Re: [PATCH v9 06/44] kasan: rename (un)poison_shadow to (un)poison_memory

[Alexander Potapenko <glider@google.com>]

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.
>
> The new mode won't be using shadow memory, but will reuse the same
> functions. Rename kasan_unpoison_shadow to kasan_unpoison_memory,
> and kasan_poison_shadow to kasan_poison_memory.
>
> No functional changes.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>

> ---
> Change-Id: Ia359f32815242c4704e49a5f1639ca2d2f8cba69
> ---
>  include/linux/kasan.h |  6 +++---
>  kernel/fork.c         |  4 ++--
>  mm/kasan/common.c     | 38 +++++++++++++++++++-------------------
>  mm/kasan/generic.c    | 12 ++++++------
>  mm/kasan/kasan.h      |  2 +-
>  mm/kasan/tags.c       |  2 +-
>  mm/slab_common.c      |  2 +-
>  7 files changed, 33 insertions(+), 33 deletions(-)
>
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index 26f2ab92e7ca..f6435b9f889c 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -71,7 +71,7 @@ extern void kasan_enable_current(void);
>  /* Disable reporting bugs for current task */
>  extern void kasan_disable_current(void);
>
> -void kasan_unpoison_shadow(const void *address, size_t size);
> +void kasan_unpoison_memory(const void *address, size_t size);
>
>  void kasan_unpoison_task_stack(struct task_struct *task);
>
> @@ -108,7 +108,7 @@ struct kasan_cache {
>  size_t __ksize(const void *);
>  static inline void kasan_unpoison_slab(const void *ptr)
>  {
> -       kasan_unpoison_shadow(ptr, __ksize(ptr));
> +       kasan_unpoison_memory(ptr, __ksize(ptr));
>  }
>  size_t kasan_metadata_size(struct kmem_cache *cache);
>
> @@ -117,7 +117,7 @@ void kasan_restore_multi_shot(bool enabled);
>
>  #else /* CONFIG_KASAN */
>
> -static inline void kasan_unpoison_shadow(const void *address, size_t size) {}
> +static inline void kasan_unpoison_memory(const void *address, size_t size) {}
>
>  static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
>
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 6d266388d380..1c905e4290ab 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -225,8 +225,8 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node)
>                 if (!s)
>                         continue;
>
> -               /* Clear the KASAN shadow of the stack. */
> -               kasan_unpoison_shadow(s->addr, THREAD_SIZE);
> +               /* Mark stack accessible for KASAN. */
> +               kasan_unpoison_memory(s->addr, THREAD_SIZE);
>
>                 /* Clear stale pointers from reused stack. */
>                 memset(s->addr, 0, THREAD_SIZE);
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 89e5ef9417a7..a4b73fa0dd7e 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -108,7 +108,7 @@ void *memcpy(void *dest, const void *src, size_t len)
>   * Poisons the shadow memory for 'size' bytes starting from 'addr'.
>   * Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE.
>   */
> -void kasan_poison_shadow(const void *address, size_t size, u8 value)
> +void kasan_poison_memory(const void *address, size_t size, u8 value)
>  {
>         void *shadow_start, *shadow_end;
>
> @@ -125,7 +125,7 @@ void kasan_poison_shadow(const void *address, size_t size, u8 value)
>         __memset(shadow_start, value, shadow_end - shadow_start);
>  }
>
> -void kasan_unpoison_shadow(const void *address, size_t size)
> +void kasan_unpoison_memory(const void *address, size_t size)
>  {
>         u8 tag = get_tag(address);
>
> @@ -136,7 +136,7 @@ void kasan_unpoison_shadow(const void *address, size_t size)
>          */
>         address = reset_tag(address);
>
> -       kasan_poison_shadow(address, size, tag);
> +       kasan_poison_memory(address, size, tag);
>
>         if (size & KASAN_SHADOW_MASK) {
>                 u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size);
> @@ -153,7 +153,7 @@ static void __kasan_unpoison_stack(struct task_struct *task, const void *sp)
>         void *base = task_stack_page(task);
>         size_t size = sp - base;
>
> -       kasan_unpoison_shadow(base, size);
> +       kasan_unpoison_memory(base, size);
>  }
>
>  /* Unpoison the entire stack for a task. */
