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| author | Wu Zhangjin <wuzhangjin@gmail.com> | 2009-11-20 15:34:29 +0300 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2009-12-17 04:57:21 +0300 |
| commit | d2bb0762993e11363d8343127516b8fe88f9006f (patch) | |
| tree | f210c4c4b0234a776977e6d2b749384e1d3699c1 /arch/mips/kernel/mips_ksyms.c | |
| parent | 8922f79ee56e9dab6fc144defc0bc901ff0a7f8a (diff) | |
| download | linux-d2bb0762993e11363d8343127516b8fe88f9006f.tar.xz | |
MIPS: Tracing: Add static function tracer support for MIPS
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>
Diffstat (limited to 'arch/mips/kernel/mips_ksyms.c')
| -rw-r--r-- | arch/mips/kernel/mips_ksyms.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/mips/kernel/mips_ksyms.c b/arch/mips/kernel/mips_ksyms.c index 225755d0c1f6..1d04807874db 100644 --- a/arch/mips/kernel/mips_ksyms.c +++ b/arch/mips/kernel/mips_ksyms.c @@ -13,6 +13,7 @@ #include <asm/checksum.h> #include <asm/pgtable.h> #include <asm/uaccess.h> +#include <asm/ftrace.h> extern void *__bzero(void *__s, size_t __count); extern long __strncpy_from_user_nocheck_asm(char *__to, @@ -51,3 +52,7 @@ EXPORT_SYMBOL(csum_partial_copy_nocheck); EXPORT_SYMBOL(__csum_partial_copy_user); EXPORT_SYMBOL(invalid_pte_table); +#ifdef CONFIG_FUNCTION_TRACER +/* _mcount is defined in arch/mips/kernel/mcount.S */ +EXPORT_SYMBOL(_mcount); +#endif |