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(attr: &pe, pid: 0, cpu: -1, group_fd: -1,
102 flags: 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

source code of linux/tools/perf/tests/bp_signal_overflow.c