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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 ".globl __test_function\n"
49 "__test_function:\n"
50 "incq (%rdi)\n"
51 "ret\n");
52#elif defined (__aarch64__)
53extern void __test_function(volatile long *ptr);
54asm (
55 ".globl __test_function\n"
56 "__test_function:\n"
57 "str x30, [x0]\n"
58 "ret\n");
59
60#else
61static void __test_function(volatile long *ptr)
62{
63 *ptr = 0x1234;
64}
65#endif
66
67static noinline int test_function(void)
68{
69 __test_function(&the_var);
70 the_var++;
71 return time(NULL);
72}
73
74static void sig_handler_2(int signum __maybe_unused,
75 siginfo_t *oh __maybe_unused,
76 void *uc __maybe_unused)
77{
78 overflows_2++;
79 if (overflows_2 > 10) {
80 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
81 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
82 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
83 }
84}
85
86static void sig_handler(int signum __maybe_unused,
87 siginfo_t *oh __maybe_unused,
88 void *uc __maybe_unused)
89{
90 overflows++;
91
92 if (overflows > 10) {
93 /*
94 * This should be executed only once during
95 * this test, if we are here for the 10th
96 * time, consider this the recursive issue.
97 *
98 * We can get out of here by disable events,
99 * so no new SIGIO is delivered.
100 */
101 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
102 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
103 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
104 }
105}
106
107static int __event(bool is_x, void *addr, int sig)
108{
109 struct perf_event_attr pe;
110 int fd;
111
112 memset(&pe, 0, sizeof(struct perf_event_attr));
113 pe.type = PERF_TYPE_BREAKPOINT;
114 pe.size = sizeof(struct perf_event_attr);
115
116 pe.config = 0;
117 pe.bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
118 pe.bp_addr = (unsigned long) addr;
119 pe.bp_len = sizeof(long);
120
121 pe.sample_period = 1;
122 pe.sample_type = PERF_SAMPLE_IP;
123 pe.wakeup_events = 1;
124
125 pe.disabled = 1;
126 pe.exclude_kernel = 1;
127 pe.exclude_hv = 1;
128
129 fd = sys_perf_event_open(&pe, 0, -1, -1,
130 perf_event_open_cloexec_flag());
131 if (fd < 0) {
132 pr_debug("failed opening event %llx\n", pe.config);
133 return TEST_FAIL;
134 }
135
136 fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
137 fcntl(fd, F_SETSIG, sig);
138 fcntl(fd, F_SETOWN, getpid());
139
140 ioctl(fd, PERF_EVENT_IOC_RESET, 0);
141
142 return fd;
143}
144
145static int bp_event(void *addr, int sig)
146{
147 return __event(true, addr, sig);
148}
149
150static int wp_event(void *addr, int sig)
151{
152 return __event(false, addr, sig);
153}
154
155static long long bp_count(int fd)
156{
157 long long count;
158 int ret;
159
160 ret = read(fd, &count, sizeof(long long));
161 if (ret != sizeof(long long)) {
162 pr_debug("failed to read: %d\n", ret);
163 return TEST_FAIL;
164 }
165
166 return count;
167}
168
169int test__bp_signal(struct test *test __maybe_unused, int subtest __maybe_unused)
170{
171 struct sigaction sa;
172 long long count1, count2, count3;
173
174 /* setup SIGIO signal handler */
175 memset(&sa, 0, sizeof(struct sigaction));
176 sa.sa_sigaction = (void *) sig_handler;
177 sa.sa_flags = SA_SIGINFO;
178
179 if (sigaction(SIGIO, &sa, NULL) < 0) {
180 pr_debug("failed setting up signal handler\n");
181 return TEST_FAIL;
182 }
183
184 sa.sa_sigaction = (void *) sig_handler_2;
185 if (sigaction(SIGUSR1, &sa, NULL) < 0) {
186 pr_debug("failed setting up signal handler 2\n");
187 return TEST_FAIL;
188 }
189
190 /*
191 * We create following events:
192 *
193 * fd1 - breakpoint event on __test_function with SIGIO
194 * signal configured. We should get signal
195 * notification each time the breakpoint is hit
196 *
197 * fd2 - breakpoint event on sig_handler with SIGUSR1
198 * configured. We should get SIGUSR1 each time when
199 * breakpoint is hit
200 *
201 * fd3 - watchpoint event on __test_function with SIGIO
202 * configured.
