While we instrument atomic*() and cmpxchg(), we missed xchg().
Let's add instrumentation for xchg(), fixing up x86 to implement
arch_xchg().
Signed-off-by: Mark Rutland <mark.rutl...@arm.com>
Cc: Boqun Feng <boqun.f...@gmail.com>
Cc: Dmitry Vyukov <dvyu...@google.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Will Deacon <will.dea...@arm.com>
---
arch/x86/include/asm/atomic.h | 2 +-
arch/x86/include/asm/atomic64_64.h | 2 +-
arch/x86/include/asm/cmpxchg.h | 2 +-
include/asm-generic/atomic-instrumented.h | 7 +++++++
4 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
index 823fd2f320cf..b143717b92b3 100644
--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h
@@ -202,7 +202,7 @@ static __always_inline bool
arch_atomic_try_cmpxchg(atomic_t *v, int *old, int n
static inline int arch_atomic_xchg(atomic_t *v, int new)
{
- return xchg(&v->counter, new);
+ return arch_xchg(&v->counter, new);
}
static inline void arch_atomic_and(int i, atomic_t *v)
diff --git a/arch/x86/include/asm/atomic64_64.h
b/arch/x86/include/asm/atomic64_64.h
index 849f1c566a11..4343d9b4f30e 100644
--- a/arch/x86/include/asm/atomic64_64.h
+++ b/arch/x86/include/asm/atomic64_64.h
@@ -188,7 +188,7 @@ static __always_inline bool
arch_atomic64_try_cmpxchg(atomic64_t *v, s64 *old, l
static inline long arch_atomic64_xchg(atomic64_t *v, long new)
{
- return xchg(&v->counter, new);
+ return arch_xchg(&v->counter, new);
}
static inline void arch_atomic64_and(long i, atomic64_t *v)
diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index e3efd8a06066..a55d79b233d3 100644
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -75,7 +75,7 @@ extern void __add_wrong_size(void)
* use "asm volatile" and "memory" clobbers to prevent gcc from moving
* information around.
*/
-#define xchg(ptr, v) __xchg_op((ptr), (v), xchg, "")
+#define arch_xchg(ptr, v) __xchg_op((ptr), (v), xchg, "")
/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
diff --git a/include/asm-generic/atomic-instrumented.h
b/include/asm-generic/atomic-instrumented.h
index c7c3e4cdd942..53481b6eacdf 100644
--- a/include/asm-generic/atomic-instrumented.h
+++ b/include/asm-generic/atomic-instrumented.h
@@ -408,6 +408,13 @@ static __always_inline bool atomic64_add_negative(s64 i,
atomic64_t *v)
}
#endif
+#define xchg(ptr, new) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ kasan_check_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_xchg(__ai_ptr, (new)); \
+})
+
#define cmpxchg(ptr, old, new) \
({ \
typeof(ptr) __ai_ptr = (ptr); \
--
2.11.0
