Quelle  log_fixup.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
#include <test_progs.h>
#include <bpf/btf.h>

#include "test_log_fixup.skel.h"

enum trunc_type {
 TRUNC_NONE,
 TRUNC_PARTIAL,
 TRUNC_FULL,
};

static void bad_core_relo(size_t log_buf_size, enum trunc_type trunc_type)
{
 char log_buf[8 * 1024];
 struct test_log_fixup* skel;
 int err;

 skel = test_log_fixup__open();
 if (!ASSERT_OK_PTR(skel, "skel_open"))
  return;

 bpf_program__set_autoload(skel->progs.bad_relo, true);
 memset(log_buf, 0, sizeof(log_buf));
 bpf_program__set_log_buf(skel->progs.bad_relo, log_buf, log_buf_size ?: sizeof(log_buf));
 bpf_program__set_log_level(skel->progs.bad_relo, 1 | 8); /* BPF_LOG_FIXED to force truncation */

 err = test_log_fixup__load(skel);
 if (!ASSERT_ERR(err, "load_fail"))
  goto cleanup;

 ASSERT_HAS_SUBSTR(log_buf,
     "0: \n"
     "failed to resolve CO-RE relocation ",
     "log_buf_part1");

 switch (trunc_type) {
 case TRUNC_NONE:
  ASSERT_HAS_SUBSTR(log_buf,
      "struct task_struct___bad.fake_field (0:1 @ offset 4)\n",
      "log_buf_part2");
  ASSERT_HAS_SUBSTR(log_buf,
      "max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0\n",
      "log_buf_end");
  break;
 case TRUNC_PARTIAL:
  /* we should get full libbpf message patch */
  ASSERT_HAS_SUBSTR(log_buf,
      "struct task_struct___bad.fake_field (0:1 @ offset 4)\n",
      "log_buf_part2");
  /* we shouldn't get full end of BPF verifier log */
  ASSERT_NULL(strstr(log_buf, "max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0\n"),
       "log_buf_end");
  break;
 case TRUNC_FULL:
  /* we shouldn't get second part of libbpf message patch */
  ASSERT_NULL(strstr(log_buf, "struct task_struct___bad.fake_field (0:1 @ offset 4)\n"),
       "log_buf_part2");
  /* we shouldn't get full end of BPF verifier log */
  ASSERT_NULL(strstr(log_buf, "max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0\n"),
       "log_buf_end");
  break;
 }

 if (env.verbosity > VERBOSE_NONE)
  printf("LOG: \n=================\n%s=================\n", log_buf);
cleanup:
 test_log_fixup__destroy(skel);
}

static void bad_core_relo_subprog(void)
{
 char log_buf[8 * 1024];
 struct test_log_fixup* skel;
 int err;

 skel = test_log_fixup__open();
 if (!ASSERT_OK_PTR(skel, "skel_open"))
  return;

 bpf_program__set_autoload(skel->progs.bad_relo_subprog, true);
 bpf_program__set_log_buf(skel->progs.bad_relo_subprog, log_buf, sizeof(log_buf));

 err = test_log_fixup__load(skel);
 if (!ASSERT_ERR(err, "load_fail"))
  goto cleanup;

 ASSERT_HAS_SUBSTR(log_buf,
     ": \n"
     "failed to resolve CO-RE relocation ",
     "log_buf");
 ASSERT_HAS_SUBSTR(log_buf,
     "struct task_struct___bad.fake_field_subprog (0:2 @ offset 8)\n",
     "log_buf");

 if (env.verbosity > VERBOSE_NONE)
  printf("LOG: \n=================\n%s=================\n", log_buf);

cleanup:
 test_log_fixup__destroy(skel);
}

static void missing_map(void)
{
 char log_buf[8 * 1024];
 struct test_log_fixup* skel;
 int err;

 skel = test_log_fixup__open();
 if (!ASSERT_OK_PTR(skel, "skel_open"))
  return;

 bpf_map__set_autocreate(skel->maps.missing_map, false);

 bpf_program__set_autoload(skel->progs.use_missing_map, true);
 bpf_program__set_log_buf(skel->progs.use_missing_map, log_buf, sizeof(log_buf));

 err = test_log_fixup__load(skel);
 if (!ASSERT_ERR(err, "load_fail"))
  goto cleanup;

 ASSERT_TRUE(bpf_map__autocreate(skel->maps.existing_map), "existing_map_autocreate");
 ASSERT_FALSE(bpf_map__autocreate(skel->maps.missing_map), "missing_map_autocreate");

 ASSERT_HAS_SUBSTR(log_buf,
     ": \n"
     "BPF map 'missing_map' is referenced but wasn't created\n",
     "log_buf");

 if (env.verbosity > VERBOSE_NONE)
  printf("LOG: \n=================\n%s=================\n", log_buf);

cleanup:
 test_log_fixup__destroy(skel);
}

static void missing_kfunc(void)
{
 char log_buf[8 * 1024];
 struct test_log_fixup* skel;
 int err;

 skel = test_log_fixup__open();
 if (!ASSERT_OK_PTR(skel, "skel_open"))
  return;

 bpf_program__set_autoload(skel->progs.use_missing_kfunc, true);
 bpf_program__set_log_buf(skel->progs.use_missing_kfunc, log_buf, sizeof(log_buf));

 err = test_log_fixup__load(skel);
 if (!ASSERT_ERR(err, "load_fail"))
  goto cleanup;

 ASSERT_HAS_SUBSTR(log_buf,
     "0: \n"
     "kfunc 'bpf_nonexistent_kfunc' is referenced but wasn't resolved\n",
     "log_buf");

 if (env.verbosity > VERBOSE_NONE)
  printf("LOG: \n=================\n%s=================\n", log_buf);

cleanup:
 test_log_fixup__destroy(skel);
}

void test_log_fixup(void)
{
 if (test__start_subtest("bad_core_relo_trunc_none"))
  bad_core_relo(0, TRUNC_NONE /* full buf */);
 if (test__start_subtest("bad_core_relo_trunc_partial"))
  bad_core_relo(300, TRUNC_PARTIAL /* truncate original log a bit */);
 if (test__start_subtest("bad_core_relo_trunc_full"))
  bad_core_relo(240, TRUNC_FULL  /* truncate also libbpf's message patch */);
 if (test__start_subtest("bad_core_relo_subprog"))
  bad_core_relo_subprog();
 if (test__start_subtest("missing_map"))
  missing_map();
 if (test__start_subtest("missing_kfunc"))
  missing_kfunc();
}