1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Originally done by Vince Weaver <vincent.weaver@maine.edu> for
4  * perf_event_tests (git://github.com/deater/perf_event_tests)
5  */
6 
7 /*
8  * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
9  * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
10  */
11 #define __SANE_USERSPACE_TYPES__
12 
13 #include <stdlib.h>
14 #include <stdio.h>
15 #include <unistd.h>
16 #include <string.h>
17 #include <sys/ioctl.h>
18 #include <time.h>
19 #include <fcntl.h>
20 #include <signal.h>
21 #include <sys/mman.h>
22 #include <linux/compiler.h>
23 #include <linux/hw_breakpoint.h>
24 
25 #include "tests.h"
26 #include "debug.h"
27 #include "perf.h"
28 #include "cloexec.h"
29 
30 static int overflows;
31 
32 static noinline int test_function(void)
33 {
34 	return time(NULL);
35 }
36 
37 static void sig_handler(int signum __maybe_unused,
38 			siginfo_t *oh __maybe_unused,
39 			void *uc __maybe_unused)
40 {
41 	overflows++;
42 }
43 
44 static long long bp_count(int fd)
45 {
46 	long long count;
47 	int ret;
48 
49 	ret = read(fd, &count, sizeof(long long));
50 	if (ret != sizeof(long long)) {
51 		pr_debug("failed to read: %d\n", ret);
52 		return TEST_FAIL;
53 	}
54 
55 	return count;
56 }
57 
58 #define EXECUTIONS 10000
59 #define THRESHOLD  100
60 
61 int test__bp_signal_overflow(struct test *test __maybe_unused, int subtest __maybe_unused)
62 {
63 	struct perf_event_attr pe;
64 	struct sigaction sa;
65 	long long count;
66 	int fd, i, fails = 0;
67 
68 	/* setup SIGIO signal handler */
69 	memset(&sa, 0, sizeof(struct sigaction));
70 	sa.sa_sigaction = (void *) sig_handler;
71 	sa.sa_flags = SA_SIGINFO;
72 
73 	if (sigaction(SIGIO, &sa, NULL) < 0) {
74 		pr_debug("failed setting up signal handler\n");
75 		return TEST_FAIL;
76 	}
77 
78 	memset(&pe, 0, sizeof(struct perf_event_attr));
79 	pe.type = PERF_TYPE_BREAKPOINT;
80 	pe.size = sizeof(struct perf_event_attr);
81 
82 	pe.config = 0;
83 	pe.bp_type = HW_BREAKPOINT_X;
84 	pe.bp_addr = (unsigned long) test_function;
85 	pe.bp_len = sizeof(long);
86 
87 	pe.sample_period = THRESHOLD;
88 	pe.sample_type = PERF_SAMPLE_IP;
89 	pe.wakeup_events = 1;
90 
91 	pe.disabled = 1;
92 	pe.exclude_kernel = 1;
93 	pe.exclude_hv = 1;
94 
95 	fd = sys_perf_event_open(&pe, 0, -1, -1,
96 				 perf_event_open_cloexec_flag());
97 	if (fd < 0) {
98 		pr_debug("failed opening event %llx\n", pe.config);
99 		return TEST_FAIL;
100 	}
101 
102 	fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
103 	fcntl(fd, F_SETSIG, SIGIO);
104 	fcntl(fd, F_SETOWN, getpid());
105 
106 	ioctl(fd, PERF_EVENT_IOC_RESET, 0);
107 	ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
108 
109 	for (i = 0; i < EXECUTIONS; i++)
110 		test_function();
111 
112 	ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
113 
114 	count = bp_count(fd);
115 
116 	close(fd);
117 
118 	pr_debug("count %lld, overflow %d\n",
119 		 count, overflows);
120 
121 	if (count != EXECUTIONS) {
122 		pr_debug("\tWrong number of executions %lld != %d\n",
123 		count, EXECUTIONS);
124 		fails++;
125 	}
126 
127 	if (overflows != EXECUTIONS / THRESHOLD) {
128 		pr_debug("\tWrong number of overflows %d != %d\n",
129 		overflows, EXECUTIONS / THRESHOLD);
130 		fails++;
131 	}
132 
133 	return fails ? TEST_FAIL : TEST_OK;
134 }
135