1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (c) 2020 Facebook */
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_core_read.h>
6 #include <bpf/bpf_tracing.h>
9 /* keep in sync with the definition in main.h */
18 struct bpf_perf_link___local {
20 struct file *perf_file;
21 } __attribute__((preserve_access_index));
23 struct perf_event___local {
25 } __attribute__((preserve_access_index));
27 enum bpf_link_type___local {
28 BPF_LINK_TYPE_PERF_EVENT___local = 7,
31 extern const void bpf_link_fops __ksym;
32 extern const void bpf_map_fops __ksym;
33 extern const void bpf_prog_fops __ksym;
34 extern const void btf_fops __ksym;
36 const volatile enum bpf_obj_type obj_type = BPF_OBJ_UNKNOWN;
38 static __always_inline __u32 get_obj_id(void *ent, enum bpf_obj_type type)
42 return BPF_CORE_READ((struct bpf_prog *)ent, aux, id);
44 return BPF_CORE_READ((struct bpf_map *)ent, id);
46 return BPF_CORE_READ((struct btf *)ent, id);
48 return BPF_CORE_READ((struct bpf_link *)ent, id);
54 /* could be used only with BPF_LINK_TYPE_PERF_EVENT links */
55 static __u64 get_bpf_cookie(struct bpf_link *link)
57 struct bpf_perf_link___local *perf_link;
58 struct perf_event___local *event;
60 perf_link = container_of(link, struct bpf_perf_link___local, link);
61 event = BPF_CORE_READ(perf_link, perf_file, private_data);
62 return BPF_CORE_READ(event, bpf_cookie);
66 int iter(struct bpf_iter__task_file *ctx)
68 struct file *file = ctx->file;
69 struct task_struct *task = ctx->task;
70 struct pid_iter_entry e;
78 fops = &bpf_prog_fops;
87 fops = &bpf_link_fops;
93 if (file->f_op != fops)
96 __builtin_memset(&e, 0, sizeof(e));
98 e.id = get_obj_id(file->private_data, obj_type);
100 if (obj_type == BPF_OBJ_LINK &&
101 bpf_core_enum_value_exists(enum bpf_link_type___local,
102 BPF_LINK_TYPE_PERF_EVENT___local)) {
103 struct bpf_link *link = (struct bpf_link *) file->private_data;
105 if (link->type == bpf_core_enum_value(enum bpf_link_type___local,
106 BPF_LINK_TYPE_PERF_EVENT___local)) {
107 e.has_bpf_cookie = true;
108 e.bpf_cookie = get_bpf_cookie(link);
112 bpf_probe_read_kernel_str(&e.comm, sizeof(e.comm),
113 task->group_leader->comm);
114 bpf_seq_write(ctx->meta->seq, &e, sizeof(e));
119 char LICENSE[] SEC("license") = "Dual BSD/GPL";