Commit 888468ce authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/32: Disable KASAN with pages bigger than 16k 



Mapping of early shadow area is implemented by using a single static
page table having all entries pointing to the same early shadow page.
The shadow area must therefore occupy full PGD entries.

The shadow area has a size of 128MB starting at 0xf8000000.
With 4k pages, a PGD entry is 4MB
With 16k pages, a PGD entry is 64MB
With 64k pages, a PGD entry is 1GB which is too big.

Until we rework the early shadow mapping, disable KASAN when the page
size is too big.

Fixes: 2edb16ef ("powerpc/32: Add KASAN support")
Cc: stable@vger.kernel.org # v5.2+
Reported-by: default avatarkbuild test robot <lkp@intel.com>
Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7195fcde7314ccbf7a081b356084a69d421b10d4.1590660977.git.christophe.leroy@csgroup.eu
parent c3ba4dbb

arch/powerpc/Kconfig

+2 −2
Original line number Diff line number Diff line
@@ -169,8 +169,8 @@ config PPC 
	select HAVE_ARCH_AUDITSYSCALL

	select HAVE_ARCH_HUGE_VMAP		if PPC_BOOK3S_64 && PPC_RADIX_MMU

	select HAVE_ARCH_JUMP_LABEL

	select HAVE_ARCH_KASAN			if PPC32

	select HAVE_ARCH_KASAN_VMALLOC		if PPC32

	select HAVE_ARCH_KASAN			if PPC32 && PPC_PAGE_SHIFT <= 14

	select HAVE_ARCH_KASAN_VMALLOC		if PPC32 && PPC_PAGE_SHIFT <= 14

	select HAVE_ARCH_KGDB

	select HAVE_ARCH_MMAP_RND_BITS

	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if COMPAT