tools/testing/selftests/bpf/progs/bpf_iter_task_btf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2020, Oracle and/or its affiliates. */
   3 #include "bpf_iter.h"
   4 #include <bpf/bpf_helpers.h>
   5 #include <bpf/bpf_tracing.h>
   6 #include <bpf/bpf_core_read.h>
   7
   8 #include <errno.h>
   9
  10 char _license[] SEC("license") = "GPL";
  11
  12 long tasks = 0;
  13 long seq_err = 0;
  14 bool skip = false;
  15
  16 SEC("iter/task")
  17 int dump_task_struct(struct bpf_iter__task *ctx)
  18 {
  19         struct seq_file *seq = ctx->meta->seq;
  20         struct task_struct *task = ctx->task;
  21         static struct btf_ptr ptr = { };
  22         long ret;
  23
  24 #if __has_builtin(__builtin_btf_type_id)
  25         ptr.type_id = bpf_core_type_id_kernel(struct task_struct);
  26         ptr.ptr = task;
  27
  28         if (ctx->meta->seq_num == 0)
  29                 BPF_SEQ_PRINTF(seq, "Raw BTF task\n");
  30
  31         ret = bpf_seq_printf_btf(seq, &ptr, sizeof(ptr), 0);
  32         switch (ret) {
  33         case 0:
  34                 tasks++;
  35                 break;
  36         case -ERANGE:
  37                 /* NULL task or task->fs, don't count it as an error. */
  38                 break;
  39         case -E2BIG:
  40                 return 1;
  41         default:
  42                 seq_err = ret;
  43                 break;
  44         }
  45 #else
  46         skip = true;
  47 #endif
  48
  49         return 0;
  50 }