> @@ -172,7 +172,7 @@ asmlinkage void kasan_unpoison_task_stack_below(const void *watermark)
>          */
>         void *base = (void *)((unsigned long)watermark & ~(THREAD_SIZE - 1));
>
> -       kasan_unpoison_shadow(base, watermark - base);
> +       kasan_unpoison_memory(base, watermark - base);
>  }
>
>  void kasan_alloc_pages(struct page *page, unsigned int order)
> @@ -186,13 +186,13 @@ void kasan_alloc_pages(struct page *page, unsigned int order)
>         tag = random_tag();
>         for (i = 0; i < (1 << order); i++)
>                 page_kasan_tag_set(page + i, tag);
> -       kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order);
> +       kasan_unpoison_memory(page_address(page), PAGE_SIZE << order);
>  }
>
>  void kasan_free_pages(struct page *page, unsigned int order)
>  {
>         if (likely(!PageHighMem(page)))
> -               kasan_poison_shadow(page_address(page),
> +               kasan_poison_memory(page_address(page),
>                                 PAGE_SIZE << order,
>                                 KASAN_FREE_PAGE);
>  }
> @@ -284,18 +284,18 @@ void kasan_poison_slab(struct page *page)
>
>         for (i = 0; i < compound_nr(page); i++)
>                 page_kasan_tag_reset(page + i);
> -       kasan_poison_shadow(page_address(page), page_size(page),
> +       kasan_poison_memory(page_address(page), page_size(page),
>                         KASAN_KMALLOC_REDZONE);
>  }
>
>  void kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
>  {
> -       kasan_unpoison_shadow(object, cache->object_size);
> +       kasan_unpoison_memory(object, cache->object_size);
>  }
>
>  void kasan_poison_object_data(struct kmem_cache *cache, void *object)
>  {
> -       kasan_poison_shadow(object,
> +       kasan_poison_memory(object,
>                         round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE),
>                         KASAN_KMALLOC_REDZONE);
>  }
> @@ -408,7 +408,7 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
>         }
>
>         rounded_up_size = round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE);
> -       kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE);
> +       kasan_poison_memory(object, rounded_up_size, KASAN_KMALLOC_FREE);
>
>         if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine) ||
>                         unlikely(!(cache->flags & SLAB_KASAN)))
> @@ -448,8 +448,8 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
>                 tag = assign_tag(cache, object, false, keep_tag);
>
>         /* Tag is ignored in set_tag without CONFIG_KASAN_SW_TAGS */
> -       kasan_unpoison_shadow(set_tag(object, tag), size);
> -       kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
> +       kasan_unpoison_memory(set_tag(object, tag), size);
> +       kasan_poison_memory((void *)redzone_start, redzone_end - redzone_start,
>                 KASAN_KMALLOC_REDZONE);
>
>         if (cache->flags & SLAB_KASAN)
> @@ -489,8 +489,8 @@ void * __must_check kasan_kmalloc_large(const void *ptr, size_t size,
>                                 KASAN_SHADOW_SCALE_SIZE);
>         redzone_end = (unsigned long)ptr + page_size(page);
>
> -       kasan_unpoison_shadow(ptr, size);
> -       kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
> +       kasan_unpoison_memory(ptr, size);
> +       kasan_poison_memory((void *)redzone_start, redzone_end - redzone_start,
>                 KASAN_PAGE_REDZONE);
>
>         return (void *)ptr;
> @@ -523,7 +523,7 @@ void kasan_poison_kfree(void *ptr, unsigned long ip)
>                         kasan_report_invalid_free(ptr, ip);
>                         return;
>                 }
> -               kasan_poison_shadow(ptr, page_size(page), KASAN_FREE_PAGE);
> +               kasan_poison_memory(ptr, page_size(page), KASAN_FREE_PAGE);
>         } else {
>                 __kasan_slab_free(page->slab_cache, ptr, ip, false);
>         }
> @@ -709,7 +709,7 @@ int kasan_populate_vmalloc(unsigned long addr, unsigned long size)
>          * // vmalloc() allocates memory
>          * // let a = area->addr
>          * // we reach kasan_populate_vmalloc
> -        * // and call kasan_unpoison_shadow:
> +        * // and call kasan_unpoison_memory:
