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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Inspired by breakpoint overflow test done by
4 * Vince Weaver <vincent.weaver@maine.edu> for perf_event_tests
5 * (git://github.com/deater/perf_event_tests)
6 */
7
8/*
9 * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
10 * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
11 */
12#define __SANE_USERSPACE_TYPES__
13
14#include <stdlib.h>
15#include <stdio.h>
16#include <unistd.h>
17#include <string.h>
18#include <sys/ioctl.h>
19#include <time.h>
20#include <fcntl.h>
21#include <signal.h>
22#include <sys/mman.h>
23#include <linux/compiler.h>
24#include <linux/hw_breakpoint.h>
25
26#include "tests.h"
27#include "debug.h"
28#include "event.h"
29#include "perf-sys.h"
30#include "cloexec.h"
31
32static int fd1;
33static int fd2;
34static int fd3;
35static int overflows;
36static int overflows_2;
37
38volatile long the_var;
39
40
41/*
42 * Use ASM to ensure watchpoint and breakpoint can be triggered
43 * at one instruction.
44 */
45#if defined (__x86_64__)
46extern void __test_function(volatile long *ptr);
47asm (
48 ".pushsection .text;"
49 ".globl __test_function\n"
50 ".type __test_function, @function;"
51 "__test_function:\n"
52 "incq (%rdi)\n"
53 "ret\n"
54 ".popsection\n");
55#else
56static void __test_function(volatile long *ptr)
57{
58 *ptr = 0x1234;
59}
60#endif
61
62static noinline int test_function(void)
63{
64 __test_function(&the_var);
65 the_var++;
66 return time(NULL);
67}
68
69static void sig_handler_2(int signum __maybe_unused,
70 siginfo_t *oh __maybe_unused,
71 void *uc __maybe_unused)
72{
73 overflows_2++;
74 if (overflows_2 > 10) {
75 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
76 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
77 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
78 }
79}
80
81static void sig_handler(int signum __maybe_unused,
82 siginfo_t *oh __maybe_unused,
83 void *uc __maybe_unused)
84{
85 overflows++;
86
87 if (overflows > 10) {
88 /*
89 * This should be executed only once during
90 * this test, if we are here for the 10th
91 * time, consider this the recursive issue.
92 *
93 * We can get out of here by disable events,
94 * so no new SIGIO is delivered.
95 */
96 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
97 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
98 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
99 }
100}
101
102static int __event(bool is_x, void *addr, int sig)
103{
104 struct perf_event_attr pe;
105 int fd;
106
107 memset(&pe, 0, sizeof(struct perf_event_attr));
108 pe.type = PERF_TYPE_BREAKPOINT;
109 pe.size = sizeof(struct perf_event_attr);
110
111 pe.config = 0;
112 pe.bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
113 pe.bp_addr = (unsigned long) addr;
114 pe.bp_len = sizeof(long);
115
116 pe.sample_period = 1;
117 pe.sample_type = PERF_SAMPLE_IP;
118 pe.wakeup_events = 1;
119
120 pe.disabled = 1;
121 pe.exclude_kernel = 1;
122 pe.exclude_hv = 1;
123
124 fd = sys_perf_event_open(&pe, 0, -1, -1,
125 perf_event_open_cloexec_flag());
126 if (fd < 0) {
127 pr_debug("failed opening event %llx\n", pe.config);
128 return TEST_FAIL;
129 }
130
131 fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
132 fcntl(fd, F_SETSIG, sig);
133 fcntl(fd, F_SETOWN, getpid());
134
135 ioctl(fd, PERF_EVENT_IOC_RESET, 0);
136
137 return fd;
138}
139
140static int bp_event(void *addr, int sig)
141{
142 return __event(true, addr, sig);
143}
144
145static int wp_event(void *addr, int sig)
146{
147 return __event(false, addr, sig);
148}
149
150static long long bp_count(int fd)
151{
152 long long count;
153 int ret;
154
155 ret = read(fd, &count, sizeof(long long));
156 if (ret != sizeof(long long)) {
157 pr_debug("failed to read: %d\n", ret);
158 return TEST_FAIL;
159 }
160
161 return count;
162}
163
164int test__bp_signal(struct test *test __maybe_unused, int subtest __maybe_unused)
165{
166 struct sigaction sa;
167 long long count1, count2, count3;
168
169 /* setup SIGIO signal handler */
170 memset(&sa, 0, sizeof(struct sigaction));
171 sa.sa_sigaction = (void *) sig_handler;
172 sa.sa_flags = SA_SIGINFO;
173
174 if (sigaction(SIGIO, &sa, NULL) < 0) {
175 pr_debug("failed setting up signal handler\n");
176 return TEST_FAIL;
177 }
178
179 sa.sa_sigaction = (void *) sig_handler_2;
180 if (sigaction(SIGUSR1, &sa, NULL) < 0) {
181 pr_debug("failed setting up signal handler 2\n");
182 return TEST_FAIL;
183 }
184
185 /*
186 * We create following events:
187 *
188 * fd1 - breakpoint event on __test_function with SIGIO
189 * signal configured. We should get signal
190 * notification each time the breakpoint is hit
191 *
192 * fd2 - breakpoint event on sig_handler with SIGUSR1
193 * configured. We should get SIGUSR1 each time when
194 * breakpoint is hit
195 *
196 * fd3 - watchpoint event on __test_function with SIGIO
197 * configured.
