| 1 | /* Copyright 2016 Netflix, Inc. |
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| 2 | * |
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| 3 | * This program is free software; you can redistribute it and/or |
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| 4 | * modify it under the terms of version 2 of the GNU General Public |
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| 5 | * License as published by the Free Software Foundation. |
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| 6 | */ |
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| 7 | #include <linux/ptrace.h> |
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| 8 | #include <uapi/linux/bpf.h> |
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| 9 | #include <uapi/linux/bpf_perf_event.h> |
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| 10 | #include <bpf/bpf_helpers.h> |
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| 11 | #include <bpf/bpf_tracing.h> |
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| 12 | |
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| 13 | #define MAX_IPS 8192 |
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| 14 | |
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| 15 | struct { |
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| 16 | __uint(type, BPF_MAP_TYPE_HASH); |
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| 17 | __type(key, u64); |
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| 18 | __type(value, u32); |
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| 19 | __uint(max_entries, MAX_IPS); |
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| 20 | } ip_map SEC(".maps" ); |
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| 21 | |
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| 22 | SEC("perf_event" ) |
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| 23 | int do_sample(struct bpf_perf_event_data *ctx) |
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| 24 | { |
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| 25 | u64 ip; |
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| 26 | u32 *value, init_val = 1; |
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| 27 | |
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| 28 | ip = PT_REGS_IP(&ctx->regs); |
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| 29 | value = bpf_map_lookup_elem(&ip_map, &ip); |
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| 30 | if (value) |
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| 31 | *value += 1; |
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| 32 | else |
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| 33 | /* E2BIG not tested for this example only */ |
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| 34 | bpf_map_update_elem(&ip_map, &ip, &init_val, BPF_NOEXIST); |
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| 35 | |
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| 36 | return 0; |
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| 37 | } |
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| 38 | char _license[] SEC("license" ) = "GPL" ; |
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| 39 | |
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