From: Christophe Leroy <[email protected]>

commit 888468ce725a4cd56d72dc7e5096078f7a9251a0 upstream.

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: 2edb16efc899 ("powerpc/32: Add KASAN support")
Cc: [email protected] # v5.2+
Reported-by: kbuild test robot <[email protected]>
Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: 
https://lore.kernel.org/r/7195fcde7314ccbf7a081b356084a69d421b10d4.1590660977.git.christophe.le...@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 arch/powerpc/Kconfig |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -170,8 +170,8 @@ 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


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