[src/trunk]: src/sys/compat/netbsd32 data_len == 0 on mount means "the kernel...

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

details:   https://anonhg.NetBSD.org/src/rev/a307c57b0c70
branches:  trunk
changeset: 931367:a307c57b0c70
user:      christos <christos%NetBSD.org@localhost>
date:      Mon Apr 27 17:37:34 2020 +0000

description:
data_len == 0 on mount means "the kernel knows". Fixes amd on compat32.

diffstat:

 sys/compat/netbsd32/netbsd32_fs.c |  34 ++++++++++++++++++++--------------
 1 files changed, 20 insertions(+), 14 deletions(-)

diffs (132 lines):

diff -r f11c98a806fe -r a307c57b0c70 sys/compat/netbsd32/netbsd32_fs.c
--- a/sys/compat/netbsd32/netbsd32_fs.c Mon Apr 27 16:57:31 2020 +0000
+++ b/sys/compat/netbsd32/netbsd32_fs.c Mon Apr 27 17:37:34 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: netbsd32_fs.c,v 1.88 2020/04/21 21:42:47 ad Exp $      */
+/*     $NetBSD: netbsd32_fs.c,v 1.89 2020/04/27 17:37:34 christos Exp $        */
 
 /*
  * Copyright (c) 1998, 2001 Matthew R. Green
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_fs.c,v 1.88 2020/04/21 21:42:47 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_fs.c,v 1.89 2020/04/27 17:37:34 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -829,7 +829,7 @@
                return error;
 
        if (strcmp(mtype, MOUNT_TMPFS) == 0) {
-               if (data_len < sizeof(fs_args32.tmpfs_args))
+               if (data_len != 0 && data_len < sizeof(fs_args32.tmpfs_args))
                        return EINVAL;
                if ((flags & MNT_GETARGS) == 0) {
                        error = copyin(data, &fs_args32.tmpfs_args, 
@@ -853,7 +853,7 @@
                data = &fs_args.tmpfs_args;
                data_len = sizeof(fs_args.tmpfs_args);
        } else if (strcmp(mtype, MOUNT_MFS) == 0) {
-               if (data_len < sizeof(fs_args32.mfs_args))
+               if (data_len != 0 && data_len < sizeof(fs_args32.mfs_args))
                        return EINVAL;
                if ((flags & MNT_GETARGS) == 0) {
                        error = copyin(data, &fs_args32.mfs_args, 
@@ -874,7 +874,7 @@
        } else if ((strcmp(mtype, MOUNT_UFS) == 0) ||
                   (strcmp(mtype, MOUNT_EXT2FS) == 0) ||
                   (strcmp(mtype, MOUNT_LFS) == 0)) {
-               if (data_len < sizeof(fs_args32.ufs_args))
+               if (data_len != 0 && data_len < sizeof(fs_args32.ufs_args))
                        return EINVAL;
                if ((flags & MNT_GETARGS) == 0) {
                        error = copyin(data, &fs_args32.ufs_args, 
@@ -888,7 +888,7 @@
                data = &fs_args.ufs_args;
                data_len = sizeof(fs_args.ufs_args);
        } else if (strcmp(mtype, MOUNT_CD9660) == 0) {
-               if (data_len < sizeof(fs_args32.iso_args))
+               if (data_len != 0 && data_len < sizeof(fs_args32.iso_args))
                        return EINVAL;
                if ((flags & MNT_GETARGS) == 0) {
                        error = copyin(data, &fs_args32.iso_args, 
@@ -935,7 +935,7 @@
                data = &fs_args.msdosfs_args;
                data_len = sizeof(fs_args.msdosfs_args);
        } else if (strcmp(mtype, MOUNT_NFS) == 0) {
-               if (data_len < sizeof(fs_args32.nfs_args))
+               if (data_len != 0 && data_len < sizeof(fs_args32.nfs_args))
                        return EINVAL;
                /* XXX: NFS requires copyin even with MNT_GETARGS */
                if ((flags & MNT_GETARGS) == 0) {
@@ -963,7 +963,7 @@
                data = &fs_args.nfs_args;
                data_len = sizeof(fs_args.nfs_args);
        } else if (strcmp(mtype, MOUNT_NULL) == 0) {
-               if (data_len < sizeof(fs_args32.null_args))
+               if (data_len != 0 && data_len < sizeof(fs_args32.null_args))
                        return EINVAL;
                if ((flags & MNT_GETARGS) == 0) {
                        error = copyin(data, &fs_args32.null_args, 
@@ -988,7 +988,8 @@
        if (flags & MNT_GETARGS) {
                data_len = *retval;
                if (strcmp(mtype, MOUNT_TMPFS) == 0) {
-                       if (data_len != sizeof(fs_args.tmpfs_args))
+                       if (data_len != 0 &&
+                           data_len != sizeof(fs_args.tmpfs_args))
                                return EINVAL;
                        fs_args32.tmpfs_args.ta_version =
                            fs_args.tmpfs_args.ta_version;
@@ -1006,7 +1007,8 @@
                                    sizeof(fs_args32.tmpfs_args));
                        *retval = sizeof(fs_args32.tmpfs_args);
                } else if (strcmp(mtype, MOUNT_MFS) == 0) {
-                       if (data_len != sizeof(fs_args.mfs_args))
+                       if (data_len != 0 &&
+                           data_len != sizeof(fs_args.mfs_args))
                                return EINVAL;
                        NETBSD32PTR32(fs_args32.mfs_args.fspec,
                            fs_args.mfs_args.fspec);
@@ -1019,7 +1021,8 @@
                                    sizeof(fs_args32.mfs_args));
                        *retval = sizeof(fs_args32.mfs_args);
                } else if (strcmp(mtype, MOUNT_UFS) == 0) {
-                       if (data_len != sizeof(fs_args.ufs_args))
+                       if (data_len != 0 &&
+                           data_len != sizeof(fs_args.ufs_args))
                                return EINVAL;
                        NETBSD32PTR32(fs_args32.ufs_args.fspec,
                            fs_args.ufs_args.fspec);
@@ -1027,7 +1030,8 @@
                            sizeof(fs_args32.ufs_args));
                        *retval = sizeof(fs_args32.ufs_args);
                } else if (strcmp(mtype, MOUNT_CD9660) == 0) {
-                       if (data_len != sizeof(fs_args.iso_args))
+                       if (data_len != 0 &&
+                           data_len != sizeof(fs_args.iso_args))
                                return EINVAL;
                        NETBSD32PTR32(fs_args32.iso_args.fspec,
                            fs_args.iso_args.fspec);
@@ -1038,7 +1042,8 @@
                                    sizeof(fs_args32.iso_args));
                        *retval = sizeof(fs_args32.iso_args);
                } else if (strcmp(mtype, MOUNT_NFS) == 0) {
-                       if (data_len != sizeof(fs_args.nfs_args))
+                       if (data_len != 0 &&
+                           data_len != sizeof(fs_args.nfs_args))
                                return EINVAL;
                        NETBSD32PTR32(fs_args32.nfs_args.addr,
                            fs_args.nfs_args.addr);
@@ -1058,7 +1063,8 @@
                            sizeof(fs_args32.nfs_args));
                        *retval = sizeof(fs_args32.nfs_args);
                } else if (strcmp(mtype, MOUNT_NULL) == 0) {
-                       if (data_len != sizeof(fs_args.null_args))
+                       if (data_len != 0 &&
+                           data_len != sizeof(fs_args.null_args))
                                return EINVAL;
                        NETBSD32PTR32(fs_args32.null_args.la.target,
                            fs_args.null_args.la.target);