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5a6bef47 JO |
1 | /* |
2 | * Inspired by breakpoint overflow test done by | |
3 | * Vince Weaver <vincent.weaver@maine.edu> for perf_event_tests | |
4 | * (git://github.com/deater/perf_event_tests) | |
5 | */ | |
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 | ||
19 | #include "tests.h" | |
20 | #include "debug.h" | |
21 | #include "perf.h" | |
22 | ||
23 | static int fd1; | |
24 | static int fd2; | |
25 | static int overflows; | |
26 | ||
27 | __attribute__ ((noinline)) | |
28 | static int test_function(void) | |
29 | { | |
30 | return time(NULL); | |
31 | } | |
32 | ||
33 | static void sig_handler(int signum __maybe_unused, | |
34 | siginfo_t *oh __maybe_unused, | |
35 | void *uc __maybe_unused) | |
36 | { | |
37 | overflows++; | |
38 | ||
39 | if (overflows > 10) { | |
40 | /* | |
41 | * This should be executed only once during | |
42 | * this test, if we are here for the 10th | |
43 | * time, consider this the recursive issue. | |
44 | * | |
45 | * We can get out of here by disable events, | |
46 | * so no new SIGIO is delivered. | |
47 | */ | |
48 | ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); | |
49 | ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); | |
50 | } | |
51 | } | |
52 | ||
53 | static int bp_event(void *fn, int setup_signal) | |
54 | { | |
55 | struct perf_event_attr pe; | |
56 | int fd; | |
57 | ||
58 | memset(&pe, 0, sizeof(struct perf_event_attr)); | |
59 | pe.type = PERF_TYPE_BREAKPOINT; | |
60 | pe.size = sizeof(struct perf_event_attr); | |
61 | ||
62 | pe.config = 0; | |
63 | pe.bp_type = HW_BREAKPOINT_X; | |
64 | pe.bp_addr = (unsigned long) fn; | |
65 | pe.bp_len = sizeof(long); | |
66 | ||
67 | pe.sample_period = 1; | |
68 | pe.sample_type = PERF_SAMPLE_IP; | |
69 | pe.wakeup_events = 1; | |
70 | ||
71 | pe.disabled = 1; | |
72 | pe.exclude_kernel = 1; | |
73 | pe.exclude_hv = 1; | |
74 | ||
75 | fd = sys_perf_event_open(&pe, 0, -1, -1, 0); | |
76 | if (fd < 0) { | |
77 | pr_debug("failed opening event %llx\n", pe.config); | |
78 | return TEST_FAIL; | |
79 | } | |
80 | ||
81 | if (setup_signal) { | |
82 | fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC); | |
83 | fcntl(fd, F_SETSIG, SIGIO); | |
84 | fcntl(fd, F_SETOWN, getpid()); | |
85 | } | |
86 | ||
87 | ioctl(fd, PERF_EVENT_IOC_RESET, 0); | |
88 | ||
89 | return fd; | |
90 | } | |
91 | ||
92 | static long long bp_count(int fd) | |
93 | { | |
94 | long long count; | |
95 | int ret; | |
96 | ||
97 | ret = read(fd, &count, sizeof(long long)); | |
98 | if (ret != sizeof(long long)) { | |
99 | pr_debug("failed to read: %d\n", ret); | |
100 | return TEST_FAIL; | |
101 | } | |
102 | ||
103 | return count; | |
104 | } | |
105 | ||
106 | int test__bp_signal(void) | |
107 | { | |
108 | struct sigaction sa; | |
109 | long long count1, count2; | |
110 | ||
111 | /* setup SIGIO signal handler */ | |
112 | memset(&sa, 0, sizeof(struct sigaction)); | |
113 | sa.sa_sigaction = (void *) sig_handler; | |
114 | sa.sa_flags = SA_SIGINFO; | |
115 | ||
116 | if (sigaction(SIGIO, &sa, NULL) < 0) { | |
117 | pr_debug("failed setting up signal handler\n"); | |
118 | return TEST_FAIL; | |
119 | } | |
120 | ||
121 | /* | |
122 | * We create following events: | |
123 | * | |
124 | * fd1 - breakpoint event on test_function with SIGIO | |
125 | * signal configured. We should get signal | |
126 | * notification each time the breakpoint is hit | |
127 | * | |
128 | * fd2 - breakpoint event on sig_handler without SIGIO | |
129 | * configured. | |
130 | * | |
131 | * Following processing should happen: | |
132 | * - execute test_function | |
133 | * - fd1 event breakpoint hit -> count1 == 1 | |
134 | * - SIGIO is delivered -> overflows == 1 | |
135 | * - fd2 event breakpoint hit -> count2 == 1 | |
136 | * | |
137 | * The test case check following error conditions: | |
138 | * - we get stuck in signal handler because of debug | |
139 | * exception being triggered receursively due to | |
140 | * the wrong RF EFLAG management | |
141 | * | |
142 | * - we never trigger the sig_handler breakpoint due | |
143 | * to the rong RF EFLAG management | |
144 | * | |
145 | */ | |
146 | ||
147 | fd1 = bp_event(test_function, 1); | |
148 | fd2 = bp_event(sig_handler, 0); | |
149 | ||
150 | ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0); | |
151 | ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0); | |
152 | ||
153 | /* | |
154 | * Kick off the test by trigering 'fd1' | |
155 | * breakpoint. | |
156 | */ | |
157 | test_function(); | |
158 | ||
159 | ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); | |
160 | ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); | |
161 | ||
162 | count1 = bp_count(fd1); | |
163 | count2 = bp_count(fd2); | |
164 | ||
165 | close(fd1); | |
166 | close(fd2); | |
167 | ||
168 | pr_debug("count1 %lld, count2 %lld, overflow %d\n", | |
169 | count1, count2, overflows); | |
170 | ||
171 | if (count1 != 1) { | |
172 | if (count1 == 11) | |
173 | pr_debug("failed: RF EFLAG recursion issue detected\n"); | |
174 | else | |
175 | pr_debug("failed: wrong count for bp1%lld\n", count1); | |
176 | } | |
177 | ||
178 | if (overflows != 1) | |
179 | pr_debug("failed: wrong overflow hit\n"); | |
180 | ||
181 | if (count2 != 1) | |
182 | pr_debug("failed: wrong count for bp2\n"); | |
183 | ||
184 | return count1 == 1 && overflows == 1 && count2 == 1 ? | |
185 | TEST_OK : TEST_FAIL; | |
186 | } |