[PATCH v2] arm64: Fix warning in mte_get_random_tag()

[Vincenzo Frascino]

The simplification of mte_get_random_tag() caused the introduction of the
warning below:

In file included from arch/arm64/include/asm/kasan.h:9,
                 from include/linux/kasan.h:16,
                 from mm/kasan/common.c:14:
mm/kasan/common.c: In function ‘mte_get_random_tag’:
arch/arm64/include/asm/mte-kasan.h:45:9: warning: ‘addr’ is used
                                         uninitialized [-Wuninitialized]
   45 |         asm(__MTE_PREAMBLE "irg %0, %0"
      |

Fix the warning using "=r" for the address in the asm inline.

Fixes: c8f8de4c0887 ("arm64: kasan: simplify and inline MTE functions")
Cc: Catalin Marinas <catalin.mari...@arm.com>
Cc: Will Deacon <w...@kernel.org>
Cc: Andrey Konovalov <andreyk...@google.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frasc...@arm.com>
---

This patch is based on linux-next/akpm

 arch/arm64/include/asm/mte-kasan.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/mte-kasan.h 
b/arch/arm64/include/asm/mte-kasan.h
index 3d58489228c0..7ab500e2ad17 100644
--- a/arch/arm64/include/asm/mte-kasan.h
+++ b/arch/arm64/include/asm/mte-kasan.h
@@ -43,7 +43,7 @@ static inline u8 mte_get_random_tag(void)
        void *addr;
 
        asm(__MTE_PREAMBLE "irg %0, %0"
-               : "+r" (addr));
+               : "=r" (addr));
 
        return mte_get_ptr_tag(addr);
 }
-- 
2.30.0