Hi all,

After merging the tip tree, today's linux-next build (powerpc
ppc64_defconfig) failed like this:

arch/powerpc/lib/code-patching.c: In function 'text_area_cpu_up_mm':
arch/powerpc/lib/code-patching.c:157:14: error: implicit declaration of function 'copy_init_mm' [-Werror=implicit-function-declaration]
  157 |         mm = copy_init_mm();
      |              ^~~~~~~~~~~~

Caused by commit

  107b6828a7cd ("x86/mm: Use mm_alloc() in poking_init()")

interacting with commit

  55a02e6ea958 ("powerpc/code-patching: Use temporary mm for Radix MMU")

from the powerpc tree.

I partially reverted commit 107b6828a7cd - I left the change to
arch/x86/mm/init.c applied.  Though, I wonder if the powerpc tree should
use mm_alloc() instead of copy_init_mm() as well?  The tip tree commit
says:

    Instead of duplicating init_mm, allocate a fresh mm. The advantage is
    that mm_alloc() has much simpler dependencies. Additionally it makes
    more conceptual sense, init_mm has no (and must not have) user state
    to duplicate.

-- 
Cheers,
Stephen Rothwell