From 4242e224e6b7d00020a9fcee9bc020d0816630df Mon Sep 17 00:00:00 2001
From: Vladimir Kondratyev <wulf@FreeBSD.org>
Date: Mon, 8 Apr 2024 09:47:42 +0300
Subject: [PATCH] LinuxKPI: Add get_random_u32_below function

get_random_u32_below returns a random integer in the interval [0, ceil),
with uniform distribution.

Sponsored by:	Serenity CyberSecurity, LLC
Reviewed by:	emaste
MFC after:	1 week

(cherry picked from commit 9289c1f6f1514e714b17026c50ec09282f079cba)
---
 sys/compat/linuxkpi/common/include/linux/random.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/random.h b/sys/compat/linuxkpi/common/include/linux/random.h
index e87d4412ea4..808c5bc5597 100644
--- a/sys/compat/linuxkpi/common/include/linux/random.h
+++ b/sys/compat/linuxkpi/common/include/linux/random.h
@@ -96,6 +96,12 @@ get_random_u64(void)
 	return (val);
 }
 
+static inline uint32_t
+get_random_u32_below(uint32_t max)
+{
+	return (arc4random_uniform(max));
+}
+
 static __inline uint32_t
 prandom_u32(void)
 {