@@ -151,13 +151,20 @@ static __always_inline bool memory_is_poisoned_2_4_8(unsigned long addr,
static __always_inline bool memory_is_poisoned_16(unsigned long addr)
{
- u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);
-
- /* Unaligned 16-bytes access maps into 3 shadow bytes. */
- if (unlikely(!IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE)))
- return *shadow_addr || memory_is_poisoned_1(addr + 15);
+ u8 *shadow_addr = (u8 *)kasan_mem_to_shadow((void *)addr);
- return *shadow_addr;
+ if (unlikely(shadow_addr[0] || shadow_addr[1])) {
+ return true;
+ } else if (likely(IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE))) {
+ /*
+ * If two shadow bytes covers 16-byte access, we don't
+ * need to do anything more. Otherwise, test the last
+ * shadow byte.
+ */
+ return false;
+ } else {
+ return memory_is_poisoned_1(addr + 15);
+ }
}
static __always_inline unsigned long bytes_is_nonzero(const u8 *start,