Annotate atomic_add_return() and atomic_sub_return() to avoid signed
overflow instrumentation. They are expected to wrap around.
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
---
arch/arm64/include/asm/atomic_lse.h | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/atomic_lse.h b/arch/arm64/include/asm/atomic_lse.h
index 87f568a94e55..a33576b20b52 100644
--- a/arch/arm64/include/asm/atomic_lse.h
+++ b/arch/arm64/include/asm/atomic_lse.h
@@ -10,6 +10,8 @@
#ifndef __ASM_ATOMIC_LSE_H
#define __ASM_ATOMIC_LSE_H
+#include <linux/overflow.h>
+
#define ATOMIC_OP(op, asm_op) \
static __always_inline void \
__lse_atomic_##op(int i, atomic_t *v) \
@@ -82,13 +84,13 @@ ATOMIC_FETCH_OP_SUB( )
static __always_inline int \
__lse_atomic_add_return##name(int i, atomic_t *v) \
{ \
- return __lse_atomic_fetch_add##name(i, v) + i; \
+ return wrapping_add(int, __lse_atomic_fetch_add##name(i, v), i);\
} \
\
static __always_inline int \
__lse_atomic_sub_return##name(int i, atomic_t *v) \
{ \
- return __lse_atomic_fetch_sub(i, v) - i; \
+ return wrapping_sub(int, __lse_atomic_fetch_sub(i, v), i); \
}
ATOMIC_OP_ADD_SUB_RETURN(_relaxed)
@@ -189,13 +191,13 @@ ATOMIC64_FETCH_OP_SUB( )
static __always_inline long \
__lse_atomic64_add_return##name(s64 i, atomic64_t *v) \
{ \
- return __lse_atomic64_fetch_add##name(i, v) + i; \
+ return wrapping_add(s64, __lse_atomic64_fetch_add##name(i, v), i); \
} \
\
static __always_inline long \
__lse_atomic64_sub_return##name(s64 i, atomic64_t *v) \
{ \
- return __lse_atomic64_fetch_sub##name(i, v) - i; \
+ return wrapping_sub(s64, __lse_atomic64_fetch_sub##name(i, v), i); \
}
ATOMIC64_OP_ADD_SUB_RETURN(_relaxed)
--
2.34.1
