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Subject[PATCH 06/11] change memory_is_poisoned_16 for aligned error
Date
 Because arm instruction set don't support access the address which is
not aligned, so must change memory_is_poisoned_16 for arm.

Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Signed-off-by: Abbott Liu <liuwenliang@huawei.com>
---
mm/kasan/kasan.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 12749da..e0e152b 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -149,6 +149,25 @@ static __always_inline bool memory_is_poisoned_2_4_8(unsigned long addr,
return memory_is_poisoned_1(addr + size - 1);
}

+#ifdef CONFIG_ARM
+static __always_inline bool memory_is_poisoned_16(unsigned long addr)
+{
+ u8 *shadow_addr = (u8 *)kasan_mem_to_shadow((void *)addr);
+
+ if (unlikely(shadow_addr[0] || shadow_addr[1])) return true;
+ else {
+ /*
+ * If two shadow bytes covers 16-byte access, we don't
+ * need to do anything more. Otherwise, test the last
+ * shadow byte.
+ */
+ if (likely(IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE)))
+ return false;
+ return memory_is_poisoned_1(addr + 15);
+ }
+}
+
+#else
static __always_inline bool memory_is_poisoned_16(unsigned long addr)
{
u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);
@@ -159,6 +178,7 @@ static __always_inline bool memory_is_poisoned_16(unsigned long addr)

return *shadow_addr;
}
+#endif

static __always_inline unsigned long bytes_is_nonzero(const u8 *start,
size_t size)
--
2.9.0
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