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
perf_event_open(struct perf_event_attr * pe,pid_t pid,int cpu,int group_fd,unsigned long flags)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
status_check(char * status_page,int status_bit)38 static inline int status_check(char *status_page, int status_bit)
39 {
40 return status_page[status_bit >> 3] & (1 << (status_bit & 7));
41 }
42
get_id(void)43 static int get_id(void)
44 {
45 FILE *fp = fopen(id_file, "r");
46 int ret, id = 0;
47
48 if (!fp)
49 return -1;
50
51 ret = fscanf(fp, "%d", &id);
52 fclose(fp);
53
54 if (ret != 1)
55 return -1;
56
57 return id;
58 }
59
get_offset(void)60 static int get_offset(void)
61 {
62 FILE *fp = fopen(fmt_file, "r");
63 int ret, c, last = 0, offset = 0;
64
65 if (!fp)
66 return -1;
67
68 /* Read until empty line */
69 while (true) {
70 c = getc(fp);
71
72 if (c == EOF)
73 break;
74
75 if (last == '\n' && c == '\n')
76 break;
77
78 last = c;
79 }
80
81 ret = fscanf(fp, "\tfield:u32 field1;\toffset:%d;", &offset);
82 fclose(fp);
83
84 if (ret != 1)
85 return -1;
86
87 return offset;
88 }
89
FIXTURE(user)90 FIXTURE(user) {
91 int status_fd;
92 int data_fd;
93 };
94
FIXTURE_SETUP(user)95 FIXTURE_SETUP(user) {
96 self->status_fd = open(status_file, O_RDONLY);
97 ASSERT_NE(-1, self->status_fd);
98
99 self->data_fd = open(data_file, O_RDWR);
100 ASSERT_NE(-1, self->data_fd);
101 }
102
FIXTURE_TEARDOWN(user)103 FIXTURE_TEARDOWN(user) {
104 close(self->status_fd);
105 close(self->data_fd);
106 }
107
TEST_F(user,perf_write)108 TEST_F(user, perf_write) {
109 struct perf_event_attr pe = {0};
110 struct user_reg reg = {0};
111 int page_size = sysconf(_SC_PAGESIZE);
112 char *status_page;
113 struct event event;
114 struct perf_event_mmap_page *perf_page;
115 int id, fd, offset;
116 __u32 *val;
117
118 reg.size = sizeof(reg);
119 reg.name_args = (__u64)"__test_event u32 field1; u32 field2";
120
121 status_page = mmap(NULL, page_size, PROT_READ, MAP_SHARED,
122 self->status_fd, 0);
123 ASSERT_NE(MAP_FAILED, status_page);
124
125 /* Register should work */
126 ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, ®));
127 ASSERT_EQ(0, reg.write_index);
128 ASSERT_NE(0, reg.status_bit);
129 ASSERT_EQ(0, status_check(status_page, reg.status_bit));
130
131 /* Id should be there */
132 id = get_id();
133 ASSERT_NE(-1, id);
134 offset = get_offset();
135 ASSERT_NE(-1, offset);
136
137 pe.type = PERF_TYPE_TRACEPOINT;
138 pe.size = sizeof(pe);
139 pe.config = id;
140 pe.sample_type = PERF_SAMPLE_RAW;
141 pe.sample_period = 1;
142 pe.wakeup_events = 1;
143
144 /* Tracepoint attach should work */
145 fd = perf_event_open(&pe, 0, -1, -1, 0);
146 ASSERT_NE(-1, fd);
147
148 perf_page = mmap(NULL, page_size * 2, PROT_READ, MAP_SHARED, fd, 0);
149 ASSERT_NE(MAP_FAILED, perf_page);
150
151 /* Status should be updated */
152 ASSERT_NE(0, status_check(status_page, reg.status_bit));
153
154 event.index = reg.write_index;
155 event.field1 = 0xc001;
156 event.field2 = 0xc01a;
157
158 /* Ensure write shows up at correct offset */
159 ASSERT_NE(-1, write(self->data_fd, &event, sizeof(event)));
160 val = (void *)(((char *)perf_page) + perf_page->data_offset);
161 ASSERT_EQ(PERF_RECORD_SAMPLE, *val);
162 /* Skip over header and size, move to offset */
163 val += 3;
164 val = (void *)((char *)val) + offset;
165 /* Ensure correct */
166 ASSERT_EQ(event.field1, *val++);
167 ASSERT_EQ(event.field2, *val++);
168 }
169
main(int argc,char ** argv)170 int main(int argc, char **argv)
171 {
172 return test_harness_run(argc, argv);
173 }
174