git: be1b2da855cc - main - sys/abi_compat.h: fix UB for bintime32 handling

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=be1b2da855cc38531733b5c97891cd4a40a993bc

commit be1b2da855cc38531733b5c97891cd4a40a993bc
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2026-01-12 04:46:15 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2026-01-20 14:42:35 +0000

    sys/abi_compat.h: fix UB for bintime32 handling
    
    Do not cast and then access potentially unaligned uint64_t in the BT_CP()
    macro.  Use freebsd32_uint64_t type and FU64_CP() for the frac member.
    
    Noted by:       des
    Reviewed by:    des, emaste
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D54663
---
 sys/compat/freebsd32/freebsd32.h | 2 +-
 sys/sys/abi_compat.h             | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/compat/freebsd32/freebsd32.h b/sys/compat/freebsd32/freebsd32.h
index 7324f9adf70c..7d21a5be5570 100644
--- a/sys/compat/freebsd32/freebsd32.h
+++ b/sys/compat/freebsd32/freebsd32.h
@@ -70,7 +70,7 @@ struct itimerspec32 {
 
 struct bintime32 {
 	time32_t sec;
-	uint32_t frac[2];
+	freebsd32_uint64_t frac;
 };
 
 struct ffclock_estimate32 {
diff --git a/sys/sys/abi_compat.h b/sys/sys/abi_compat.h
index 0a7110191430..bd99a21d8e23 100644
--- a/sys/sys/abi_compat.h
+++ b/sys/sys/abi_compat.h
@@ -77,7 +77,7 @@
 
 #define	BT_CP(src, dst, fld) do {				\
 	CP((src).fld, (dst).fld, sec);				\
-	*(uint64_t *)&(dst).fld.frac[0] = (src).fld.frac;	\
+	FU64_CP((src).fld, (dst).fld, frac);			\
 } while (0)
 
 #endif /* !_COMPAT_H_ */