tools/perf/tests/bpf.c

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