diff mbox series

[v9,15/44] kasan, arm64: only init shadow for software modes

Message ID 3aae3b3f931618b4418af7992bff1e258e4eb1ad.1605046192.git.andreyknvl@google.com (mailing list archive)
State New, archived
Headers show
Series kasan: add hardware tag-based mode for arm64 | expand

Commit Message

Andrey Konovalov Nov. 10, 2020, 10:10 p.m. UTC 
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 <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
---
Change-Id: I055e0651369b14d3e54cdaa8c48e6329b2e8952d
---
 arch/arm64/include/asm/kasan.h |  8 ++++++--
 arch/arm64/mm/kasan_init.c     | 15 ++++++++++++++-
 2 files changed, 20 insertions(+), 3 deletions(-)

Comments

Alexander Potapenko Nov. 11, 2020, 2:30 p.m. UTC | #1 
On Tue, Nov 10, 2020 at 11:11 PM Andrey Konovalov <andreyknvl@google.com> 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 <andreyknvl@google.com>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
> ---
> 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
>
diff mbox series

Patch

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;