linux/tools/testing/selftests/bpf/progs/perf_event_stackmap.c

60 lines
1.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2020 Facebook
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#ifndef PERF_MAX_STACK_DEPTH
#define PERF_MAX_STACK_DEPTH 127
#endif
typedef __u64 stack_trace_t[PERF_MAX_STACK_DEPTH];
struct {
__uint(type, BPF_MAP_TYPE_STACK_TRACE);
__uint(max_entries, 16384);
__uint(key_size, sizeof(__u32));
__uint(value_size, sizeof(stack_trace_t));
} stackmap SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__uint(max_entries, 1);
__type(key, __u32);
__type(value, stack_trace_t);
} stackdata_map SEC(".maps");
long stackid_kernel = 1;
long stackid_user = 1;
long stack_kernel = 1;
long stack_user = 1;
SEC("perf_event")
int oncpu(void *ctx)
{
stack_trace_t *trace;
__u32 key = 0;
long val;
val = bpf_get_stackid(ctx, &stackmap, 0);
if (val > 0)
stackid_kernel = 2;
val = bpf_get_stackid(ctx, &stackmap, BPF_F_USER_STACK);
if (val > 0)
stackid_user = 2;
trace = bpf_map_lookup_elem(&stackdata_map, &key);
if (!trace)
return 0;
val = bpf_get_stack(ctx, trace, sizeof(stack_trace_t), 0);
if (val > 0)
stack_kernel = 2;
val = bpf_get_stack(ctx, trace, sizeof(stack_trace_t), BPF_F_USER_STACK);
if (val > 0)
stack_user = 2;
return 0;
}
char LICENSE[] SEC("license") = "GPL";