198 *
199 * Following processing should happen:
200 * Exec: Action: Result:
201 * incq (%rdi) - fd1 event breakpoint hit -> count1 == 1
202 * - SIGIO is delivered
203 * sig_handler - fd2 event breakpoint hit -> count2 == 1
204 * - SIGUSR1 is delivered
205 * sig_handler_2 -> overflows_2 == 1 (nested signal)
206 * sys_rt_sigreturn - return from sig_handler_2
207 * overflows++ -> overflows = 1
208 * sys_rt_sigreturn - return from sig_handler
209 * incq (%rdi) - fd3 event watchpoint hit -> count3 == 1 (wp and bp in one insn)
210 * - SIGIO is delivered
211 * sig_handler - fd2 event breakpoint hit -> count2 == 2
212 * - SIGUSR1 is delivered
213 * sig_handler_2 -> overflows_2 == 2 (nested signal)
214 * sys_rt_sigreturn - return from sig_handler_2
215 * overflows++ -> overflows = 2
216 * sys_rt_sigreturn - return from sig_handler
217 * the_var++ - fd3 event watchpoint hit -> count3 == 2 (standalone watchpoint)
218 * - SIGIO is delivered
219 * sig_handler - fd2 event breakpoint hit -> count2 == 3
220 * - SIGUSR1 is delivered
221 * sig_handler_2 -> overflows_2 == 3 (nested signal)
222 * sys_rt_sigreturn - return from sig_handler_2
223 * overflows++ -> overflows == 3
224 * sys_rt_sigreturn - return from sig_handler
225 *
226 * The test case check following error conditions:
227 * - we get stuck in signal handler because of debug
228 * exception being triggered recursively due to
229 * the wrong RF EFLAG management
230 *
231 * - we never trigger the sig_handler breakpoint due
232 * to the wrong RF EFLAG management
233 *
234 */
235
236 fd1 = bp_event(__test_function, SIGIO);
237 fd2 = bp_event(sig_handler, SIGUSR1);
238 fd3 = wp_event((void *)&the_var, SIGIO);
239
240 ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0);
241 ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0);
242 ioctl(fd3, PERF_EVENT_IOC_ENABLE, 0);
243
244 /*
245 * Kick off the test by triggering 'fd1'
246 * breakpoint.
247 */
248 test_function();
249
250 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
251 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
252 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
253
254 count1 = bp_count(fd1);
255 count2 = bp_count(fd2);
256 count3 = bp_count(fd3);
257
258 close(fd1);
259 close(fd2);
260 close(fd3);
261
262 pr_debug("count1 %lld, count2 %lld, count3 %lld, overflow %d, overflows_2 %d\n",
263 count1, count2, count3, overflows, overflows_2);
264
265 if (count1 != 1) {
266 if (count1 == 11)
267 pr_debug("failed: RF EFLAG recursion issue detected\n");
268 else
269 pr_debug("failed: wrong count for bp1: %lld, expected 1\n", count1);
270 }
271
272 if (overflows != 3)
273 pr_debug("failed: wrong overflow (%d) hit, expected 3\n", overflows);
274
275 if (overflows_2 != 3)
276 pr_debug("failed: wrong overflow_2 (%d) hit, expected 3\n", overflows_2);
277
278 if (count2 != 3)
279 pr_debug("failed: wrong count for bp2 (%lld), expected 3\n", count2);
280
281 if (count3 != 2)
282 pr_debug("failed: wrong count for bp3 (%lld), expected 2\n", count3);
283
284 return count1 == 1 && overflows == 3 && count2 == 3 && overflows_2 == 3 && count3 == 2 ?
285 TEST_OK : TEST_FAIL;
286}
287
288bool test__bp_signal_is_supported(void)
289{
290 /*
291 * PowerPC and S390 do not support creation of instruction
292 * breakpoints using the perf_event interface.
293 *
294 * ARM requires explicit rounding down of the instruction
295 * pointer in Thumb mode, and then requires the single-step
296 * to be handled explicitly in the overflow handler to avoid
297 * stepping into the SIGIO handler and getting stuck on the
298 * breakpointed instruction.
299 *
300 * Since arm64 has the same issue with arm for the single-step
301 * handling, this case also gets stuck on the breakpointed
302 * instruction.
