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authorNamhyung Kim <namhyung@kernel.org>2015-11-17 09:43:24 +0900
committerThomas Gleixner <tglx@linutronix.de>2015-11-19 11:07:49 +0100
commit112677d683d31ebd6a8e8b02e0620ae512354b2d (patch)
tree46d382c56ebb730d4e84b604177374e1e3816d89 /arch
parenta05917b6ba9dc9a95fc42bdcbe3a875e8ad83935 (diff)
downloadlinux-sh-112677d683d31ebd6a8e8b02e0620ae512354b2d.tar.gz
x86/ftrace: Add comment on static function tracing
There was a confusion between update_ftrace_function() and static function tracing trampoline regarding 3rd parameter (ftrace_ops). Add a comment for clarification. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1447721004-2551-1-git-send-email-namhyung@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/mcount_64.S6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
index 94ea120fa21f..87e1762e2bca 100644
--- a/arch/x86/kernel/mcount_64.S
+++ b/arch/x86/kernel/mcount_64.S
@@ -278,6 +278,12 @@ trace:
/* save_mcount_regs fills in first two parameters */
save_mcount_regs
+ /*
+ * When DYNAMIC_FTRACE is not defined, ARCH_SUPPORTS_FTRACE_OPS is not
+ * set (see include/asm/ftrace.h and include/linux/ftrace.h). Only the
+ * ip and parent ip are used and the list function is called when
+ * function tracing is enabled.
+ */
call *ftrace_trace_function
restore_mcount_regs