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