John Fastabend 34f79502bb 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 <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

2017-10-20 13:01:29 +01:00

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Makefile

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sockmap_kern.c

bpf: avoid preempt enable/disable in sockmap using tcp_skb_cb region

2017-10-20 13:01:29 +01:00

sockmap_user.c

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