[OpenAFS-devel] LWP and clang

[Benjamin Kaduk]

On Wed, 16 Oct 2013, Marc Dionne wrote:

> On Wed, Oct 16, 2013 at 1:26 PM, Benjamin Kaduk <kaduk@mit.edu> wrote:
>> Hi all,
>>
>> I've been seeing lots of runtime crashes when running clang-compiled
>> LWP-using binaries, for several months now at least.  My experiences have
>
> Anything interesting about where the crashes occur - in the lwp
> functions themselves (savecontext, etc.) ?  and does it crash every
> time it is switching lwps or are these sporadic?

I only remember crashes that reliably occur at program startup, perhaps 
even before switching LWPs.

Hmm, the example I have handy (aklog.core from ~tip-of-1.6.x) shows the 
faulting line of source as:
rx_lwp.c:174:
174	char name[MAXTHREADNAMELENGTH] = "srv_0";
which disassembles to 'movaps'.
I wonder if I just need to disable mmx/sse/etc....

-Ben

> One thing that might be worth trying is to see if switching to
> setcontext/getcontext helps (see platforms that define USE_UCONTEXT),
> if available, since it avoids the ugly manipulation of stack pointers
> where maybe clang is doing something different..