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/debug/tracing/user_events_data";
22const char *status_file = "/sys/kernel/debug/tracing/user_events_status";
23const char *id_file = "/sys/kernel/debug/tracing/events/user_events/__test_event/id";
24const char *fmt_file = "/sys/kernel/debug/tracing/events/user_events/__test_event/format";
25
26struct event {
27 __u32 index;
28 __u32 field1;
29 __u32 field2;
30};
31
32static 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
38static 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
55static 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
85FIXTURE(user) {
86 int status_fd;
87 int data_fd;
88};
89
90FIXTURE_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
98FIXTURE_TEARDOWN(user) {
99 close(self->status_fd);
100 close(self->data_fd);
101}
102
103TEST_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
165int main(int argc, char **argv)
166{
167 return test_harness_run(argc, argv);
168}