tools/perf/tests/bpf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <errno.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <sys/epoll.h>
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include <fcntl.h>
   9 #include <util/record.h>
  10 #include <util/util.h>
  11 #include <util/bpf-loader.h>
  12 #include <util/evlist.h>
  13 #include <linux/filter.h>
  14 #include <linux/kernel.h>
  15 #include <linux/string.h>
  16 #include <api/fs/fs.h>
  17 #include <perf/mmap.h>
  18 #include "tests.h"
  19 #include "llvm.h"
  20 #include "debug.h"
  21 #include "parse-events.h"
  22 #include "util/mmap.h"
  23 #define NR_ITERS       111
  24 #define PERF_TEST_BPF_PATH "/sys/fs/bpf/perf_test"
  25
  26 #ifdef HAVE_LIBBPF_SUPPORT
  27 #include <linux/bpf.h>
  28 #include <bpf/bpf.h>
  29
  30 static int epoll_pwait_loop(void)
  31 {
  32         int i;
  33
  34         /* Should fail NR_ITERS times */
  35         for (i = 0; i < NR_ITERS; i++)
  36                 epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
  37         return 0;
  38 }
  39
  40 #ifdef HAVE_BPF_PROLOGUE
  41
  42 static int llseek_loop(void)
  43 {
  44         int fds[2], i;
  45
  46         fds[0] = open("/dev/null", O_RDONLY);
  47         fds[1] = open("/dev/null", O_RDWR);
  48
  49         if (fds[0] < 0 || fds[1] < 0)
  50                 return -1;
  51
  52         for (i = 0; i < NR_ITERS; i++) {
  53                 lseek(fds[i % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
  54                 lseek(fds[(i + 1) % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
  55         }
  56         close(fds[0]);
  57         close(fds[1]);
  58         return 0;
  59 }
  60
  61 #endif
  62
  63 static struct {
  64         enum test_llvm__testcase prog_id;
  65         const char *name;
  66         const char *msg_compile_fail;
  67         const char *msg_load_fail;
  68         int (*target_func)(void);
  69         int expect_result;
  70         bool    pin;
  71 } bpf_testcase_table[] = {
  72         {
  73                 .prog_id          = LLVM_TESTCASE_BASE,
  74                 .name             = "[basic_bpf_test]",
  75                 .msg_compile_fail = "fix 'perf test LLVM' first",
  76                 .msg_load_fail    = "load bpf object failed",
  77                 .target_func      = &epoll_pwait_loop,
  78                 .expect_result    = (NR_ITERS + 1) / 2,
  79         },
  80         {
  81                 .prog_id          = LLVM_TESTCASE_BASE,
  82                 .name             = "[bpf_pinning]",
  83                 .msg_compile_fail = "fix kbuild first",
  84                 .msg_load_fail    = "check your vmlinux setting?",
  85                 .target_func      = &epoll_pwait_loop,
  86                 .expect_result    = (NR_ITERS + 1) / 2,
  87                 .pin              = true,
  88         },
  89 #ifdef HAVE_BPF_PROLOGUE
  90         {
  91                 .prog_id          = LLVM_TESTCASE_BPF_PROLOGUE,
  92                 .name             = "[bpf_prologue_test]",
  93                 .msg_compile_fail = "fix kbuild first",
  94                 .msg_load_fail    = "check your vmlinux setting?",
  95                 .target_func      = &llseek_loop,
  96                 .expect_result    = (NR_ITERS + 1) / 4,
  97         },
  98 #endif
  99 };
 100
 101 static int do_test(struct bpf_object *obj, int (*func)(void),
 102                    int expect)
 103 {
 104         struct record_opts opts = {
 105                 .target = {
 106                         .uid = UINT_MAX,
 107                         .uses_mmap = true,
 108                 },
 109                 .freq         = 0,
 110                 .mmap_pages   = 256,
 111                 .default_interval = 1,
 112         };
 113
 114         char pid[16];
 115         char sbuf[STRERR_BUFSIZE];
 116         struct evlist *evlist;
 117         int i, ret = TEST_FAIL, err = 0, count = 0;
 118
 119         struct parse_events_state parse_state;
 120         struct parse_events_error parse_error;
 121
 122         parse_events_error__init(&parse_error);
 123         bzero(&parse_state, sizeof(parse_state));
 124         parse_state.error = &parse_error;
 125         INIT_LIST_HEAD(&parse_state.list);
 126
 127         err = parse_events_load_bpf_obj(&parse_state, &parse_state.list, obj, NULL);
 128         parse_events_error__exit(&parse_error);
 129         if (err || list_empty(&parse_state.list)) {
 130                 pr_debug("Failed to add events selected by BPF\n");
 131                 return TEST_FAIL;
 132         }
 133
 134         snprintf(pid, sizeof(pid), "%d", getpid());
