1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
* Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
* 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
*/
#define __SANE_USERSPACE_TYPES__
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#include <time.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/mman.h>
#include <linux/compiler.h>
#include <linux/hw_breakpoint.h>
#include <sys/ioctl.h>
#include "tests.h"
#include "debug.h"
#include "perf.h"
#include "cloexec.h"
static volatile long the_var;
static noinline int test_function(void)
{
return 0;
}
static int __event(bool is_x, void *addr, struct perf_event_attr *attr)
{
int fd;
memset(attr, 0, sizeof(struct perf_event_attr));
attr->type = PERF_TYPE_BREAKPOINT;
attr->size = sizeof(struct perf_event_attr);
attr->config = 0;
attr->bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
attr->bp_addr = (unsigned long) addr;
attr->bp_len = sizeof(long);
attr->sample_period = 1;
attr->sample_type = PERF_SAMPLE_IP;
attr->exclude_kernel = 1;
attr->exclude_hv = 1;
fd = sys_perf_event_open(attr, -1, 0, -1,
perf_event_open_cloexec_flag());
if (fd < 0) {
pr_debug("failed opening event %llx\n", attr->config);
return TEST_FAIL;
}
return fd;
}
static int wp_event(void *addr, struct perf_event_attr *attr)
{
return __event(false, addr, attr);
}
static int bp_event(void *addr, struct perf_event_attr *attr)
{
return __event(true, addr, attr);
}
static int bp_accounting(int wp_cnt, int share)
{
struct perf_event_attr attr, attr_mod, attr_new;
int i, fd[wp_cnt], fd_wp, ret;
for (i = 0; i < wp_cnt; i++) {
fd[i] = wp_event((void *)&the_var, &attr);
TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1);
pr_debug("wp %d created\n", i);
}
attr_mod = attr;
attr_mod.bp_type = HW_BREAKPOINT_X;
attr_mod.bp_addr = (unsigned long) test_function;
ret = ioctl(fd[0], PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr_mod);
TEST_ASSERT_VAL("failed to modify wp\n", ret == 0);
pr_debug("wp 0 modified to bp\n");
if (!share) {
fd_wp = wp_event((void *)&the_var, &attr_new);
TEST_ASSERT_VAL("failed to create max wp\n", fd_wp != -1);
pr_debug("wp max created\n");
}
for (i = 0; i < wp_cnt; i++)
close(fd[i]);
return 0;
}
static int detect_cnt(bool is_x)
{
struct perf_event_attr attr;
void *addr = is_x ? (void *)test_function : (void *)&the_var;
int fd[100], cnt = 0, i;
while (1) {
if (cnt == 100) {
pr_debug("way too many debug registers, fix the test\n");
return 0;
}
fd[cnt] = __event(is_x, addr, &attr);
if (fd[cnt] < 0)
break;
cnt++;
}
for (i = 0; i < cnt; i++)
close(fd[i]);
return cnt;
}
static int detect_ioctl(void)
{
struct perf_event_attr attr;
int fd, ret = 1;
fd = wp_event((void *) &the_var, &attr);
if (fd > 0) {
ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr);
close(fd);
}
return ret ? 0 : 1;
}
static int detect_share(int wp_cnt, int bp_cnt)
{
struct perf_event_attr attr;
int i, fd[wp_cnt + bp_cnt], ret;
for (i = 0; i < wp_cnt; i++) {
fd[i] = wp_event((void *)&the_var, &attr);
TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1);
}
for (; i < (bp_cnt + wp_cnt); i++) {
fd[i] = bp_event((void *)test_function, &attr);
if (fd[i] == -1)
break;
}
ret = i != (bp_cnt + wp_cnt);
while (i--)
close(fd[i]);
return ret;
}
/*
* This test does following:
* - detects the number of watch/break-points,
* skip test if any is missing
* - detects PERF_EVENT_IOC_MODIFY_ATTRIBUTES ioctl,
* skip test if it's missing
* - detects if watchpoints and breakpoints share
* same slots
* - create all possible watchpoints on cpu 0
* - change one of it to breakpoint
* - in case wp and bp do not share slots,
* we create another watchpoint to ensure
* the slot accounting is correct
*/
int test__bp_accounting(struct test *test __maybe_unused, int subtest __maybe_unused)
{
int has_ioctl = detect_ioctl();
int wp_cnt = detect_cnt(false);
int bp_cnt = detect_cnt(true);
int share = detect_share(wp_cnt, bp_cnt);
pr_debug("watchpoints count %d, breakpoints count %d, has_ioctl %d, share %d\n",
wp_cnt, bp_cnt, has_ioctl, share);
if (!wp_cnt || !bp_cnt || !has_ioctl)
return TEST_SKIP;
return bp_accounting(wp_cnt, share);
}
|
