LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount()

... leaving the "is it kernel-internal" logics in the caller.
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/super.c

@@ -1275,10 +1275,16 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
 	smp_wmb();
 	sb->s_flags |= SB_BORN;
 
-	error = security_sb_kern_mount(sb, flags, &opts);
+	error = security_sb_set_mnt_opts(sb, &opts, 0, NULL);
 	if (error)
 		goto out_sb;
 
+	if (!(flags & MS_KERNMOUNT)) {
+		error = security_sb_kern_mount(sb);
+		if (error)
+			goto out_sb;
+	}
+
 	/*
 	 * filesystems should never set s_maxbytes larger than MAX_LFS_FILESIZE
 	 * but s_maxbytes was an unsigned long long for many releases. Throw

include/linux/lsm_hooks.h

@@ -1464,8 +1464,7 @@ union security_list_options {
 	int (*sb_copy_data)(char *orig, char *copy);
 	int (*sb_remount)(struct super_block *sb,
 			  struct security_mnt_opts *opts);
-	int (*sb_kern_mount)(struct super_block *sb, int flags,
-			     struct security_mnt_opts *opts);
+	int (*sb_kern_mount)(struct super_block *sb);
 	int (*sb_show_options)(struct seq_file *m, struct super_block *sb);
 	int (*sb_statfs)(struct dentry *dentry);
 	int (*sb_mount)(const char *dev_name, const struct path *path,

include/linux/security.h

@@ -250,8 +250,7 @@ int security_sb_alloc(struct super_block *sb);
 void security_sb_free(struct super_block *sb);
 int security_sb_eat_lsm_opts(char *options, struct security_mnt_opts *opts);
 int security_sb_remount(struct super_block *sb, struct security_mnt_opts *opts);
-int security_sb_kern_mount(struct super_block *sb, int flags,
-			   struct security_mnt_opts *opts);
+int security_sb_kern_mount(struct super_block *sb);
 int security_sb_show_options(struct seq_file *m, struct super_block *sb);
 int security_sb_statfs(struct dentry *dentry);
 int security_sb_mount(const char *dev_name, const struct path *path,
@@ -568,8 +567,7 @@ static inline int security_sb_remount(struct super_block *sb,
 	return 0;
 }
 
-static inline int security_sb_kern_mount(struct super_block *sb, int flags,
-					 struct security_mnt_opts *opts)
+static inline int security_sb_kern_mount(struct super_block *sb)
 {
 	return 0;
 }

security/security.c

@@ -405,10 +405,9 @@ int security_sb_remount(struct super_block *sb,
 	return call_int_hook(sb_remount, 0, sb, opts);
 }
 
-int security_sb_kern_mount(struct super_block *sb, int flags,
-			   struct security_mnt_opts *opts)
+int security_sb_kern_mount(struct super_block *sb)
 {
-	return call_int_hook(sb_kern_mount, 0, sb, flags, opts);
+	return call_int_hook(sb_kern_mount, 0, sb);
 }
 
 int security_sb_show_options(struct seq_file *m, struct super_block *sb)

security/selinux/hooks.c

@@ -2874,18 +2874,10 @@ static int selinux_sb_remount(struct super_block *sb,
 	return -EINVAL;
 }
 
-static int selinux_sb_kern_mount(struct super_block *sb, int flags,
-				 struct security_mnt_opts *opts)
+static int selinux_sb_kern_mount(struct super_block *sb)
 {
 	const struct cred *cred = current_cred();
 	struct common_audit_data ad;
-	int rc = selinux_set_mnt_opts(sb, opts, 0, NULL);
-	if (rc)
-		return rc;
-
-	/* Allow all mounts performed by the kernel */
-	if (flags & MS_KERNMOUNT)
-		return 0;
 
 	ad.type = LSM_AUDIT_DATA_DENTRY;
 	ad.u.dentry = sb->s_root;

security/smack/smack_lsm.c

@@ -851,20 +851,6 @@ static int smack_set_mnt_opts(struct super_block *sb,
 	return 0;
 }
 
-/**
- * smack_sb_kern_mount - Smack specific mount processing
- * @sb: the file system superblock
- * @flags: the mount flags
- * @data: the smack mount options
- *
- * Returns 0 on success, an error code on failure
- */
-static int smack_sb_kern_mount(struct super_block *sb, int flags,
-			       struct security_mnt_opts *opts)
-{
-	return smack_set_mnt_opts(sb, opts, 0, NULL);
-}
-
 /**
  * smack_sb_statfs - Smack check on statfs
  * @dentry: identifies the file system in question
@@ -4652,7 +4638,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
 	LSM_HOOK_INIT(sb_free_security, smack_sb_free_security),
 	LSM_HOOK_INIT(sb_copy_data, smack_sb_copy_data),
-	LSM_HOOK_INIT(sb_kern_mount, smack_sb_kern_mount),
 	LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
 	LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
 	LSM_HOOK_INIT(sb_parse_opts_str, smack_parse_opts_str),