120 lines
2.8 KiB
C
120 lines
2.8 KiB
C
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
|
|
/* Copyright (c) 2020 Facebook */
|
|
#include <vmlinux.h>
|
|
#include <bpf/bpf_helpers.h>
|
|
#include <bpf/bpf_core_read.h>
|
|
#include <bpf/bpf_tracing.h>
|
|
#include "pid_iter.h"
|
|
|
|
/* keep in sync with the definition in main.h */
|
|
enum bpf_obj_type {
|
|
BPF_OBJ_UNKNOWN,
|
|
BPF_OBJ_PROG,
|
|
BPF_OBJ_MAP,
|
|
BPF_OBJ_LINK,
|
|
BPF_OBJ_BTF,
|
|
};
|
|
|
|
struct bpf_perf_link___local {
|
|
struct bpf_link link;
|
|
struct file *perf_file;
|
|
} __attribute__((preserve_access_index));
|
|
|
|
struct perf_event___local {
|
|
u64 bpf_cookie;
|
|
} __attribute__((preserve_access_index));
|
|
|
|
enum bpf_link_type___local {
|
|
BPF_LINK_TYPE_PERF_EVENT___local = 7,
|
|
};
|
|
|
|
extern const void bpf_link_fops __ksym;
|
|
extern const void bpf_map_fops __ksym;
|
|
extern const void bpf_prog_fops __ksym;
|
|
extern const void btf_fops __ksym;
|
|
|
|
const volatile enum bpf_obj_type obj_type = BPF_OBJ_UNKNOWN;
|
|
|
|
static __always_inline __u32 get_obj_id(void *ent, enum bpf_obj_type type)
|
|
{
|
|
switch (type) {
|
|
case BPF_OBJ_PROG:
|
|
return BPF_CORE_READ((struct bpf_prog *)ent, aux, id);
|
|
case BPF_OBJ_MAP:
|
|
return BPF_CORE_READ((struct bpf_map *)ent, id);
|
|
case BPF_OBJ_BTF:
|
|
return BPF_CORE_READ((struct btf *)ent, id);
|
|
case BPF_OBJ_LINK:
|
|
return BPF_CORE_READ((struct bpf_link *)ent, id);
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* could be used only with BPF_LINK_TYPE_PERF_EVENT links */
|
|
static __u64 get_bpf_cookie(struct bpf_link *link)
|
|
{
|
|
struct bpf_perf_link___local *perf_link;
|
|
struct perf_event___local *event;
|
|
|
|
perf_link = container_of(link, struct bpf_perf_link___local, link);
|
|
event = BPF_CORE_READ(perf_link, perf_file, private_data);
|
|
return BPF_CORE_READ(event, bpf_cookie);
|
|
}
|
|
|
|
SEC("iter/task_file")
|
|
int iter(struct bpf_iter__task_file *ctx)
|
|
{
|
|
struct file *file = ctx->file;
|
|
struct task_struct *task = ctx->task;
|
|
struct pid_iter_entry e;
|
|
const void *fops;
|
|
|
|
if (!file || !task)
|
|
return 0;
|
|
|
|
switch (obj_type) {
|
|
case BPF_OBJ_PROG:
|
|
fops = &bpf_prog_fops;
|
|
break;
|
|
case BPF_OBJ_MAP:
|
|
fops = &bpf_map_fops;
|
|
break;
|
|
case BPF_OBJ_BTF:
|
|
fops = &btf_fops;
|
|
break;
|
|
case BPF_OBJ_LINK:
|
|
fops = &bpf_link_fops;
|
|
break;
|
|
default:
|
|
return 0;
|
|
}
|
|
|
|
if (file->f_op != fops)
|
|
return 0;
|
|
|
|
__builtin_memset(&e, 0, sizeof(e));
|
|
e.pid = task->tgid;
|
|
e.id = get_obj_id(file->private_data, obj_type);
|
|
|
|
if (obj_type == BPF_OBJ_LINK &&
|
|
bpf_core_enum_value_exists(enum bpf_link_type___local,
|
|
BPF_LINK_TYPE_PERF_EVENT___local)) {
|
|
struct bpf_link *link = (struct bpf_link *) file->private_data;
|
|
|
|
if (link->type == bpf_core_enum_value(enum bpf_link_type___local,
|
|
BPF_LINK_TYPE_PERF_EVENT___local)) {
|
|
e.has_bpf_cookie = true;
|
|
e.bpf_cookie = get_bpf_cookie(link);
|
|
}
|
|
}
|
|
|
|
bpf_probe_read_kernel_str(&e.comm, sizeof(e.comm),
|
|
task->group_leader->comm);
|
|
bpf_seq_write(ctx->meta->seq, &e, sizeof(e));
|
|
|
|
return 0;
|
|
}
|
|
|
|
char LICENSE[] SEC("license") = "Dual BSD/GPL";
|