From: Zhang Changzhong <zhangchangzhong@huawei.com>
Date: Fri, 4 Dec 2020 10:21:16 +0000 (+0800)
Subject: xsk: Return error code if force_zc is set
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=12c8a8ca117f3d734babc3fba131fdaa329d2163;p=uclinux-h8%2Flinux.git

xsk: Return error code if force_zc is set

If force_zc is set, we should exit out with an error, not fall back to
copy mode.

Fixes: 921b68692abb ("xsk: Enable sharing of dma mappings")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/1607077277-41995-1-git-send-email-zhangchangzhong@huawei.com
---

diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 9287eddec52c..d5adeee9d5d9 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -175,6 +175,7 @@ static int __xp_assign_dev(struct xsk_buff_pool *pool,
 
 	if (!pool->dma_pages) {
 		WARN(1, "Driver did not DMA map zero-copy buffers");
+		err = -EINVAL;
 		goto err_unreg_xsk;
 	}
 	pool->umem->zc = true;