 135         pid[sizeof(pid) - 1] = '\0';
 136         opts.target.tid = opts.target.pid = pid;
 137
 138         /* Instead of evlist__new_default, don't add default events */
 139         evlist = evlist__new();
 140         if (!evlist) {
 141                 pr_debug("Not enough memory to create evlist\n");
 142                 return TEST_FAIL;
 143         }
 144
 145         err = evlist__create_maps(evlist, &opts.target);
 146         if (err < 0) {
 147                 pr_debug("Not enough memory to create thread/cpu maps\n");
 148                 goto out_delete_evlist;
 149         }
 150
 151         evlist__splice_list_tail(evlist, &parse_state.list);
 152         evlist->core.nr_groups = parse_state.nr_groups;
 153
 154         evlist__config(evlist, &opts, NULL);
 155
 156         err = evlist__open(evlist);
 157         if (err < 0) {
 158                 pr_debug("perf_evlist__open: %s\n",
 159                          str_error_r(errno, sbuf, sizeof(sbuf)));
 160                 goto out_delete_evlist;
 161         }
 162
 163         err = evlist__mmap(evlist, opts.mmap_pages);
 164         if (err < 0) {
 165                 pr_debug("evlist__mmap: %s\n",
 166                          str_error_r(errno, sbuf, sizeof(sbuf)));
 167                 goto out_delete_evlist;
 168         }
 169
 170         evlist__enable(evlist);
 171         (*func)();
 172         evlist__disable(evlist);
 173
 174         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 175                 union perf_event *event;
 176                 struct mmap *md;
 177
 178                 md = &evlist->mmap[i];
 179                 if (perf_mmap__read_init(&md->core) < 0)
 180                         continue;
 181
 182                 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
 183                         const u32 type = event->header.type;
 184
 185                         if (type == PERF_RECORD_SAMPLE)
 186                                 count ++;
 187                 }
 188                 perf_mmap__read_done(&md->core);
 189         }
 190
 191         if (count != expect * evlist->core.nr_entries) {
 192                 pr_debug("BPF filter result incorrect, expected %d, got %d samples\n", expect * evlist->core.nr_entries, count);
 193                 goto out_delete_evlist;
 194         }
 195
 196         ret = TEST_OK;
 197
 198 out_delete_evlist:
 199         evlist__delete(evlist);
 200         return ret;
 201 }
 202
 203 static struct bpf_object *
 204 prepare_bpf(void *obj_buf, size_t obj_buf_sz, const char *name)
 205 {
 206         struct bpf_object *obj;
 207
 208         obj = bpf__prepare_load_buffer(obj_buf, obj_buf_sz, name);
 209         if (IS_ERR(obj)) {
 210                 pr_debug("Compile BPF program failed.\n");
 211                 return NULL;
 212         }
 213         return obj;
 214 }
 215
 216 static int __test__bpf(int idx)
 217 {
 218         int ret;
 219         void *obj_buf;
 220         size_t obj_buf_sz;
 221         struct bpf_object *obj;
 222
 223         ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
 224                                        bpf_testcase_table[idx].prog_id,
 225                                        false, NULL);
 226         if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
 227                 pr_debug("Unable to get BPF object, %s\n",
 228                          bpf_testcase_table[idx].msg_compile_fail);
 229                 if ((idx == 0) || (ret == TEST_SKIP))
 230                         return TEST_SKIP;
 231                 else
 232                         return TEST_FAIL;
 233         }
 234
 235         obj = prepare_bpf(obj_buf, obj_buf_sz,
 236                           bpf_testcase_table[idx].name);
 237         if ((!!bpf_testcase_table[idx].target_func) != (!!obj)) {
 238                 if (!obj)
 239                         pr_debug("Fail to load BPF object: %s\n",
 240                                  bpf_testcase_table[idx].msg_load_fail);
 241                 else
 242                         pr_debug("Success unexpectedly: %s\n",
 243                                  bpf_testcase_table[idx].msg_load_fail);
 244                 ret = TEST_FAIL;
 245                 goto out;
 246         }
 247
 248         if (obj) {
 249                 ret = do_test(obj,
 250                               bpf_testcase_table[idx].target_func,
 251                               bpf_testcase_table[idx].expect_result);
 252                 if (ret != TEST_OK)
 253                         goto out;
 254                 if (bpf_testcase_table[idx].pin) {
