LXR linux/tools/testing/selftests/bpf/progs/perf_event

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (c) 2020 Facebook
   3#include "vmlinux.h"
   4#include <bpf/bpf_helpers.h>
   5
   6#ifndef PERF_MAX_STACK_DEPTH
   7#define PERF_MAX_STACK_DEPTH         127
   8#endif
   9
  10typedef __u64 stack_trace_t[PERF_MAX_STACK_DEPTH];
  11struct {
  12        __uint(type, BPF_MAP_TYPE_STACK_TRACE);
  13        __uint(max_entries, 16384);
  14        __uint(key_size, sizeof(__u32));
  15        __uint(value_size, sizeof(stack_trace_t));
  16} stackmap SEC(".maps");
  17
  18struct {
  19        __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
  20        __uint(max_entries, 1);
  21        __type(key, __u32);
  22        __type(value, stack_trace_t);
  23} stackdata_map SEC(".maps");
  24
  25long stackid_kernel = 1;
  26long stackid_user = 1;
  27long stack_kernel = 1;
  28long stack_user = 1;
  29
  30SEC("perf_event")
  31int oncpu(void *ctx)
  32{
  33        stack_trace_t *trace;
  34        __u32 key = 0;
  35        long val;
  36
  37        val = bpf_get_stackid(ctx, &stackmap, 0);
  38        if (val > 0)
  39                stackid_kernel = 2;
  40        val = bpf_get_stackid(ctx, &stackmap, BPF_F_USER_STACK);
  41        if (val > 0)
  42                stackid_user = 2;
  43
  44        trace = bpf_map_lookup_elem(&stackdata_map, &key);
  45        if (!trace)
  46                return 0;
  47
  48        val = bpf_get_stack(ctx, trace, sizeof(stack_trace_t), 0);
  49        if (val > 0)
  50                stack_kernel = 2;
  51
  52        val = bpf_get_stack(ctx, trace, sizeof(stack_trace_t), BPF_F_USER_STACK);
  53        if (val > 0)
  54                stack_user = 2;
  55
  56        return 0;
  57}
  58
  59char LICENSE[] SEC("license") = "GPL";
  60