1*4882a593Smuzhiyun // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2*4882a593Smuzhiyun /* Copyright (c) 2020 Facebook */
3*4882a593Smuzhiyun #include <vmlinux.h>
4*4882a593Smuzhiyun #include <bpf/bpf_helpers.h>
5*4882a593Smuzhiyun #include <bpf/bpf_core_read.h>
6*4882a593Smuzhiyun #include <bpf/bpf_tracing.h>
7*4882a593Smuzhiyun #include "pid_iter.h"
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun /* keep in sync with the definition in main.h */
10*4882a593Smuzhiyun enum bpf_obj_type {
11*4882a593Smuzhiyun BPF_OBJ_UNKNOWN,
12*4882a593Smuzhiyun BPF_OBJ_PROG,
13*4882a593Smuzhiyun BPF_OBJ_MAP,
14*4882a593Smuzhiyun BPF_OBJ_LINK,
15*4882a593Smuzhiyun BPF_OBJ_BTF,
16*4882a593Smuzhiyun };
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun extern const void bpf_link_fops __ksym;
19*4882a593Smuzhiyun extern const void bpf_map_fops __ksym;
20*4882a593Smuzhiyun extern const void bpf_prog_fops __ksym;
21*4882a593Smuzhiyun extern const void btf_fops __ksym;
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun const volatile enum bpf_obj_type obj_type = BPF_OBJ_UNKNOWN;
24*4882a593Smuzhiyun
get_obj_id(void * ent,enum bpf_obj_type type)25*4882a593Smuzhiyun static __always_inline __u32 get_obj_id(void *ent, enum bpf_obj_type type)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun switch (type) {
28*4882a593Smuzhiyun case BPF_OBJ_PROG:
29*4882a593Smuzhiyun return BPF_CORE_READ((struct bpf_prog *)ent, aux, id);
30*4882a593Smuzhiyun case BPF_OBJ_MAP:
31*4882a593Smuzhiyun return BPF_CORE_READ((struct bpf_map *)ent, id);
32*4882a593Smuzhiyun case BPF_OBJ_BTF:
33*4882a593Smuzhiyun return BPF_CORE_READ((struct btf *)ent, id);
34*4882a593Smuzhiyun case BPF_OBJ_LINK:
35*4882a593Smuzhiyun return BPF_CORE_READ((struct bpf_link *)ent, id);
36*4882a593Smuzhiyun default:
37*4882a593Smuzhiyun return 0;
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun }
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun SEC("iter/task_file")
iter(struct bpf_iter__task_file * ctx)42*4882a593Smuzhiyun int iter(struct bpf_iter__task_file *ctx)
43*4882a593Smuzhiyun {
44*4882a593Smuzhiyun struct file *file = ctx->file;
45*4882a593Smuzhiyun struct task_struct *task = ctx->task;
46*4882a593Smuzhiyun struct pid_iter_entry e;
47*4882a593Smuzhiyun const void *fops;
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun if (!file || !task)
50*4882a593Smuzhiyun return 0;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun switch (obj_type) {
53*4882a593Smuzhiyun case BPF_OBJ_PROG:
54*4882a593Smuzhiyun fops = &bpf_prog_fops;
55*4882a593Smuzhiyun break;
56*4882a593Smuzhiyun case BPF_OBJ_MAP:
57*4882a593Smuzhiyun fops = &bpf_map_fops;
58*4882a593Smuzhiyun break;
59*4882a593Smuzhiyun case BPF_OBJ_BTF:
60*4882a593Smuzhiyun fops = &btf_fops;
61*4882a593Smuzhiyun break;
62*4882a593Smuzhiyun case BPF_OBJ_LINK:
63*4882a593Smuzhiyun fops = &bpf_link_fops;
64*4882a593Smuzhiyun break;
65*4882a593Smuzhiyun default:
66*4882a593Smuzhiyun return 0;
67*4882a593Smuzhiyun }
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun if (file->f_op != fops)
70*4882a593Smuzhiyun return 0;
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun e.pid = task->tgid;
73*4882a593Smuzhiyun e.id = get_obj_id(file->private_data, obj_type);
74*4882a593Smuzhiyun bpf_probe_read_kernel(&e.comm, sizeof(e.comm),
75*4882a593Smuzhiyun task->group_leader->comm);
76*4882a593Smuzhiyun bpf_seq_write(ctx->meta->seq, &e, sizeof(e));
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun return 0;
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun char LICENSE[] SEC("license") = "Dual BSD/GPL";
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