Re: [patch 2.6.13-rc4] fix get_user_pages bug

Russell King
2005-08-04T16:33:22Z

On Thu, Aug 04, 2005 at 04:35:06PM +0100, Hugh Dickins wrote:
> And it does miss arm, the only arch which actually needs changing
> right now, if we simply restore the original values which Nick shifted
> - although arm references the VM_FAULT_ codes in some places, it also
> uses "> 0". arm26 looks at first as if it needs changing too, but
> a closer look shows it's remapping the faults and is okay - agreed?

Your patch doesn't look right. Firstly, I'd rather stay away from
switch() if at all possible - past experience has shown that it
generates inherently poor code on ARM. Whether that's still true
or not I've no idea, but I don't particularly want to find out at
the moment.

> Restore VM_FAULT_SIGBUS, VM_FAULT_MINOR and VM_FAULT_MAJOR to their
> original values, so that arches which have them hardcoded will still
> work before they're cleaned up. And correct arm to use the VM_FAULT_
> codes throughout, not assuming MINOR and MAJOR are the only ones > 0.

And the above rules this out.

As I say, I fixed ARM this morning, so changing these constants will
break it again. Let's just wait for things to stabilise instead of
trying to race with architecture maintainers...

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core