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 
31 static int overflows;
32 
test_function(void)33 static noinline int test_function(void)
34 {
35 	return time(NULL);
36 }
37 
sig_handler(int signum __maybe_unused,siginfo_t * oh __maybe_unused,void * uc __maybe_unused)38 static void sig_handler(int signum __maybe_unused,
39 			siginfo_t *oh __maybe_unused,
40 			void *uc __maybe_unused)
41 {
42 	overflows++;
43 }
44 
bp_count(int fd)45 static 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 
test__bp_signal_overflow(struct test_suite * test __maybe_unused,int subtest __maybe_unused)62 static 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 
142 DEFINE_SUITE("Breakpoint overflow sampling", bp_signal_overflow);
143