Re: Re: 2.6.28.7 domU: 32-bit emulation seems to be broken

[Jeremy Fitzhardinge <jeremy@goop.org>]

Sven Köhler wrote:
> Jeremy Fitzhardinge schrieb:
>> Jeremy Fitzhardinge wrote:
>>> Sven Köhler wrote:
>>>> Also asking the devel-list for help:
>>>>
>>>> Sven Köhler schrieb:
>>>>> Hi,
>>>>>
>>>>> I cannot execute any 32-bit executables. Same problem with 
>>>>> 2.6.29-rc7.
>>>>>
>>>>> I compiled and linked them statically on another machine where 
>>>>> they work
>>>>> just fine! But inside the xen domU, they just segfault:
>>>>>
>>>>>
>>>>> a.out[32093] general protection ip:f7f7042f sp:ffc6f2d4 error:0
>>>>>
>>>>>
>>>>> Is this a knows problem? CONFIG_IA32_EMULATION is turned on!
>>>
>>> Hm, it works for me.  Can you give more detail about what you're 
>>> trying to run, the kernel .config and the distro?  dmesg output 
>>> would have some clues too. 
>>
>> Oh, and what's the CPU?  AMD?
>
> The host is running Xen version 3.3.0.
> The host CPU is:
>
> # cat /proc/cpuinfo
> processor    : 0
> vendor_id    : AuthenticAMD
> cpu family    : 15
> model        : 47
> model name    : AMD Athlon(tm) 64 Processor 3800+
> stepping    : 2
> cpu MHz        : 2399.822
> cache size    : 512 KB
> fpu        : yes
> fpu_exception    : yes
> cpuid level    : 1
> wp        : yes
> flags        : fpu de tsc msr pae cx8 apic mtrr cmov pat clflush mmx 
> fxsr sse sse2 syscall nx mmxext fxsr_opt lm 3dnowext 3dnow pni lahf_lm
> bogomips    : 4800.70
> TLB size    : 1024 4K pages
> clflush size    : 64
> cache_alignment    : 64
> address sizes    : 40 bits physical, 48 bits virtual
> power management: ts fid vid ttp tm stc
>
> The kernel is vanilla (except for the xen/blkfront: use blk_rq_map_sg 
> to generate ring entries patch). The config of my 2.6.28.7 is attached.
>
> The program I'm trying to run is:
> $ cat test.c
> #include <stdio.h>
>
> int main(void)
> {
>   printf("Hallo Welt!\n");
>   return 0;
> }
>
> I compiled it with "gcc --static test.c" on other box where the 
> program runs fine and copied the output to my domU. I checked with 
> ldd, that it really isn't a dynamic executable.
>
> The dmesg output on the domU is this mysterious:
> a.out[32093] general protection ip:f7f7042f sp:ffc6f2d4 error:0
>
> The line appears each time, that the program segfaults.

Has it ever worked?  If so, what kernel version did it stop working at?  
Does it fail with all 32-bit executables or just your "hello world"?

Can you get a coredump from the fault and see what the faulting 
instruction was?

    J