diff options
Diffstat (limited to 'mm/kasan/shadow.c')
| -rw-r--r-- | mm/kasan/shadow.c | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index 1372a2fc0ca9..1ed7817e4ee6 100644 --- a/mm/kasan/shadow.c +++ b/mm/kasan/shadow.c @@ -69,10 +69,6 @@ void *memcpy(void *dest, const void *src, size_t len) return __memcpy(dest, src, len); } -/* - * Poisons the shadow memory for 'size' bytes starting from 'addr'. - * Memory addresses should be aligned to KASAN_GRANULE_SIZE. - */ void kasan_poison(const void *address, size_t size, u8 value) { void *shadow_start, *shadow_end; @@ -83,12 +79,12 @@ void kasan_poison(const void *address, size_t size, u8 value) * addresses to this function. */ address = kasan_reset_tag(address); - size = round_up(size, KASAN_GRANULE_SIZE); /* Skip KFENCE memory if called explicitly outside of sl*b. */ if (is_kfence_address(address)) return; + size = round_up(size, KASAN_GRANULE_SIZE); shadow_start = kasan_mem_to_shadow(address); shadow_end = kasan_mem_to_shadow(address + size); @@ -96,6 +92,16 @@ void kasan_poison(const void *address, size_t size, u8 value) } EXPORT_SYMBOL(kasan_poison); +#ifdef CONFIG_KASAN_GENERIC +void kasan_poison_last_granule(const void *address, size_t size) +{ + if (size & KASAN_GRANULE_MASK) { + u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); + *shadow = size & KASAN_GRANULE_MASK; + } +} +#endif + void kasan_unpoison(const void *address, size_t size) { u8 tag = get_tag(address); @@ -115,16 +121,12 @@ void kasan_unpoison(const void *address, size_t size) if (is_kfence_address(address)) return; + /* Unpoison round_up(size, KASAN_GRANULE_SIZE) bytes. */ kasan_poison(address, size, tag); - if (size & KASAN_GRANULE_MASK) { - u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); - - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) - *shadow = tag; - else /* CONFIG_KASAN_GENERIC */ - *shadow = size & KASAN_GRANULE_MASK; - } + /* Partially poison the last granule for the generic mode. */ + if (IS_ENABLED(CONFIG_KASAN_GENERIC)) + kasan_poison_last_granule(address, size); } #ifdef CONFIG_MEMORY_HOTPLUG |