostedt [this message]
2012-08-08 4:34 ` [RFC PATCH 3/4] ftrace: Do not test frame pointers if -mfentry is used Masami Hiramatsu
2012-08-08 12:49 ` Steven Rostedt
2012-08-09 2:58 ` Masami Hiramatsu
2012-08-09 3:45 ` Linus Torvalds
2012-08-09 3:57 ` Steven Rostedt
2012-08-09 4:15 ` H. Peter Anvin
2012-08-09 12:37 ` Andi Kleen
2012-08-27 17:05 ` [tip:perf/core] " tip-bot for Steven Rostedt
2012-08-07 19:38 ` [RFC PATCH 4/4] ftrace/x86: Add support for -mfentry to x86_64 Steven Rostedt
2012-08-09 8:34 ` Masami Hiramatsu
2012-08-09 13:46 ` Steven Rostedt
2012-08-09 13:48 ` Steven Rostedt
2012-08-10 7:45 ` Masami Hiramatsu
2012-08-27 17:06 ` [tip:perf/core] " tip-bot for Steven Rostedt
2012-08-07 20:23 ` [RFC PATCH 0/4] ftrace: Add use of -mfentry for x86_64 H. Peter Anvin
2012-08-13 8:42 ` Ingo Molnar
-- strict thread matches above, loose matches on Subject: below --
2011-02-09 20:02 [RFC][PATCH 0/4] ftrace: Use -mfentry when supported (this is for x86_64 right now) Steven Rostedt
2011-02-09 20:02 ` [RFC][PATCH 3/4] ftrace: Do not test frame pointers if -mfentry is used Steven Rostedt
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