[PATCH] Fix dwarf2 unwinding through futex functions v2

Carlos O'Donell carlos@redhat.com
Thu Mar 6 16:29:00 GMT 2014


On 03/04/2014 07:28 PM, Andi Kleen wrote:
> Andi Kleen <andi@firstfloor.org> writes:
> 
>> From: Andi Kleen <ak@linux.intel.com>
>>
>> When profiling programs with lock problems with perf record -g dwarf, libunwind
>> can currently not backtrace through the futex and unlock functions in pthread.
>> This is because they use out of line sections, and those are not correctly
>> described in dwarf2 (I believe needs dwarf3 or 4).
> 
> What happened to this patch? I had assumed it was committed, but it's 
> not in current master and the profiling problem is still there.

My last comment was November 11th 2013:
https://sourceware.org/ml/libc-alpha/2013-11/msg00194.html
~~~
I'm OK with this patch as long as you've tried to at least debug a
program built with these new libpthread code and you can unwind through
them. That is to say build some application with the newly built glibc
e.g. -Wl,--dynamic-linker=xxx -Wl,-rpath=xxx:xxx, and you can break on
some instruction deep in the lock sequence and backtrace correctly.
~~~

If you did this verification then I'm happy with you checking it in.

Andreas said he had no opinion.

Cheers,
Carlos.



More information about the Libc-alpha mailing list