Re: [PATCH 1/1] fill vdso with syscall32_setup_pages if TIF_IA32 on x86_64

[Oren Laadan <orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>]

[snip]

>> original	original	restart		target
>> program		kernel		program		kernel
>> --------	---------	--------	--------
>> 64 bit		64 bit		64 bit		64 bit	  [0] works
>>
>> 32 bit		32 bit		32 bit		32 bit	  [0] works
>> 32 bit		64 bit		32 bit		64 bit	  [0] works
>>
>> 32 bit		32 bit		32 bit		64 bit	  [1]
>> 32 bit		64 bit		32 bit		32 bit	  [1]
>>
>> 32 bit		any		64 bit		64 bit	  [2]
>> 64 bit		64 bit		32 bit		64 bit	  [2]
>>
>> [0] The first 3 cases are "homogeneous", with conditions equal at
>> checkpoint and restart. AFAIK, they work.
>>
>> [1] The next two cases consider 32 bit program, and vary only the
>> environment - the kernel may change from 32 to 64 or back. We want
>> them to work.
>>
>> IIUC, your comment above means that they don't work because the
>> CKPT_ARCH_ID is a mismatch. The fix should be trivial - either
>> make 'restart' modify it, or make the kernel tolerate it.
>>
>> [2] The last two cases consider the case when the restart program
>> itself has different bit-ness than the checkpointed program (and
>> transition may occur in either direction). While lower priority,
>> we would like this to work, too.
> 
> Great table. Is it posted in the ckpt wiki too?
> 

I updated the wiki:
     http://ckpt.wiki.kernel.org/index.php/Architecture

For powerpc I just assumed it's like x86 ... :)
Can you please approve or modify for archs other than x86-{32,64} ?

Thanks,

Oren.