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authorJohn Fastabend <john.fastabend@gmail.com>2017-10-18 07:10:36 -0700
committerDavid S. Miller <davem@davemloft.net>2017-10-20 13:01:29 +0100
commit34f79502bbcfab659b8729da68b5e387f96eb4c1 (patch)
tree27084757c315fdf13c682c3d6c57922ed5f8447c /samples/sockmap
parent435bf0d3f99a164df7e8c30428cef266b91d1d3b (diff)
downloadlinux-34f79502bbcfab659b8729da68b5e387f96eb4c1.tar.bz2
bpf: avoid preempt enable/disable in sockmap using tcp_skb_cb region
SK_SKB BPF programs are run from the socket/tcp context but early in the stack before much of the TCP metadata is needed in tcp_skb_cb. So we can use some unused fields to place BPF metadata needed for SK_SKB programs when implementing the redirect function. This allows us to drop the preempt disable logic. It does however require an API change so sk_redirect_map() has been updated to additionally provide ctx_ptr to skb. Note, we do however continue to disable/enable preemption around actual BPF program running to account for map updates. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'samples/sockmap')
-rw-r--r--samples/sockmap/sockmap_kern.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/samples/sockmap/sockmap_kern.c b/samples/sockmap/sockmap_kern.c
index f9b38ef82dc2..52b0053274f4 100644
--- a/samples/sockmap/sockmap_kern.c
+++ b/samples/sockmap/sockmap_kern.c
@@ -62,7 +62,7 @@ int bpf_prog2(struct __sk_buff *skb)
ret = 1;
bpf_printk("sockmap: %d -> %d @ %d\n", lport, bpf_ntohl(rport), ret);
- return bpf_sk_redirect_map(&sock_map, ret, 0);
+ return bpf_sk_redirect_map(skb, &sock_map, ret, 0);
}
SEC("sockops")