mirror of
https://github.com/torvalds/linux.git
synced 2024-12-19 09:32:32 +00:00
d2bb076299
If -pg of gcc is enabled with CONFIG_FUNCTION_TRACER=y. a calling to _mcount will be inserted into each kernel function. so, there is a possibility to trace the kernel functions in _mcount. This patch add the MIPS specific _mcount support for static function tracing. by default, ftrace_trace_function is initialized as ftrace_stub(an empty function), so, the default _mcount will introduce very little overhead. after enabling ftrace in user-space, it will jump to a real tracing function and do static function tracing for us. and -ffunction-sections is incompatible with -pg, so, disable it when ftracer is enabled. Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Nicholas Mc Guire <der.herr@hofr.at> Cc: zhangfx@lemote.com Cc: Wu Zhangjin <wuzhangjin@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/672/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
25 lines
633 B
C
25 lines
633 B
C
/*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive for
|
|
* more details.
|
|
*
|
|
* Copyright (C) 2009 DSLab, Lanzhou University, China
|
|
* Author: Wu Zhangjin <wuzj@lemote.com>
|
|
*/
|
|
|
|
#ifndef _ASM_MIPS_FTRACE_H
|
|
#define _ASM_MIPS_FTRACE_H
|
|
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
|
|
#define MCOUNT_ADDR ((unsigned long)(_mcount))
|
|
#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
|
|
|
|
#ifndef __ASSEMBLY__
|
|
extern void _mcount(void);
|
|
#define mcount _mcount
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
#endif /* CONFIG_FUNCTION_TRACER */
|
|
#endif /* _ASM_MIPS_FTRACE_H */
|