tools/perf/tests/bpf.c

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