 255                         int err;
 256
 257                         if (!bpf_fs__mount()) {
 258                                 pr_debug("BPF filesystem not mounted\n");
 259                                 ret = TEST_FAIL;
 260                                 goto out;
 261                         }
 262                         err = mkdir(PERF_TEST_BPF_PATH, 0777);
 263                         if (err && errno != EEXIST) {
 264                                 pr_debug("Failed to make perf_test dir: %s\n",
 265                                          strerror(errno));
 266                                 ret = TEST_FAIL;
 267                                 goto out;
 268                         }
 269                         if (bpf_object__pin(obj, PERF_TEST_BPF_PATH))
 270                                 ret = TEST_FAIL;
 271                         if (rm_rf(PERF_TEST_BPF_PATH))
 272                                 ret = TEST_FAIL;
 273                 }
 274         }
 275
 276 out:
 277         free(obj_buf);
 278         bpf__clear();
 279         return ret;
 280 }
 281
 282 static int check_env(void)
 283 {
 284         LIBBPF_OPTS(bpf_prog_load_opts, opts);
 285         int err;
 286         char license[] = "GPL";
 287
 288         struct bpf_insn insns[] = {
 289                 BPF_MOV64_IMM(BPF_REG_0, 1),
 290                 BPF_EXIT_INSN(),
 291         };
 292
 293         err = fetch_kernel_version(&opts.kern_version, NULL, 0);
 294         if (err) {
 295                 pr_debug("Unable to get kernel version\n");
 296                 return err;
 297         }
 298         err = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, license, insns,
 299                             ARRAY_SIZE(insns), &opts);
 300         if (err < 0) {
 301                 pr_err("Missing basic BPF support, skip this test: %s\n",
 302                        strerror(errno));
 303                 return err;
 304         }
 305         close(err);
 306
 307         return 0;
 308 }
 309
 310 static int test__bpf(int i)
 311 {
 312         int err;
 313
 314         if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
 315                 return TEST_FAIL;
 316
 317         if (geteuid() != 0) {
 318                 pr_debug("Only root can run BPF test\n");
 319                 return TEST_SKIP;
 320         }
 321
 322         if (check_env())
 323                 return TEST_SKIP;
 324
 325         err = __test__bpf(i);
 326         return err;
 327 }
 328 #endif
 329
 330 static int test__basic_bpf_test(struct test_suite *test __maybe_unused,
 331                                 int subtest __maybe_unused)
 332 {
 333 #ifdef HAVE_LIBBPF_SUPPORT
 334         return test__bpf(0);
 335 #else
 336         pr_debug("Skip BPF test because BPF support is not compiled\n");
 337         return TEST_SKIP;
 338 #endif
 339 }
 340
 341 static int test__bpf_pinning(struct test_suite *test __maybe_unused,
 342                              int subtest __maybe_unused)
 343 {
 344 #ifdef HAVE_LIBBPF_SUPPORT
 345         return test__bpf(1);
 346 #else
 347         pr_debug("Skip BPF test because BPF support is not compiled\n");
 348         return TEST_SKIP;
 349 #endif
 350 }
 351
 352 static int test__bpf_prologue_test(struct test_suite *test __maybe_unused,
 353                                    int subtest __maybe_unused)
 354 {
 355 #if defined(HAVE_LIBBPF_SUPPORT) && defined(HAVE_BPF_PROLOGUE)
 356         return test__bpf(2);
 357 #else
 358         pr_debug("Skip BPF test because BPF support is not compiled\n");
 359         return TEST_SKIP;
 360 #endif
 361 }
 362
 363
 364 static struct test_case bpf_tests[] = {
 365 #ifdef HAVE_LIBBPF_SUPPORT
 366         TEST_CASE("Basic BPF filtering", basic_bpf_test),
 367         TEST_CASE_REASON("BPF pinning", bpf_pinning,
 368                         "clang isn't installed or environment missing BPF support"),
 369 #ifdef HAVE_BPF_PROLOGUE
 370         TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test,
 371                         "clang isn't installed or environment missing BPF support"),
 372 #else
 373         TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test, "not compiled in"),
 374 #endif
 375 #else
 376         TEST_CASE_REASON("Basic BPF filtering", basic_bpf_test, "not compiled in"),
 377         TEST_CASE_REASON("BPF pinning", bpf_pinning, "not compiled in"),
 378         TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test, "not compiled in"),
 379 #endif
 380         { .name = NULL, }
 381 };
 382
 383 struct test_suite suite__bpf = {
 384         .desc = "BPF filter",
 385         .test_cases = bpf_tests,
 386 };