Re: RFC: is_compat_task

[Arnd Bergmann <arnd@arndb.de>]

On Middeweken 29 Juni 2005 08:41, Stephen Rothwell wrote:
> How about the patch below which defines is_compat_syscall() for ppc64 (and
> all the non-compat-requiring archs)?  (Yes, the ppc64 syscall entry really
> checks the thread flag.) The patch alos includes the fixes for the input
> layer mess.

Looks ok to me (as in better than all the previous alternatives), though I've
been wondering what is_compat_task() should return outside of syscall context,
e.g. in the exception path or in softirq. I guess the safe choice here would
be to BUG(), but maybe it's just not important.

> If this is acceptable, I will try to figure out what the macro should be
> for the other 64 bit architectures.

Martin Schwidefsky is on holidays this week, so he won't be able to comment
on the s390 part. Testing TIF_31BIT should be the right thing to do there,
for a reason similar to what you wrote about ppc64. The s390 entry code checks
the addressing mode of the user task, which is always set together with the
TIF bit.

	Arnd <><