proc: use named enums for better readability

Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

fs/proc/base.c

@@ -699,7 +699,7 @@ int proc_setattr(struct dentry *dentry, struct iattr *attr)
  */
 static bool has_pid_permissions(struct proc_fs_info *fs_info,
 				 struct task_struct *task,
-				 int hide_pid_min)
+				 enum proc_hidepid hide_pid_min)
 {
 	/*
 	 * If 'hidpid' mount option is set force a ptrace check,

fs/proc/inode.c

@@ -166,7 +166,7 @@ void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock
 		deactivate_super(old_sb);
 }
 
-static inline const char *hidepid2str(int v)
+static inline const char *hidepid2str(enum proc_hidepid v)
 {
 	switch (v) {
 		case HIDEPID_OFF: return "off";

fs/proc/root.c

@@ -32,9 +32,9 @@
 struct proc_fs_context {
 	struct pid_namespace	*pid_ns;
 	unsigned int		mask;
-	int			hidepid;
+	enum proc_hidepid	hidepid;
 	int			gid;
-	int			pidonly;
+	enum proc_pidonly	pidonly;
 };
 
 enum proc_param {

include/linux/proc_fs.h

@@ -43,7 +43,7 @@ struct proc_ops {
 } __randomize_layout;
 
 /* definitions for hide_pid field */
-enum {
+enum proc_hidepid {
 	HIDEPID_OFF	  = 0,
 	HIDEPID_NO_ACCESS = 1,
 	HIDEPID_INVISIBLE = 2,
@@ -51,7 +51,7 @@ enum {
 };
 
 /* definitions for proc mount option pidonly */
-enum {
+enum proc_pidonly {
 	PROC_PIDONLY_OFF = 0,
 	PROC_PIDONLY_ON  = 1,
 };
@@ -61,8 +61,8 @@ struct proc_fs_info {
 	struct dentry *proc_self;        /* For /proc/self */
 	struct dentry *proc_thread_self; /* For /proc/thread-self */
 	kgid_t pid_gid;
-	int hide_pid;
-	int pidonly;
+	enum proc_hidepid hide_pid;
+	enum proc_pidonly pidonly;
 };
 
 static inline struct proc_fs_info *proc_sb_info(struct super_block *sb)