1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
 2/* Copyright (c) 2020 Facebook */
 3#include <vmlinux.h>
 4#include <bpf/bpf_helpers.h>
 5#include <bpf/bpf_core_read.h>
 6#include <bpf/bpf_tracing.h>
 7#include "pid_iter.h"
 8
 9/* keep in sync with the definition in main.h */
10enum bpf_obj_type {
11	BPF_OBJ_UNKNOWN,
12	BPF_OBJ_PROG,
13	BPF_OBJ_MAP,
14	BPF_OBJ_LINK,
15	BPF_OBJ_BTF,
16};
17
18extern const void bpf_link_fops __ksym;
19extern const void bpf_map_fops __ksym;
20extern const void bpf_prog_fops __ksym;
21extern const void btf_fops __ksym;
22
23const volatile enum bpf_obj_type obj_type = BPF_OBJ_UNKNOWN;
24
25static __always_inline __u32 get_obj_id(void *ent, enum bpf_obj_type type)
26{
27	switch (type) {
28	case BPF_OBJ_PROG:
29		return BPF_CORE_READ((struct bpf_prog *)ent, aux, id);
30	case BPF_OBJ_MAP:
31		return BPF_CORE_READ((struct bpf_map *)ent, id);
32	case BPF_OBJ_BTF:
33		return BPF_CORE_READ((struct btf *)ent, id);
34	case BPF_OBJ_LINK:
35		return BPF_CORE_READ((struct bpf_link *)ent, id);
36	default:
37		return 0;
38	}
39}
40
41SEC("iter/task_file")
42int iter(struct bpf_iter__task_file *ctx)
43{
44	struct file *file = ctx->file;
45	struct task_struct *task = ctx->task;
46	struct pid_iter_entry e;
47	const void *fops;
48
49	if (!file || !task)
50		return 0;
51
52	switch (obj_type) {
53	case BPF_OBJ_PROG:
54		fops = &bpf_prog_fops;
55		break;
56	case BPF_OBJ_MAP:
57		fops = &bpf_map_fops;
58		break;
59	case BPF_OBJ_BTF:
60		fops = &btf_fops;
61		break;
62	case BPF_OBJ_LINK:
63		fops = &bpf_link_fops;
64		break;
65	default:
66		return 0;
67	}
68
69	if (file->f_op != fops)
70		return 0;
71
72	e.pid = task->tgid;
73	e.id = get_obj_id(file->private_data, obj_type);
74	bpf_probe_read_kernel(&e.comm, sizeof(e.comm),
75			      task->group_leader->comm);
76	bpf_seq_write(ctx->meta->seq, &e, sizeof(e));
77
78	return 0;
79}
80
81char LICENSE[] SEC("license") = "Dual BSD/GPL";