tools/testing/selftests/bpf/prog_tests/rcu_read_lock.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates.*/
   3
   4 #define _GNU_SOURCE
   5 #include <unistd.h>
   6 #include <sys/syscall.h>
   7 #include <sys/types.h>
   8 #include <test_progs.h>
   9 #include <bpf/btf.h>
  10 #include "rcu_read_lock.skel.h"
  11 #include "cgroup_helpers.h"
  12
  13 static unsigned long long cgroup_id;
  14
  15 static void test_success(void)
  16 {
  17         struct rcu_read_lock *skel;
  18         int err;
  19
  20         skel = rcu_read_lock__open();
  21         if (!ASSERT_OK_PTR(skel, "skel_open"))
  22                 return;
  23
  24         skel->bss->target_pid = syscall(SYS_gettid);
  25
  26         bpf_program__set_autoload(skel->progs.get_cgroup_id, true);
  27         bpf_program__set_autoload(skel->progs.task_succ, true);
  28         bpf_program__set_autoload(skel->progs.no_lock, true);
  29         bpf_program__set_autoload(skel->progs.two_regions, true);
  30         bpf_program__set_autoload(skel->progs.non_sleepable_1, true);
  31         bpf_program__set_autoload(skel->progs.non_sleepable_2, true);
  32         err = rcu_read_lock__load(skel);
  33         if (!ASSERT_OK(err, "skel_load"))
  34                 goto out;
  35
  36         err = rcu_read_lock__attach(skel);
  37         if (!ASSERT_OK(err, "skel_attach"))
  38                 goto out;
  39
  40         syscall(SYS_getpgid);
  41
  42         ASSERT_EQ(skel->bss->task_storage_val, 2, "task_storage_val");
  43         ASSERT_EQ(skel->bss->cgroup_id, cgroup_id, "cgroup_id");
  44 out:
  45         rcu_read_lock__destroy(skel);
  46 }
  47
  48 static void test_rcuptr_acquire(void)
  49 {
  50         struct rcu_read_lock *skel;
  51         int err;
  52
  53         skel = rcu_read_lock__open();
  54         if (!ASSERT_OK_PTR(skel, "skel_open"))
  55                 return;
  56
  57         skel->bss->target_pid = syscall(SYS_gettid);
  58
  59         bpf_program__set_autoload(skel->progs.task_acquire, true);
  60         err = rcu_read_lock__load(skel);
  61         if (!ASSERT_OK(err, "skel_load"))
  62                 goto out;
  63
  64         err = rcu_read_lock__attach(skel);
  65         ASSERT_OK(err, "skel_attach");
  66 out:
  67         rcu_read_lock__destroy(skel);
  68 }
  69
  70 static const char * const inproper_region_tests[] = {
  71         "miss_lock",
  72         "miss_unlock",
  73         "non_sleepable_rcu_mismatch",
  74         "inproper_sleepable_helper",
  75         "inproper_sleepable_kfunc",
  76         "nested_rcu_region",
  77 };
  78
  79 static void test_inproper_region(void)
  80 {
  81         struct rcu_read_lock *skel;
  82         struct bpf_program *prog;
  83         int i, err;
  84
  85         for (i = 0; i < ARRAY_SIZE(inproper_region_tests); i++) {
  86                 skel = rcu_read_lock__open();
  87                 if (!ASSERT_OK_PTR(skel, "skel_open"))
  88                         return;
  89
  90                 prog = bpf_object__find_program_by_name(skel->obj, inproper_region_tests[i]);
  91                 if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
  92                         goto out;
  93                 bpf_program__set_autoload(prog, true);
  94                 err = rcu_read_lock__load(skel);
  95                 ASSERT_ERR(err, "skel_load");
  96 out:
  97                 rcu_read_lock__destroy(skel);
  98         }
  99 }
 100
 101 static const char * const rcuptr_misuse_tests[] = {
 102         "task_untrusted_non_rcuptr",
 103         "task_untrusted_rcuptr",
 104         "cross_rcu_region",
 105 };
 106
 107 static void test_rcuptr_misuse(void)
 108 {
 109         struct rcu_read_lock *skel;
 110         struct bpf_program *prog;
 111         int i, err;
 112
 113         for (i = 0; i < ARRAY_SIZE(rcuptr_misuse_tests); i++) {
 114                 skel = rcu_read_lock__open();
 115                 if (!ASSERT_OK_PTR(skel, "skel_open"))
 116                         return;
 117
 118                 prog = bpf_object__find_program_by_name(skel->obj, rcuptr_misuse_tests[i]);
 119                 if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
 120                         goto out;
 121                 bpf_program__set_autoload(prog, true);
 122                 err = rcu_read_lock__load(skel);
 123                 ASSERT_ERR(err, "skel_load");
 124 out:
 125                 rcu_read_lock__destroy(skel);
 126         }
 127 }
 128
 129 void test_rcu_read_lock(void)
 130 {
 131         struct btf *vmlinux_btf;
 132         int cgroup_fd;
 133
 134         vmlinux_btf = btf__load_vmlinux_btf();
 135         if (!ASSERT_OK_PTR(vmlinux_btf, "could not load vmlinux BTF"))
 136                 return;
 137         if (btf__find_by_name_kind(vmlinux_btf, "rcu", BTF_KIND_TYPE_TAG) < 0) {
 138                 test__skip();
 139                 goto out;
 140         }
 141
 142         cgroup_fd = test__join_cgroup("/rcu_read_lock");
 143         if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup /rcu_read_lock"))
 144                 goto out;
 145
 146         cgroup_id = get_cgroup_id("/rcu_read_lock");
 147         if (test__start_subtest("success"))
 148                 test_success();
 149         if (test__start_subtest("rcuptr_acquire"))
 150                 test_rcuptr_acquire();
 151         if (test__start_subtest("negative_tests_inproper_region"))
 152                 test_inproper_region();
 153         if (test__start_subtest("negative_tests_rcuptr_misuse"))
 154                 test_rcuptr_misuse();
 155         close(cgroup_fd);
 156 out:
 157         btf__free(vmlinux_btf);
 158 }