1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <inttypes.h>
4 /* For the CLR_() macros */
5 #include <pthread.h>
6 #include <stdlib.h>
7 #include <perf/cpumap.h>
8
9 #include "debug.h"
10 #include "evlist.h"
11 #include "evsel.h"
12 #include "thread_map.h"
13 #include "tests.h"
14 #include "util/mmap.h"
15 #include <linux/err.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <perf/evlist.h>
19 #include <perf/mmap.h>
20
21 /*
22 * This test will generate random numbers of calls to some getpid syscalls,
23 * then establish an mmap for a group of events that are created to monitor
24 * the syscalls.
25 *
26 * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
27 * sample.id field to map back to its respective perf_evsel instance.
28 *
29 * Then it checks if the number of syscalls reported as perf events by
30 * the kernel corresponds to the number of syscalls made.
31 */
test__basic_mmap(struct test * test __maybe_unused,int subtest __maybe_unused)32 int test__basic_mmap(struct test *test __maybe_unused, int subtest __maybe_unused)
33 {
34 int err = -1;
35 union perf_event *event;
36 struct perf_thread_map *threads;
37 struct perf_cpu_map *cpus;
38 struct evlist *evlist;
39 cpu_set_t cpu_set;
40 const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
41 pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
42 #define nsyscalls ARRAY_SIZE(syscall_names)
43 unsigned int nr_events[nsyscalls],
44 expected_nr_events[nsyscalls], i, j;
45 struct evsel *evsels[nsyscalls], *evsel;
46 char sbuf[STRERR_BUFSIZE];
47 struct mmap *md;
48
49 threads = thread_map__new(-1, getpid(), UINT_MAX);
50 if (threads == NULL) {
51 pr_debug("thread_map__new\n");
52 return -1;
53 }
54
55 cpus = perf_cpu_map__new(NULL);
56 if (cpus == NULL) {
57 pr_debug("perf_cpu_map__new\n");
58 goto out_free_threads;
59 }
60
61 CPU_ZERO(&cpu_set);
62 CPU_SET(cpus->map[0], &cpu_set);
63 sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
64 if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
65 pr_debug("sched_setaffinity() failed on CPU %d: %s ",
66 cpus->map[0], str_error_r(errno, sbuf, sizeof(sbuf)));
67 goto out_free_cpus;
68 }
69
70 evlist = evlist__new();
71 if (evlist == NULL) {
72 pr_debug("perf_evlist__new\n");
73 goto out_free_cpus;
74 }
75
76 perf_evlist__set_maps(&evlist->core, cpus, threads);
77
78 for (i = 0; i < nsyscalls; ++i) {
79 char name[64];
80
81 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
82 evsels[i] = evsel__newtp("syscalls", name);
83 if (IS_ERR(evsels[i])) {
84 pr_debug("evsel__new(%s)\n", name);
85 goto out_delete_evlist;
86 }
87
88 evsels[i]->core.attr.wakeup_events = 1;
89 evsel__set_sample_id(evsels[i], false);
90
91 evlist__add(evlist, evsels[i]);
92
93 if (evsel__open(evsels[i], cpus, threads) < 0) {
94 pr_debug("failed to open counter: %s, "
95 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
96 str_error_r(errno, sbuf, sizeof(sbuf)));
97 goto out_delete_evlist;
98 }
99
100 nr_events[i] = 0;
101 expected_nr_events[i] = 1 + rand() % 127;
102 }
103
104 if (evlist__mmap(evlist, 128) < 0) {
105 pr_debug("failed to mmap events: %d (%s)\n", errno,
106 str_error_r(errno, sbuf, sizeof(sbuf)));
107 goto out_delete_evlist;
108 }
109
110 for (i = 0; i < nsyscalls; ++i)
111 for (j = 0; j < expected_nr_events[i]; ++j) {
112 int foo = syscalls[i]();
113 ++foo;
114 }
115
116 md = &evlist->mmap[0];
117 if (perf_mmap__read_init(&md->core) < 0)
118 goto out_init;
119
120 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
121 struct perf_sample sample;
122
123 if (event->header.type != PERF_RECORD_SAMPLE) {
124 pr_debug("unexpected %s event\n",
125 perf_event__name(event->header.type));
126 goto out_delete_evlist;
127 }
128
129 err = perf_evlist__parse_sample(evlist, event, &sample);
130 if (err) {
131 pr_err("Can't parse sample, err = %d\n", err);
132 goto out_delete_evlist;
133 }
134
135 err = -1;
136 evsel = perf_evlist__id2evsel(evlist, sample.id);
137 if (evsel == NULL) {
138 pr_debug("event with id %" PRIu64
139 " doesn't map to an evsel\n", sample.id);
140 goto out_delete_evlist;
141 }
142 nr_events[evsel->idx]++;
143 perf_mmap__consume(&md->core);
144 }
145 perf_mmap__read_done(&md->core);
146
147 out_init:
148 err = 0;
149 evlist__for_each_entry(evlist, evsel) {
150 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
151 pr_debug("expected %d %s events, got %d\n",
152 expected_nr_events[evsel->idx],
153 evsel__name(evsel), nr_events[evsel->idx]);
154 err = -1;
155 goto out_delete_evlist;
156 }
157 }
158
159 out_delete_evlist:
160 evlist__delete(evlist);
161 cpus = NULL;
162 threads = NULL;
163 out_free_cpus:
164 perf_cpu_map__put(cpus);
165 out_free_threads:
166 perf_thread_map__put(threads);
167 return err;
168 }
169