proc: don't allow async path resolution of /proc/self components

If this is attempted by a kthread, then return -EOPNOTSUPP as we don't
currently support that. Once we can get task_pid_ptr() doing the right
thing, then this can go away again.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/proc/self.c b/fs/proc/self.c
index 72cd69b..cc71ce3 100644 (file)
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -16,6 +16,13 @@ static const char *proc_self_get_link(struct dentry *dentry,
        pid_t tgid = task_tgid_nr_ns(current, ns);
        char *name;
 
+       /*
+        * Not currently supported. Once we can inherit all of struct pid,
+        * we can allow this.
+        */
+       if (current->flags & PF_KTHREAD)
+               return ERR_PTR(-EOPNOTSUPP);
+
        if (!tgid)
                return ERR_PTR(-ENOENT);
        /* max length of unsigned int in decimal + NULL term */