Subject: linux-next: manual merge of the userns tree with the vfs tree

From: Stephen Rothwell <[email-masked]>
Date: Wed, 10 Dec 2014 17:27:05 +1100

Hi Eric,

Today's linux-next merge of the userns tree got a conflict in
kernel/user_namespace.c between commits 3c0411846118 ("switch the rest
of proc_ns_operations to working with &...->ns") and 64964528b24e
("make proc_ns_operations work with struct ns_common * instead of void
*") from the vfs tree and commit 2b714ea67ed4 ("userns: Add a knob to
disable setgroups on a per user namespace basis") from the userns tree.

I fixed it up (see below) and can carry the fix as necessary (no action
is required).

-- 
Cheers,
Stephen Rothwell                    [email-masked]

diff --cc kernel/user_namespace.c
index 1491ad00388f,1db950ec08ce..000000000000
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@@ -842,12 -851,99 +852,104 @@@ static bool new_idmap_permitted(const s
  	return false;
  }
  
 +static inline struct user_namespace *to_user_ns(struct ns_common *ns)
 +{
 +	return container_of(ns, struct user_namespace, ns);
 +}
 +
+ static void *setgroups_m_start(struct seq_file *seq, loff_t *ppos)
+ {
+ 	struct user_namespace *ns = seq->private;
+ 
+ 	return (*ppos == 0) ?  ns : NULL;
+ }
+ 
+ static void *setgroups_m_next(struct seq_file *seq, void *v, loff_t *ppos)
+ {
+ 	++*ppos;
+ 	return NULL;
+ }
+ 
+ static void setgroups_m_stop(struct seq_file *seq, void *v)
+ {
+ }
+ 
+ static int setgroups_m_show(struct seq_file *seq, void *v)
+ {
+ 	struct user_namespace *ns = seq->private;
+ 
+ 	seq_printf(seq, "%s\n",
+ 		   test_bit(USERNS_SETGROUPS_ALLOWED, &ns->flags) ?
+ 		   "allow" : "deny");
+ 	return 0;
+ }
+ 
+ const struct seq_operations proc_setgroups_seq_operations = {
+ 	.start	= setgroups_m_start,
+ 	.stop = setgroups_m_stop,
+ 	.next = setgroups_m_next,
+ 	.show = setgroups_m_show,
+ };
+ 
+ ssize_t proc_setgroups_write(struct file *file, const char __user *buf,
+ 			     size_t count, loff_t *ppos)
+ {
+ 	struct seq_file *seq = file->private_data;
+ 	struct user_namespace *ns = seq->private;
+ 	char kbuf[8], *pos;
+ 	bool setgroups_allowed;
+ 	ssize_t ret;
+ 
+ 	ret = -EACCES;
+ 	if (!file_ns_capable(file, ns, CAP_SYS_ADMIN))
+ 		goto out;
+ 
+ 	/* Only allow a very narrow range of strings to be written */
+ 	ret = -EINVAL;
+ 	if ((*ppos != 0) || (count >= sizeof(kbuf)))
+ 		goto out;
+ 
+ 	/* What was written? */
+ 	ret = -EFAULT;
+ 	if (copy_from_user(kbuf, buf, count))
+ 		goto out;
+ 	kbuf[count] = '\0';
+ 	pos = kbuf;
+ 
+ 	/* What is being requested? */
+ 	ret = -EINVAL;
+ 	if (strncmp(pos, "allow", 5) == 0) {
+ 		pos += 5;
+ 		setgroups_allowed = true;
+ 	}
+ 	else if (strncmp(pos, "deny", 4) == 0) {
+ 		pos += 4;
+ 		setgroups_allowed = false;
+ 	}
+ 	else
+ 		goto out;
+ 
+ 	/* Verify there is not trailing junk on the line */
+ 	pos = skip_spaces(pos);
+ 	if (*pos != '\0')
+ 		goto out;
+ 
+ 	if (setgroups_allowed) {
+ 		ret = -EPERM;
+ 		if (!userns_setgroups_allowed(ns))
+ 			goto out;
+ 	} else {
+ 		userns_disable_setgroups(ns);
+ 	}
+ 
+ 	/* Report a successful write */
+ 	*ppos = count;
+ 	ret = count;
+ out:
+ 	return ret;
+ }
+ 
 -static void *userns_get(struct task_struct *task)
 +static struct ns_common *userns_get(struct task_struct *task)
  {
  	struct user_namespace *user_ns;