tools/perf/tests/sdt.c

   1 #include <errno.h>
   2 #include <stdio.h>
   3 #include <sys/epoll.h>
   4 #include <util/evlist.h>
   5 #include <linux/filter.h>
   6 #include "tests.h"
   7 #include "debug.h"
   8 #include "probe-file.h"
   9 #include "build-id.h"
  10
  11 /* To test SDT event, we need libelf support to scan elf binary */
  12 #if defined(HAVE_SDT_EVENT) && defined(HAVE_LIBELF_SUPPORT)
  13
  14 #include <sys/sdt.h>
  15
  16 static int target_function(void)
  17 {
  18         DTRACE_PROBE(perf, test_target);
  19         return TEST_OK;
  20 }
  21
  22 /* Copied from builtin-buildid-cache.c */
  23 static int build_id_cache__add_file(const char *filename)
  24 {
  25         char sbuild_id[SBUILD_ID_SIZE];
  26         u8 build_id[BUILD_ID_SIZE];
  27         int err;
  28
  29         err = filename__read_build_id(filename, &build_id, sizeof(build_id));
  30         if (err < 0) {
  31                 pr_debug("Failed to read build id of %s\n", filename);
  32                 return err;
  33         }
  34
  35         build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
  36         err = build_id_cache__add_s(sbuild_id, filename, NULL, false, false);
  37         if (err < 0)
  38                 pr_debug("Failed to add build id cache of %s\n", filename);
  39         return err;
  40 }
  41
  42 static char *get_self_path(void)
  43 {
  44         char *buf = calloc(PATH_MAX, sizeof(char));
  45
  46         if (buf && readlink("/proc/self/exe", buf, PATH_MAX - 1) < 0) {
  47                 pr_debug("Failed to get correct path of perf\n");
  48                 free(buf);
  49                 return NULL;
  50         }
  51         return buf;
  52 }
  53
  54 static int search_cached_probe(const char *target,
  55                                const char *group, const char *event)
  56 {
  57         struct probe_cache *cache = probe_cache__new(target, NULL);
  58         int ret = 0;
  59
  60         if (!cache) {
  61                 pr_debug("Failed to open probe cache of %s\n", target);
  62                 return -EINVAL;
  63         }
  64
  65         if (!probe_cache__find_by_name(cache, group, event)) {
  66                 pr_debug("Failed to find %s:%s in the cache\n", group, event);
  67                 ret = -ENOENT;
  68         }
  69         probe_cache__delete(cache);
  70
  71         return ret;
  72 }
  73
  74 int test__sdt_event(struct test *test __maybe_unused, int subtests __maybe_unused)
  75 {
  76         int ret = TEST_FAIL;
  77         char __tempdir[] = "./test-buildid-XXXXXX";
  78         char *tempdir = NULL, *myself = get_self_path();
  79
  80         if (myself == NULL || mkdtemp(__tempdir) == NULL) {
  81                 pr_debug("Failed to make a tempdir for build-id cache\n");
  82                 goto error;
  83         }
  84         /* Note that buildid_dir must be an absolute path */
  85         tempdir = realpath(__tempdir, NULL);
  86         if (tempdir == NULL)
  87                 goto error_rmdir;
  88
  89         /* At first, scan itself */
  90         set_buildid_dir(tempdir);
  91         if (build_id_cache__add_file(myself) < 0)
  92                 goto error_rmdir;
  93
  94         /* Open a cache and make sure the SDT is stored */
  95         if (search_cached_probe(myself, "sdt_perf", "test_target") < 0)
  96                 goto error_rmdir;
  97
  98         /* TBD: probing on the SDT event and collect logs */
  99
 100         /* Call the target and get an event */
 101         ret = target_function();
 102
 103 error_rmdir:
 104         /* Cleanup temporary buildid dir */
 105         rm_rf(__tempdir);
 106 error:
 107         free(tempdir);
 108         free(myself);
 109         return ret;
 110 }
 111 #else
 112 int test__sdt_event(struct test *test __maybe_unused, int subtests __maybe_unused)
 113 {
 114         pr_debug("Skip SDT event test because SDT support is not compiled\n");
 115         return TEST_SKIP;
 116 }
 117 #endif