sys/compat/freebsd32: FF clock struct: Don't pack, use 'ffcounter32'

Packing 'struct ffclock_estimate32', in absence of substitution of
'ffcounter' (some 'uint64_t') by a 32-bit compatible type, was necessary
on amd64 since 'uint64_t' is 8-byte aligned, which leaves a padding gap
of 4-byte between fields 'update_time' and 'update_ffcount'.  This gap
does not exist on i386 (or amd64 32-bit mode), as 'uint64_t' there is
only 4-byte aligned.

Change the type of the 'update_ffcount' and 'leapsec_next' fields to the
recently introduced 'freebsd32_uint64_t', and adapt copy-in and copy-out
accordingly.  Using `CP()` previously worked due to the '__packed__'
attribute.

Reviewed by:    kib
MFC after:      2 weeks
Sponsored by:   The FreeBSD Foundation
Differential Revision:  https://reviews.freebsd.org/D55282

2 files changed, 9 insertions, 11 deletions

diff --git a/sys/compat/freebsd32/freebsd32.h b/sys/compat/freebsd32/freebsd32.h
index 5210ce55b228..1436b630689f 100644
--- a/sys/compat/freebsd32/freebsd32.h
+++ b/sys/compat/freebsd32/freebsd32.h
@@ -60,8 +60,8 @@ struct bintime32 {
 
 struct ffclock_estimate32 {
 	struct bintime32 update_time;
-	ffcounter update_ffcount;
-	ffcounter leapsec_next;
+	freebsd32_uint64_t update_ffcount;
+	freebsd32_uint64_t leapsec_next;
 	freebsd32_uint64_t period;
 	uint32_t errb_abs;
 	uint32_t errb_rate;
@@ -69,11 +69,9 @@ struct ffclock_estimate32 {
 	int16_t leapsec_total;
 	int8_t leapsec;
 	int8_t _pad;
-}
-#if defined(__amd64__)
-__attribute__((packed))
-#endif
-;
+};
+_Static_assert(sizeof(ffcounter) == sizeof(freebsd32_uint64_t),
+    "'ffcounter' size discrepancy'");
 #if defined(__amd64__) || defined(__i386__)
 _Static_assert(sizeof(struct ffclock_estimate32) == 52, "ffclock_estimate32 size");
 #else
diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
index 457e599c22d2..1064987c3abf 100644
--- a/sys/compat/freebsd32/freebsd32_misc.c
+++ b/sys/compat/freebsd32/freebsd32_misc.c
@@ -4147,8 +4147,8 @@ freebsd32_ffclock_setestimate(struct thread *td,
 
 	CP(cest.update_time, cest32.update_time, sec);
 	memcpy(&cest.update_time.frac, &cest32.update_time.frac, sizeof(uint64_t));
-	CP(cest, cest32, update_ffcount);
-	CP(cest, cest32, leapsec_next);
+	FU64_CP(cest, cest32, update_ffcount);
+	FU64_CP(cest, cest32, leapsec_next);
 	FU64_CP(cest, cest32, period);
 	CP(cest, cest32, errb_abs);
 	CP(cest, cest32, errb_rate);
@@ -4177,8 +4177,8 @@ freebsd32_ffclock_getestimate(struct thread *td,
 
 	CP(cest32.update_time, cest.update_time, sec);
 	memcpy(&cest32.update_time.frac, &cest.update_time.frac, sizeof(uint64_t));
-	CP(cest32, cest, update_ffcount);
-	CP(cest32, cest, leapsec_next);
+	FU64_CP(cest32, cest, update_ffcount);
+	FU64_CP(cest32, cest, leapsec_next);
 	FU64_CP(cest32, cest, period);
 	CP(cest32, cest, errb_abs);
 	CP(cest32, cest, errb_rate);