[PATCH mm v10 05/42] kasan: rename (un)poison_shadow to (un)poison_range

From: Andrey Konovalov
Date: Fri Nov 13 2020 - 17:16:38 EST

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. Rename external annotation
kasan_unpoison_shadow() to kasan_unpoison_range(), and introduce internal
functions (un)poison_range() (without kasan_ prefix).

Co-developed-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
---
Change-Id: Ia359f32815242c4704e49a5f1639ca2d2f8cba69
---
include/linux/kasan.h | 6 +++---
kernel/fork.c | 4 ++--
mm/kasan/common.c | 49 ++++++++++++++++++++++++-------------------
mm/kasan/generic.c | 23 ++++++++++----------
mm/kasan/kasan.h | 3 ++-
mm/kasan/tags.c | 2 +-
mm/slab_common.c | 2 +-
7 files changed, 47 insertions(+), 42 deletions(-)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 26f2ab92e7ca..d237051dca58 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_range(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_range(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_range(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 15f189bb8ec4..bee52236f09b 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_range(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 f5739be60edc..6adbf5891aff 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -109,7 +109,7 @@ 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 poison_range(const void *address, size_t size, u8 value)
{
void *shadow_start, *shadow_end;

@@ -130,7 +130,7 @@ 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 unpoison_range(const void *address, size_t size)
{
u8 tag = get_tag(address);

@@ -149,7 +149,7 @@ void kasan_unpoison_shadow(const void *address, size_t size)
if (is_kfence_address(address))
return;

- kasan_poison_shadow(address, size, tag);
+ poison_range(address, size, tag);

if (size & KASAN_SHADOW_MASK) {
u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size);
@@ -161,12 +161,17 @@ void kasan_unpoison_shadow(const void *address, size_t size)
}
}

+void kasan_unpoison_range(const void *address, size_t size)
+{
+ unpoison_range(address, size);
+}
+
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);
+ unpoison_range(base, size);
}

/* Unpoison the entire stack for a task. */
@@ -185,7 +190,7 @@ 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);
+ unpoison_range(base, watermark - base);
}

void kasan_alloc_pages(struct page *page, unsigned int order)
@@ -199,13 +204,13 @@ 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);
+ unpoison_range(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),
+ poison_range(page_address(page),
PAGE_SIZE << order,
KASAN_FREE_PAGE);
}
@@ -297,18 +302,18 @@ 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_KMALLOC_REDZONE);
+ poison_range(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);
+ unpoison_range(object, cache->object_size);
}

void kasan_poison_object_data(struct kmem_cache *cache, void *object)
{
- kasan_poison_shadow(object,
+ poison_range(object,
round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE),
KASAN_KMALLOC_REDZONE);
}
@@ -424,7 +429,7 @@ 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);
+ poison_range(object, rounded_up_size, KASAN_KMALLOC_FREE);

if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine) ||
unlikely(!(cache->flags & SLAB_KASAN)))
@@ -467,9 +472,9 @@ 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_KMALLOC_REDZONE);
+ unpoison_range(set_tag(object, tag), size);
+ poison_range((void *)redzone_start, redzone_end - redzone_start,
+ KASAN_KMALLOC_REDZONE);

if (cache->flags & SLAB_KASAN)
kasan_set_track(&get_alloc_info(cache, object)->alloc_track, flags);
@@ -508,9 +513,9 @@ 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_PAGE_REDZONE);
+ unpoison_range(ptr, size);
+ poison_range((void *)redzone_start, redzone_end - redzone_start,
+ KASAN_PAGE_REDZONE);

return (void *)ptr;
}
@@ -542,7 +547,7 @@ 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);
+ poison_range(ptr, page_size(page), KASAN_FREE_PAGE);
} else {
__kasan_slab_free(page->slab_cache, ptr, ip, false);
}
@@ -728,7 +733,7 @@ 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 unpoison_range:
* STORE shadow(a), unpoison_val
* ...
* STORE shadow(a+99), unpoison_val x = LOAD p
@@ -763,7 +768,7 @@ 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);
+ poison_range(start, size, KASAN_VMALLOC_INVALID);
}

void kasan_unpoison_vmalloc(const void *start, unsigned long size)
@@ -771,7 +776,7 @@ void kasan_unpoison_vmalloc(const void *start, unsigned long size)
if (!is_vmalloc_or_module_addr(start))
return;

- kasan_unpoison_shadow(start, size);
+ unpoison_range(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 d6a386255007..cdc2d8112f3e 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -203,11 +203,11 @@ 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);
+ unpoison_range(global->beg, global->size);

- kasan_poison_shadow(global->beg + aligned_size,
- global->size_with_redzone - aligned_size,
- KASAN_GLOBAL_REDZONE);
+ poison_range(global->beg + aligned_size,
+ global->size_with_redzone - aligned_size,
+ KASAN_GLOBAL_REDZONE);
}

void __asan_register_globals(struct kasan_global *globals, size_t size)
@@ -286,13 +286,12 @@ 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),
- size - rounded_down_size);
- kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
- KASAN_ALLOCA_LEFT);
- kasan_poison_shadow(right_redzone,
- padding_size + KASAN_ALLOCA_REDZONE_SIZE,
- KASAN_ALLOCA_RIGHT);
+ unpoison_range((const void *)(addr + rounded_down_size),
+ size - rounded_down_size);
+ poison_range(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
+ KASAN_ALLOCA_LEFT);
+ poison_range(right_redzone, padding_size + KASAN_ALLOCA_REDZONE_SIZE,
+ KASAN_ALLOCA_RIGHT);
}
EXPORT_SYMBOL(__asan_alloca_poison);

@@ -302,7 +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);
+ unpoison_range(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..42ab02c61331 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -150,7 +150,8 @@ 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 poison_range(const void *address, size_t size, u8 value);
+void unpoison_range(const void *address, size_t size);

/**
* 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..c0b3f327812b 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);
+ poison_range((void *)addr, size, tag);
}
EXPORT_SYMBOL(__hwasan_tag_memory);

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 479d17b90155..0b5ae1819a8b 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1179,7 +1179,7 @@ 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_range(objp, size);
return size;
}
EXPORT_SYMBOL(ksize);
--
2.29.2.299.gdc1121823c-goog