LXR linux/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
  17static int target_function(void)
  18{
  19        DTRACE_PROBE(perf, test_target);
  20        return TEST_OK;
  21}
  22
  23/* Copied from builtin-buildid-cache.c */
  24static 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
  43static 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
  55static 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
  75int 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
 104error_rmdir:
 105        /* Cleanup temporary buildid dir */
 106        rm_rf(__tempdir);
 107error:
 108        free(tempdir);
 109        free(myself);
 110        return ret;
 111}
 112#else
 113int 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
 119