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