303 *
304 * Just disable the test for these architectures until these
305 * issues are resolved.
306 */
307#if defined(__powerpc__) || defined(__s390x__) || defined(__arm__) || \
308 defined(__aarch64__)
309 return false;
310#else
311 return true;
312#endif
313}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Inspired by breakpoint overflow test done by
4 * Vince Weaver <vincent.weaver@maine.edu> for perf_event_tests
5 * (git://github.com/deater/perf_event_tests)
6 */
7
8/*
9 * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
10 * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
11 */
12#define __SANE_USERSPACE_TYPES__
13
14#include <stdlib.h>
15#include <stdio.h>
16#include <unistd.h>
17#include <string.h>
18#include <sys/ioctl.h>
19#include <time.h>
20#include <fcntl.h>
21#include <signal.h>
22#include <sys/mman.h>
23#include <linux/compiler.h>
24#include <linux/hw_breakpoint.h>
25
26#include "tests.h"
27#include "debug.h"
28#include "event.h"
29#include "parse-events.h"
30#include "perf-sys.h"
31#include "cloexec.h"
32
33static int fd1;
34static int fd2;
35static int fd3;
36static int overflows;
37static int overflows_2;
38
39volatile long the_var;
40
41
42/*
43 * Use ASM to ensure watchpoint and breakpoint can be triggered
44 * at one instruction.
45 */
46#if defined (__x86_64__)
47extern void __test_function(volatile long *ptr);
48asm (
49 ".pushsection .text;"
50 ".globl __test_function\n"
51 ".type __test_function, @function;"
52 "__test_function:\n"
53 "incq (%rdi)\n"
54 "ret\n"
55 ".popsection\n");
56#else
57static void __test_function(volatile long *ptr)
58{
59 *ptr = 0x1234;
60}
61#endif
62
63static noinline int test_function(void)
64{
65 __test_function(&the_var);
66 the_var++;
67 return time(NULL);
68}
69
70static void sig_handler_2(int signum __maybe_unused,
71 siginfo_t *oh __maybe_unused,
72 void *uc __maybe_unused)
73{
74 overflows_2++;
75 if (overflows_2 > 10) {
76 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
77 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
78 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
79 }
80}
81
82static void sig_handler(int signum __maybe_unused,
83 siginfo_t *oh __maybe_unused,
84 void *uc __maybe_unused)
85{
86 overflows++;
87
88 if (overflows > 10) {
89 /*
90 * This should be executed only once during
91 * this test, if we are here for the 10th
92 * time, consider this the recursive issue.
93 *
94 * We can get out of here by disable events,
95 * so no new SIGIO is delivered.
96 */
97 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
98 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
99 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
100 }
101}
102
103static int __event(bool is_x, void *addr, int sig)
104{
105 struct perf_event_attr pe;
106 int fd;
107
108 memset(&pe, 0, sizeof(struct perf_event_attr));
109 pe.type = PERF_TYPE_BREAKPOINT;
110 pe.size = sizeof(struct perf_event_attr);
111
112 pe.config = 0;
113 pe.bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
114 pe.bp_addr = (unsigned long) addr;
115 pe.bp_len = is_x ? default_breakpoint_len() : sizeof(long);
116
117 pe.sample_period = 1;
118 pe.sample_type = PERF_SAMPLE_IP;
119 pe.wakeup_events = 1;
120
121 pe.disabled = 1;
122 pe.exclude_kernel = 1;
123 pe.exclude_hv = 1;
124
125 fd = sys_perf_event_open(&pe, 0, -1, -1,
126 perf_event_open_cloexec_flag());
127 if (fd < 0) {
128 pr_debug("failed opening event %llx\n", pe.config);
129 return TEST_FAIL;
130 }
131
132 fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
133 fcntl(fd, F_SETSIG, sig);
134 fcntl(fd, F_SETOWN, getpid());
135
136 ioctl(fd, PERF_EVENT_IOC_RESET, 0);
137
138 return fd;
139}
140
141static int bp_event(void *addr, int sig)
142{
143 return __event(true, addr, sig);
144}
145
146static int wp_event(void *addr, int sig)
147{
148 return __event(false, addr, sig);
149}
150
151static long long bp_count(int fd)
152{
153 long long count;
154 int ret;
155
156 ret = read(fd, &count, sizeof(long long));
157 if (ret != sizeof(long long)) {
158 pr_debug("failed to read: %d\n", ret);
159 return TEST_FAIL;
160 }
161
162 return count;
163}
164
165static int test__bp_signal(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
166{
167 struct sigaction sa;
168 long long count1, count2, count3;
169
170 if (!BP_SIGNAL_IS_SUPPORTED) {
171 pr_debug("Test not supported on this architecture");
172 return TEST_SKIP;
173 }
174
175 /* setup SIGIO signal handler */
176 memset(&sa, 0, sizeof(struct sigaction));
177 sa.sa_sigaction = (void *) sig_handler;
178 sa.sa_flags = SA_SIGINFO;
179
180 if (sigaction(SIGIO, &sa, NULL) < 0) {
181 pr_debug("failed setting up signal handler\n");
182 return TEST_FAIL;
183 }
184
185 sa.sa_sigaction = (void *) sig_handler_2;
186 if (sigaction(SIGUSR1, &sa, NULL) < 0) {
187 pr_debug("failed setting up signal handler 2\n");
188 return TEST_FAIL;
189 }
190
191 /*
192 * We create following events:
193 *
194 * fd1 - breakpoint event on __test_function with SIGIO
195 * signal configured. We should get signal
196 * notification each time the breakpoint is hit
197 *
198 * fd2 - breakpoint event on sig_handler with SIGUSR1
199 * configured. We should get SIGUSR1 each time when
200 * breakpoint is hit
201 *
202 * fd3 - watchpoint event on __test_function with SIGIO
203 * configured.
