From f3ab0d86e8070c73bf2e2852341f8e5c709f5682 Mon Sep 17 00:00:00 2001
From: Olivier Certner <olce@FreeBSD.org>
Date: Mon, 3 Jun 2024 15:22:12 -0400
Subject: [PATCH] bitset: Fix __BIT_FFS_AT()'s herald comment

The manual page is correct though.

No functional change.

Reviewed by:    emaste
Approved by:    emaste (mentor)
MFC after:      3 days
Event:          Kitchener-Waterloo Hackathon 202406
Sponsored by:   The FreeBSD Foundation
---
 sys/sys/bitset.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sys/sys/bitset.h b/sys/sys/bitset.h
index 4afac9b172e..2b26e8bcdbf 100644
--- a/sys/sys/bitset.h
+++ b/sys/sys/bitset.h
@@ -232,8 +232,9 @@
 } while (0)
 
 /*
- * Note that `start` and the returned value from __BIT_FFS_AT are
- * 1-based bit indices.
+ * 'start' and 'end' are 0-based bit (runtime) indices. Note that, as for ffs(),
+ * the returned index is 1-based, 0 being reserved to indicate that no bits are
+ * set.
  */
 #define	__BIT_FFS_AT(_s, p, start) __extension__ ({			\
 	__size_t __i;							\