Re: [PATCH 1/2] perf probe: Improve error message when function notfound

From: Masami Hiramatsu
Date: Mon Dec 02 2013 - 00:59:46 EST


(2013/12/02 9:07), David Ahern wrote:
> When requesting a function from a userspace library the error message to
> the user is less than helpful. e.g.,
>
> perf probe -x /lib64/libpthread-2.14.90.so -a 'lock_full=__pthread_mutex_lock_full'
> no symbols found in /lib64/libpthread-2.14.90.so, maybe install a debug package?
> Failed to load map.
> Error: Failed to add events. (-22)
>
> In this cae the symbol really does exist but is a local symbol which is
> filtered:
>
> nm /lib64/libpthread-2.14.90.so | grep __pthread_mutex_lock_full
> 0000000000005700 t __pthread_mutex_lock_full
>
> With this patch:
> perf probe -x /lib64/libpthread-2.14.90.so -a 'lock_full=__pthread_mutex_lock_full'
>
> no symbols found in /lib64/libpthread-2.14.90.so, maybe install a debug package?
> Failed to find function in /lib64/libpthread-2.14.90.so. Perhaps it is a local variable?

Hmm, indeed current message is too less information, but your message looks
wired. I think just showing "Failed to find requested symbol in %s" is enough. :)

Thank you,

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


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