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
 33static 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 */
 64static 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(NULL);
 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
153out_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
164DEFINE_SUITE("Use a dummy software event to keep tracking", keep_tracking);