Re: problems with perf probe and system libraries

From: Masami Hiramatsu
Date: Tue Dec 30 2014 - 17:18:57 EST


Hi David,

(2014/12/30 13:21), David Ahern wrote:
> Hi Masami:
>
> I have been looking at perf-probe again and having a number of problems
> with top of tree.
>
> Here's the first one I have isolated:
>
> $ perf probe -x /lib64/libc-2.18.so -a 'malloc size=%di'
> Probe point 'malloc' not found.
> Error: Failed to add events.

It seems to fail when failed to open debuginfo.
I confirmed it on ubuntu 14.04 too.
I'll try to fix that.

Thank you for reporting!

>
> $ perf probe -x /lib64/libc-2.18.so -F | grep malloc
> malloc
> malloc@plt
> malloc_atfork
> malloc_check
> malloc_consolidate
> malloc_hook_ini
> malloc_info
> malloc_printerr
> mallochook
> ptmalloc_init
> ptmalloc_init.part.8
> ptmalloc_lock_all
> ptmalloc_unlock_all
> ptmalloc_unlock_all2
> tr_mallochook
>
> $ perf probe -x /lib64/libc-2.18.so -a 'malloc=malloc size=%di'
> Probe point 'malloc' not found.
> Error: Failed to add events.
>
> A year ago (v3.12) this worked fine so I did a git bisect which points to:
>
> commit fb7345bbf7fad9bf72ef63a19c707970b9685812
> Author: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Date: Thu Dec 26 05:41:53 2013 +0000
>
> perf probe: Support basic dwarf-based operations on uprobe events
>
> I have tried top of tree on Fedora 16, 18 and 20 with a variety of
> kernels - and a variety of results. Reverting to
> 8a613d40e389b723fd5889ac8d4033ed4030be31 which is the commit before this
> one and it works again.
>
> David
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>


--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/