glibc 2.15 and libasound

Allin Cottrell cottrell@wfu.edu
Mon Mar 26 02:58:00 GMT 2012


On Sun, 25 Mar 2012, Mike Frysinger wrote:

> On Sunday 25 March 2012 13:45:09 Allin Cottrell wrote:
>> There's a problem that quite a few people have noted with
>> recent glibc and libasound (specifically the use of libdl by
>> the latter). I was hoping this might have gone away with glibc
>> 2.15 but it's still there. Maybe it's not a glibc bug, though
>> it looks rather like it. The symptom is that (e.g.) alsa's
>> "aplay" utility reliably segfaults when called to play a wav
>> file.
>>
>> I have inserted debugging statements in libasound (version
>> 1.0.25, dlmisc.c), to announce all its uses of the libdl
>> functions, and run aplay under valgrind (where it doesn't
>> actually segfault). I'm attaching the results. It looks as if
>> there's something wrong with glibc's do_lookup_x(): it's
>> reading from freed memory in response to dlsym() following a
>> successful invocation of dlopen() by libasound.
>
> please try some of the patches for known issues.  you can find some:
> 	http://sources.gentoo.org/gentoo/src/patchsets/glibc/2.15/
>
> i think you want the 0050 one.

Thanks, will do. However, I think this has been a "known issue" 
since before glibc 2.14.1 (which, BTW, seemed to sink without much 
trace), so the fact that that it's still present in the 2.15 release
seems strange.

I mean, it seems that on downloading a brand-new glibc release one 
shouldn't have to start searching for patchsets from third parties. 
Or trying to judge whether the proferred third-party patches will 
help or create a worse situation.

Is it the case that "fixes" for the problem I mentioned are 
sufficiently controversial that there's been no authoritative 
resolution in the last 10 months or so?

Allin Cottrell




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