xref: /linux/tools/perf/tests/keep-tracking.c (revision 8520a98dbab61e9e340cdfb72dd17ccc8a98961e)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/types.h>
3 #include <unistd.h>
4 #include <sys/prctl.h>
5 #include <perf/cpumap.h>
6 #include <perf/evlist.h>
7 
8 #include "debug.h"
9 #include "parse-events.h"
10 #include "evlist.h"
11 #include "evsel.h"
12 #include "record.h"
13 #include "thread_map.h"
14 #include "cpumap.h"
15 #include "tests.h"
16 
17 #define CHECK__(x) {				\
18 	while ((x) < 0) {			\
19 		pr_debug(#x " failed!\n");	\
20 		goto out_err;			\
21 	}					\
22 }
23 
24 #define CHECK_NOT_NULL__(x) {			\
25 	while ((x) == NULL) {			\
26 		pr_debug(#x " failed!\n");	\
27 		goto out_err;			\
28 	}					\
29 }
30 
31 static int find_comm(struct evlist *evlist, const char *comm)
32 {
33 	union perf_event *event;
34 	struct perf_mmap *md;
35 	int i, found;
36 
37 	found = 0;
38 	for (i = 0; i < evlist->nr_mmaps; i++) {
39 		md = &evlist->mmap[i];
40 		if (perf_mmap__read_init(md) < 0)
41 			continue;
42 		while ((event = perf_mmap__read_event(md)) != NULL) {
43 			if (event->header.type == PERF_RECORD_COMM &&
44 			    (pid_t)event->comm.pid == getpid() &&
45 			    (pid_t)event->comm.tid == getpid() &&
46 			    strcmp(event->comm.comm, comm) == 0)
47 				found += 1;
48 			perf_mmap__consume(md);
49 		}
50 		perf_mmap__read_done(md);
51 	}
52 	return found;
53 }
54 
55 /**
56  * test__keep_tracking - test using a dummy software event to keep tracking.
57  *
58  * This function implements a test that checks that tracking events continue
59  * when an event is disabled but a dummy software event is not disabled.  If the
60  * test passes %0 is returned, otherwise %-1 is returned.
61  */
62 int test__keep_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
63 {
64 	struct record_opts opts = {
65 		.mmap_pages	     = UINT_MAX,
66 		.user_freq	     = UINT_MAX,
67 		.user_interval	     = ULLONG_MAX,
68 		.target		     = {
69 			.uses_mmap   = true,
70 		},
71 	};
72 	struct perf_thread_map *threads = NULL;
73 	struct perf_cpu_map *cpus = NULL;
74 	struct evlist *evlist = NULL;
75 	struct evsel *evsel = NULL;
76 	int found, err = -1;
77 	const char *comm;
78 
79 	threads = thread_map__new(-1, getpid(), UINT_MAX);
80 	CHECK_NOT_NULL__(threads);
81 
82 	cpus = perf_cpu_map__new(NULL);
83 	CHECK_NOT_NULL__(cpus);
84 
85 	evlist = evlist__new();
86 	CHECK_NOT_NULL__(evlist);
87 
88 	perf_evlist__set_maps(&evlist->core, cpus, threads);
89 
90 	CHECK__(parse_events(evlist, "dummy:u", NULL));
91 	CHECK__(parse_events(evlist, "cycles:u", NULL));
92 
93 	perf_evlist__config(evlist, &opts, NULL);
94 
95 	evsel = perf_evlist__first(evlist);
96 
97 	evsel->core.attr.comm = 1;
98 	evsel->core.attr.disabled = 1;
99 	evsel->core.attr.enable_on_exec = 0;
100 
101 	if (evlist__open(evlist) < 0) {
102 		pr_debug("Unable to open dummy and cycles event\n");
103 		err = TEST_SKIP;
104 		goto out_err;
105 	}
106 
107 	CHECK__(perf_evlist__mmap(evlist, UINT_MAX));
108 
109 	/*
110 	 * First, test that a 'comm' event can be found when the event is
111 	 * enabled.
112 	 */
113 
114 	evlist__enable(evlist);
115 
116 	comm = "Test COMM 1";
117 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
118 
119 	evlist__disable(evlist);
120 
121 	found = find_comm(evlist, comm);
122 	if (found != 1) {
123 		pr_debug("First time, failed to find tracking event.\n");
124 		goto out_err;
125 	}
126 
127 	/*
128 	 * Secondly, test that a 'comm' event can be found when the event is
129 	 * disabled with the dummy event still enabled.
130 	 */
131 
132 	evlist__enable(evlist);
133 
134 	evsel = perf_evlist__last(evlist);
135 
136 	CHECK__(evsel__disable(evsel));
137 
138 	comm = "Test COMM 2";
139 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
140 
141 	evlist__disable(evlist);
142 
143 	found = find_comm(evlist, comm);
144 	if (found != 1) {
145 		pr_debug("Seconf time, failed to find tracking event.\n");
146 		goto out_err;
147 	}
148 
149 	err = 0;
150 
151 out_err:
152 	if (evlist) {
153 		evlist__disable(evlist);
154 		evlist__delete(evlist);
155 	} else {
156 		perf_cpu_map__put(cpus);
157 		perf_thread_map__put(threads);
158 	}
159 
160 	return err;
161 }
162