Am 28.01.2010 um 18:10 schrieb Linus Torvalds:

>
>
> On Thu, 28 Jan 2010, Mathias Krause wrote:
>>
>> 1. Enable core dumps
>> 2. Start an 32 bit program that tries to execve() an 64 bit program
>> 3. The 64 bit program cannot be started by the kernel because it  
>> can't find
>> the interpreter, i.e. execve returns with an error
>> 4. Generate a segmentation fault
>> 5. panic
>
> Hmm. Nothing happens for me when I try this. I just get the expected
> SIGSEGV. Can you post the oops/panic message?
>

I currently have no access to the actual machine but will send it to  
you tomorrow.

> I don't get a core-dump, even though it says I do:
>
> 	[torvalds@nehalem amd64_killer]$ ./run.sh
> 	* look at /proc/22768/maps and press enter to continue...
> 	* executing ./poison...
> 	* that failed (No such file or directory), as expected :)
> 	* look at /proc/22768/maps and press enter to continue...

Have you looked at /proc/PID/maps at this point? On our machine the  
[vdso] was gone and [vsyscall] was there instead -- at an 64 bit  
address of course.

> 	* fasten your seat belt, generating segmentation fault...
> 	./run.sh: line 6: 22768 Segmentation fault      (core dumped) ./ 
> amd64_killer ./poison
>
> This is with current -git (I don't have any machines around running  
> older
> kernels), so maybe we fixed it already, of course.

Since this is a production server I would rather stick to a stable  
kernel and just pick the commit that fixes the issue. Can you please  
tell me which one that may be?


Greets,
Mathias