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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2021 Facebook */
   3 #include <test_progs.h>
   4 #include <network_helpers.h>
   5 #include "kfunc_call_fail.skel.h"
   6 #include "kfunc_call_test.skel.h"
   7 #include "kfunc_call_test.lskel.h"
   8 #include "kfunc_call_test_subprog.skel.h"
   9 #include "kfunc_call_test_subprog.lskel.h"
  10 #include "kfunc_call_destructive.skel.h"
  11
  12 #include "cap_helpers.h"
  13
  14 static size_t log_buf_sz = 1048576; /* 1 MB */
  15 static char obj_log_buf[1048576];
  16
  17 enum kfunc_test_type {
  18         tc_test = 0,
  19         syscall_test,
  20         syscall_null_ctx_test,
  21 };
  22
  23 struct kfunc_test_params {
  24         const char *prog_name;
  25         unsigned long lskel_prog_desc_offset;
  26         int retval;
  27         enum kfunc_test_type test_type;
  28         const char *expected_err_msg;
  29 };
  30
  31 #define __BPF_TEST_SUCCESS(name, __retval, type) \
  32         { \
  33           .prog_name = #name, \
  34           .lskel_prog_desc_offset = offsetof(struct kfunc_call_test_lskel, progs.name), \
  35           .retval = __retval, \
  36           .test_type = type, \
  37           .expected_err_msg = NULL, \
  38         }
  39
  40 #define __BPF_TEST_FAIL(name, __retval, type, error_msg) \
  41         { \
  42           .prog_name = #name, \
  43           .lskel_prog_desc_offset = 0 /* unused when test is failing */, \
  44           .retval = __retval, \
  45           .test_type = type, \
  46           .expected_err_msg = error_msg, \
  47         }
  48
  49 #define TC_TEST(name, retval) __BPF_TEST_SUCCESS(name, retval, tc_test)
  50 #define SYSCALL_TEST(name, retval) __BPF_TEST_SUCCESS(name, retval, syscall_test)
  51 #define SYSCALL_NULL_CTX_TEST(name, retval) __BPF_TEST_SUCCESS(name, retval, syscall_null_ctx_test)
  52
  53 #define TC_FAIL(name, retval, error_msg) __BPF_TEST_FAIL(name, retval, tc_test, error_msg)
  54 #define SYSCALL_NULL_CTX_FAIL(name, retval, error_msg) \
  55         __BPF_TEST_FAIL(name, retval, syscall_null_ctx_test, error_msg)
  56
  57 static struct kfunc_test_params kfunc_tests[] = {
  58         /* failure cases:
  59          * if retval is 0 -> the program will fail to load and the error message is an error
  60          * if retval is not 0 -> the program can be loaded but running it will gives the
  61          *                       provided return value. The error message is thus the one
  62          *                       from a successful load
  63          */
  64         SYSCALL_NULL_CTX_FAIL(kfunc_syscall_test_fail, -EINVAL, "processed 4 insns"),
  65         SYSCALL_NULL_CTX_FAIL(kfunc_syscall_test_null_fail, -EINVAL, "processed 4 insns"),
  66         TC_FAIL(kfunc_call_test_get_mem_fail_rdonly, 0, "R0 cannot write into rdonly_mem"),
  67         TC_FAIL(kfunc_call_test_get_mem_fail_use_after_free, 0, "invalid mem access 'scalar'"),
  68         TC_FAIL(kfunc_call_test_get_mem_fail_oob, 0, "min value is outside of the allowed memory range"),
  69         TC_FAIL(kfunc_call_test_get_mem_fail_not_const, 0, "is not a const"),
  70         TC_FAIL(kfunc_call_test_mem_acquire_fail, 0, "acquire kernel function does not return PTR_TO_BTF_ID"),
  71
  72         /* success cases */
  73         TC_TEST(kfunc_call_test1, 12),
  74         TC_TEST(kfunc_call_test2, 3),
  75         TC_TEST(kfunc_call_test4, -1234),
  76         TC_TEST(kfunc_call_test_ref_btf_id, 0),
  77         TC_TEST(kfunc_call_test_get_mem, 42),
  78         SYSCALL_TEST(kfunc_syscall_test, 0),
  79         SYSCALL_NULL_CTX_TEST(kfunc_syscall_test_null, 0),
  80         TC_TEST(kfunc_call_test_static_unused_arg, 0),
  81 };
  82
  83 struct syscall_test_args {
  84         __u8 data[16];
  85         size_t size;
  86 };
  87
  88 static void verify_success(struct kfunc_test_params *param)
  89 {
  90         struct kfunc_call_test_lskel *lskel = NULL;
  91         LIBBPF_OPTS(bpf_test_run_opts, topts);
  92         struct bpf_prog_desc *lskel_prog;
  93         struct kfunc_call_test *skel;
