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1/* Copyright (c) 2016 Facebook2 *3 * This program is free software; you can redistribute it and/or4 * modify it under the terms of version 2 of the GNU General Public5 * License as published by the Free Software Foundation.6 */7#include <linux/ptrace.h>8#include <uapi/linux/bpf.h>9#include <uapi/linux/bpf_perf_event.h>10#include <uapi/linux/perf_event.h>11#include <bpf/bpf_helpers.h>12#include <bpf/bpf_tracing.h>13 14struct key_t {15 char comm[TASK_COMM_LEN];16 u32 kernstack;17 u32 userstack;18};19 20struct {21 __uint(type, BPF_MAP_TYPE_HASH);22 __type(key, struct key_t);23 __type(value, u64);24 __uint(max_entries, 10000);25} counts SEC(".maps");26 27struct {28 __uint(type, BPF_MAP_TYPE_STACK_TRACE);29 __uint(key_size, sizeof(u32));30 __uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));31 __uint(max_entries, 10000);32} stackmap SEC(".maps");33 34#define KERN_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)35#define USER_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP | BPF_F_USER_STACK)36 37SEC("perf_event")38int bpf_prog1(struct bpf_perf_event_data *ctx)39{40 char time_fmt1[] = "Time Enabled: %llu, Time Running: %llu";41 char time_fmt2[] = "Get Time Failed, ErrCode: %d";42 char addr_fmt[] = "Address recorded on event: %llx";43 char fmt[] = "CPU-%d period %lld ip %llx";44 u32 cpu = bpf_get_smp_processor_id();45 struct bpf_perf_event_value value_buf;46 struct key_t key;47 u64 *val, one = 1;48 int ret;49 50 if (ctx->sample_period < 10000)51 /* ignore warmup */52 return 0;53 bpf_get_current_comm(&key.comm, sizeof(key.comm));54 key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS);55 key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS);56 if ((int)key.kernstack < 0 && (int)key.userstack < 0) {57 bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period,58 PT_REGS_IP(&ctx->regs));59 return 0;60 }61 62 ret = bpf_perf_prog_read_value(ctx, (void *)&value_buf, sizeof(struct bpf_perf_event_value));63 if (!ret)64 bpf_trace_printk(time_fmt1, sizeof(time_fmt1), value_buf.enabled, value_buf.running);65 else66 bpf_trace_printk(time_fmt2, sizeof(time_fmt2), ret);67 68 if (ctx->addr != 0)69 bpf_trace_printk(addr_fmt, sizeof(addr_fmt), ctx->addr);70 71 val = bpf_map_lookup_elem(&counts, &key);72 if (val)73 (*val)++;74 else75 bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST);76 return 0;77}78 79char _license[] SEC("license") = "GPL";80