1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020, Oracle and/or its affiliates. */
3 #include "bpf_iter.h"
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_tracing.h>
6 #include <bpf/bpf_core_read.h>
7 
8 #include <errno.h>
9 
10 char _license[] SEC("license") = "GPL";
11 
12 long tasks = 0;
13 long seq_err = 0;
14 bool skip = false;
15 
16 SEC("iter/task")
17 int dump_task_struct(struct bpf_iter__task *ctx)
18 {
19 	struct seq_file *seq = ctx->meta->seq;
20 	struct task_struct *task = ctx->task;
21 	static struct btf_ptr ptr = { };
22 	long ret;
23 
24 #if __has_builtin(__builtin_btf_type_id)
25 	ptr.type_id = bpf_core_type_id_kernel(struct task_struct);
26 	ptr.ptr = task;
27 
28 	if (ctx->meta->seq_num == 0)
29 		BPF_SEQ_PRINTF(seq, "Raw BTF task\n");
30 
31 	ret = bpf_seq_printf_btf(seq, &ptr, sizeof(ptr), 0);
32 	switch (ret) {
33 	case 0:
34 		tasks++;
35 		break;
36 	case -ERANGE:
37 		/* NULL task or task->fs, don't count it as an error. */
38 		break;
39 	case -E2BIG:
40 		return 1;
41 	default:
42 		seq_err = ret;
43 		break;
44 	}
45 #else
46 	skip = true;
47 #endif
48 
49 	return 0;
50 }
51