Re: [PATCH] fix signals instrumentation

Folded in lttng-instrumentation-kernel.patch.

* Pierre-Marc Fournier ([email protected]) wrote:
> The kernel_send_signal marker could not catch all the signals that were sent
> to processes due to its location, in specific_send_sig_info(), which is not
> visited by all signal dispaching paths. Most notably, signals arriving through
> sys_kill() could not be traced. Moving the marker in send_signal() ensures
> that all signals are recorded.
> 
> Also rename the marker to kernel_send_signal to match the function name.
> 
> Signed-off-by: Pierre-Marc Fournier <[email protected]>
> ---
>  kernel/signal.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/signal.c b/kernel/signal.c
> index 6130be7..f700cb6 100644
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -664,6 +664,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
>  	struct sigqueue * q = NULL;
>  	int ret = 0;
>  
> +	trace_mark(kernel_send_signal, "pid %d signal %d", t->pid, sig);
> +
>  	/*
>  	 * Deliver the signal to listening signalfds. This must be called
>  	 * with the sighand lock held.
> @@ -770,8 +772,6 @@ specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
>  	if (sig_ignored(t, sig))
>  		goto out;
>  
> -	trace_mark(kernel_process_signal, "pid %d signal %d", t->pid, sig);
> -
>  	/* Support queueing exactly one non-rt signal, so that we
>  	   can get more detailed information about the cause of
>  	   the signal. */
> -- 
> 1.5.3.4
> 

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68