FROMLIST: kfence: skip all GFP_ZONEMASK allocations

Allocation requests outside ZONE_NORMAL (MOVABLE, HIGHMEM or DMA) cannot
be fulfilled by KFENCE, because KFENCE memory pool is located in a
zone different from the requested one.

Because callers of kmem_cache_alloc() may actually rely on the
allocation to reside in the requested zone (e.g. memory allocations done
with __GFP_DMA must be DMAable), skip all allocations done with
GFP_ZONEMASK and/or respective SLAB flags (SLAB_CACHE_DMA and
SLAB_CACHE_DMA32).

Fixes: 0ce20dd8 ("mm: add Kernel Electric-Fence infrastructure")
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: stable@vger.kernel.org # 5.12+
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Souptick Joarder <jrdr.linux@gmail.com>

Bug: 192294212
Bug: 193906385

Test: ran KFENCE test suite with __GFP_DMA on QEMU
Link: https://lore.kernel.org/linux-mm/20210714092222.1890268-2-glider@google.com/


Change-Id: I72d2e24185e213d0ce60155d5a78f29bca8c88cc
Signed-off-by: Alexander Potapenko <glider@google.com>