kasan: rename (un)poison_shadow to (un)poison_range

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@google.com>
Link: https://lkml.kernel.org/r/fccdcaa13dc6b2211bf363d6c6d499279a54fe3a.1606161801.git.andreyknvl@google.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 7828436a3a999347e3a97b0e35fdd153372251bb..9740c06a04a14458f2e319ac23d28d7985a18531 100644 (file)
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -72,7 +72,7 @@ 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);
 
@@ -109,7 +109,7 @@ 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);
 
@@ -118,7 +118,7 @@ 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 41906a52a7646346167d4979f6b1eaeb6b49a580..37720a6d04eaa8c61cdae87092df4a75daa59c75 100644 (file)
--- 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 89e5ef9417a7992a7c3dc5bc6d7f7414fc1abd9b..73e79a34671b4edb6eb5a003a927f376fd689dcb 100644 (file)
--- 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 poison_range(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 unpoison_range(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);
+       poison_range(address, size, tag);
 
        if (size & KASAN_SHADOW_MASK) {
                u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size);
@@ -148,12 +148,17 @@ 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. */
@@ -172,7 +177,7 @@ 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)
@@ -186,13 +191,13 @@ 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);
 }
@@ -284,18 +289,18 @@ 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);
 }
@@ -408,7 +413,7 @@ 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)))
@@ -448,9 +453,9 @@ 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);
@@ -489,9 +494,9 @@ 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;
 }
@@ -523,7 +528,7 @@ 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);
        }
@@ -709,7 +714,7 @@ 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
@@ -744,7 +749,7 @@ 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)
@@ -752,7 +757,7 @@ 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 d341859a1b955d35787f99877c0878d7eb4d8a84..9fe44f9b3b30c334839b0c2ea3096f6b37ef9ef3 100644 (file)
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -202,11 +202,11 @@ 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)
@@ -285,13 +285,12 @@ 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);
 
@@ -301,7 +300,7 @@ 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 ac499456740f1f8b9805a991e8e71faa54256e8e..42ab02c61331ded6d1370e34839dab7dea0a37d7 100644 (file)
--- 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 5c8b08a2571570b098761aafeea9fea00cdd3f9a..c0b3f327812b9b1f8eafc8b780881e1f494b11cd 100644 (file)
--- 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 2f2b55c2798e749536f84af20f6f3494a380782e..573fbacd9ef508c8e2cc0b1f39fc7c39ba21a56a 100644 (file)
--- 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_range(objp, size);
        return size;
 }
 EXPORT_SYMBOL(ksize);