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
|
/*
* Inspired by breakpoint overflow test done by
* Vince Weaver <vincent.weaver@maine.edu> for perf_event_tests
* (git://github.com/deater/perf_event_tests)
*/
#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 "tests.h"
#include "debug.h"
#include "perf.h"
static int fd1;
static int fd2;
static int overflows;
__attribute__ ((noinline))
static int test_function(void)
{
return time(NULL);
}
static void sig_handler(int signum __maybe_unused,
siginfo_t *oh __maybe_unused,
void *uc __maybe_unused)
{
overflows++;
if (overflows > 10) {
/*
* This should be executed only once during
* this test, if we are here for the 10th
* time, consider this the recursive issue.
*
* We can get out of here by disable events,
* so no new SIGIO is delivered.
*/
ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
}
}
static int bp_event(void *fn, int setup_signal)
{
struct perf_event_attr pe;
int fd;
memset(&pe, 0, sizeof(struct perf_event_attr));
pe.type = PERF_TYPE_BREAKPOINT;
pe.size = sizeof(struct perf_event_attr);
pe.config = 0;
pe.bp_type = HW_BREAKPOINT_X;
pe.bp_addr = (unsigned long) fn;
pe.bp_len = sizeof(long);
pe.sample_period = 1;
pe.sample_type = PERF_SAMPLE_IP;
pe.wakeup_events = 1;
pe.disabled = 1;
pe.exclude_kernel = 1;
pe.exclude_hv = 1;
fd = sys_perf_event_open(&pe, 0, -1, -1, 0);
if (fd < 0) {
pr_debug("failed opening event %llx\n", pe.config);
return TEST_FAIL;
}
if (setup_signal) {
fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
fcntl(fd, F_SETSIG, SIGIO);
fcntl(fd, F_SETOWN, getpid());
}
ioctl(fd, PERF_EVENT_IOC_RESET, 0);
return fd;
}
static long long bp_count(int fd)
{
long long count;
int ret;
ret = read(fd, &count, sizeof(long long));
if (ret != sizeof(long long)) {
pr_debug("failed to read: %d\n", ret);
return TEST_FAIL;
}
return count;
}
int test__bp_signal(void)
{
struct sigaction sa;
long long count1, count2;
/* setup SIGIO signal handler */
memset(&sa, 0, sizeof(struct sigaction));
sa.sa_sigaction = (void *) sig_handler;
sa.sa_flags = SA_SIGINFO;
if (sigaction(SIGIO, &sa, NULL) < 0) {
pr_debug("failed setting up signal handler\n");
return TEST_FAIL;
}
/*
* We create following events:
*
* fd1 - breakpoint event on test_function with SIGIO
* signal configured. We should get signal
* notification each time the breakpoint is hit
*
* fd2 - breakpoint event on sig_handler without SIGIO
* configured.
*
* Following processing should happen:
* - execute test_function
* - fd1 event breakpoint hit -> count1 == 1
* - SIGIO is delivered -> overflows == 1
* - fd2 event breakpoint hit -> count2 == 1
*
* The test case check following error conditions:
* - we get stuck in signal handler because of debug
* exception being triggered receursively due to
* the wrong RF EFLAG management
*
* - we never trigger the sig_handler breakpoint due
* to the rong RF EFLAG management
*
*/
fd1 = bp_event(test_function, 1);
fd2 = bp_event(sig_handler, 0);
ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0);
ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0);
/*
* Kick off the test by trigering 'fd1'
* breakpoint.
*/
test_function();
ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
count1 = bp_count(fd1);
count2 = bp_count(fd2);
close(fd1);
close(fd2);
pr_debug("count1 %lld, count2 %lld, overflow %d\n",
count1, count2, overflows);
if (count1 != 1) {
if (count1 == 11)
pr_debug("failed: RF EFLAG recursion issue detected\n");
else
pr_debug("failed: wrong count for bp1%lld\n", count1);
}
if (overflows != 1)
pr_debug("failed: wrong overflow hit\n");
if (count2 != 1)
pr_debug("failed: wrong count for bp2\n");
return count1 == 1 && overflows == 1 && count2 == 1 ?
TEST_OK : TEST_FAIL;
}
|
