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Diffstat (limited to 'samples/bpf/test_current_task_under_cgroup.bpf.c')
-rw-r--r--samples/bpf/test_current_task_under_cgroup.bpf.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/samples/bpf/test_current_task_under_cgroup.bpf.c b/samples/bpf/test_current_task_under_cgroup.bpf.c
new file mode 100644
index 000000000000..0b059cee3cba
--- /dev/null
+++ b/samples/bpf/test_current_task_under_cgroup.bpf.c
@@ -0,0 +1,41 @@
+/* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+
+#include "vmlinux.h"
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+ __uint(type, BPF_MAP_TYPE_CGROUP_ARRAY);
+ __uint(key_size, sizeof(u32));
+ __uint(value_size, sizeof(u32));
+ __uint(max_entries, 1);
+} cgroup_map SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, u32);
+ __type(value, u64);
+ __uint(max_entries, 1);
+} perf_map SEC(".maps");
+
+/* Writes the last PID that called sync to a map at index 0 */
+SEC("ksyscall/sync")
+int bpf_prog1(struct pt_regs *ctx)
+{
+ u64 pid = bpf_get_current_pid_tgid();
+ int idx = 0;
+
+ if (!bpf_current_task_under_cgroup(&cgroup_map, 0))
+ return 0;
+
+ bpf_map_update_elem(&perf_map, &idx, &pid, BPF_ANY);
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;