Make sure all intermediate variables holding mount flags (mnt_flag)

and that all internal kernel calls passing mount flags are declared
as uint64_t so that flags in the top 32-bits are not lost.

MFC after: 2 weeks

1 files changed, 11 insertions, 3 deletions

diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
index 9390bc6a70a3..aff280ad0b7d 100644
--- a/sys/compat/freebsd32/freebsd32_misc.c
+++ b/sys/compat/freebsd32/freebsd32_misc.c
@@ -2485,9 +2485,17 @@ freebsd32_nmount(struct thread *td,
     } */ *uap)
 {
 	struct uio *auio;
+	uint64_t flags;
 	int error;
 
-	AUDIT_ARG_FFLAGS(uap->flags);
+	/*
+	 * Mount flags are now 64-bits. On 32-bit archtectures only
+	 * 32-bits are passed in, but from here on everything handles
+	 * 64-bit flags correctly.
+	 */
+	flags = uap->flags;
+
+	AUDIT_ARG_FFLAGS(flags);
 
 	/*
 	 * Filter out MNT_ROOTFS.  We do not want clients of nmount() in
@@ -2496,7 +2504,7 @@ freebsd32_nmount(struct thread *td,
 	 * MNT_ROOTFS should only be set by the kernel when mounting its
 	 * root file system.
 	 */
-	uap->flags &= ~MNT_ROOTFS;
+	flags &= ~MNT_ROOTFS;
 
 	/*
 	 * check that we have an even number of iovec's
@@ -2508,7 +2516,7 @@ freebsd32_nmount(struct thread *td,
 	error = freebsd32_copyinuio(uap->iovp, uap->iovcnt, &auio);
 	if (error)
 		return (error);
-	error = vfs_donmount(td, uap->flags, auio);
+	error = vfs_donmount(td, flags, auio);
 
 	free(auio, M_IOV);
 	return error;