xref: /openbmc/linux/tools/perf/tests/sdt.c (revision 9be08a27)
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 
17 static int target_function(void)
18 {
19 	DTRACE_PROBE(perf, test_target);
20 	return TEST_OK;
21 }
22 
23 /* Copied from builtin-buildid-cache.c */
24 static 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 
43 static 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 
55 static 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 
75 int 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 
104 error_rmdir:
105 	/* Cleanup temporary buildid dir */
106 	rm_rf(__tempdir);
107 error:
108 	free(tempdir);
109 	free(myself);
110 	return ret;
111 }
112 #else
113 int 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