1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdlib.h>
3 #include <string.h>
4 #include <unistd.h>
5 #include <sys/ioctl.h>
6 #include <linux/hw_breakpoint.h>
7 #include <linux/kernel.h>
8 #include "tests.h"
9 #include "debug.h"
10 #include "event.h"
11 #include "cloexec.h"
12 #include "../perf-sys.h"
13
14 #define WP_TEST_ASSERT_VAL(fd, text, val) \
15 do { \
16 long long count; \
17 wp_read(fd, &count, sizeof(long long)); \
18 TEST_ASSERT_VAL(text, count == val); \
19 } while (0)
20
21 volatile u64 data1;
22 volatile u8 data2[3];
23
wp_read(int fd,long long * count,int size)24 static int wp_read(int fd, long long *count, int size)
25 {
26 int ret = read(fd, count, size);
27
28 if (ret != size) {
29 pr_debug("failed to read: %d\n", ret);
30 return -1;
31 }
32 return 0;
33 }
34
get__perf_event_attr(struct perf_event_attr * attr,int wp_type,void * wp_addr,unsigned long wp_len)35 static void get__perf_event_attr(struct perf_event_attr *attr, int wp_type,
36 void *wp_addr, unsigned long wp_len)
37 {
38 memset(attr, 0, sizeof(struct perf_event_attr));
39 attr->type = PERF_TYPE_BREAKPOINT;
40 attr->size = sizeof(struct perf_event_attr);
41 attr->config = 0;
42 attr->bp_type = wp_type;
43 attr->bp_addr = (unsigned long)wp_addr;
44 attr->bp_len = wp_len;
45 attr->sample_period = 1;
46 attr->sample_type = PERF_SAMPLE_IP;
47 attr->exclude_kernel = 1;
48 attr->exclude_hv = 1;
49 }
50
__event(int wp_type,void * wp_addr,unsigned long wp_len)51 static int __event(int wp_type, void *wp_addr, unsigned long wp_len)
52 {
53 int fd;
54 struct perf_event_attr attr;
55
56 get__perf_event_attr(&attr, wp_type, wp_addr, wp_len);
57 fd = sys_perf_event_open(&attr, 0, -1, -1,
58 perf_event_open_cloexec_flag());
59 if (fd < 0)
60 pr_debug("failed opening event %x\n", attr.bp_type);
61
62 return fd;
63 }
64
wp_ro_test(void)65 static int wp_ro_test(void)
66 {
67 int fd;
68 unsigned long tmp, tmp1 = rand();
69
70 fd = __event(HW_BREAKPOINT_R, (void *)&data1, sizeof(data1));
71 if (fd < 0)
72 return -1;
73
74 tmp = data1;
75 WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
76
77 data1 = tmp1 + tmp;
78 WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
79
80 close(fd);
81 return 0;
82 }
83
wp_wo_test(void)84 static int wp_wo_test(void)
85 {
86 int fd;
87 unsigned long tmp, tmp1 = rand();
88
89 fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
90 if (fd < 0)
91 return -1;
92
93 tmp = data1;
94 WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 0);
95
96 data1 = tmp1 + tmp;
97 WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 1);
98
99 close(fd);
100 return 0;
101 }
102
wp_rw_test(void)103 static int wp_rw_test(void)
104 {
105 int fd;
106 unsigned long tmp, tmp1 = rand();
107
108 fd = __event(HW_BREAKPOINT_R | HW_BREAKPOINT_W, (void *)&data1,
109 sizeof(data1));
110 if (fd < 0)
111 return -1;
112
113 tmp = data1;
114 WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 1);
115
116 data1 = tmp1 + tmp;
117 WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 2);
118
119 close(fd);
120 return 0;
121 }
122
wp_modify_test(void)123 static int wp_modify_test(void)
124 {
125 int fd, ret;
126 unsigned long tmp = rand();
127 struct perf_event_attr new_attr;
128
129 fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
130 if (fd < 0)
131 return -1;
132
133 data1 = tmp;
134 WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
135
136 /* Modify watchpoint with disabled = 1 */
137 get__perf_event_attr(&new_attr, HW_BREAKPOINT_W, (void *)&data2[0],
138 sizeof(u8) * 2);
139 new_attr.disabled = 1;
140 ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &new_attr);
141 if (ret < 0) {
142 pr_debug("ioctl(PERF_EVENT_IOC_MODIFY_ATTRIBUTES) failed\n");
143 close(fd);
144 return ret;
145 }
146
147 data2[1] = tmp; /* Not Counted */
148 WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
149
150 /* Enable the event */
151 ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
152 if (ret < 0) {
153 pr_debug("Failed to enable event\n");
154 close(fd);
155 return ret;
156 }
157
158 data2[1] = tmp; /* Counted */
159 WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 2);
160
161 data2[2] = tmp; /* Not Counted */
162 WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 2);
163
164 close(fd);
165 return 0;
166 }
167
wp_ro_supported(void)168 static bool wp_ro_supported(void)
169 {
170 #if defined (__x86_64__) || defined (__i386__)
171 return false;
172 #else
173 return true;
174 #endif
175 }
176
wp_ro_skip_msg(void)177 static void wp_ro_skip_msg(void)
178 {
179 #if defined (__x86_64__) || defined (__i386__)
180 pr_debug("Hardware does not support read only watchpoints.\n");
181 #endif
182 }
183
184 static struct {
185 const char *desc;
186 int (*target_func)(void);
187 bool (*is_supported)(void);
188 void (*skip_msg)(void);
189 } wp_testcase_table[] = {
190 {
191 .desc = "Read Only Watchpoint",
192 .target_func = &wp_ro_test,
193 .is_supported = &wp_ro_supported,
194 .skip_msg = &wp_ro_skip_msg,
195 },
196 {
197 .desc = "Write Only Watchpoint",
198 .target_func = &wp_wo_test,
199 },
200 {
201 .desc = "Read / Write Watchpoint",
202 .target_func = &wp_rw_test,
203 },
204 {
205 .desc = "Modify Watchpoint",
206 .target_func = &wp_modify_test,
207 },
208 };
209
test__wp_subtest_get_nr(void)210 int test__wp_subtest_get_nr(void)
211 {
212 return (int)ARRAY_SIZE(wp_testcase_table);
213 }
214
test__wp_subtest_get_desc(int i)215 const char *test__wp_subtest_get_desc(int i)
216 {
217 if (i < 0 || i >= (int)ARRAY_SIZE(wp_testcase_table))
218 return NULL;
219 return wp_testcase_table[i].desc;
220 }
221
test__wp(struct test * test __maybe_unused,int i)222 int test__wp(struct test *test __maybe_unused, int i)
223 {
224 if (i < 0 || i >= (int)ARRAY_SIZE(wp_testcase_table))
225 return TEST_FAIL;
226
227 if (wp_testcase_table[i].is_supported &&
228 !wp_testcase_table[i].is_supported()) {
229 wp_testcase_table[i].skip_msg();
230 return TEST_SKIP;
231 }
232
233 return !wp_testcase_table[i].target_func() ? TEST_OK : TEST_FAIL;
234 }
235
236 /* The s390 so far does not have support for
237 * instruction breakpoint using the perf_event_open() system call.
238 */
test__wp_is_supported(void)239 bool test__wp_is_supported(void)
240 {
241 #if defined(__s390x__)
242 return false;
243 #else
244 return true;
245 #endif
246 }
247