[PATCH] powerpc/mm: Fix CONFIG_PPC_KUAP_DEBUG on PPC32

[Michael Ellerman]

On Fri, 2020-04-17 at 11:58:36 UTC, Christophe Leroy wrote:
> CONFIG_PPC_KUAP_DEBUG is not selectable because it depends on PPC_32
> which doesn't exists.
> 
> Fixing it leads to a deadlock due to a vital register getting
> clobbered in _switch().
> 
> Change dependency to PPC32 and use r0 instead of r4 in _switch()
> 
> Fixes: e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
> Cc: stable at vger.kernel.org
> Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/feb8e960d780e170e992a70491eec9dd68f4dbf2

cheers