tools/perf/tests/bpf.c

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