tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
21const char *data_file = "/sys/kernel/tracing/user_events_data";
22const char *id_file = "/sys/kernel/tracing/events/user_events/__test_event/id";
23const char *fmt_file = "/sys/kernel/tracing/events/user_events/__test_event/format";
24
25struct event {
26 __u32 index;
27 __u32 field1;
28 __u32 field2;
29};
30
31static long perf_event_open(struct perf_event_attr *pe, pid_t pid,
32 int cpu, int group_fd, unsigned long flags)
33{
34 return syscall(__NR_perf_event_open, pe, pid, cpu, group_fd, flags);
35}
36
37static int get_id(void)
38{
39 FILE *fp = fopen(id_file, "r");
40 int ret, id = 0;
41
42 if (!fp)
43 return -1;
44
45 ret = fscanf(fp, "%d", &id);
46 fclose(fp);
47
48 if (ret != 1)
49 return -1;
50
51 return id;
52}
53
54static int get_offset(void)
55{
56 FILE *fp = fopen(fmt_file, "r");
57 int ret, c, last = 0, offset = 0;
58
59 if (!fp)
60 return -1;
61
62 /* Read until empty line */
63 while (true) {
64 c = getc(fp);
65
66 if (c == EOF)
67 break;
68
69 if (last == '\n' && c == '\n')
70 break;
71
72 last = c;
73 }
74
75 ret = fscanf(fp, "\tfield:u32 field1;\toffset:%d;", &offset);
76 fclose(fp);
77
78 if (ret != 1)
79 return -1;
80
81 return offset;
82}
83
84FIXTURE(user) {
85 int data_fd;
86 int check;
87};
88
89FIXTURE_SETUP(user) {
90 self->data_fd = open(data_file, O_RDWR);
91 ASSERT_NE(-1, self->data_fd);
92}
93
94FIXTURE_TEARDOWN(user) {
95 close(self->data_fd);
96}
97
98TEST_F(user, perf_write) {
99 struct perf_event_attr pe = {0};
100 struct user_reg reg = {0};
101 struct event event;
102 struct perf_event_mmap_page *perf_page;
103 int page_size = sysconf(_SC_PAGESIZE);
104 int id, fd, offset;
105 __u32 *val;
106
107 reg.size = sizeof(reg);
108 reg.name_args = (__u64)"__test_event u32 field1; u32 field2";
109 reg.enable_bit = 31;
110 reg.enable_addr = (__u64)&self->check;
111 reg.enable_size = sizeof(self->check);
112
113 /* Register should work */
114 ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, ®));
115 ASSERT_EQ(0, reg.write_index);
116 ASSERT_EQ(0, self->check);
117
118 /* Id should be there */
119 id = get_id();
120 ASSERT_NE(-1, id);
121 offset = get_offset();
122 ASSERT_NE(-1, offset);
123
124 pe.type = PERF_TYPE_TRACEPOINT;
125 pe.size = sizeof(pe);
126 pe.config = id;
127 pe.sample_type = PERF_SAMPLE_RAW;
128 pe.sample_period = 1;
129 pe.wakeup_events = 1;
130
131 /* Tracepoint attach should work */
132 fd = perf_event_open(&pe, 0, -1, -1, 0);
133 ASSERT_NE(-1, fd);
134
135 perf_page = mmap(NULL, page_size * 2, PROT_READ, MAP_SHARED, fd, 0);
136 ASSERT_NE(MAP_FAILED, perf_page);
137
138 /* Status should be updated */
139 ASSERT_EQ(1 << reg.enable_bit, self->check);
140
141 event.index = reg.write_index;
142 event.field1 = 0xc001;
143 event.field2 = 0xc01a;
144
145 /* Ensure write shows up at correct offset */
146 ASSERT_NE(-1, write(self->data_fd, &event, sizeof(event)));
147 val = (void *)(((char *)perf_page) + perf_page->data_offset);
148 ASSERT_EQ(PERF_RECORD_SAMPLE, *val);
149 /* Skip over header and size, move to offset */
150 val += 3;
151 val = (void *)((char *)val) + offset;
152 /* Ensure correct */
153 ASSERT_EQ(event.field1, *val++);
154 ASSERT_EQ(event.field2, *val++);
155
156 munmap(perf_page, page_size * 2);
157 close(fd);
158
159 /* Status should be updated */
160 ASSERT_EQ(0, self->check);
161}
162
163int main(int argc, char **argv)
164{
165 return test_harness_run(argc, argv);
166}