1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/types.h>
3 #include <limits.h>
4 #include <unistd.h>
5 #include <sys/prctl.h>
6 #include <perf/cpumap.h>
7 #include <perf/evlist.h>
8 #include <perf/mmap.h>
9
10 #include "debug.h"
11 #include "parse-events.h"
12 #include "evlist.h"
13 #include "evsel.h"
14 #include "record.h"
15 #include "thread_map.h"
16 #include "tests.h"
17 #include "util/mmap.h"
18
19 #define CHECK__(x) { \
20 while ((x) < 0) { \
21 pr_debug(#x " failed!\n"); \
22 goto out_err; \
23 } \
24 }
25
26 #define CHECK_NOT_NULL__(x) { \
27 while ((x) == NULL) { \
28 pr_debug(#x " failed!\n"); \
29 goto out_err; \
30 } \
31 }
32
33 static int find_comm(struct evlist *evlist, const char *comm)
34 {
35 union perf_event *event;
36 struct mmap *md;
37 int i, found;
38
39 found = 0;
40 for (i = 0; i < evlist->core.nr_mmaps; i++) {
41 md = &evlist->mmap[i];
42 if (perf_mmap__read_init(&md->core) < 0)
43 continue;
44 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
45 if (event->header.type == PERF_RECORD_COMM &&
46 (pid_t)event->comm.pid == getpid() &&
47 (pid_t)event->comm.tid == getpid() &&
48 strcmp(event->comm.comm, comm) == 0)
49 found += 1;
50 perf_mmap__consume(&md->core);
51 }
52 perf_mmap__read_done(&md->core);
53 }
54 return found;
55 }
56
57 /**
58 * test__keep_tracking - test using a dummy software event to keep tracking.
59 *
60 * This function implements a test that checks that tracking events continue
61 * when an event is disabled but a dummy software event is not disabled. If the
62 * test passes %0 is returned, otherwise %-1 is returned.
63 */
64 static int test__keep_tracking(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
65 {
66 struct record_opts opts = {
67 .mmap_pages = UINT_MAX,
68 .user_freq = UINT_MAX,
69 .user_interval = ULLONG_MAX,
70 .target = {
71 .uses_mmap = true,
72 },
73 };
74 struct perf_thread_map *threads = NULL;
75 struct perf_cpu_map *cpus = NULL;
76 struct evlist *evlist = NULL;
77 struct evsel *evsel = NULL;
78 int found, err = -1;
79 const char *comm;
80
81 threads = thread_map__new(-1, getpid(), UINT_MAX);
82 CHECK_NOT_NULL__(threads);
83
84 cpus = perf_cpu_map__new_online_cpus();
85 CHECK_NOT_NULL__(cpus);
86
87 evlist = evlist__new();
88 CHECK_NOT_NULL__(evlist);
89
90 perf_evlist__set_maps(&evlist->core, cpus, threads);
91
92 CHECK__(parse_event(evlist, "dummy:u"));
93 CHECK__(parse_event(evlist, "cycles:u"));
94
95 evlist__config(evlist, &opts, NULL);
96
97 evsel = evlist__first(evlist);
98
99 evsel->core.attr.comm = 1;
100 evsel->core.attr.disabled = 1;
101 evsel->core.attr.enable_on_exec = 0;
102
103 if (evlist__open(evlist) < 0) {
104 pr_debug("Unable to open dummy and cycles event\n");
105 err = TEST_SKIP;
106 goto out_err;
107 }
108
109 CHECK__(evlist__mmap(evlist, UINT_MAX));
110
111 /*
112 * First, test that a 'comm' event can be found when the event is
113 * enabled.
114 */
115
116 evlist__enable(evlist);
117
118 comm = "Test COMM 1";
119 CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
120
121 evlist__disable(evlist);
122
123 found = find_comm(evlist, comm);
124 if (found != 1) {
125 pr_debug("First time, failed to find tracking event.\n");
126 goto out_err;
127 }
128
129 /*
130 * Secondly, test that a 'comm' event can be found when the event is
131 * disabled with the dummy event still enabled.
132 */
133
134 evlist__enable(evlist);
135
136 evsel = evlist__last(evlist);
137
138 CHECK__(evsel__disable(evsel));
139
140 comm = "Test COMM 2";
141 CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
142
143 evlist__disable(evlist);
144
145 found = find_comm(evlist, comm);
146 if (found != 1) {
147 pr_debug("Second time, failed to find tracking event.\n");
148 goto out_err;
149 }
150
151 err = 0;
152
153 out_err:
154 if (evlist) {
155 evlist__disable(evlist);
156 evlist__delete(evlist);
157 }
158 perf_cpu_map__put(cpus);
159 perf_thread_map__put(threads);
160
161 return err;
162 }
163
164 DEFINE_SUITE("Use a dummy software event to keep tracking", keep_tracking);
165
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