UPSTREAM: arm64: kasan: don't populate vmalloc area for CONFIG_KASAN_VMALLOC
Linux support KAsan for VMALLOC since commit 3c5c3cfb9ef4da9
("kasan: support backing vmalloc space with real shadow memory")
Like how the MODULES_VADDR does now, just not to early populate
the VMALLOC_START between VMALLOC_END.
Before:
MODULE_VADDR: no mapping, no zero shadow at init
VMALLOC_VADDR: backed with zero shadow at init
After:
MODULE_VADDR: no mapping, no zero shadow at init
VMALLOC_VADDR: no mapping, no zero shadow at init
Thus the mapping will get allocated on demand by the core function
of KASAN_VMALLOC.
----------- vmalloc_shadow_start
| |
| |
| | <= non-mapping
| |
| |
|-----------|
|///////////|<- kimage shadow with page table mapping.
|-----------|
| |
| | <= non-mapping
| |
------------- vmalloc_shadow_end
|00000000000|
|00000000000| <= Zero shadow
|00000000000|
------------- KASAN_SHADOW_END
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210324040522.15548-2-lecopzer.chen@mediatek.com
[catalin.marinas@arm.com: add a build check on VMALLOC_START != MODULES_END]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 201711661
(cherry picked from commit 9a0732efa77418fc85b1bdc5ddee619e62f59545)
Signed-off-by: Yee Lee <yee.lee@mediatek.com>
Change-Id: I82c4b624685cc9e083d720904787df2326cb9cc0
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index d8e66c7..7598b0a 100644
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -214,6 +214,7 @@ static void __init kasan_init_shadow(void)
{
u64 kimg_shadow_start, kimg_shadow_end;
u64 mod_shadow_start, mod_shadow_end;
+ u64 vmalloc_shadow_end;
phys_addr_t pa_start, pa_end;
u64 i;
@@ -223,6 +224,8 @@ static void __init kasan_init_shadow(void)
mod_shadow_start = (u64)kasan_mem_to_shadow((void *)MODULES_VADDR);
mod_shadow_end = (u64)kasan_mem_to_shadow((void *)MODULES_END);
+ vmalloc_shadow_end = (u64)kasan_mem_to_shadow((void *)VMALLOC_END);
+
/*
* We are going to perform proper setup of shadow memory.
* At first we should unmap early shadow (clear_pgds() call below).
@@ -241,12 +244,18 @@ static void __init kasan_init_shadow(void)
kasan_populate_early_shadow(kasan_mem_to_shadow((void *)PAGE_END),
(void *)mod_shadow_start);
- kasan_populate_early_shadow((void *)kimg_shadow_end,
- (void *)KASAN_SHADOW_END);
- if (kimg_shadow_start > mod_shadow_end)
- kasan_populate_early_shadow((void *)mod_shadow_end,
- (void *)kimg_shadow_start);
+ if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
+ BUILD_BUG_ON(VMALLOC_START != MODULES_END);
+ kasan_populate_early_shadow((void *)vmalloc_shadow_end,
+ (void *)KASAN_SHADOW_END);
+ } else {
+ kasan_populate_early_shadow((void *)kimg_shadow_end,
+ (void *)KASAN_SHADOW_END);
+ if (kimg_shadow_start > mod_shadow_end)
+ kasan_populate_early_shadow((void *)mod_shadow_end,
+ (void *)kimg_shadow_start);
+ }
for_each_mem_range(i, &pa_start, &pa_end) {
void *start = (void *)__phys_to_virt(pa_start);