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)       \
17do {                                            \
18	long long count;                        \
19	wp_read(fd, &count, sizeof(long long)); \
20	TEST_ASSERT_VAL(text, count == val);    \
21} while (0)
22
23volatile u64 data1;
24volatile u8 data2[3];
25
26#ifndef __s390x__
27static 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
38static 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
54static 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
71static 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
95static 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
119static 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
144static 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
198static 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
206struct test_suite suite__wp = {
207	.desc = "Watchpoint",
208	.test_cases = wp_tests,
209};
210