• Michal Simek's avatar
    microblaze: ftrace: Add dynamic trace support · 7d241ff0
    Michal Simek authored
    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: default avatarSteven Rostedt <rostedt@goodmis.org>
    Signed-off-by: default avatarMichal Simek <monstr@monstr.eu>
    7d241ff0
ftrace.c 4.15 KB