#define _LTTNG_WRAPPER_COMPILER_H
#include <linux/compiler.h>
+#include <linux/version.h>
/*
* Don't allow compiling with buggy compiler.
# define WRITE_ONCE(x, val) ({ ACCESS_ONCE(x) = val; })
#endif
+/*
+ * In v4.15 a smp read barrier was added to READ_ONCE to replace
+ * lockless_dereference(), replicate this behavior on prior kernels
+ * and remove calls to smp_read_barrier_depends which was dropped
+ * in v5.9.
+ */
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,15,0))
+#define LTTNG_READ_ONCE(x) READ_ONCE(x)
+#else
+#define LTTNG_READ_ONCE(x) \
+({ \
+ typeof(x) __val = READ_ONCE(x); \
+ smp_read_barrier_depends(); \
+ __val; \
+})
+#endif
+
#endif /* _LTTNG_WRAPPER_COMPILER_H */