  94         struct bpf_program *prog;
  95         int prog_fd, err;
  96         struct syscall_test_args args = {
  97                 .size = 10,
  98         };
  99
 100         switch (param->test_type) {
 101         case syscall_test:
 102                 topts.ctx_in = &args;
 103                 topts.ctx_size_in = sizeof(args);
 104                 /* fallthrough */
 105         case syscall_null_ctx_test:
 106                 break;
 107         case tc_test:
 108                 topts.data_in = &pkt_v4;
 109                 topts.data_size_in = sizeof(pkt_v4);
 110                 topts.repeat = 1;
 111                 break;
 112         }
 113
 114         /* first test with normal libbpf */
 115         skel = kfunc_call_test__open_and_load();
 116         if (!ASSERT_OK_PTR(skel, "skel"))
 117                 return;
 118
 119         prog = bpf_object__find_program_by_name(skel->obj, param->prog_name);
 120         if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
 121                 goto cleanup;
 122
 123         prog_fd = bpf_program__fd(prog);
 124         err = bpf_prog_test_run_opts(prog_fd, &topts);
 125         if (!ASSERT_OK(err, param->prog_name))
 126                 goto cleanup;
 127
 128         if (!ASSERT_EQ(topts.retval, param->retval, "retval"))
 129                 goto cleanup;
 130
 131         /* second test with light skeletons */
 132         lskel = kfunc_call_test_lskel__open_and_load();
 133         if (!ASSERT_OK_PTR(lskel, "lskel"))
 134                 goto cleanup;
 135
 136         lskel_prog = (struct bpf_prog_desc *)((char *)lskel + param->lskel_prog_desc_offset);
 137
 138         prog_fd = lskel_prog->prog_fd;
 139         err = bpf_prog_test_run_opts(prog_fd, &topts);
 140         if (!ASSERT_OK(err, param->prog_name))
 141                 goto cleanup;
 142
 143         ASSERT_EQ(topts.retval, param->retval, "retval");
 144
 145 cleanup:
 146         kfunc_call_test__destroy(skel);
 147         if (lskel)
 148                 kfunc_call_test_lskel__destroy(lskel);
 149 }
 150
 151 static void verify_fail(struct kfunc_test_params *param)
 152 {
 153         LIBBPF_OPTS(bpf_object_open_opts, opts);
 154         LIBBPF_OPTS(bpf_test_run_opts, topts);
 155         struct bpf_program *prog;
 156         struct kfunc_call_fail *skel;
 157         int prog_fd, err;
 158         struct syscall_test_args args = {
 159                 .size = 10,
 160         };
 161
 162         opts.kernel_log_buf = obj_log_buf;
 163         opts.kernel_log_size = log_buf_sz;
 164         opts.kernel_log_level = 1;
 165
 166         switch (param->test_type) {
 167         case syscall_test:
 168                 topts.ctx_in = &args;
 169                 topts.ctx_size_in = sizeof(args);
 170                 /* fallthrough */
 171         case syscall_null_ctx_test:
 172                 break;
 173         case tc_test:
 174                 topts.data_in = &pkt_v4;
 175                 topts.data_size_in = sizeof(pkt_v4);
 176                 topts.repeat = 1;
 177                 break;
 178         }
 179
 180         skel = kfunc_call_fail__open_opts(&opts);
 181         if (!ASSERT_OK_PTR(skel, "kfunc_call_fail__open_opts"))
 182                 goto cleanup;
 183
 184         prog = bpf_object__find_program_by_name(skel->obj, param->prog_name);
 185         if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
 186                 goto cleanup;
 187
 188         bpf_program__set_autoload(prog, true);
 189
 190         err = kfunc_call_fail__load(skel);
 191         if (!param->retval) {
 192                 /* the verifier is supposed to complain and refuses to load */
 193                 if (!ASSERT_ERR(err, "unexpected load success"))
 194                         goto out_err;
 195
 196         } else {
 197                 /* the program is loaded but must dynamically fail */
 198                 if (!ASSERT_OK(err, "unexpected load error"))
 199                         goto out_err;
 200
 201                 prog_fd = bpf_program__fd(prog);
 202                 err = bpf_prog_test_run_opts(prog_fd, &topts);
