1 files changed, 52 insertions, 0 deletions
diff --git a/backport-include/linux/random.h b/backport-include/linux/random.h
new file mode 100644
index 0000000..7d817d8
--- /dev/null
+++ b/backport-include/linux/random.h
@@ -0,0 +1,52 @@
+#ifndef __BACKPORT_RANDOM_H
+#define __BACKPORT_RANDOM_H
+#include_next <linux/random.h>
+#include <linux/version.h>
+
+#if (LINUX_VERSION_IS_GEQ(3,3,0) && LINUX_VERSION_IS_LESS(3,4,10)) || \
+    (LINUX_VERSION_IS_GEQ(3,1,0) && LINUX_VERSION_IS_LESS(3,2,27)) || \
+    LINUX_VERSION_IS_LESS(3,0,41)
+#define add_device_randomness LINUX_BACKPORT(add_device_randomness)
+static inline void add_device_randomness(const void *buf, unsigned int size)
+{
+}
+#endif
+
+#if LINUX_VERSION_IS_LESS(3,8,0)
+/* backports 496f2f9 */
+#define prandom_seed(_seed)		srandom32(_seed)
+#define prandom_u32()			random32()
+#define prandom_u32_state(_state)	prandom32(_state)
+/* backport 6582c665d6b882dad8329e05749fbcf119f1ab88 */
+#define prandom_bytes LINUX_BACKPORT(prandom_bytes)
+void prandom_bytes(void *buf, int bytes);
+#endif
+
+#if LINUX_VERSION_IS_LESS(3,14,0)
+/**
+ * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro)
+ * @ep_ro: right open interval endpoint
+ *
+ * Returns a pseudo-random number that is in interval [0, ep_ro). Note
+ * that the result depends on PRNG being well distributed in [0, ~0U]
+ * u32 space. Here we use maximally equidistributed combined Tausworthe
+ * generator, that is, prandom_u32(). This is useful when requesting a
+ * random index of an array containing ep_ro elements, for example.
+ *
+ * Returns: pseudo-random number in interval [0, ep_ro)
+ */
+#define prandom_u32_max LINUX_BACKPORT(prandom_u32_max)
+static inline u32 prandom_u32_max(u32 ep_ro)
+{
+	return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
+}
+#endif /* LINUX_VERSION_IS_LESS(3,14,0) */
+
+#if LINUX_VERSION_IS_LESS(4,11,0)
+static inline u32 get_random_u32(void)
+{
+	return get_random_int();
+}
+#endif
+
+#endif /* __BACKPORT_RANDOM_H */