204 *
205 * Following processing should happen:
206 * Exec: Action: Result:
207 * incq (%rdi) - fd1 event breakpoint hit -> count1 == 1
208 * - SIGIO is delivered
209 * sig_handler - fd2 event breakpoint hit -> count2 == 1
210 * - SIGUSR1 is delivered
211 * sig_handler_2 -> overflows_2 == 1 (nested signal)
212 * sys_rt_sigreturn - return from sig_handler_2
213 * overflows++ -> overflows = 1
214 * sys_rt_sigreturn - return from sig_handler
215 * incq (%rdi) - fd3 event watchpoint hit -> count3 == 1 (wp and bp in one insn)
216 * - SIGIO is delivered
217 * sig_handler - fd2 event breakpoint hit -> count2 == 2
218 * - SIGUSR1 is delivered
219 * sig_handler_2 -> overflows_2 == 2 (nested signal)
220 * sys_rt_sigreturn - return from sig_handler_2
221 * overflows++ -> overflows = 2
222 * sys_rt_sigreturn - return from sig_handler
223 * the_var++ - fd3 event watchpoint hit -> count3 == 2 (standalone watchpoint)
224 * - SIGIO is delivered
225 * sig_handler - fd2 event breakpoint hit -> count2 == 3
226 * - SIGUSR1 is delivered
227 * sig_handler_2 -> overflows_2 == 3 (nested signal)
228 * sys_rt_sigreturn - return from sig_handler_2
229 * overflows++ -> overflows == 3
230 * sys_rt_sigreturn - return from sig_handler
231 *
232 * The test case check following error conditions:
233 * - we get stuck in signal handler because of debug
234 * exception being triggered recursively due to
235 * the wrong RF EFLAG management
236 *
237 * - we never trigger the sig_handler breakpoint due
238 * to the wrong RF EFLAG management
239 *
240 */
241
242 fd1 = bp_event(__test_function, SIGIO);
243 fd2 = bp_event(sig_handler, SIGUSR1);
244 fd3 = wp_event((void *)&the_var, SIGIO);
245
246 ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0);
247 ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0);
248 ioctl(fd3, PERF_EVENT_IOC_ENABLE, 0);
249
250 /*
251 * Kick off the test by triggering 'fd1'
252 * breakpoint.
253 */
254 test_function();
255
256 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
257 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
258 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
259
260 count1 = bp_count(fd1);
261 count2 = bp_count(fd2);
262 count3 = bp_count(fd3);
263
264 close(fd1);
265 close(fd2);
266 close(fd3);
267
268 pr_debug("count1 %lld, count2 %lld, count3 %lld, overflow %d, overflows_2 %d\n",
269 count1, count2, count3, overflows, overflows_2);
270
271 if (count1 != 1) {
272 if (count1 == 11)
273 pr_debug("failed: RF EFLAG recursion issue detected\n");
274 else
275 pr_debug("failed: wrong count for bp1: %lld, expected 1\n", count1);
276 }
277
278 if (overflows != 3)
279 pr_debug("failed: wrong overflow (%d) hit, expected 3\n", overflows);
280
281 if (overflows_2 != 3)
282 pr_debug("failed: wrong overflow_2 (%d) hit, expected 3\n", overflows_2);
283
284 if (count2 != 3)
285 pr_debug("failed: wrong count for bp2 (%lld), expected 3\n", count2);
286
287 if (count3 != 2)
288 pr_debug("failed: wrong count for bp3 (%lld), expected 2\n", count3);
289
290 return count1 == 1 && overflows == 3 && count2 == 3 && overflows_2 == 3 && count3 == 2 ?
291 TEST_OK : TEST_FAIL;
292}
293
294DEFINE_SUITE("Breakpoint overflow signal handler", bp_signal);