90 lines
1.5 KiB
C
90 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2020 Facebook
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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char _license[] SEC("license") = "GPL";
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struct sample {
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int pid;
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int seq;
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long value;
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char comm[16];
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};
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struct ringbuf_map {
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__uint(type, BPF_MAP_TYPE_RINGBUF);
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/* libbpf will adjust to valid page size */
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__uint(max_entries, 1000);
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} ringbuf1 SEC(".maps"),
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ringbuf2 SEC(".maps");
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
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__uint(max_entries, 4);
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__type(key, int);
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__array(values, struct ringbuf_map);
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} ringbuf_arr SEC(".maps") = {
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.values = {
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[0] = &ringbuf1,
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[2] = &ringbuf2,
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},
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};
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struct {
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__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
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__uint(max_entries, 1);
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__type(key, int);
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__array(values, struct ringbuf_map);
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} ringbuf_hash SEC(".maps") = {
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.values = {
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[0] = &ringbuf1,
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},
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};
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/* inputs */
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int pid = 0;
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int target_ring = 0;
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long value = 0;
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/* outputs */
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long total = 0;
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long dropped = 0;
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long skipped = 0;
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SEC("tp/syscalls/sys_enter_getpgid")
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int test_ringbuf(void *ctx)
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{
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int cur_pid = bpf_get_current_pid_tgid() >> 32;
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struct sample *sample;
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void *rb;
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int zero = 0;
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if (cur_pid != pid)
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return 0;
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rb = bpf_map_lookup_elem(&ringbuf_arr, &target_ring);
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if (!rb) {
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skipped += 1;
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return 1;
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}
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sample = bpf_ringbuf_reserve(rb, sizeof(*sample), 0);
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if (!sample) {
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dropped += 1;
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return 1;
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}
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sample->pid = pid;
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bpf_get_current_comm(sample->comm, sizeof(sample->comm));
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sample->value = value;
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sample->seq = total;
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total += 1;
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bpf_ringbuf_submit(sample, 0);
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return 0;
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}
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