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 initializing the address to NULL.
Note: mte_get_random_tag() returns a tag and it never dereferences the address,
hence 'addr' can be safely initialized to NULL.
Fixes: c8f8de4c0887 ("arm64: kasan: simplify and inline MTE functions")
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Andrew Morton <[email protected]>
Signed-off-by: Vincenzo Frascino <[email protected]>
---
This patch is based on linux-next/akpm
arch/arm64/include/asm/mte-kasan.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/mte-kasan.h
b/arch/arm64/include/asm/mte-kasan.h
index 3d58489228c0..b2850b750726 100644
--- a/arch/arm64/include/asm/mte-kasan.h
+++ b/arch/arm64/include/asm/mte-kasan.h
@@ -40,7 +40,12 @@ static inline u8 mte_get_mem_tag(void *addr)
/* Generate a random tag. */
static inline u8 mte_get_random_tag(void)
{
- void *addr;
+ /*
+ * mte_get_random_tag() returns a tag and it
+ * never dereferences the address, hence addr
+ * can be safely initialized to NULL.
+ */
+ void *addr = NULL;
asm(__MTE_PREAMBLE "irg %0, %0"
: "+r" (addr));
--
2.30.0
