arm64: move untagged_addr macro from uaccess.h to memory.h

Move the untagged_addr() macro from arch/arm64/include/asm/uaccess.h
to arch/arm64/include/asm/memory.h to be later reused by KASAN.

Also make the untagged_addr() macro accept all kinds of address types
(void *, unsigned long, etc.). This allows not to specify type casts in
each place where the macro is used. This is done by using __typeof__.

Link: http://lkml.kernel.org/r/2e9ef8d2ed594106eca514b268365b5419113f6a.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/arm64/include/asm/memory.h

@@ -218,6 +218,14 @@ extern u64			vabits_user;
  */
 #define PHYS_PFN_OFFSET	(PHYS_OFFSET >> PAGE_SHIFT)
 
+/*
+ * When dealing with data aborts, watchpoints, or instruction traps we may end
+ * up with a tagged userland pointer. Clear the tag to get a sane pointer to
+ * pass on to access_ok(), for instance.
+ */
+#define untagged_addr(addr)	\
+	((__typeof__(addr))sign_extend64((u64)(addr), 55))
+
 /*
  * Physical vs virtual RAM address space conversion.  These are
  * private definitions which should NOT be used outside memory.h

arch/arm64/include/asm/uaccess.h

@@ -95,13 +95,6 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si
 	return ret;
 }
 
-/*
- * When dealing with data aborts, watchpoints, or instruction traps we may end
- * up with a tagged userland pointer. Clear the tag to get a sane pointer to
- * pass on to access_ok(), for instance.
- */
-#define untagged_addr(addr)		sign_extend64(addr, 55)
-
 #define access_ok(type, addr, size)	__range_ok(addr, size)
 #define user_addr_max			get_fs