bpf: make cavium thunder compatible w/ bpf_xdp_adjust_tail

w/ bpf_xdp_adjust_tail helper xdp's data_end pointer could be changed as
well (only "decrease" of pointer's location is going to be supported).
changing of this pointer will change packet's size.
for cavium's thunder driver we will just calculate packet's length
unconditionally

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
index 707db33043967e00d5c9013bd334ccef7660a8c1..7135db45927e59a56e231f172544ce10d76665d5 100644 (file)
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -538,9 +538,9 @@ static inline bool nicvf_xdp_rx(struct nicvf *nic, struct bpf_prog *prog,
        action = bpf_prog_run_xdp(prog, &xdp);
        rcu_read_unlock();
 
+       len = xdp.data_end - xdp.data;
        /* Check if XDP program has changed headers */
        if (orig_data != xdp.data) {
-               len = xdp.data_end - xdp.data;
                offset = orig_data - xdp.data;
                dma_addr -= offset;
        }