Re: Duplicate registration of tracepoint probes

Re: Duplicate registration of tracepoint probes

[Adam Crume]

I figured it out.  The duplicate __tracepoint__init_urcu_sym symbols
apparently aren't an issue.  The problem is that I had tracepoints in
a static library that was then linked into the main executable as well
as a dynamic library loaded by the executable.  (It wasn't obvious
because the relevant symbols in the dynamic library were not
exported.)  Anyway, mixing static and dynamic linking is a bad idea.
:)

Adam

On Wed, Jul 23, 2014 at 5:06 PM, Adam Crume <adamcrume@gmail.com> wrote:
> I have an application which compiles and links fine, but at runtime it fails
> with:
>
> LTTng-UST: Error (-17) while registering tracepoint probe. Duplicate
> registration of tracepoint probes having the same name is not allowed.
> Aborted (core dumped)
>
> What's the best way to debug this?  I've seen this before when a library
> gets linked in multiple times, but that doesn't seem to be the case this
> time (as far as I can tell).  I ran nm on the app, and all of the probes
> (__event_probe__*) are unique.  I do see duplicates for
> __tracepoint__init_urcu_sym, type 't'.  I also see duplicates for
> __tracepoint_ptrs_registered, __tracepoint_registered, and
> tracepoint_dlopen, all of type 'V'.
>
> I have multiple *.tp files, which each get compiled and linked into their
> own library, and I'm using -DTRACEPOINT_PROBE_DYNAMIC_LINKAGE.
>
> Can anyone tell me what's wrong, or how to fix it?
>
> Thanks,
> Adam

Duplicate registration of tracepoint probes

[Adam Crume]

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I have an application which compiles and links fine, but at runtime it
fails with:

LTTng-UST: Error (-17) while registering tracepoint probe. Duplicate
registration of tracepoint probes having the same name is not allowed.
Aborted (core dumped)

What's the best way to debug this?  I've seen this before when a library
gets linked in multiple times, but that doesn't seem to be the case this
time (as far as I can tell).  I ran nm on the app, and all of the probes
(__event_probe__*) are unique.  I do see duplicates for
__tracepoint__init_urcu_sym, type 't'.  I also see duplicates for
__tracepoint_ptrs_registered, __tracepoint_registered, and
tracepoint_dlopen, all of type 'V'.

I have multiple *.tp files, which each get compiled and linked into their
own library, and I'm using -DTRACEPOINT_PROBE_DYNAMIC_LINKAGE.

Can anyone tell me what's wrong, or how to fix it?

Thanks,
Adam

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