1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3 /* "undefine" structs in vmlinux.h, because we "override" them below */
4 #define bpf_iter_meta bpf_iter_meta___not_used
5 #define bpf_iter__task bpf_iter__task___not_used
6 #include "vmlinux.h"
7 #undef bpf_iter_meta
8 #undef bpf_iter__task
9 #include <bpf/bpf_helpers.h>
10 #include <bpf/bpf_tracing.h>
11 
12 char _license[] SEC("license") = "GPL";
13 
14 struct bpf_iter_meta {
15 	struct seq_file *seq;
16 	__u64 session_id;
17 	__u64 seq_num;
18 } __attribute__((preserve_access_index));
19 
20 struct bpf_iter__task {
21 	struct bpf_iter_meta *meta;
22 	struct task_struct *task;
23 } __attribute__((preserve_access_index));
24 
25 SEC("iter/task")
26 int dump_task(struct bpf_iter__task *ctx)
27 {
28 	struct seq_file *seq = ctx->meta->seq;
29 	struct task_struct *task = ctx->task;
30 
31 	if (task == (void *)0) {
32 		BPF_SEQ_PRINTF(seq, "    === END ===\n");
33 		return 0;
34 	}
35 
36 	if (ctx->meta->seq_num == 0)
37 		BPF_SEQ_PRINTF(seq, "    tgid      gid\n");
38 
39 	BPF_SEQ_PRINTF(seq, "%8d %8d\n", task->tgid, task->pid);
40 	return 0;
41 }
42