Warning from ORe stub driver

Adam Lackorzynski adam at os.inf.tu-dresden.de
Sun May 3 23:30:25 CEST 2009


On Mon Apr 27, 2009 at 18:08:33 +0400, Alexey Zaytsev wrote:
> Alexander Valitov wrote:
>> Hi,
>>> I found the source of problem. It is GCC bug.
>>> The bug is DSE (dead storage elimination) related.
>>> The issue is valid for GCC 4.3.x, 4.4.x, 4.5.x.
>>> In 4.2.x and earlier problem does not exist.     
>> I was wrong. It's not GCC bug. "GCC guys" told that problem is in l4sys
>> package.
>> Please see file:
>> /l4/pkg/l4sys/include/ARCH-x86/L4API-l4v2/ipc-l42-gcc3-nopic.h
>> here l4_ipc_send_tag() misses "memory" constraint in clobber list.
>> It definitely must have one.
>> Please fix it.
>> At the same time following file contains correct l4_ipc_send_tag()
>> implementation:
>> /l4/pkg/l4sys/include/ARCH-x86/L4API-l4v2/ipc-l42-gcc3-nopic.h
>> So i guess the bug is just oversight. Anyway I think it's wise to look
>> through l4sys for similar errors.

Thanks for the fix!

>> Best Regards,
>>   Alexander Valitov
> And, by the way, we even got a patch with this and a few other
> missing asm hints added. It mostly covers ia32 code, and not
> all packages, but these are the cases I was able to locate quickly,
> and this potentially might save someone some gray hair.

Thanks, I'll work through the list.

Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/

More information about the l4-hackers mailing list