9p-trans_fd: don't do fs segment mangling in p9_fd_poll()

p9_fd_poll() is never called with user pointers and f_op->poll()
doesn't expect its arguments to be from userland.  There's no need to
set kernel ds before calling f_op->poll() from p9_fd_poll().  Remove
it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 6c88e89..f6d4af1 100644 (file)
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -1344,7 +1344,6 @@ p9_fd_poll(struct p9_trans *trans, struct poll_table_struct *pt)
 {
        int ret, n;
        struct p9_trans_fd *ts = NULL;
-       mm_segment_t oldfs;
 
        if (trans && trans->status == Connected)
                ts = trans->priv;
@@ -1358,24 +1357,17 @@ p9_fd_poll(struct p9_trans *trans, struct poll_table_struct *pt)
        if (!ts->wr->f_op || !ts->wr->f_op->poll)
                return -EIO;
 
-       oldfs = get_fs();
-       set_fs(get_ds());
-
        ret = ts->rd->f_op->poll(ts->rd, pt);
        if (ret < 0)
-               goto end;
+               return ret;
 
        if (ts->rd != ts->wr) {
                n = ts->wr->f_op->poll(ts->wr, pt);
-               if (n < 0) {
-                       ret = n;
-                       goto end;
-               }
+               if (n < 0)
+                       return n;
                ret = (ret & ~POLLOUT) | (n & ~POLLIN);
        }
 
-end:
-       set_fs(oldfs);
        return ret;
 }