[src/trunk]: src/sys/compat/netbsd32 never pass mp->mnt_stat to dostatvfs(), ...

[chs <chs%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/942476099efc
branches:  trunk
changeset: 352375:942476099efc
user:      chs <chs%NetBSD.org@localhost>
date:      Tue Mar 28 18:44:04 2017 +0000

description:
never pass mp->mnt_stat to dostatvfs(), always use a separate buffer.
dostatvfs() clears its buffer, but mp->mnt_stat should never be cleared.

diffstat:

 sys/compat/netbsd32/netbsd32_compat_20.c |  16 ++++++++++------
 1 files changed, 10 insertions(+), 6 deletions(-)

diffs (52 lines):

diff -r 48d993f2edf5 -r 942476099efc sys/compat/netbsd32/netbsd32_compat_20.c
--- a/sys/compat/netbsd32/netbsd32_compat_20.c  Tue Mar 28 17:42:52 2017 +0000
+++ b/sys/compat/netbsd32/netbsd32_compat_20.c  Tue Mar 28 18:44:04 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: netbsd32_compat_20.c,v 1.34 2014/09/05 09:21:54 matt Exp $     */
+/*     $NetBSD: netbsd32_compat_20.c,v 1.35 2017/03/28 18:44:04 chs Exp $      */
 
 /*
  * Copyright (c) 1998, 2001 Matthew R. Green
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_compat_20.c,v 1.34 2014/09/05 09:21:54 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_compat_20.c,v 1.35 2017/03/28 18:44:04 chs Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -166,12 +166,15 @@
        if (error != 0)
                return (error);
        mp = vp->v_mount;
-       sb = &mp->mnt_stat;
        vrele(vp);
+       sb = STATVFSBUF_GET();
        if ((error = dostatvfs(mp, sb, l, 0, 0)) != 0)
-               return (error);
+               goto out;
        compat_20_netbsd32_from_statvfs(sb, &s32);
-       return copyout(&s32, SCARG_P32(uap, buf), sizeof(s32));
+       error = copyout(&s32, SCARG_P32(uap, buf), sizeof(s32));
+out:
+       STATVFSBUF_PUT(sb);
+       return error;
 }
 
 int
@@ -191,12 +194,13 @@
        if ((error = fd_getvnode(SCARG(uap, fd), &fp)) != 0)
                return (error);
        mp = fp->f_vnode->v_mount;
-       sb = &mp->mnt_stat;
+       sb = STATVFSBUF_GET();
        if ((error = dostatvfs(mp, sb, l, 0, 0)) != 0)
                goto out;
        compat_20_netbsd32_from_statvfs(sb, &s32);
        error = copyout(&s32, SCARG_P32(uap, buf), sizeof(s32));
  out:
+       STATVFSBUF_PUT(sb);
        fd_putfile(SCARG(uap, fd));
        return (error);
 }