 203                 if (!ASSERT_EQ(err, param->retval, param->prog_name))
 204                         goto out_err;
 205         }
 206
 207 out_err:
 208         if (!ASSERT_OK_PTR(strstr(obj_log_buf, param->expected_err_msg), "expected_err_msg")) {
 209                 fprintf(stderr, "Expected err_msg: %s\n", param->expected_err_msg);
 210                 fprintf(stderr, "Verifier output: %s\n", obj_log_buf);
 211         }
 212
 213 cleanup:
 214         kfunc_call_fail__destroy(skel);
 215 }
 216
 217 static void test_main(void)
 218 {
 219         int i;
 220
 221         for (i = 0; i < ARRAY_SIZE(kfunc_tests); i++) {
 222                 if (!test__start_subtest(kfunc_tests[i].prog_name))
 223                         continue;
 224
 225                 if (!kfunc_tests[i].expected_err_msg)
 226                         verify_success(&kfunc_tests[i]);
 227                 else
 228                         verify_fail(&kfunc_tests[i]);
 229         }
 230 }
 231
 232 static void test_subprog(void)
 233 {
 234         struct kfunc_call_test_subprog *skel;
 235         int prog_fd, err;
 236         LIBBPF_OPTS(bpf_test_run_opts, topts,
 237                 .data_in = &pkt_v4,
 238                 .data_size_in = sizeof(pkt_v4),
 239                 .repeat = 1,
 240         );
 241
 242         skel = kfunc_call_test_subprog__open_and_load();
 243         if (!ASSERT_OK_PTR(skel, "skel"))
 244                 return;
 245
 246         prog_fd = bpf_program__fd(skel->progs.kfunc_call_test1);
 247         err = bpf_prog_test_run_opts(prog_fd, &topts);
 248         ASSERT_OK(err, "bpf_prog_test_run(test1)");
 249         ASSERT_EQ(topts.retval, 10, "test1-retval");
 250         ASSERT_NEQ(skel->data->active_res, -1, "active_res");
 251         ASSERT_EQ(skel->data->sk_state_res, BPF_TCP_CLOSE, "sk_state_res");
 252
 253         kfunc_call_test_subprog__destroy(skel);
 254 }
 255
 256 static void test_subprog_lskel(void)
 257 {
 258         struct kfunc_call_test_subprog_lskel *skel;
 259         int prog_fd, err;
 260         LIBBPF_OPTS(bpf_test_run_opts, topts,
 261                 .data_in = &pkt_v4,
 262                 .data_size_in = sizeof(pkt_v4),
 263                 .repeat = 1,
 264         );
 265
 266         skel = kfunc_call_test_subprog_lskel__open_and_load();
 267         if (!ASSERT_OK_PTR(skel, "skel"))
 268                 return;
 269
 270         prog_fd = skel->progs.kfunc_call_test1.prog_fd;
 271         err = bpf_prog_test_run_opts(prog_fd, &topts);
 272         ASSERT_OK(err, "bpf_prog_test_run(test1)");
 273         ASSERT_EQ(topts.retval, 10, "test1-retval");
 274         ASSERT_NEQ(skel->data->active_res, -1, "active_res");
 275         ASSERT_EQ(skel->data->sk_state_res, BPF_TCP_CLOSE, "sk_state_res");
 276
 277         kfunc_call_test_subprog_lskel__destroy(skel);
 278 }
 279
 280 static int test_destructive_open_and_load(void)
 281 {
 282         struct kfunc_call_destructive *skel;
 283         int err;
 284
 285         skel = kfunc_call_destructive__open();
 286         if (!ASSERT_OK_PTR(skel, "prog_open"))
 287                 return -1;
 288
 289         err = kfunc_call_destructive__load(skel);
 290
 291         kfunc_call_destructive__destroy(skel);
 292
 293         return err;
 294 }
 295
 296 static void test_destructive(void)
 297 {
 298         __u64 save_caps = 0;
 299
 300         ASSERT_OK(test_destructive_open_and_load(), "successful_load");
 301
 302         if (!ASSERT_OK(cap_disable_effective(1ULL << CAP_SYS_BOOT, &save_caps), "drop_caps"))
 303                 return;
 304
 305         ASSERT_EQ(test_destructive_open_and_load(), -13, "no_caps_failure");
 306
 307         cap_enable_effective(save_caps, NULL);
 308 }
 309
 310 void test_kfunc_call(void)
 311 {
 312         test_main();
 313
 314         if (test__start_subtest("subprog"))
 315                 test_subprog();
 316
 317         if (test__start_subtest("subprog_lskel"))
 318                 test_subprog_lskel();
 319
 320         if (test__start_subtest("destructive"))
 321                 test_destructive();
 322 }