Commit 45158876 authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
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samples: bpf: Add BPF support for xdp_exception tracepoint 



This would allow us to store stats for each XDP action, including their
per-CPU counts. Consolidating this here allows all redirect samples to
detect xdp_exception events.

Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-7-memxor@gmail.com
parent 1d930fd2

samples/bpf/xdp_sample.bpf.c

+27 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 


array_map rx_cnt SEC(".maps");

array_map redir_err_cnt SEC(".maps");

array_map exception_cnt SEC(".maps");



const volatile int nr_cpus = 0;
@@ -110,3 +111,29 @@ int BPF_PROG(tp_xdp_redirect_map, const struct net_device *dev, 
{

	return xdp_redirect_collect_stat(dev->ifindex, err);

}



SEC("tp_btf/xdp_exception")

int BPF_PROG(tp_xdp_exception, const struct net_device *dev,

	     const struct bpf_prog *xdp, u32 act)

{

	u32 cpu = bpf_get_smp_processor_id();

	struct datarec *rec;

	u32 key = act, idx;



	if (!IN_SET(from_match, dev->ifindex))

		return 0;

	if (!IN_SET(to_match, dev->ifindex))

		return 0;



	if (key > XDP_REDIRECT)

		key = XDP_REDIRECT + 1;



	idx = key * nr_cpus + cpu;

	rec = bpf_map_lookup_elem(&exception_cnt, &idx);

	if (!rec)

		return 0;

	NO_TEAR_INC(rec->dropped);



	return 0;

}