Commit 48d2f040 authored Aug 05, 2020 by Christophe Leroy Committed by Michael Ellerman Aug 18, 2020

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: 6ca05532 ("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

parent fdc6edbb

arch/powerpc/include/asm/kasan.h

+8 −1

Original line number	Diff line number	Diff line
		@@ -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)

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