xref: /linux/tools/perf/tests/bp_signal_overflow.c (revision 2cd86f02c017bf9733e5cd891381b7d40f6f37ad)
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 "event.h"
28 #include "parse-events.h"
29 #include "../perf-sys.h"
30 #include "cloexec.h"
31 
32 static int overflows;
33 
34 static noinline int test_function(void)
35 {
36 	return time(NULL);
37 }
38 
39 static void sig_handler(int signum __maybe_unused,
40 			siginfo_t *oh __maybe_unused,
41 			void *uc __maybe_unused)
42 {
43 	overflows++;
44 }
45 
46 static long long bp_count(int fd)
47 {
48 	long long count;
49 	int ret;
50 
51 	ret = read(fd, &count, sizeof(long long));
52 	if (ret != sizeof(long long)) {
53 		pr_debug("failed to read: %d\n", ret);
54 		return TEST_FAIL;
55 	}
56 
57 	return count;
58 }
59 
60 #define EXECUTIONS 10000
61 #define THRESHOLD  100
62 
63 static int test__bp_signal_overflow(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
64 {
65 	struct perf_event_attr pe;
66 	struct sigaction sa;
67 	long long count;
68 	int fd, i, fails = 0;
69 
70 	if (!BP_SIGNAL_IS_SUPPORTED) {
71 		pr_debug("Test not supported on this architecture");
72 		return TEST_SKIP;
73 	}
74 
75 	/* setup SIGIO signal handler */
76 	memset(&sa, 0, sizeof(struct sigaction));
77 	sa.sa_sigaction = (void *) sig_handler;
78 	sa.sa_flags = SA_SIGINFO;
79 
80 	if (sigaction(SIGIO, &sa, NULL) < 0) {
81 		pr_debug("failed setting up signal handler\n");
82 		return TEST_FAIL;
83 	}
84 
85 	memset(&pe, 0, sizeof(struct perf_event_attr));
86 	pe.type = PERF_TYPE_BREAKPOINT;
87 	pe.size = sizeof(struct perf_event_attr);
88 
89 	pe.config = 0;
90 	pe.bp_type = HW_BREAKPOINT_X;
91 	pe.bp_addr = (unsigned long) test_function;
92 	pe.bp_len = default_breakpoint_len();
93 
94 	pe.sample_period = THRESHOLD;
95 	pe.sample_type = PERF_SAMPLE_IP;
96 	pe.wakeup_events = 1;
97 
98 	pe.disabled = 1;
99 	pe.exclude_kernel = 1;
100 	pe.exclude_hv = 1;
101 
102 	fd = sys_perf_event_open(&pe, 0, -1, -1,
103 				 perf_event_open_cloexec_flag());
104 	if (fd < 0) {
105 		pr_debug("failed opening event %llx\n", pe.config);
106 		return TEST_FAIL;
107 	}
108 
109 	fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
110 	fcntl(fd, F_SETSIG, SIGIO);
111 	fcntl(fd, F_SETOWN, getpid());
112 
113 	ioctl(fd, PERF_EVENT_IOC_RESET, 0);
114 	ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
115 
116 	for (i = 0; i < EXECUTIONS; i++)
117 		test_function();
118 
119 	ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
120 
121 	count = bp_count(fd);
122 
123 	close(fd);
124 
125 	pr_debug("count %lld, overflow %d\n",
126 		 count, overflows);
127 
128 	if (count != EXECUTIONS) {
129 		pr_debug("\tWrong number of executions %lld != %d\n",
130 		count, EXECUTIONS);
131 		fails++;
132 	}
133 
134 	if (overflows != EXECUTIONS / THRESHOLD) {
135 		pr_debug("\tWrong number of overflows %d != %d\n",
136 		overflows, EXECUTIONS / THRESHOLD);
137 		fails++;
138 	}
139 
140 	return fails ? TEST_FAIL : TEST_OK;
141 }
142 
143 DEFINE_SUITE("Breakpoint overflow sampling", bp_signal_overflow);
144