Re: Compat 32-bit syscall entry from 64-bit task!?

[H. Peter Anvin]

On 01/18/2012 01:26 PM, Linus Torvalds wrote:
> On Wed, Jan 18, 2012 at 1:04 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
>>
>> Fair enough.  Sigh.  I still think an actual pseudo-register would be
>> better.
> 
> .. and that breaks existing binaries too, because the indexing is
> based on offsets into "struct pt_regs", and while we *could* change
> that - leave pt_regs untouched but add a new virtual register - it
> would be problematic.
> 
> We could add a whole new ptrace() access command (eg
> PTRACE_GETSYSTEMREGSET), of course. But that's a lot of effort for
> very little gain.
> 
> So on the whole, putting it in eflags seemed like the *much* simpler approach.
> 

I would have assumed it would be a new register set (which could be
expanded in the future if we have additional system information to provide.)

	-hpa

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