[ltt-dev] [UST PATCH] Fix missing data pointer

[Mathieu Desnoyers]

* David Goulet (david.goulet at polymtl.ca) wrote:
> This applies to tracepoint using a marker (trace_mark_tp)
> 
> At commit 9dec086e052cf7f583a3afaa3aab48a6de8d38ac,
> the tracepoint_probe_register/unregister_noupdate function has been
> changed with the addition of a void data pointer. In set_marker(),
> the call to that function was not updated with this new parameter.
> The effect was that on a second register_trace with an already
> registered probe, the data ptr was corrupted with false data and
> thus the probe checking failed to validate duplicates. So, the same
> data was reproduced for a single trace call. Same behavior for
> unregistering the marker, it was not found.
> 
> NOTE : For now, this pointer is NULL because we don't have at this
> point tracing session.
> 
> Signed-off-by: David Goulet <david.goulet at polymtl.ca>

Acked-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>

> ---
>  libust/marker.c |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/libust/marker.c b/libust/marker.c
> index 0c85cc3..cb8ffc1 100644
> --- a/libust/marker.c
> +++ b/libust/marker.c
> @@ -594,11 +594,11 @@ static int set_marker(struct marker_entry *entry, struct marker *elem,
>  //ust//			BUG_ON(!ret);
>  			ret = tracepoint_probe_register_noupdate(
>  				elem->tp_name,
> -				elem->tp_cb);
> +				elem->tp_cb, NULL);
>  		} else {
>  			ret = tracepoint_probe_unregister_noupdate(
>  				elem->tp_name,
> -				elem->tp_cb);
> +				elem->tp_cb, NULL);
>  			/*
>  			 * tracepoint_probe_update_all() must be called
>  			 * before the module containing tp_cb is unloaded.
> @@ -630,7 +630,7 @@ static void disable_marker(struct marker *elem)
>  		 * checking has been done in the __trace_mark_tp() macro.
>  		 */
>  		ret = tracepoint_probe_unregister_noupdate(elem->tp_name,
> -			elem->tp_cb);
> +			elem->tp_cb, NULL);
>  		WARN_ON(ret);
>  		/*
>  		 * tracepoint_probe_update_all() must be called
> -- 
> 1.7.3
> 
> 
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> ltt-dev at lists.casi.polymtl.ca
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> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com