kho: mm: don't allow deferred struct page with KHO

KHO uses struct pages for the preserved memory early in boot, however,
with deferred struct page initialization, only a small portion of memory
has properly initialized struct pages.

This problem was detected where vmemmap is poisoned, and illegal flag
combinations are detected.

Don't allow them to be enabled together, and later we will have to teach
KHO to work properly with deferred struct page init kernel feature.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 4e1d010 ("kexec: add config option for KHO")
Signed-off-by: Pasha Tatashin <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Acked-by: Pratyush Yadav <[email protected]>
Cc: Alexander Graf <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Changyuan Lyu <[email protected]>
Cc: Coiby Xu <[email protected]>
Cc: Dave Vasilevsky <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: soleen

kernel/Kconfig.kexec

@@ -97,6 +97,7 @@ config KEXEC_JUMP
 config KEXEC_HANDOVER
 	bool "kexec handover"
 	depends on ARCH_SUPPORTS_KEXEC_HANDOVER && ARCH_SUPPORTS_KEXEC_FILE
+	depends on !DEFERRED_STRUCT_PAGE_INIT
 	select MEMBLOCK_KHO_SCRATCH
 	select KEXEC_FILE
 	select DEBUG_FS