1 /*
2  * Originally done by Vince Weaver <vincent.weaver@maine.edu> for
3  * perf_event_tests (git://github.com/deater/perf_event_tests)
4  */
5 
6 /*
7  * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
8  * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
9  */
10 #define __SANE_USERSPACE_TYPES__
11 
12 #include <stdlib.h>
13 #include <stdio.h>
14 #include <unistd.h>
15 #include <string.h>
16 #include <sys/ioctl.h>
17 #include <time.h>
18 #include <fcntl.h>
19 #include <signal.h>
20 #include <sys/mman.h>
21 #include <linux/compiler.h>
22 #include <linux/hw_breakpoint.h>
23 
24 #include "tests.h"
25 #include "debug.h"
26 #include "perf.h"
27 
28 static int overflows;
29 
30 __attribute__ ((noinline))
31 static int test_function(void)
32 {
33 	return time(NULL);
34 }
35 
36 static void sig_handler(int signum __maybe_unused,
37 			siginfo_t *oh __maybe_unused,
38 			void *uc __maybe_unused)
39 {
40 	overflows++;
41 }
42 
43 static long long bp_count(int fd)
44 {
45 	long long count;
46 	int ret;
47 
48 	ret = read(fd, &count, sizeof(long long));
49 	if (ret != sizeof(long long)) {
50 		pr_debug("failed to read: %d\n", ret);
51 		return TEST_FAIL;
52 	}
53 
54 	return count;
55 }
56 
57 #define EXECUTIONS 10000
58 #define THRESHOLD  100
59 
60 int test__bp_signal_overflow(void)
61 {
62 	struct perf_event_attr pe;
63 	struct sigaction sa;
64 	long long count;
65 	int fd, i, fails = 0;
66 
67 	/* setup SIGIO signal handler */
68 	memset(&sa, 0, sizeof(struct sigaction));
69 	sa.sa_sigaction = (void *) sig_handler;
70 	sa.sa_flags = SA_SIGINFO;
71 
72 	if (sigaction(SIGIO, &sa, NULL) < 0) {
73 		pr_debug("failed setting up signal handler\n");
74 		return TEST_FAIL;
75 	}
76 
77 	memset(&pe, 0, sizeof(struct perf_event_attr));
78 	pe.type = PERF_TYPE_BREAKPOINT;
79 	pe.size = sizeof(struct perf_event_attr);
80 
81 	pe.config = 0;
82 	pe.bp_type = HW_BREAKPOINT_X;
83 	pe.bp_addr = (unsigned long) test_function;
84 	pe.bp_len = sizeof(long);
85 
86 	pe.sample_period = THRESHOLD;
87 	pe.sample_type = PERF_SAMPLE_IP;
88 	pe.wakeup_events = 1;
89 
90 	pe.disabled = 1;
91 	pe.exclude_kernel = 1;
92 	pe.exclude_hv = 1;
93 
94 	fd = sys_perf_event_open(&pe, 0, -1, -1, 0);
95 	if (fd < 0) {
96 		pr_debug("failed opening event %llx\n", pe.config);
97 		return TEST_FAIL;
98 	}
99 
100 	fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
101 	fcntl(fd, F_SETSIG, SIGIO);
102 	fcntl(fd, F_SETOWN, getpid());
103 
104 	ioctl(fd, PERF_EVENT_IOC_RESET, 0);
105 	ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
106 
107 	for (i = 0; i < EXECUTIONS; i++)
108 		test_function();
109 
110 	ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
111 
112 	count = bp_count(fd);
113 
114 	close(fd);
115 
116 	pr_debug("count %lld, overflow %d\n",
117 		 count, overflows);
118 
119 	if (count != EXECUTIONS) {
120 		pr_debug("\tWrong number of executions %lld != %d\n",
121 		count, EXECUTIONS);
122 		fails++;
123 	}
124 
125 	if (overflows != EXECUTIONS / THRESHOLD) {
126 		pr_debug("\tWrong number of overflows %d != %d\n",
127 		overflows, EXECUTIONS / THRESHOLD);
128 		fails++;
129 	}
130 
131 	return fails ? TEST_FAIL : TEST_OK;
132 }
133