xref: /linux/tools/perf/tests/wp.c (revision 6a87e0f0ce1ae8d70566935215430e718ea776ff)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdlib.h>
3 #include <string.h>
4 #include <unistd.h>
5 #include <errno.h>
6 #include <sys/ioctl.h>
7 #include <linux/compiler.h>
8 #include <linux/hw_breakpoint.h>
9 #include <linux/kernel.h>
10 #include "tests.h"
11 #include "debug.h"
12 #include "event.h"
13 #include "cloexec.h"
14 #include "../perf-sys.h"
15 
16 #define WP_TEST_ASSERT_VAL(fd, text, val)       \
17 do {                                            \
18 	long long count;                        \
19 	wp_read(fd, &count, sizeof(long long)); \
20 	TEST_ASSERT_VAL(text, count == val);    \
21 } while (0)
22 
23 volatile u64 data1;
24 volatile u8 data2[3];
25 
26 #ifndef __s390x__
27 static int wp_read(int fd, long long *count, int size)
28 {
29 	int ret = read(fd, count, size);
30 
31 	if (ret != size) {
32 		pr_debug("failed to read: %d\n", ret);
33 		return -1;
34 	}
35 	return 0;
36 }
37 
38 static void get__perf_event_attr(struct perf_event_attr *attr, int wp_type,
39 				 void *wp_addr, unsigned long wp_len)
40 {
41 	memset(attr, 0, sizeof(struct perf_event_attr));
42 	attr->type           = PERF_TYPE_BREAKPOINT;
43 	attr->size           = sizeof(struct perf_event_attr);
44 	attr->config         = 0;
45 	attr->bp_type        = wp_type;
46 	attr->bp_addr        = (unsigned long)wp_addr;
47 	attr->bp_len         = wp_len;
48 	attr->sample_period  = 1;
49 	attr->sample_type    = PERF_SAMPLE_IP;
50 	attr->exclude_kernel = 1;
51 	attr->exclude_hv     = 1;
52 }
53 
54 static int __event(int wp_type, void *wp_addr, unsigned long wp_len)
55 {
56 	int fd;
57 	struct perf_event_attr attr;
58 
59 	get__perf_event_attr(&attr, wp_type, wp_addr, wp_len);
60 	fd = sys_perf_event_open(&attr, 0, -1, -1,
61 				 perf_event_open_cloexec_flag());
62 	if (fd < 0) {
63 		fd = -errno;
64 		pr_debug("failed opening event %x\n", attr.bp_type);
65 	}
66 
67 	return fd;
68 }
69 #endif
70 
71 static int test__wp_ro(struct test_suite *test __maybe_unused,
72 		       int subtest __maybe_unused)
73 {
74 #if defined(__s390x__) || defined(__x86_64__) || defined(__i386__)
75 	return TEST_SKIP;
76 #else
77 	int fd;
78 	unsigned long tmp, tmp1 = rand();
79 
80 	fd = __event(HW_BREAKPOINT_R, (void *)&data1, sizeof(data1));
81 	if (fd < 0)
82 		return fd == -ENODEV ? TEST_SKIP : -1;
83 
84 	tmp = data1;
85 	WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
86 
87 	data1 = tmp1 + tmp;
88 	WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
89 
90 	close(fd);
91 	return 0;
92 #endif
93 }
94 
95 static int test__wp_wo(struct test_suite *test __maybe_unused,
96 		       int subtest __maybe_unused)
97 {
98 #if defined(__s390x__)
99 	return TEST_SKIP;
100 #else
101 	int fd;
102 	unsigned long tmp, tmp1 = rand();
103 
104 	fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
105 	if (fd < 0)
106 		return fd == -ENODEV ? TEST_SKIP : -1;
107 
108 	tmp = data1;
109 	WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 0);
110 
111 	data1 = tmp1 + tmp;
112 	WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 1);
113 
114 	close(fd);
115 	return 0;
116 #endif
117 }
118 
119 static int test__wp_rw(struct test_suite *test __maybe_unused,
120 		       int subtest __maybe_unused)
121 {
122 #if defined(__s390x__)
123 	return TEST_SKIP;
124 #else
125 	int fd;
126 	unsigned long tmp, tmp1 = rand();
127 
128 	fd = __event(HW_BREAKPOINT_R | HW_BREAKPOINT_W, (void *)&data1,
129 		     sizeof(data1));
130 	if (fd < 0)
131 		return fd == -ENODEV ? TEST_SKIP : -1;
132 
133 	tmp = data1;
134 	WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 1);
135 
136 	data1 = tmp1 + tmp;
137 	WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 2);
138 
139 	close(fd);
140 	return 0;
141 #endif
142 }
143 
144 static int test__wp_modify(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
145 {
146 #if defined(__s390x__)
147 	return TEST_SKIP;
148 #else
149 	int fd, ret;
150 	unsigned long tmp = rand();
151 	struct perf_event_attr new_attr;
152 
153 	fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
154 	if (fd < 0)
155 		return fd == -ENODEV ? TEST_SKIP : -1;
156 
157 	data1 = tmp;
158 	WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
159 
160 	/* Modify watchpoint with disabled = 1 */
161 	get__perf_event_attr(&new_attr, HW_BREAKPOINT_W, (void *)&data2[0],
162 			     sizeof(u8) * 2);
163 	new_attr.disabled = 1;
164 	ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &new_attr);
165 	if (ret < 0) {
166 		if (errno == ENOTTY) {
167 			test->test_cases[subtest].skip_reason = "missing kernel support";
168 			ret = TEST_SKIP;
169 		}
170 
171 		pr_debug("ioctl(PERF_EVENT_IOC_MODIFY_ATTRIBUTES) failed\n");
172 		close(fd);
173 		return ret;
174 	}
175 
176 	data2[1] = tmp; /* Not Counted */
177 	WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
178 
179 	/* Enable the event */
180 	ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
181 	if (ret < 0) {
182 		pr_debug("Failed to enable event\n");
183 		close(fd);
184 		return ret;
185 	}
186 
187 	data2[1] = tmp; /* Counted */
188 	WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 2);
189 
190 	data2[2] = tmp; /* Not Counted */
191 	WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 2);
192 
193 	close(fd);
194 	return 0;
195 #endif
196 }
197 
198 static struct test_case wp_tests[] = {
199 	TEST_CASE_REASON("Read Only Watchpoint", wp_ro, "missing hardware support"),
200 	TEST_CASE_REASON("Write Only Watchpoint", wp_wo, "missing hardware support"),
201 	TEST_CASE_REASON("Read / Write Watchpoint", wp_rw, "missing hardware support"),
202 	TEST_CASE_REASON("Modify Watchpoint", wp_modify, "missing hardware support"),
203 	{ .name = NULL, }
204 };
205 
206 struct test_suite suite__wp = {
207 	.desc = "Watchpoint",
208 	.test_cases = wp_tests,
209 };
210