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(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; 152 153 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