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Message-ID: <20180321233104.2142764-3-yhs@fb.com>
Date: Wed, 21 Mar 2018 16:31:04 -0700
From: Yonghong Song <yhs@...com>
To: <edumazet@...gle.com>, <ast@...com>, <daniel@...earbox.net>,
<diptanu@...com>, <netdev@...r.kernel.org>
CC: <kernel-team@...com>
Subject: [PATCH net-next v6 2/2] net: bpf: add a test for skb_segment in test_bpf module
Without the previous commit,
"modprobe test_bpf" will have the following errors:
...
[ 98.149165] ------------[ cut here ]------------
[ 98.159362] kernel BUG at net/core/skbuff.c:3667!
[ 98.169756] invalid opcode: 0000 [#1] SMP PTI
[ 98.179370] Modules linked in:
[ 98.179371] test_bpf(+)
...
which triggers the bug the previous commit intends to fix.
The skbs are constructed to mimic what mlx5 may generate.
The packet size/header may not mimic real cases in production. But
the processing flow is similar.
Signed-off-by: Yonghong Song <yhs@...com>
---
lib/test_bpf.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 91 insertions(+), 2 deletions(-)
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 2efb213..a468b5c 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -6574,6 +6574,93 @@ static bool exclude_test(int test_id)
return test_id < test_range[0] || test_id > test_range[1];
}
+static __init struct sk_buff *build_test_skb(void)
+{
+ u32 headroom = NET_SKB_PAD + NET_IP_ALIGN + ETH_HLEN;
+ struct sk_buff *skb[2];
+ struct page *page[2];
+ int i, data_size = 8;
+
+ for (i = 0; i < 2; i++) {
+ page[i] = alloc_page(GFP_KERNEL);
+ if (!page[i]) {
+ if (i == 0)
+ goto err_page0;
+ else
+ goto err_page1;
+ }
+
+ /* this will set skb[i]->head_frag */
+ skb[i] = dev_alloc_skb(headroom + data_size);
+ if (!skb[i]) {
+ if (i == 0)
+ goto err_skb0;
+ else
+ goto err_skb1;
+ }
+
+ skb_reserve(skb[i], headroom);
+ skb_put(skb[i], data_size);
+ skb[i]->protocol = htons(ETH_P_IP);
+ skb_reset_network_header(skb[i]);
+ skb_set_mac_header(skb[i], -ETH_HLEN);
+
+ skb_add_rx_frag(skb[i], 0, page[i], 0, 64, 64);
+ // skb_headlen(skb[i]): 8, skb[i]->head_frag = 1
+ }
+
+ /* setup shinfo */
+ skb_shinfo(skb[0])->gso_size = 1448;
+ skb_shinfo(skb[0])->gso_type = SKB_GSO_TCPV4;
+ skb_shinfo(skb[0])->gso_type |= SKB_GSO_DODGY;
+ skb_shinfo(skb[0])->gso_segs = 0;
+ skb_shinfo(skb[0])->frag_list = skb[1];
+
+ /* adjust skb[0]'s len */
+ skb[0]->len += skb[1]->len;
+ skb[0]->data_len += skb[1]->data_len;
+ skb[0]->truesize += skb[1]->truesize;
+
+ return skb[0];
+
+err_skb1:
+ __free_page(page[1]);
+err_page1:
+ kfree_skb(skb[0]);
+err_skb0:
+ __free_page(page[0]);
+err_page0:
+ return NULL;
+}
+
+static __init int test_skb_segment(void)
+{
+ netdev_features_t features;
+ struct sk_buff *skb, *segs;
+ int ret = -1;
+
+ features = NETIF_F_SG | NETIF_F_GSO_PARTIAL | NETIF_F_IP_CSUM |
+ NETIF_F_IPV6_CSUM;
+ features |= NETIF_F_RXCSUM;
+ skb = build_test_skb();
+ if (!skb) {
+ pr_info("%s: failed to build_test_skb", __func__);
+ goto done;
+ }
+
+ segs = skb_segment(skb, features);
+ if (segs) {
+ kfree_skb_list(segs);
+ ret = 0;
+ pr_info("%s: success in skb_segment!", __func__);
+ } else {
+ pr_info("%s: failed in skb_segment!", __func__);
+ }
+ kfree_skb(skb);
+done:
+ return ret;
+}
+
static __init int test_bpf(void)
{
int i, err_cnt = 0, pass_cnt = 0;
@@ -6632,9 +6719,11 @@ static int __init test_bpf_init(void)
return ret;
ret = test_bpf();
-
destroy_bpf_tests();
- return ret;
+ if (ret)
+ return ret;
+
+ return test_skb_segment();
}
static void __exit test_bpf_exit(void)
--
2.9.5
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