Re: [PATCH 2/2] x86-64: seccomp: fix 32/64 syscall hole

From: Linus Torvalds
Date: Sat Feb 28 2009 - 12:25:05 EST




On Fri, 27 Feb 2009, Roland McGrath wrote:
>
> I don't know any other arch well enough to be sure that TIF_32BIT isn't the
> wrong test there too. I'd like to leave that worry to the arch maintainers.

Agreed - it may be that others will want to not use TIF_32BIT too. It
really does make much more sense to have it as a thread-local status flag
than as an atomic (and thus expensive to modify) thread-flag, not just on
x86.

But I think other architectures will find it easier to see what's going on
if the code is straightforward and they can just fix their
'is_compat_task()' function. And:

> But here is the patch you asked for.

Yes, this looks much more straightforward.

And I guess the seccomp interaction means that this is potentially a
2.6.29 thing. Not that I know whether anybody actually _uses_ seccomp. It
does seem to be enabled in at least Fedora kernels, but it might not be
used anywhere.

Linus
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