linux-stable/tools/testing/selftests/bpf/progs/test_perf_branches.c
Andrii Nakryiko df8ff35311 libbpf: Merge selftests' bpf_trace_helpers.h into libbpf's bpf_tracing.h
Move BPF_PROG, BPF_KPROBE, and BPF_KRETPROBE macro into libbpf's bpf_tracing.h
header to make it available for non-selftests users.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200229231112.1240137-5-andriin@fb.com
2020-03-02 16:25:14 -08:00

50 lines
1.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Facebook
#include <stddef.h>
#include <linux/ptrace.h>
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
int valid = 0;
int required_size_out = 0;
int written_stack_out = 0;
int written_global_out = 0;
struct {
__u64 _a;
__u64 _b;
__u64 _c;
} fpbe[30] = {0};
SEC("perf_event")
int perf_branches(void *ctx)
{
__u64 entries[4 * 3] = {0};
int required_size, written_stack, written_global;
/* write to stack */
written_stack = bpf_read_branch_records(ctx, entries, sizeof(entries), 0);
/* ignore spurious events */
if (!written_stack)
return 1;
/* get required size */
required_size = bpf_read_branch_records(ctx, NULL, 0,
BPF_F_GET_BRANCH_RECORDS_SIZE);
written_global = bpf_read_branch_records(ctx, fpbe, sizeof(fpbe), 0);
/* ignore spurious events */
if (!written_global)
return 1;
required_size_out = required_size;
written_stack_out = written_stack;
written_global_out = written_global;
valid = 1;
return 0;
}
char _license[] SEC("license") = "GPL";