+/*
+ * The following defines are extracted from the toplevel Linux Makefile and
+ * passed on the command line -with '-D'.
+ */
+
+#ifndef LTTNG_LINUX_MAJOR
+#define LTTNG_LINUX_MAJOR 0
+#endif
+
+#ifndef LTTNG_LINUX_MINOR
+#define LTTNG_LINUX_MINOR 0
+#endif
+
+#ifndef LTTNG_LINUX_PATCH
+#define LTTNG_LINUX_PATCH 0
+#endif
+
+/*
+ * Some stable releases have overflowed the 8bits allocated to the sublevel in
+ * the version code. To determine if the current kernel is affected, use the
+ * sublevel version from the Makefile. This is currently true for the 4.4.256
+ * and 4.9.256 stable releases.
+ *
+ * When the sublevel has overflowed, use the values from the Makefile instead
+ * of LINUX_VERSION_CODE from the kernel headers and allocate 16bits.
+ * Otherwise, keep using the version code from the headers to minimise the
+ * behavior change and avoid regressions.
+ *
+ * Cast the result to uint64_t to prevent overflowing when we append distro
+ * specific version information.
+ */
+#if (LTTNG_LINUX_PATCH >= 256)
+
+#define LTTNG_KERNEL_VERSION(a, b, c) \
+ ((((a) << 24) + ((b) << 16) + (c)) * 1ULL)
+
+#define LTTNG_LINUX_VERSION_CODE \
+ LTTNG_KERNEL_VERSION(LTTNG_LINUX_MAJOR, LTTNG_LINUX_MINOR, LTTNG_LINUX_PATCH)
+
+#else
+
+#define LTTNG_KERNEL_VERSION(a, b, c) (KERNEL_VERSION(a, b, c) * 1ULL)
+#define LTTNG_LINUX_VERSION_CODE (LINUX_VERSION_CODE * 1ULL)
+
+#endif