xref: /linux/tools/perf/tests/sdt.c (revision 8520a98dbab61e9e340cdfb72dd17ccc8a98961e)
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 #include "util.h"
13 
14 /* To test SDT event, we need libelf support to scan elf binary */
15 #if defined(HAVE_SDT_EVENT) && defined(HAVE_LIBELF_SUPPORT)
16 
17 #include <sys/sdt.h>
18 
19 static int target_function(void)
20 {
21 	DTRACE_PROBE(perf, test_target);
22 	return TEST_OK;
23 }
24 
25 /* Copied from builtin-buildid-cache.c */
26 static int build_id_cache__add_file(const char *filename)
27 {
28 	char sbuild_id[SBUILD_ID_SIZE];
29 	u8 build_id[BUILD_ID_SIZE];
30 	int err;
31 
32 	err = filename__read_build_id(filename, &build_id, sizeof(build_id));
33 	if (err < 0) {
34 		pr_debug("Failed to read build id of %s\n", filename);
35 		return err;
36 	}
37 
38 	build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
39 	err = build_id_cache__add_s(sbuild_id, filename, NULL, false, false);
40 	if (err < 0)
41 		pr_debug("Failed to add build id cache of %s\n", filename);
42 	return err;
43 }
44 
45 static char *get_self_path(void)
46 {
47 	char *buf = calloc(PATH_MAX, sizeof(char));
48 
49 	if (buf && readlink("/proc/self/exe", buf, PATH_MAX - 1) < 0) {
50 		pr_debug("Failed to get correct path of perf\n");
51 		free(buf);
52 		return NULL;
53 	}
54 	return buf;
55 }
56 
57 static int search_cached_probe(const char *target,
58 			       const char *group, const char *event)
59 {
60 	struct probe_cache *cache = probe_cache__new(target, NULL);
61 	int ret = 0;
62 
63 	if (!cache) {
64 		pr_debug("Failed to open probe cache of %s\n", target);
65 		return -EINVAL;
66 	}
67 
68 	if (!probe_cache__find_by_name(cache, group, event)) {
69 		pr_debug("Failed to find %s:%s in the cache\n", group, event);
70 		ret = -ENOENT;
71 	}
72 	probe_cache__delete(cache);
73 
74 	return ret;
75 }
76 
77 int test__sdt_event(struct test *test __maybe_unused, int subtests __maybe_unused)
78 {
79 	int ret = TEST_FAIL;
80 	char __tempdir[] = "./test-buildid-XXXXXX";
81 	char *tempdir = NULL, *myself = get_self_path();
82 
83 	if (myself == NULL || mkdtemp(__tempdir) == NULL) {
84 		pr_debug("Failed to make a tempdir for build-id cache\n");
85 		goto error;
86 	}
87 	/* Note that buildid_dir must be an absolute path */
88 	tempdir = realpath(__tempdir, NULL);
89 	if (tempdir == NULL)
90 		goto error_rmdir;
91 
92 	/* At first, scan itself */
93 	set_buildid_dir(tempdir);
94 	if (build_id_cache__add_file(myself) < 0)
95 		goto error_rmdir;
96 
97 	/* Open a cache and make sure the SDT is stored */
98 	if (search_cached_probe(myself, "sdt_perf", "test_target") < 0)
99 		goto error_rmdir;
100 
101 	/* TBD: probing on the SDT event and collect logs */
102 
103 	/* Call the target and get an event */
104 	ret = target_function();
105 
106 error_rmdir:
107 	/* Cleanup temporary buildid dir */
108 	rm_rf(__tempdir);
109 error:
110 	free(tempdir);
111 	free(myself);
112 	return ret;
113 }
114 #else
115 int test__sdt_event(struct test *test __maybe_unused, int subtests __maybe_unused)
116 {
117 	pr_debug("Skip SDT event test because SDT support is not compiled\n");
118 	return TEST_SKIP;
119 }
120 #endif
121