diff options
| author | Michal Simek <monstr@monstr.eu> | 2009-12-10 14:15:44 +0100 |
|---|---|---|
| committer | Michal Simek <monstr@monstr.eu> | 2009-12-14 08:44:01 +0100 |
| commit | 7d241ff0567b9503d79ee775c40927d09b509f83 (patch) | |
| tree | 8de1af72c5643416ee427edc7e9ff2170e0d73db /arch/microblaze/kernel/mcount.S | |
| parent | 6d9e60ce30a1be35491c74df00aaa25d869f8a02 (diff) | |
microblaze: ftrace: Add dynamic trace support
With dynamic function tracer, by default, _mcount is defined as an
"empty" function, it returns directly without any more action. When
enabling it in user-space, it will jump to a real tracing
function(ftrace_caller), and do the real job for us.
Differ from the static function tracer, dynamic function tracer provides
two functions ftrace_make_call()/ftrace_make_nop() to enable/disable the
tracing of some indicated kernel functions(set_ftrace_filter).
In the kernel version, there is only one "_mcount" string for every
kernel function, so, we just need to match this one in mcount_regex of
scripts/recordmcount.pl.
For more information please look at code and Documentation/trace folder.
Steven ACK that scripts/recordmcount.pl part.
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/kernel/mcount.S')
| -rw-r--r-- | arch/microblaze/kernel/mcount.S | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/mcount.S b/arch/microblaze/kernel/mcount.S index 97eef3eea944..30aaf8fb55b2 100644 --- a/arch/microblaze/kernel/mcount.S +++ b/arch/microblaze/kernel/mcount.S @@ -83,6 +83,12 @@ ENTRY(ftrace_stub) nop; ENTRY(_mcount) +#ifdef CONFIG_DYNAMIC_FTRACE +ENTRY(ftrace_caller) + /* MS: It is just barrier which is removed from C code */ + rtsd r15, 8 + nop +#endif /* CONFIG_DYNAMIC_FTRACE */ SAVE_REGS swi r15, r1, 0; /* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST begin of checking */ @@ -90,12 +96,19 @@ ENTRY(_mcount) bneid r5, end; nop; /* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST end of checking */ +#ifndef CONFIG_DYNAMIC_FTRACE /* MS: test function trace if is taken or not */ lwi r20, r0, ftrace_trace_function; addik r6, r0, ftrace_stub; cmpu r5, r20, r6; /* ftrace_trace_function != ftrace_stub */ beqid r5, end; /* MS: not taken -> jump over */ nop; +#else /* CONFIG_DYNAMIC_FTRACE */ +NOALIGN_ENTRY(ftrace_call) +/* instruction for setup imm FUNC_part1, addik r20, r0, FUNC_part2 */ + nop + nop +#endif /* CONFIG_DYNAMIC_FTRACE */ /* static normal trace */ lwi r6, r1, 120; /* MS: load parent addr */ addik r5, r15, 0; /* MS: load current function addr */ |