[PATCH AUTOSEL 5.19 54/64] ARM: 9202/1: kasan: support CONFIG_KASAN_VMALLOC

Sasha Levin
2022-08-14T15:33:27Z

From: Lecopzer Chen <lecopzer.chen@mediatek.com>

[ Upstream commit 565cbaad83d83e288927b96565211109bc984007 ]

Simply make shadow of vmalloc area mapped on demand.

Since the virtual address of vmalloc for Arm is also between
MODULE_VADDR and 0x100000000 (ZONE_HIGHMEM), which means the shadow
address has already included between KASAN_SHADOW_START and
KASAN_SHADOW_END.
Thus we need to change nothing for memory map of Arm.

This can fix ARM_MODULE_PLTS with KASan, support KASan for higmem
and support CONFIG_VMAP_STACK with KASan.

Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm/Kconfig | 1 +
arch/arm/mm/kasan_init.c | 6 +++++-
2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 7630ba9cb6cc..545d2d4a492b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -75,6 +75,7 @@ config ARM
select HAVE_ARCH_KFENCE if MMU && !XIP_KERNEL
select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
+ select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
select HAVE_ARCH_MMAP_RND_BITS if MMU
select HAVE_ARCH_PFN_VALID
select HAVE_ARCH_SECCOMP
diff --git a/arch/arm/mm/kasan_init.c b/arch/arm/mm/kasan_init.c
index 5ad0d6c56d56..29caee9c79ce 100644
--- a/arch/arm/mm/kasan_init.c
+++ b/arch/arm/mm/kasan_init.c
@@ -236,7 +236,11 @@ void __init kasan_init(void)

clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);

- kasan_populate_early_shadow(kasan_mem_to_shadow((void *)VMALLOC_START),
+ if (!IS_ENABLED(CONFIG_KASAN_VMALLOC))
+ kasan_populate_early_shadow(kasan_mem_to_shadow((void *)VMALLOC_START),
+ kasan_mem_to_shadow((void *)VMALLOC_END));
+
+ kasan_populate_early_shadow(kasan_mem_to_shadow((void *)VMALLOC_END),
kasan_mem_to_shadow((void *)-1UL) + 1);

for_each_mem_range(i, &pa_start, &pa_end) {
--
2.35.1