tools/perf/tests/bpf.c

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