• Frederic Weisbecker's avatar
    tracing/function-graph-tracer: introduce __notrace_funcgraph to filter special functions · 8b96f011
    Frederic Weisbecker authored
    Impact: trace more functions
    
    When the function graph tracer is configured, three more files are not
    traced to prevent only four functions to be traced. And this impacts the
    normal function tracer too.
    
    arch/x86/kernel/process_64/32.c:
    
    I had crashes when I let this file traced. After some debugging, I saw
    that the "current" task point was changed inside__swtich_to(), ie:
    "write_pda(pcurrent, next_p);" inside process_64.c Since the tracer store
    the original return address of the function inside current, we had
    crashes. Only __switch_to() has to be excluded from tracing.
    
    kernel/module.c and kernel/extable.c:
    
    Because of a function used internally by the function graph tracer:
    __kernel_text_address()
    
    To let the other functions inside these files to be traced, this patch
    introduces the __notrace_funcgraph function prefix which is __notrace if
    function graph tracer is configured and nothing if not.
    Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    8b96f011
process_32.c 18.2 KB