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-rw-r--r--tools/testing/selftests/bpf/progs/test_perf_buffer.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_perf_buffer.c b/tools/testing/selftests/bpf/progs/test_perf_buffer.c
new file mode 100644
index 000000000..17d5b6774
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_perf_buffer.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Facebook
+
+#include <linux/ptrace.h>
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, int);
+ __type(value, int);
+ __uint(max_entries, 1);
+} my_pid_map SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+ __type(key, int);
+ __type(value, int);
+} perf_buf_map SEC(".maps");
+
+SEC("tp/raw_syscalls/sys_enter")
+int handle_sys_enter(void *ctx)
+{
+ int zero = 0, *my_pid, cur_pid;
+ int cpu = bpf_get_smp_processor_id();
+
+ my_pid = bpf_map_lookup_elem(&my_pid_map, &zero);
+ if (!my_pid)
+ return 1;
+
+ cur_pid = bpf_get_current_pid_tgid() >> 32;
+ if (cur_pid != *my_pid)
+ return 1;
+
+ bpf_perf_event_output(ctx, &perf_buf_map, BPF_F_CURRENT_CPU,
+ &cpu, sizeof(cpu));
+ return 1;
+}
+
+char _license[] SEC("license") = "GPL";