[PATCH v2 4/5] selftests/futex: introduce the declaration of atomic_t from types.h

[Yuwen Chen <ywen.chen@foxmail.com>]

Introduce the header files specifically prepared for test programs
from the tools/include directory. And solve the problem that
atomic_read and atomic_set may not be safe in a multi - threaded
environment.

Signed-off-by: Yuwen Chen <ywen.chen@foxmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202512112344.gsyPl2ag-lkp@intel.com/
---
 .../selftests/futex/functional/Makefile       |  2 +-
 .../testing/selftests/futex/include/atomic.h  | 25 +++++++++----------
 2 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/tools/testing/selftests/futex/functional/Makefile b/tools/testing/selftests/futex/functional/Makefile
index 490ace1f017e8..8589917a4b126 100644
--- a/tools/testing/selftests/futex/functional/Makefile
+++ b/tools/testing/selftests/futex/functional/Makefile
@@ -2,7 +2,7 @@
 PKG_CONFIG ?= pkg-config
 LIBNUMA_TEST = $(shell sh -c "$(PKG_CONFIG) numa --atleast-version 2.0.16 > /dev/null 2>&1 && echo SUFFICIENT || echo NO")
 
-INCLUDES := -I../include -I../../ $(KHDR_INCLUDES)
+INCLUDES := -I../include -I../../ $(KHDR_INCLUDES) -I../../../../include
 CFLAGS := $(CFLAGS) -g -O2 -Wall -pthread -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 $(INCLUDES) $(KHDR_INCLUDES) -DLIBNUMA_VER_$(LIBNUMA_TEST)=1
 LDLIBS := -lpthread -lrt -lnuma
 
diff --git a/tools/testing/selftests/futex/include/atomic.h b/tools/testing/selftests/futex/include/atomic.h
index c0dccb1b966ba..b23e1a50949a7 100644
--- a/tools/testing/selftests/futex/include/atomic.h
+++ b/tools/testing/selftests/futex/include/atomic.h
@@ -18,9 +18,8 @@
 #ifndef _ATOMIC_H
 #define _ATOMIC_H
 
-typedef struct {
-	volatile int val;
-} atomic_t;
+#include <linux/types.h>
+#include <linux/compiler.h>
 
 #define ATOMIC_INITIALIZER { 0 }
 
@@ -30,36 +29,36 @@ typedef struct {
  * @oldval:	The expected value of the futex
  * @newval:	The new value to try and assign the futex
  *
- * Return the old value of addr->val.
+ * Return the old value of addr->counter.
  */
 static inline int
 atomic_cmpxchg(atomic_t *addr, int oldval, int newval)
 {
-	return __sync_val_compare_and_swap(&addr->val, oldval, newval);
+	return __sync_val_compare_and_swap(&addr->counter, oldval, newval);
 }
 
 /**
  * atomic_inc() - Atomic incrememnt
  * @addr:	Address of the variable to increment
  *
- * Return the new value of addr->val.
+ * Return the new value of addr->counter.
  */
 static inline int
 atomic_inc(atomic_t *addr)
 {
-	return __sync_add_and_fetch(&addr->val, 1);
+	return __sync_add_and_fetch(&addr->counter, 1);
 }
 
 /**
  * atomic_dec() - Atomic decrement
  * @addr:	Address of the variable to decrement
  *
- * Return the new value of addr-val.
+ * Return the new value of addr-counter.
  */
 static inline int
 atomic_dec(atomic_t *addr)
 {
-	return __sync_sub_and_fetch(&addr->val, 1);
+	return __sync_sub_and_fetch(&addr->counter, 1);
 }
 
 /**
@@ -67,12 +66,12 @@ atomic_dec(atomic_t *addr)
  * @addr:	Address of the variable to set
  * @newval:	New value for the atomic_t
  *
- * Return the new value of addr->val.
+ * Return the new value of addr->counter.
  */
 static inline int
 atomic_set(atomic_t *addr, int newval)
 {
-	addr->val = newval;
+	WRITE_ONCE(addr->counter, newval);
 	return newval;
 }
 
@@ -80,12 +79,12 @@ atomic_set(atomic_t *addr, int newval)
  * atomic_read() - Atomic read
  * @addr:	Address of the variable to read
  *
- * Return the value of addr->val.
+ * Return the value of addr->counter.
  */
 static inline int
 atomic_read(atomic_t *addr)
 {
-	return addr->val;
+	return READ_ONCE(addr->counter);
 }
 
 #endif
-- 
2.34.1