tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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
32static int overflows;
33
34static noinline int test_function(void)
35{
36 return time(NULL);
37}
38
39static void sig_handler(int signum __maybe_unused,
40 siginfo_t *oh __maybe_unused,
41 void *uc __maybe_unused)
42{
43 overflows++;
44}
45
46static 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
63static 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
143DEFINE_SUITE("Breakpoint overflow sampling", bp_signal_overflow);