xref: /linux/tools/perf/tests/sdt.c (revision 03ab8e6297acd1bc0eedaa050e2a1635c576fd11)
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 
target_function(void)21 static int target_function(void)
22 {
23 	DTRACE_PROBE(perf, test_target);
24 	return TEST_OK;
25 }
26 
27 /* Copied from builtin-buildid-cache.c */
build_id_cache__add_file(const char * filename)28 static 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 
get_self_path(void)47 static 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 
search_cached_probe(const char * target,const char * group,const char * event)59 static 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 
test__sdt_event(struct test_suite * test __maybe_unused,int subtests __maybe_unused)79 static int test__sdt_event(struct test_suite *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 
108 error_rmdir:
109 	/* Cleanup temporary buildid dir */
110 	rm_rf(__tempdir);
111 error:
112 	free(tempdir);
113 	free(myself);
114 	return ret;
115 }
116 #else
test__sdt_event(struct test_suite * test __maybe_unused,int subtests __maybe_unused)117 static int test__sdt_event(struct test_suite *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 
124 DEFINE_SUITE("Probe SDT events", sdt_event);
125