diff mbox series

[v2,4/6] kasan: Add __HAVE_ARCH_SHADOW_MAP to support arch specific mapping

Message ID 20230404084308.813-1-zhangqing@loongson.cn
State New
Headers
Series LoongArch: Add kernel address sanitizer support |

Commit Message

Qing Zhang April 4, 2023, 8:43 a.m. UTC 
  Like the LoongArch, which has many holes between different segments
and valid address space(256T available) is insufficient to map all
these segments to kasan shadow memory with the common formula provided
by kasan core, We need architecture specific mapping formula,different
segments are mapped individually, and only limited length of space of
that specific segment is mapped to shadow.

Therefore, when the incoming address is converted to a shadow, we need
to add a condition to determine whether it is valid.

Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
---
 include/linux/kasan.h | 2 ++
 mm/kasan/kasan.h      | 6 ++++++
 2 files changed, 8 insertions(+)

Comments

Andrey Konovalov April 4, 2023, 10:09 p.m. UTC | #1 
On Tue, Apr 4, 2023 at 10:43 AM Qing Zhang <zhangqing@loongson.cn> wrote:
>
> Like the LoongArch, which has many holes between different segments
> and valid address space(256T available) is insufficient to map all
> these segments to kasan shadow memory with the common formula provided
> by kasan core, We need architecture specific mapping formula,different
> segments are mapped individually, and only limited length of space of
> that specific segment is mapped to shadow.
>
> Therefore, when the incoming address is converted to a shadow, we need
> to add a condition to determine whether it is valid.
>
> Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
> ---
>  include/linux/kasan.h | 2 ++
>  mm/kasan/kasan.h      | 6 ++++++
>  2 files changed, 8 insertions(+)
>
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index f7ef70661ce2..3b91b941873d 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -54,11 +54,13 @@ extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
>  int kasan_populate_early_shadow(const void *shadow_start,
>                                 const void *shadow_end);
>
> +#ifndef __HAVE_ARCH_SHADOW_MAP
>  static inline void *kasan_mem_to_shadow(const void *addr)
>  {
>         return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)
>                 + KASAN_SHADOW_OFFSET;
>  }
> +#endif
>
>  int kasan_add_zero_shadow(void *start, unsigned long size);
>  void kasan_remove_zero_shadow(void *start, unsigned long size);
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index a61eeee3095a..033335c13b25 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -291,16 +291,22 @@ struct kasan_stack_ring {
>
>  #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
>
> +#ifndef __HAVE_ARCH_SHADOW_MAP
>  static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
>  {
>         return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
>                 << KASAN_SHADOW_SCALE_SHIFT);
>  }
> +#endif
>
>  static __always_inline bool addr_has_metadata(const void *addr)
>  {
> +#ifdef __HAVE_ARCH_SHADOW_MAP
> +       return (kasan_mem_to_shadow((void *)addr) != NULL);
> +#else
>         return (kasan_reset_tag(addr) >=
>                 kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
> +#endif
>  }
>
>  /**
> --
> 2.20.1
>

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>

Thanks!
diff mbox series

Patch

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index f7ef70661ce2..3b91b941873d 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -54,11 +54,13 @@  extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
 int kasan_populate_early_shadow(const void *shadow_start,
 				const void *shadow_end);
 
+#ifndef __HAVE_ARCH_SHADOW_MAP
 static inline void *kasan_mem_to_shadow(const void *addr)
 {
 	return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)
 		+ KASAN_SHADOW_OFFSET;
 }
+#endif
 
 int kasan_add_zero_shadow(void *start, unsigned long size);
 void kasan_remove_zero_shadow(void *start, unsigned long size);
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index a61eeee3095a..033335c13b25 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -291,16 +291,22 @@  struct kasan_stack_ring {
 
 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 
+#ifndef __HAVE_ARCH_SHADOW_MAP
 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
 {
 	return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
 		<< KASAN_SHADOW_SCALE_SHIFT);
 }
+#endif
 
 static __always_inline bool addr_has_metadata(const void *addr)
 {
+#ifdef __HAVE_ARCH_SHADOW_MAP
+	return (kasan_mem_to_shadow((void *)addr) != NULL);
+#else
 	return (kasan_reset_tag(addr) >=
 		kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
+#endif
 }
 
 /**