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