LXR linux/tools/perf/tests/sdt.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <errno.h>
   3#include <limits.h>
   4#include <stdio.h>
   5#include <stdlib.h>
   6#include <unistd.h>
   7#include <sys/epoll.h>
   8#include <util/symbol.h>
   9#include <linux/filter.h>
  10#include "tests.h"
  11#include "debug.h"
  12#include "probe-file.h"
  13#include "build-id.h"
  14#include "util.h"
  15
  16/* To test SDT event, we need libelf support to scan elf binary */
  17#if defined(HAVE_SDT_EVENT) && defined(HAVE_LIBELF_SUPPORT)
  18
  19#include <sys/sdt.h>
  20
  21static int target_function(void)
  22{
  23        DTRACE_PROBE(perf, test_target);
  24        return TEST_OK;
  25}
  26
  27/* Copied from builtin-buildid-cache.c */
  28static int build_id_cache__add_file(const char *filename)
  29{
  30        char sbuild_id[SBUILD_ID_SIZE];
  31        struct build_id bid;
  32        int err;
  33
  34        err = filename__read_build_id(filename, &bid);
  35        if (err < 0) {
  36                pr_debug("Failed to read build id of %s\n", filename);
  37                return err;
  38        }
  39
  40        build_id__sprintf(&bid, sbuild_id);
  41        err = build_id_cache__add_s(sbuild_id, filename, NULL, false, false);
  42        if (err < 0)
  43                pr_debug("Failed to add build id cache of %s\n", filename);
  44        return err;
  45}
  46
  47static char *get_self_path(void)
  48{
  49        char *buf = calloc(PATH_MAX, sizeof(char));
  50
  51        if (buf && readlink("/proc/self/exe", buf, PATH_MAX - 1) < 0) {
  52                pr_debug("Failed to get correct path of perf\n");
  53                free(buf);
  54                return NULL;
  55        }
  56        return buf;
  57}
  58
  59static int search_cached_probe(const char *target,
  60                               const char *group, const char *event)
  61{
  62        struct probe_cache *cache = probe_cache__new(target, NULL);
  63        int ret = 0;
  64
  65        if (!cache) {
  66                pr_debug("Failed to open probe cache of %s\n", target);
  67                return -EINVAL;
  68        }
  69
  70        if (!probe_cache__find_by_name(cache, group, event)) {
  71                pr_debug("Failed to find %s:%s in the cache\n", group, event);
  72                ret = -ENOENT;
  73        }
  74        probe_cache__delete(cache);
  75
  76        return ret;
  77}
  78
  79int test__sdt_event(struct test *test __maybe_unused, int subtests __maybe_unused)
  80{
  81        int ret = TEST_FAIL;
  82        char __tempdir[] = "./test-buildid-XXXXXX";
  83        char *tempdir = NULL, *myself = get_self_path();
  84
  85        if (myself == NULL || mkdtemp(__tempdir) == NULL) {
  86                pr_debug("Failed to make a tempdir for build-id cache\n");
  87                goto error;
  88        }
  89        /* Note that buildid_dir must be an absolute path */
  90        tempdir = realpath(__tempdir, NULL);
  91        if (tempdir == NULL)
  92                goto error_rmdir;
  93
  94        /* At first, scan itself */
  95        set_buildid_dir(tempdir);
  96        if (build_id_cache__add_file(myself) < 0)
  97                goto error_rmdir;
  98
  99        /* Open a cache and make sure the SDT is stored */
 100        if (search_cached_probe(myself, "sdt_perf", "test_target") < 0)
 101                goto error_rmdir;
 102
 103        /* TBD: probing on the SDT event and collect logs */
 104
 105        /* Call the target and get an event */
 106        ret = target_function();
 107
 108error_rmdir:
 109        /* Cleanup temporary buildid dir */
 110        rm_rf(__tempdir);
 111error:
 112        free(tempdir);
 113        free(myself);
 114        return ret;
 115}
 116#else
 117int test__sdt_event(struct test *test __maybe_unused, int subtests __maybe_unused)
 118{
 119        pr_debug("Skip SDT event test because SDT support is not compiled\n");
 120        return TEST_SKIP;
 121}
 122#endif
 123