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 <util/symbol.h>
   7 #include <linux/filter.h>
   8 #include "tests.h"
   9 #include "debug.h"
  10 #include "probe-file.h"
  11 #include "build-id.h"
  12 #include "util.h"
  13
  14 /* To test SDT event, we need libelf support to scan elf binary */
  15 #if defined(HAVE_SDT_EVENT) && defined(HAVE_LIBELF_SUPPORT)
  16
  17 #include <sys/sdt.h>
  18
  19 static int target_function(void)
  20 {
  21         DTRACE_PROBE(perf, test_target);
  22         return TEST_OK;
  23 }
  24
  25 /* Copied from builtin-buildid-cache.c */
  26 static int build_id_cache__add_file(const char *filename)
  27 {
  28         char sbuild_id[SBUILD_ID_SIZE];
  29         u8 build_id[BUILD_ID_SIZE];
  30         int err;
  31
  32         err = filename__read_build_id(filename, &build_id, sizeof(build_id));
  33         if (err < 0) {
  34                 pr_debug("Failed to read build id of %s\n", filename);
  35                 return err;
  36         }
  37
  38         build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
  39         err = build_id_cache__add_s(sbuild_id, filename, NULL, false, false);
  40         if (err < 0)
  41                 pr_debug("Failed to add build id cache of %s\n", filename);
  42         return err;
  43 }
  44
  45 static char *get_self_path(void)
  46 {
  47         char *buf = calloc(PATH_MAX, sizeof(char));
  48
  49         if (buf && readlink("/proc/self/exe", buf, PATH_MAX - 1) < 0) {
  50                 pr_debug("Failed to get correct path of perf\n");
  51                 free(buf);
  52                 return NULL;
  53         }
  54         return buf;
  55 }
  56
  57 static int search_cached_probe(const char *target,
  58                                const char *group, const char *event)
  59 {
  60         struct probe_cache *cache = probe_cache__new(target, NULL);
  61         int ret = 0;
  62
  63         if (!cache) {
  64                 pr_debug("Failed to open probe cache of %s\n", target);
  65                 return -EINVAL;
  66         }
  67
  68         if (!probe_cache__find_by_name(cache, group, event)) {
  69                 pr_debug("Failed to find %s:%s in the cache\n", group, event);
  70                 ret = -ENOENT;
  71         }
  72         probe_cache__delete(cache);
  73
  74         return ret;
  75 }
  76
  77 int test__sdt_event(struct test *test __maybe_unused, int subtests __maybe_unused)
  78 {
  79         int ret = TEST_FAIL;
  80         char __tempdir[] = "./test-buildid-XXXXXX";
  81         char *tempdir = NULL, *myself = get_self_path();
  82
  83         if (myself == NULL || mkdtemp(__tempdir) == NULL) {
  84                 pr_debug("Failed to make a tempdir for build-id cache\n");
  85                 goto error;
  86         }
  87         /* Note that buildid_dir must be an absolute path */
  88         tempdir = realpath(__tempdir, NULL);
  89         if (tempdir == NULL)
  90                 goto error_rmdir;
  91
  92         /* At first, scan itself */
  93         set_buildid_dir(tempdir);
  94         if (build_id_cache__add_file(myself) < 0)
  95                 goto error_rmdir;
  96
  97         /* Open a cache and make sure the SDT is stored */
  98         if (search_cached_probe(myself, "sdt_perf", "test_target") < 0)
  99                 goto error_rmdir;
 100
 101         /* TBD: probing on the SDT event and collect logs */
 102
 103         /* Call the target and get an event */
 104         ret = target_function();
 105
 106 error_rmdir:
 107         /* Cleanup temporary buildid dir */
 108         rm_rf(__tempdir);
 109 error:
 110         free(tempdir);
 111         free(myself);
 112         return ret;
 113 }
 114 #else
 115 int test__sdt_event(struct test *test __maybe_unused, int subtests __maybe_unused)
 116 {
 117         pr_debug("Skip SDT event test because SDT support is not compiled\n");
 118         return TEST_SKIP;
 119 }
 120 #endif