bpf/progs/test_pe_preserve_elems.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 // Copyright (c) 2020 Facebook
0003 #include <linux/bpf.h>
0004 #include <bpf/bpf_helpers.h>
0005 #include <bpf/bpf_tracing.h>
0006
0007 struct {
0008     __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
0009     __uint(max_entries, 1);
0010     __type(key, int);
0011     __type(value, int);
0012 } array_1 SEC(".maps");
0013
0014 struct {
0015     __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
0016     __uint(max_entries, 1);
0017     __type(key, int);
0018     __type(value, int);
0019     __uint(map_flags, BPF_F_PRESERVE_ELEMS);
0020 } array_2 SEC(".maps");
0021
0022 SEC("raw_tp/sched_switch")
0023 int BPF_PROG(read_array_1)
0024 {
0025     struct bpf_perf_event_value val;
0026
0027     return bpf_perf_event_read_value(&array_1, 0, &val, sizeof(val));
0028 }
0029
0030 SEC("raw_tp/task_rename")
0031 int BPF_PROG(read_array_2)
0032 {
0033     struct bpf_perf_event_value val;
0034
0035     return bpf_perf_event_read_value(&array_2, 0, &val, sizeof(val));
0036 }
0037
0038 char LICENSE[] SEC("license") = "GPL";