Merge the fueword(9) and casueword(9). In particular,

MFC r273783:
Add fueword(9) and casueword(9) functions.
MFC note: ia64 is handled like arm, with NO_FUEWORD define.

MFC r273784:
Replace some calls to fuword() by fueword() with proper error checking.

MFC r273785:
Convert kern_umtx.c to use fueword() and casueword().
MFC note: the sys__umtx_lock and sys__umtx_unlock syscalls are not
converted, they are removed from HEAD, and not used.  The do_sem2*()
family is not yet merged to stable/10, corresponding chunk will be
merged after do_sem2* are committed.

MFC r273788 (by jkim):
Actually install casuword(9) to fix build.

MFC r273911:
Add type qualifier volatile to the base (userspace) address argument
of fuword(9) and suword(9).

1 files changed, 8 insertions, 3 deletions

diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
index ff72aad..eeb8347 100644
--- a/sys/compat/freebsd32/freebsd32_misc.c
+++ b/sys/compat/freebsd32/freebsd32_misc.c
@@ -1924,16 +1924,21 @@ freebsd32_sysctl(struct thread *td, struct freebsd32_sysctl_args *uap)
 {
 	int error, name[CTL_MAXNAME];
 	size_t j, oldlen;
+	uint32_t tmp;
 
 	if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
 		return (EINVAL);
  	error = copyin(uap->name, name, uap->namelen * sizeof(int));
  	if (error)
 		return (error);
-	if (uap->oldlenp)
-		oldlen = fuword32(uap->oldlenp);
-	else
+	if (uap->oldlenp) {
+		error = fueword32(uap->oldlenp, &tmp);
+		oldlen = tmp;
+	} else {
 		oldlen = 0;
+	}
+	if (error != 0)
+		return (EFAULT);
 	error = userland_sysctl(td, name, uap->namelen,
 		uap->old, &oldlen, 1,
 		uap->new, uap->newlen, &j, SCTL_MASK32);