From e205435056770826b349e171f3d3aebe303e0119 Mon Sep 17 00:00:00 2001
From: Pawel Zmarzly <pzmarzly0@gmail.com>
Date: Tue, 31 Mar 2026 13:52:26 +0000
Subject: [PATCH] lib: cgen: make _bf_round_next_power_of_2 correct

size_t can be 32-bit or 64-bit integer. And 2**0 should be 1.
---
 src/libbpfilter/cgen/program.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/libbpfilter/cgen/program.c b/src/libbpfilter/cgen/program.c
index 84f8d7b5..423462ee 100644
--- a/src/libbpfilter/cgen/program.c
+++ b/src/libbpfilter/cgen/program.c
@@ -65,12 +65,18 @@
 
 static inline size_t _bf_round_next_power_of_2(size_t value)
 {
+    if (value == 0)
+        return 1;
+
     value--;
     value |= value >> 1;
     value |= value >> 2;
     value |= value >> 4;
     value |= value >> 8;
     value |= value >> 16;
+#if SIZE_MAX > 0xFFFFFFFFU
+    value |= value >> 32;
+#endif
 
     return ++value;
 }