--- zzzz-none-000/linux-3.10.107/fs/proc/root.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/proc/root.c	2021-02-04 17:41:59.000000000 +0000
@@ -92,6 +92,8 @@
 int proc_remount(struct super_block *sb, int *flags, char *data)
 {
 	struct pid_namespace *pid = sb->s_fs_info;
+
+	sync_filesystem(sb);
 	return !proc_parse_options(data, pid);
 }
 
@@ -110,8 +112,8 @@
 		ns = task_active_pid_ns(current);
 		options = data;
 
-		if (!current_user_ns()->may_mount_proc ||
-		    !ns_capable(ns->user_ns, CAP_SYS_ADMIN))
+		/* Does the mounter have privilege over the pid namespace? */
+		if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN))
 			return ERR_PTR(-EPERM);
 	}
 
@@ -119,6 +121,13 @@
 	if (IS_ERR(sb))
 		return ERR_CAST(sb);
 
+	/*
+	 * procfs isn't actually a stacking filesystem; however, there is
+	 * too much magic going on inside it to permit stacking things on
+	 * top of it
+	 */
+	sb->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH;
+
 	if (!proc_parse_options(options, ns)) {
 		deactivate_locked_super(sb);
 		return ERR_PTR(-EINVAL);
@@ -132,6 +141,8 @@
 		}
 
 		sb->s_flags |= MS_ACTIVE;
+		/* User space would break if executables appear on proc */
+		sb->s_iflags |= SB_I_NOEXEC;
 	}
 
 	return dget(sb->s_root);
@@ -144,6 +155,8 @@
 	ns = (struct pid_namespace *)sb->s_fs_info;
 	if (ns->proc_self)
 		dput(ns->proc_self);
+	if (ns->proc_thread_self)
+		dput(ns->proc_thread_self);
 	kill_anon_super(sb);
 	put_pid_ns(ns);
 }
@@ -152,7 +165,7 @@
 	.name		= "proc",
 	.mount		= proc_mount,
 	.kill_sb	= proc_kill_sb,
-	.fs_flags	= FS_USERNS_MOUNT,
+	.fs_flags	= FS_USERNS_VISIBLE | FS_USERNS_MOUNT,
 };
 
 void __init proc_root_init(void)
@@ -165,6 +178,7 @@
 		return;
 
 	proc_self_init();
+	proc_thread_self_init();
 	proc_symlink("mounts", NULL, "self/mounts");
 
 	proc_net_init();
@@ -174,15 +188,12 @@
 #endif
 	proc_mkdir("fs", NULL);
 	proc_mkdir("driver", NULL);
-	proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
+	proc_create_mount_point("fs/nfsd"); /* somewhere for the nfsd filesystem to be mounted */
 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
 	/* just give it a mountpoint */
-	proc_mkdir("openprom", NULL);
+	proc_create_mount_point("openprom");
 #endif
 	proc_tty_init();
-#ifdef CONFIG_PROC_DEVICETREE
-	proc_device_tree_init();
-#endif
 	proc_mkdir("bus", NULL);
 	proc_sys_init();
 }
@@ -190,34 +201,29 @@
 static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
 )
 {
-	generic_fillattr(dentry->d_inode, stat);
+	generic_fillattr(d_inode(dentry), stat);
 	stat->nlink = proc_root.nlink + nr_processes();
 	return 0;
 }
 
 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
 {
-	if (!proc_lookup(dir, dentry, flags))
+	if (!proc_pid_lookup(dir, dentry, flags))
 		return NULL;
 	
-	return proc_pid_lookup(dir, dentry, flags);
+	return proc_lookup(dir, dentry, flags);
 }
 
-static int proc_root_readdir(struct file * filp,
-	void * dirent, filldir_t filldir)
+static int proc_root_readdir(struct file *file, struct dir_context *ctx)
 {
-	unsigned int nr = filp->f_pos;
-	int ret;
-
-	if (nr < FIRST_PROCESS_ENTRY) {
-		int error = proc_readdir(filp, dirent, filldir);
-		if (error <= 0)
+	if (ctx->pos < FIRST_PROCESS_ENTRY) {
+		int error = proc_readdir(file, ctx);
+		if (unlikely(error <= 0))
 			return error;
-		filp->f_pos = FIRST_PROCESS_ENTRY;
+		ctx->pos = FIRST_PROCESS_ENTRY;
 	}
 
-	ret = proc_pid_readdir(filp, dirent, filldir);
-	return ret;
+	return proc_pid_readdir(file, ctx);
 }
 
 /*
@@ -227,7 +233,7 @@
  */
 static const struct file_operations proc_root_operations = {
 	.read		 = generic_read_dir,
-	.readdir	 = proc_root_readdir,
+	.iterate	 = proc_root_readdir,
 	.llseek		= default_llseek,
 };
 
@@ -251,6 +257,7 @@
 	.proc_iops	= &proc_root_inode_operations, 
 	.proc_fops	= &proc_root_operations,
 	.parent		= &proc_root,
+	.subdir		= RB_ROOT,
 	.name		= "/proc",
 };