tools/perf/tests/sdt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <errno.h>
   3 #include <stdio.h>
   4 #include <sys/epoll.h>
   5 #include <util/evlist.h>
   6 #include <linux/filter.h>
   7 #include "tests.h"
   8 #include "debug.h"
   9 #include "probe-file.h"
  10 #include "build-id.h"
  11
  12 /* To test SDT event, we need libelf support to scan elf binary */
  13 #if defined(HAVE_SDT_EVENT) && defined(HAVE_LIBELF_SUPPORT)
  14
  15 #include <sys/sdt.h>
  16
  17 static int target_function(void)
  18 {
  19         DTRACE_PROBE(perf, test_target);
  20         return TEST_OK;
  21 }
  22
  23 /* Copied from builtin-buildid-cache.c */
  24 static int build_id_cache__add_file(const char *filename)
  25 {
  26         char sbuild_id[SBUILD_ID_SIZE];
  27         u8 build_id[BUILD_ID_SIZE];
  28         int err;
  29
  30         err = filename__read_build_id(filename, &build_id, sizeof(build_id));
  31         if (err < 0) {
  32                 pr_debug("Failed to read build id of %s\n", filename);
  33                 return err;
  34         }
  35
  36         build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
  37         err = build_id_cache__add_s(sbuild_id, filename, NULL, false, false);
  38         if (err < 0)
  39                 pr_debug("Failed to add build id cache of %s\n", filename);
  40         return err;
  41 }
  42
  43 static char *get_self_path(void)
  44 {
  45         char *buf = calloc(PATH_MAX, sizeof(char));
  46
  47         if (buf && readlink("/proc/self/exe", buf, PATH_MAX - 1) < 0) {
  48                 pr_debug("Failed to get correct path of perf\n");
  49                 free(buf);
  50                 return NULL;
  51         }
  52         return buf;
  53 }
  54
  55 static int search_cached_probe(const char *target,
  56                                const char *group, const char *event)
  57 {
  58         struct probe_cache *cache = probe_cache__new(target, NULL);
  59         int ret = 0;
  60
  61         if (!cache) {
  62                 pr_debug("Failed to open probe cache of %s\n", target);
  63                 return -EINVAL;
  64         }
  65
  66         if (!probe_cache__find_by_name(cache, group, event)) {
  67                 pr_debug("Failed to find %s:%s in the cache\n", group, event);
  68                 ret = -ENOENT;
  69         }
  70         probe_cache__delete(cache);
  71
  72         return ret;
  73 }
  74
  75 int test__sdt_event(struct test *test __maybe_unused, int subtests __maybe_unused)
  76 {
  77         int ret = TEST_FAIL;
  78         char __tempdir[] = "./test-buildid-XXXXXX";
  79         char *tempdir = NULL, *myself = get_self_path();
  80
  81         if (myself == NULL || mkdtemp(__tempdir) == NULL) {
  82                 pr_debug("Failed to make a tempdir for build-id cache\n");
  83                 goto error;
  84         }
  85         /* Note that buildid_dir must be an absolute path */
  86         tempdir = realpath(__tempdir, NULL);
  87         if (tempdir == NULL)
  88                 goto error_rmdir;
  89
  90         /* At first, scan itself */
  91         set_buildid_dir(tempdir);
  92         if (build_id_cache__add_file(myself) < 0)
  93                 goto error_rmdir;
  94
  95         /* Open a cache and make sure the SDT is stored */
  96         if (search_cached_probe(myself, "sdt_perf", "test_target") < 0)
  97                 goto error_rmdir;
  98
  99         /* TBD: probing on the SDT event and collect logs */
 100
 101         /* Call the target and get an event */
 102         ret = target_function();
 103
 104 error_rmdir:
 105         /* Cleanup temporary buildid dir */
 106         rm_rf(__tempdir);
 107 error:
 108         free(tempdir);
 109         free(myself);
 110         return ret;
 111 }
 112 #else
 113 int test__sdt_event(struct test *test __maybe_unused, int subtests __maybe_unused)
 114 {
 115         pr_debug("Skip SDT event test because SDT support is not compiled\n");
 116         return TEST_SKIP;
 117 }
 118 #endif