1 /*
2 * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
3 * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
4 */
5 #define __SANE_USERSPACE_TYPES__
6
7 #include <stdlib.h>
8 #include <stdio.h>
9 #include <unistd.h>
10 #include <string.h>
11 #include <sys/ioctl.h>
12 #include <time.h>
13 #include <fcntl.h>
14 #include <signal.h>
15 #include <sys/mman.h>
16 #include <linux/compiler.h>
17 #include <linux/hw_breakpoint.h>
18 #include <sys/ioctl.h>
19
20 #include "tests.h"
21 #include "debug.h"
22 #include "perf.h"
23 #include "cloexec.h"
24
25 volatile long the_var;
26
test_function(void)27 static noinline int test_function(void)
28 {
29 return 0;
30 }
31
__event(bool is_x,void * addr,struct perf_event_attr * attr)32 static int __event(bool is_x, void *addr, struct perf_event_attr *attr)
33 {
34 int fd;
35
36 memset(attr, 0, sizeof(struct perf_event_attr));
37 attr->type = PERF_TYPE_BREAKPOINT;
38 attr->size = sizeof(struct perf_event_attr);
39
40 attr->config = 0;
41 attr->bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
42 attr->bp_addr = (unsigned long) addr;
43 attr->bp_len = sizeof(long);
44
45 attr->sample_period = 1;
46 attr->sample_type = PERF_SAMPLE_IP;
47
48 attr->exclude_kernel = 1;
49 attr->exclude_hv = 1;
50
51 fd = sys_perf_event_open(attr, -1, 0, -1,
52 perf_event_open_cloexec_flag());
53 if (fd < 0) {
54 pr_debug("failed opening event %llx\n", attr->config);
55 return TEST_FAIL;
56 }
57
58 return fd;
59 }
60
wp_event(void * addr,struct perf_event_attr * attr)61 static int wp_event(void *addr, struct perf_event_attr *attr)
62 {
63 return __event(false, addr, attr);
64 }
65
bp_event(void * addr,struct perf_event_attr * attr)66 static int bp_event(void *addr, struct perf_event_attr *attr)
67 {
68 return __event(true, addr, attr);
69 }
70
bp_accounting(int wp_cnt,int share)71 static int bp_accounting(int wp_cnt, int share)
72 {
73 struct perf_event_attr attr, attr_mod, attr_new;
74 int i, fd[wp_cnt], fd_wp, ret;
75
76 for (i = 0; i < wp_cnt; i++) {
77 fd[i] = wp_event((void *)&the_var, &attr);
78 TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1);
79 pr_debug("wp %d created\n", i);
80 }
81
82 attr_mod = attr;
83 attr_mod.bp_type = HW_BREAKPOINT_X;
84 attr_mod.bp_addr = (unsigned long) test_function;
85
86 ret = ioctl(fd[0], PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr_mod);
87 TEST_ASSERT_VAL("failed to modify wp\n", ret == 0);
88
89 pr_debug("wp 0 modified to bp\n");
90
91 if (!share) {
92 fd_wp = wp_event((void *)&the_var, &attr_new);
93 TEST_ASSERT_VAL("failed to create max wp\n", fd_wp != -1);
94 pr_debug("wp max created\n");
95 }
96
97 for (i = 0; i < wp_cnt; i++)
98 close(fd[i]);
99
100 return 0;
101 }
102
detect_cnt(bool is_x)103 static int detect_cnt(bool is_x)
104 {
105 struct perf_event_attr attr;
106 void *addr = is_x ? (void *)test_function : (void *)&the_var;
107 int fd[100], cnt = 0, i;
108
109 while (1) {
110 if (cnt == 100) {
111 pr_debug("way too many debug registers, fix the test\n");
112 return 0;
113 }
114 fd[cnt] = __event(is_x, addr, &attr);
115
116 if (fd[cnt] < 0)
117 break;
118 cnt++;
119 }
120
121 for (i = 0; i < cnt; i++)
122 close(fd[i]);
123
124 return cnt;
125 }
126
detect_ioctl(void)127 static int detect_ioctl(void)
128 {
129 struct perf_event_attr attr;
130 int fd, ret = 1;
131
132 fd = wp_event((void *) &the_var, &attr);
133 if (fd > 0) {
134 ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr);
135 close(fd);
136 }
137
138 return ret ? 0 : 1;
139 }
140
detect_share(int wp_cnt,int bp_cnt)141 static int detect_share(int wp_cnt, int bp_cnt)
142 {
143 struct perf_event_attr attr;
144 int i, fd[wp_cnt + bp_cnt], ret;
145
146 for (i = 0; i < wp_cnt; i++) {
147 fd[i] = wp_event((void *)&the_var, &attr);
148 TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1);
149 }
150
151 for (; i < (bp_cnt + wp_cnt); i++) {
152 fd[i] = bp_event((void *)test_function, &attr);
153 if (fd[i] == -1)
154 break;
155 }
156
157 ret = i != (bp_cnt + wp_cnt);
158
159 while (i--)
160 close(fd[i]);
161
162 return ret;
163 }
164
165 /*
166 * This test does following:
167 * - detects the number of watch/break-points,
168 * skip test if any is missing
169 * - detects PERF_EVENT_IOC_MODIFY_ATTRIBUTES ioctl,
170 * skip test if it's missing
171 * - detects if watchpoints and breakpoints share
172 * same slots
173 * - create all possible watchpoints on cpu 0
174 * - change one of it to breakpoint
175 * - in case wp and bp do not share slots,
176 * we create another watchpoint to ensure
177 * the slot accounting is correct
178 */
test__bp_accounting(struct test * test __maybe_unused,int subtest __maybe_unused)179 int test__bp_accounting(struct test *test __maybe_unused, int subtest __maybe_unused)
180 {
181 int has_ioctl = detect_ioctl();
182 int wp_cnt = detect_cnt(false);
183 int bp_cnt = detect_cnt(true);
184 int share = detect_share(wp_cnt, bp_cnt);
185
186 pr_debug("watchpoints count %d, breakpoints count %d, has_ioctl %d, share %d\n",
187 wp_cnt, bp_cnt, has_ioctl, share);
188
189 if (!wp_cnt || !bp_cnt || !has_ioctl)
190 return TEST_SKIP;
191
192 return bp_accounting(wp_cnt, share);
193 }
194
