powerpc/kasan: Fix KASAN_SHADOW_START on BOOK3S_32

On BOOK3S_32, when we have modules and strict kernel RWX, modules
are not in vmalloc space but in a dedicated segment that is
below PAGE_OFFSET.

So KASAN_SHADOW_START must take it into account.

MODULES_VADDR can't be used because it is not defined yet
in kasan.h

Fixes: 6ca055322d ("powerpc/32s: Use dedicated segment for modules with STRICT_KERNEL_RWX")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6eddca2d5611fd57312a88eae31278c87a8fc99d.1596641224.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2020-08-05 15:27:29 +00:00 committed by Michael Ellerman
parent fdc6edbb31
commit 48d2f0407b
1 changed files with 8 additions and 1 deletions

View File

@ -15,11 +15,18 @@
#ifndef __ASSEMBLY__
#include <asm/page.h>
#include <linux/sizes.h>
#define KASAN_SHADOW_SCALE_SHIFT 3
#if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_MODULES) && defined(CONFIG_STRICT_KERNEL_RWX)
#define KASAN_KERN_START ALIGN_DOWN(PAGE_OFFSET - SZ_256M, SZ_256M)
#else
#define KASAN_KERN_START PAGE_OFFSET
#endif
#define KASAN_SHADOW_START (KASAN_SHADOW_OFFSET + \
(PAGE_OFFSET >> KASAN_SHADOW_SCALE_SHIFT))
(KASAN_KERN_START >> KASAN_SHADOW_SCALE_SHIFT))
#define KASAN_SHADOW_OFFSET ASM_CONST(CONFIG_KASAN_SHADOW_OFFSET)