xref: /linux/tools/perf/tests/sdt.c (revision 96ac6d435100450f0565708d9b885ea2a7400e0a)
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
120