From: Ilya Maximets <i.maximets@samsung.com>
Date: Fri, 28 Jun 2019 11:04:06 +0300
Subject: xdp: hold device for umem regardless of zero-copy mode
Patch-mainline: v5.3-rc1
Git-commit: 162c820ed8965bf94d2685f97388aea5aee9e258
References: bsc#1109837

Device pointer stored in umem regardless of zero-copy mode,
so we heed to hold the device in all cases.

Fixes: c9b47cc1fabc ("xsk: fix bug when trying to use both copy and zero-copy on one queue id")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/xdp/xdp_umem.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -102,6 +102,9 @@ int xdp_umem_assign_dev(struct xdp_umem
 
 	umem->dev = dev;
 	umem->queue_id = queue_id;
+
+	dev_hold(dev);
+
 	if (force_copy)
 		/* For copy-mode, we are done. */
 		goto out_rtnl_unlock;
@@ -121,7 +124,6 @@ int xdp_umem_assign_dev(struct xdp_umem
 		goto err_unreg_umem;
 	rtnl_unlock();
 
-	dev_hold(dev);
 	umem->zc = true;
 	return 0;
 
@@ -160,10 +162,9 @@ static void xdp_umem_clear_dev(struct xd
 	xdp_clear_umem_at_qid(umem->dev, umem->queue_id);
 	rtnl_unlock();
 
-	if (umem->zc) {
-		dev_put(umem->dev);
-		umem->zc = false;
-	}
+	dev_put(umem->dev);
+	umem->dev = NULL;
+	umem->zc = false;
 }
 
 static void xdp_umem_unpin_pages(struct xdp_umem *umem)