From: Christophe Leroy christophe.leroy@csgroup.eu
commit 3a66a24f6060e6775f8c02ac52329ea0152d7e58 upstream.
At the time being, KASAN_SHADOW_END is 0x100000000, which is 0 in 32 bits representation.
This leads to a couple of issues: - kasan_remap_early_shadow_ro() does nothing because the comparison k_cur < k_end is always false. - In ptdump, address comparison for markers display fails and the marker's name is printed at the start of the KASAN area instead of being printed at the end.
However, there is no need to shadow the KASAN shadow area itself, so the KASAN shadow area can stop shadowing memory at the start of itself.
With a PAGE_OFFSET set to 0xc0000000, KASAN shadow area is then going from 0xf8000000 to 0xff000000.
Fixes: cbd18991e24f ("powerpc/mm: Fix an Oops in kasan_mmu_init()") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/ae1a3c0d19a37410c209c3fc453634cfcc0ee318.158986698... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/include/asm/kasan.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
--- a/arch/powerpc/include/asm/kasan.h +++ b/arch/powerpc/include/asm/kasan.h @@ -23,9 +23,7 @@
#define KASAN_SHADOW_OFFSET ASM_CONST(CONFIG_KASAN_SHADOW_OFFSET)
-#define KASAN_SHADOW_END 0UL - -#define KASAN_SHADOW_SIZE (KASAN_SHADOW_END - KASAN_SHADOW_START) +#define KASAN_SHADOW_END (-(-KASAN_SHADOW_START >> KASAN_SHADOW_SCALE_SHIFT))
#ifdef CONFIG_KASAN void kasan_early_init(void);