diff options
Diffstat (limited to 'samples/bpf/sampleip_kern.c')
| -rw-r--r-- | samples/bpf/sampleip_kern.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/samples/bpf/sampleip_kern.c b/samples/bpf/sampleip_kern.c new file mode 100644 index 0000000000..a3f8a3998e --- /dev/null +++ b/samples/bpf/sampleip_kern.c @@ -0,0 +1,38 @@ +/* Copyright 2016 Netflix, Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ +#include <linux/ptrace.h> +#include <uapi/linux/bpf.h> +#include <uapi/linux/bpf_perf_event.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +#define MAX_IPS 8192 + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __type(key, u64); + __type(value, u32); + __uint(max_entries, MAX_IPS); +} ip_map SEC(".maps"); + +SEC("perf_event") +int do_sample(struct bpf_perf_event_data *ctx) +{ + u64 ip; + u32 *value, init_val = 1; + + ip = PT_REGS_IP(&ctx->regs); + value = bpf_map_lookup_elem(&ip_map, &ip); + if (value) + *value += 1; + else + /* E2BIG not tested for this example only */ + bpf_map_update_elem(&ip_map, &ip, &init_val, BPF_NOEXIST); + + return 0; +} +char _license[] SEC("license") = "GPL"; |