This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
Hardware tag-based KASAN won't be using shadow memory. Only initialize
it when one of the software KASAN modes are enabled.
No functional changes for software modes.
Signed-off-by: Andrey Konovalov <[email protected]>
Signed-off-by: Vincenzo Frascino <[email protected]>
Reviewed-by: Catalin Marinas <[email protected]>
---
Change-Id: I055e0651369b14d3e54cdaa8c48e6329b2e8952d
---
arch/arm64/include/asm/kasan.h | 8 ++++++--
arch/arm64/mm/kasan_init.c | 15 ++++++++++++++-
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h
index b0dc4abc3589..f7ea70d02cab 100644
--- a/arch/arm64/include/asm/kasan.h
+++ b/arch/arm64/include/asm/kasan.h
@@ -13,6 +13,12 @@
#define arch_kasan_get_tag(addr) __tag_get(addr)
#ifdef CONFIG_KASAN
+void kasan_init(void);
+#else
+static inline void kasan_init(void) { }
+#endif
+
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
/*
* KASAN_SHADOW_START: beginning of the kernel virtual addresses.
@@ -33,12 +39,10 @@
#define _KASAN_SHADOW_START(va) (KASAN_SHADOW_END - (1UL << ((va) - KASAN_SHADOW_SCALE_SHIFT)))
#define KASAN_SHADOW_START _KASAN_SHADOW_START(vabits_actual)
-void kasan_init(void);
void kasan_copy_shadow(pgd_t *pgdir);
asmlinkage void kasan_early_init(void);
#else
-static inline void kasan_init(void) { }
static inline void kasan_copy_shadow(pgd_t *pgdir) { }
#endif
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index b24e43d20667..ffeb80d5aa8d 100644
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -21,6 +21,8 @@
#include <asm/sections.h>
#include <asm/tlbflush.h>
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+
static pgd_t tmp_pg_dir[PTRS_PER_PGD] __initdata __aligned(PGD_SIZE);
/*
@@ -208,7 +210,7 @@ static void __init clear_pgds(unsigned long start,
set_pgd(pgd_offset_k(start), __pgd(0));
}
-void __init kasan_init(void)
+static void __init kasan_init_shadow(void)
{
u64 kimg_shadow_start, kimg_shadow_end;
u64 mod_shadow_start, mod_shadow_end;
@@ -269,6 +271,17 @@ void __init kasan_init(void)
memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE);
cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
+}
+
+#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) */
+
+static inline void __init kasan_init_shadow(void) { }
+
+#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
+
+void __init kasan_init(void)
+{
+ kasan_init_shadow();
/* At this point kasan is fully initialized. Enable error messages */
init_task.kasan_depth = 0;
--
2.29.2.222.g5d2a92d10f8-goog
On Tue, Nov 10, 2020 at 11:11 PM Andrey Konovalov <[email protected]> wrote:
>
> This is a preparatory commit for the upcoming addition of a new hardware
> tag-based (MTE-based) KASAN mode.
>
> Hardware tag-based KASAN won't be using shadow memory. Only initialize
> it when one of the software KASAN modes are enabled.
>
> No functional changes for software modes.
>
> Signed-off-by: Andrey Konovalov <[email protected]>
> Signed-off-by: Vincenzo Frascino <[email protected]>
> Reviewed-by: Catalin Marinas <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
> ---
> Change-Id: I055e0651369b14d3e54cdaa8c48e6329b2e8952d
> ---
> arch/arm64/include/asm/kasan.h | 8 ++++++--
> arch/arm64/mm/kasan_init.c | 15 ++++++++++++++-
> 2 files changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h
> index b0dc4abc3589..f7ea70d02cab 100644
> --- a/arch/arm64/include/asm/kasan.h
> +++ b/arch/arm64/include/asm/kasan.h
> @@ -13,6 +13,12 @@
> #define arch_kasan_get_tag(addr) __tag_get(addr)
>
> #ifdef CONFIG_KASAN
> +void kasan_init(void);
> +#else
> +static inline void kasan_init(void) { }
> +#endif
> +
> +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
>
> /*
> * KASAN_SHADOW_START: beginning of the kernel virtual addresses.
> @@ -33,12 +39,10 @@
> #define _KASAN_SHADOW_START(va) (KASAN_SHADOW_END - (1UL << ((va) - KASAN_SHADOW_SCALE_SHIFT)))
> #define KASAN_SHADOW_START _KASAN_SHADOW_START(vabits_actual)
>
> -void kasan_init(void);
> void kasan_copy_shadow(pgd_t *pgdir);
> asmlinkage void kasan_early_init(void);
>
> #else
> -static inline void kasan_init(void) { }
> static inline void kasan_copy_shadow(pgd_t *pgdir) { }
> #endif
>
> diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
> index b24e43d20667..ffeb80d5aa8d 100644
> --- a/arch/arm64/mm/kasan_init.c
> +++ b/arch/arm64/mm/kasan_init.c
> @@ -21,6 +21,8 @@
> #include <asm/sections.h>
> #include <asm/tlbflush.h>
>
> +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
> +
> static pgd_t tmp_pg_dir[PTRS_PER_PGD] __initdata __aligned(PGD_SIZE);
>
> /*
> @@ -208,7 +210,7 @@ static void __init clear_pgds(unsigned long start,
> set_pgd(pgd_offset_k(start), __pgd(0));
> }
>
> -void __init kasan_init(void)
> +static void __init kasan_init_shadow(void)
> {
> u64 kimg_shadow_start, kimg_shadow_end;
> u64 mod_shadow_start, mod_shadow_end;
> @@ -269,6 +271,17 @@ void __init kasan_init(void)
>
> memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE);
> cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
> +}
> +
> +#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) */
> +
> +static inline void __init kasan_init_shadow(void) { }
> +
> +#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
> +
> +void __init kasan_init(void)
> +{
> + kasan_init_shadow();
>
> /* At this point kasan is fully initialized. Enable error messages */
> init_task.kasan_depth = 0;
> --
> 2.29.2.222.g5d2a92d10f8-goog
>
--
Alexander Potapenko
Software Engineer
Google Germany GmbH
Erika-Mann-Straße, 33
80636 München
Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
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Sitz der Gesellschaft: Hamburg