>          * STORE shadow(a), unpoison_val
>          * ...
>          * STORE shadow(a+99), unpoison_val     x = LOAD p
> @@ -744,7 +744,7 @@ void kasan_poison_vmalloc(const void *start, unsigned long size)
>                 return;
>
>         size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
> -       kasan_poison_shadow(start, size, KASAN_VMALLOC_INVALID);
> +       kasan_poison_memory(start, size, KASAN_VMALLOC_INVALID);
>  }
>
>  void kasan_unpoison_vmalloc(const void *start, unsigned long size)
> @@ -752,7 +752,7 @@ void kasan_unpoison_vmalloc(const void *start, unsigned long size)
>         if (!is_vmalloc_or_module_addr(start))
>                 return;
>
> -       kasan_unpoison_shadow(start, size);
> +       kasan_unpoison_memory(start, size);
>  }
>
>  static int kasan_depopulate_vmalloc_pte(pte_t *ptep, unsigned long addr,
> diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
> index 37ccfadd3263..7006157c674b 100644
> --- a/mm/kasan/generic.c
> +++ b/mm/kasan/generic.c
> @@ -202,9 +202,9 @@ static void register_global(struct kasan_global *global)
>  {
>         size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE);
>
> -       kasan_unpoison_shadow(global->beg, global->size);
> +       kasan_unpoison_memory(global->beg, global->size);
>
> -       kasan_poison_shadow(global->beg + aligned_size,
> +       kasan_poison_memory(global->beg + aligned_size,
>                 global->size_with_redzone - aligned_size,
>                 KASAN_GLOBAL_REDZONE);
>  }
> @@ -285,11 +285,11 @@ void __asan_alloca_poison(unsigned long addr, size_t size)
>
>         WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE));
>
> -       kasan_unpoison_shadow((const void *)(addr + rounded_down_size),
> +       kasan_unpoison_memory((const void *)(addr + rounded_down_size),
>                               size - rounded_down_size);
> -       kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
> +       kasan_poison_memory(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
>                         KASAN_ALLOCA_LEFT);
> -       kasan_poison_shadow(right_redzone,
> +       kasan_poison_memory(right_redzone,
>                         padding_size + KASAN_ALLOCA_REDZONE_SIZE,
>                         KASAN_ALLOCA_RIGHT);
>  }
> @@ -301,7 +301,7 @@ void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
>         if (unlikely(!stack_top || stack_top > stack_bottom))
>                 return;
>
> -       kasan_unpoison_shadow(stack_top, stack_bottom - stack_top);
> +       kasan_unpoison_memory(stack_top, stack_bottom - stack_top);
>  }
>  EXPORT_SYMBOL(__asan_allocas_unpoison);
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index ac499456740f..03450d3b31f7 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -150,7 +150,7 @@ static inline bool addr_has_shadow(const void *addr)
>         return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
>  }
>
> -void kasan_poison_shadow(const void *address, size_t size, u8 value);
> +void kasan_poison_memory(const void *address, size_t size, u8 value);
>
>  /**
>   * check_memory_region - Check memory region, and report if invalid access.
> diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
> index 5c8b08a25715..4bdd7dbd6647 100644
> --- a/mm/kasan/tags.c
> +++ b/mm/kasan/tags.c
> @@ -153,7 +153,7 @@ EXPORT_SYMBOL(__hwasan_storeN_noabort);
>
>  void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size)
>  {
> -       kasan_poison_shadow((void *)addr, size, tag);
> +       kasan_poison_memory((void *)addr, size, tag);
>  }
>  EXPORT_SYMBOL(__hwasan_tag_memory);
>
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index f9ccd5dc13f3..53d0f8bb57ea 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -1176,7 +1176,7 @@ size_t ksize(const void *objp)
>          * We assume that ksize callers could use whole allocated area,
>          * so we need to unpoison this area.
>          */
> -       kasan_unpoison_shadow(objp, size);
> +       kasan_unpoison_memory(objp, size);
>         return size;
>  }
>  EXPORT_SYMBOL(ksize);
> --
> 2.29.2.222.g5d2a92d10f8-goog
>


-- 
Alexander Potapenko
Software Engineer

Google Germany GmbH
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