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