kasan, arm64: untag address in _virt_addr_is_linear

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.

Link: http://lkml.kernel.org/r/df73a37dd5ed37f4deaf77bc718e9f2e590e69b1.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 25b46f88726c177d92ec7ab568d8a7eddc8d931f..907946cc767ceb065894f9cc16b83ca399bb1d4c 100644 (file)
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -329,9 +329,10 @@ 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>