1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * User Events Perf Events Test Program 4 * 5 * Copyright (c) 2021 Beau Belgrave <beaub@linux.microsoft.com> 6 */ 7 8 #include <errno.h> 9 #include <linux/user_events.h> 10 #include <linux/perf_event.h> 11 #include <stdio.h> 12 #include <stdlib.h> 13 #include <fcntl.h> 14 #include <sys/ioctl.h> 15 #include <sys/stat.h> 16 #include <unistd.h> 17 #include <asm/unistd.h> 18 19 #include "../kselftest_harness.h" 20 21 const char *data_file = "/sys/kernel/debug/tracing/user_events_data"; 22 const char *status_file = "/sys/kernel/debug/tracing/user_events_status"; 23 const char *id_file = "/sys/kernel/debug/tracing/events/user_events/__test_event/id"; 24 const char *fmt_file = "/sys/kernel/debug/tracing/events/user_events/__test_event/format"; 25 26 struct event { 27 __u32 index; 28 __u32 field1; 29 __u32 field2; 30 }; 31 32 static long perf_event_open(struct perf_event_attr *pe, pid_t pid, 33 int cpu, int group_fd, unsigned long flags) 34 { 35 return syscall(__NR_perf_event_open, pe, pid, cpu, group_fd, flags); 36 } 37 38 static int get_id(void) 39 { 40 FILE *fp = fopen(id_file, "r"); 41 int ret, id = 0; 42 43 if (!fp) 44 return -1; 45 46 ret = fscanf(fp, "%d", &id); 47 fclose(fp); 48 49 if (ret != 1) 50 return -1; 51 52 return id; 53 } 54 55 static int get_offset(void) 56 { 57 FILE *fp = fopen(fmt_file, "r"); 58 int ret, c, last = 0, offset = 0; 59 60 if (!fp) 61 return -1; 62 63 /* Read until empty line */ 64 while (true) { 65 c = getc(fp); 66 67 if (c == EOF) 68 break; 69 70 if (last == '\n' && c == '\n') 71 break; 72 73 last = c; 74 } 75 76 ret = fscanf(fp, "\tfield:u32 field1;\toffset:%d;", &offset); 77 fclose(fp); 78 79 if (ret != 1) 80 return -1; 81 82 return offset; 83 } 84 85 FIXTURE(user) { 86 int status_fd; 87 int data_fd; 88 }; 89 90 FIXTURE_SETUP(user) { 91 self->status_fd = open(status_file, O_RDONLY); 92 ASSERT_NE(-1, self->status_fd); 93 94 self->data_fd = open(data_file, O_RDWR); 95 ASSERT_NE(-1, self->data_fd); 96 } 97 98 FIXTURE_TEARDOWN(user) { 99 close(self->status_fd); 100 close(self->data_fd); 101 } 102 103 TEST_F(user, perf_write) { 104 struct perf_event_attr pe = {0}; 105 struct user_reg reg = {0}; 106 int page_size = sysconf(_SC_PAGESIZE); 107 char *status_page; 108 struct event event; 109 struct perf_event_mmap_page *perf_page; 110 int id, fd, offset; 111 __u32 *val; 112 113 reg.size = sizeof(reg); 114 reg.name_args = (__u64)"__test_event u32 field1; u32 field2"; 115 116 status_page = mmap(NULL, page_size, PROT_READ, MAP_SHARED, 117 self->status_fd, 0); 118 ASSERT_NE(MAP_FAILED, status_page); 119 120 /* Register should work */ 121 ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, ®)); 122 ASSERT_EQ(0, reg.write_index); 123 ASSERT_NE(0, reg.status_index); 124 ASSERT_EQ(0, status_page[reg.status_index]); 125 126 /* Id should be there */ 127 id = get_id(); 128 ASSERT_NE(-1, id); 129 offset = get_offset(); 130 ASSERT_NE(-1, offset); 131 132 pe.type = PERF_TYPE_TRACEPOINT; 133 pe.size = sizeof(pe); 134 pe.config = id; 135 pe.sample_type = PERF_SAMPLE_RAW; 136 pe.sample_period = 1; 137 pe.wakeup_events = 1; 138 139 /* Tracepoint attach should work */ 140 fd = perf_event_open(&pe, 0, -1, -1, 0); 141 ASSERT_NE(-1, fd); 142 143 perf_page = mmap(NULL, page_size * 2, PROT_READ, MAP_SHARED, fd, 0); 144 ASSERT_NE(MAP_FAILED, perf_page); 145 146 /* Status should be updated */ 147 ASSERT_EQ(EVENT_STATUS_PERF, status_page[reg.status_index]); 148 149 event.index = reg.write_index; 150 event.field1 = 0xc001; 151 event.field2 = 0xc01a; 152 153 /* Ensure write shows up at correct offset */ 154 ASSERT_NE(-1, write(self->data_fd, &event, sizeof(event))); 155 val = (void *)(((char *)perf_page) + perf_page->data_offset); 156 ASSERT_EQ(PERF_RECORD_SAMPLE, *val); 157 /* Skip over header and size, move to offset */ 158 val += 3; 159 val = (void *)((char *)val) + offset; 160 /* Ensure correct */ 161 ASSERT_EQ(event.field1, *val++); 162 ASSERT_EQ(event.field2, *val++); 163 } 164 165 int main(int argc, char **argv) 166 { 167 return test_harness_run(argc, argv); 168 } 169