LSM/SELinux: show LSM mount options in /proc/mounts

This patch causes SELinux mount options to show up in /proc/mounts.  As
with other code in the area seq_put errors are ignored.  Other LSM's
will not have their mount options displayed until they fill in their own
security_sb_show_options() function.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/security.h b/include/linux/security.h
index 62bd80cb7f87..c8ad8ec684b4 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -80,6 +80,7 @@ struct xfrm_selector;
 struct xfrm_policy;
 struct xfrm_state;
 struct xfrm_user_sec_ctx;
+struct seq_file;
 
 extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb);
 extern int cap_netlink_recv(struct sk_buff *skb, int cap);
@@ -1331,6 +1332,7 @@ struct security_operations {
         void (*sb_free_security) (struct super_block *sb);
         int (*sb_copy_data) (char *orig, char *copy);
         int (*sb_kern_mount) (struct super_block *sb, void *data);
+        int (*sb_show_options) (struct seq_file *m, struct super_block *sb);
         int (*sb_statfs) (struct dentry *dentry);
         int (*sb_mount) (char *dev_name, struct path *path,
                          char *type, unsigned long flags, void *data);
@@ -1610,6 +1612,7 @@ int security_sb_alloc(struct super_block *sb);
 void security_sb_free(struct super_block *sb);
 int security_sb_copy_data(char *orig, char *copy);
 int security_sb_kern_mount(struct super_block *sb, void *data);
+int security_sb_show_options(struct seq_file *m, struct super_block *sb);
 int security_sb_statfs(struct dentry *dentry);
 int security_sb_mount(char *dev_name, struct path *path,
                       char *type, unsigned long flags, void *data);
@@ -1887,6 +1890,12 @@ static inline int security_sb_kern_mount(struct super_block *sb, void *data)
         return 0;
 }
 
+static inline int security_sb_show_options(struct seq_file *m,
+                                           struct super_block *sb)
+{
+        return 0;
+}
+
 static inline int security_sb_statfs(struct dentry *dentry)
 {
         return 0;