[PATCH v11 11/24] kasan, arm64: untag address in _virt_addr_is_linear

Andrey Konovalov
2018-11-19T17:29:19Z

virt_addr_is_linear (which is used by virt_addr_valid) assumes that the
top byte of the address is 0xff, which isn't always the case with
tag-based KASAN.

This patch resets the tag in this macro.

Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
arch/arm64/include/asm/memory.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index ae741827039c..ddad7df77027 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -322,9 +322,10 @@ static inline void *phys_to_virt(phys_addr_t x)
#endif
#endif

-#define _virt_addr_is_linear(kaddr) (((u64)(kaddr)) >= PAGE_OFFSET)
-#define virt_addr_valid(kaddr) (_virt_addr_is_linear(kaddr) && \
- _virt_addr_valid(kaddr))
+#define _virt_addr_is_linear(kaddr) \
+ (__tag_reset((u64)(kaddr)) >= PAGE_OFFSET)
+#define virt_addr_valid(kaddr) \
+ (_virt_addr_is_linear(kaddr) && _virt_addr_valid(kaddr))

#include <asm-generic/memory_model.h>

--
2.19.1.1215.g8438c0b245-goog