tools/bpf/bpftool/skeleton/pid_iter.bpf.c

   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 */
  10 enum 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
  18 extern const void bpf_link_fops __ksym;
  19 extern const void bpf_map_fops __ksym;
  20 extern const void bpf_prog_fops __ksym;
  21 extern const void btf_fops __ksym;
  22
  23 const volatile enum bpf_obj_type obj_type = BPF_OBJ_UNKNOWN;
  24
  25 static __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
  41 SEC("iter/task_file")
  42 int 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
  81 char LICENSE[] SEC("license") = "Dual BSD/GPL";