Re: Resolution (Re: [uml-devel] 2.4.22-[67] problems)

[Nuno S. <nun...@vg...>]

Matt Zimmerman wrote:
> On Tue, Jan 06, 2004 at 07:41:39AM +0000, Nuno Silva wrote:
> 
> 
>>Jeff Dike wrote:
>>
>>>md...@de... said:
>>>Is it your opinion that there's no problem in UML itself?  Having a field
>>>in the sigcontext getting magically munged is somewhat worrying.  I'd be 
>>>happier knowing what exactly was happening so I can be sure this wasn't
>>>exposing some subtle UML bug.
>>>
>>
>>I've been doing some tests and I'd say that the problem is something 
>>regarding the NPTL+TLS+__thread features of recent libc6 (2.3.2 and 
>>2.3.3cvs)... But I'm clueless about the fix :-)
> 
> 
> I suspect that the problem lies in this direction, because it's the only
> relevant news that I've heard from glibc in recent months, but I wouldn't
> expect NPTL to relate directly because I'm running on 2.4 (as are several
> others who have seen the problem).
> 
> This is the issue where i386 support was dropped and i486-specific
> instructions used, right?
> 

Yes, AFAIK nptl requires 486 asm.

I just finished testing debian-unstable with glibc with nptl, tls and 
__thread support in chroot and everything works fine except UML :)

I'm recompiling glibc with profiling to get a usable backtrace right now.

With this setup linux gets a SIGSTOP (automagically) and after SIGCONT 
it just segfaults... In a few moments I'll have a backtrace :-)

Regards,
Nuno Silva