Commit 9bdeb7b5 authored Aug 15, 2008 by Huang Ying Committed by Linus Torvalds Aug 15, 2008

kexec jump: __ftrace_enabled_save/restore

Add __ftrace_enabled_save/restore, used to disable ftrace for a while.
Now, this is used by kexec jump, which need a version without lock, for
general situation, a locked version should be used.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 73bd9c72

include/linux/ftrace.h

+21 −0

Original line number	Diff line number	Diff line
		@@ -98,6 +98,27 @@ static inline void tracer_disable(void)
		#endif
		}

		/* Ftrace disable/restore without lock. Some synchronization mechanism
		* must be used to prevent ftrace_enabled to be changed between
		* disable/restore. */
		static inline int __ftrace_enabled_save(void)
		{
		#ifdef CONFIG_FTRACE
		int saved_ftrace_enabled = ftrace_enabled;
		ftrace_enabled = 0;
		return saved_ftrace_enabled;
		#else
		return 0;
		#endif
		}

		static inline void __ftrace_enabled_restore(int enabled)
		{
		#ifdef CONFIG_FTRACE
		ftrace_enabled = enabled;
		#endif
		}

		#ifdef CONFIG_FRAME_POINTER
		/* TODO: need to fix this for ARM */
		# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))