203 *
204 * Following processing should happen:
205 * Exec: Action: Result:
206 * incq (%rdi) - fd1 event breakpoint hit -> count1 == 1
207 * - SIGIO is delivered
208 * sig_handler - fd2 event breakpoint hit -> count2 == 1
209 * - SIGUSR1 is delivered
210 * sig_handler_2 -> overflows_2 == 1 (nested signal)
211 * sys_rt_sigreturn - return from sig_handler_2
212 * overflows++ -> overflows = 1
213 * sys_rt_sigreturn - return from sig_handler
214 * incq (%rdi) - fd3 event watchpoint hit -> count3 == 1 (wp and bp in one insn)
215 * - SIGIO is delivered
216 * sig_handler - fd2 event breakpoint hit -> count2 == 2
217 * - SIGUSR1 is delivered
218 * sig_handler_2 -> overflows_2 == 2 (nested signal)
219 * sys_rt_sigreturn - return from sig_handler_2
220 * overflows++ -> overflows = 2
221 * sys_rt_sigreturn - return from sig_handler
222 * the_var++ - fd3 event watchpoint hit -> count3 == 2 (standalone watchpoint)
223 * - SIGIO is delivered
224 * sig_handler - fd2 event breakpoint hit -> count2 == 3
225 * - SIGUSR1 is delivered
226 * sig_handler_2 -> overflows_2 == 3 (nested signal)
227 * sys_rt_sigreturn - return from sig_handler_2
228 * overflows++ -> overflows == 3
229 * sys_rt_sigreturn - return from sig_handler
230 *
231 * The test case check following error conditions:
232 * - we get stuck in signal handler because of debug
233 * exception being triggered receursively due to
234 * the wrong RF EFLAG management
235 *
236 * - we never trigger the sig_handler breakpoint due
237 * to the rong RF EFLAG management
238 *
239 */
240
241 fd1 = bp_event(__test_function, SIGIO);
242 fd2 = bp_event(sig_handler, SIGUSR1);
243 fd3 = wp_event((void *)&the_var, SIGIO);
244
245 ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0);
246 ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0);
247 ioctl(fd3, PERF_EVENT_IOC_ENABLE, 0);
248
249 /*
250 * Kick off the test by trigering 'fd1'
251 * breakpoint.
252 */
253 test_function();
254
255 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
256 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
257 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
258
259 count1 = bp_count(fd1);
260 count2 = bp_count(fd2);
261 count3 = bp_count(fd3);
262
263 close(fd1);
264 close(fd2);
265 close(fd3);
266
267 pr_debug("count1 %lld, count2 %lld, count3 %lld, overflow %d, overflows_2 %d\n",
268 count1, count2, count3, overflows, overflows_2);
269
270 if (count1 != 1) {
271 if (count1 == 11)
272 pr_debug("failed: RF EFLAG recursion issue detected\n");
273 else
274 pr_debug("failed: wrong count for bp1%lld\n", count1);
275 }
276
277 if (overflows != 3)
278 pr_debug("failed: wrong overflow hit\n");
279
280 if (overflows_2 != 3)
281 pr_debug("failed: wrong overflow_2 hit\n");
282
283 if (count2 != 3)
284 pr_debug("failed: wrong count for bp2\n");
285
286 if (count3 != 2)
287 pr_debug("failed: wrong count for bp3\n");
288
289 return count1 == 1 && overflows == 3 && count2 == 3 && overflows_2 == 3 && count3 == 2 ?
290 TEST_OK : TEST_FAIL;
291}
292
293bool test__bp_signal_is_supported(void)
294{
295 /*
296 * PowerPC and S390 do not support creation of instruction
297 * breakpoints using the perf_event interface.
298 *
299 * ARM requires explicit rounding down of the instruction
300 * pointer in Thumb mode, and then requires the single-step
301 * to be handled explicitly in the overflow handler to avoid
302 * stepping into the SIGIO handler and getting stuck on the
303 * breakpointed instruction.
304 *
305 * Just disable the test for these architectures until these
306 * issues are resolved.
307 */
308#if defined(__powerpc__) || defined(__s390x__) || defined(__arm__)
309 return false;
310#else
311 return true;
312#endif
313}
1/*
2 * Inspired by breakpoint overflow test done by
3 * Vince Weaver <vincent.weaver@maine.edu> for perf_event_tests
4 * (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 "perf.h"
28#include "cloexec.h"
29
30static int fd1;
31static int fd2;
32static int fd3;
33static int overflows;
34static int overflows_2;
35
36volatile long the_var;
37
38
39/*
40 * Use ASM to ensure watchpoint and breakpoint can be triggered
41 * at one instruction.
42 */
43#if defined (__x86_64__)
44extern void __test_function(volatile long *ptr);
45asm (
46 ".globl __test_function\n"
47 "__test_function:\n"
48 "incq (%rdi)\n"
49 "ret\n");
50#elif defined (__aarch64__)
51extern void __test_function(volatile long *ptr);
52asm (
53 ".globl __test_function\n"
54 "__test_function:\n"
55 "str x30, [x0]\n"
56 "ret\n");
57
58#else
59static void __test_function(volatile long *ptr)
60{
61 *ptr = 0x1234;
62}
63#endif
64
65__attribute__ ((noinline))
66static int test_function(void)
67{
68 __test_function(&the_var);
69 the_var++;
70 return time(NULL);
71}
72
73static void sig_handler_2(int signum __maybe_unused,
74 siginfo_t *oh __maybe_unused,
75 void *uc __maybe_unused)
76{
77 overflows_2++;
78 if (overflows_2 > 10) {
79 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
80 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
81 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
82 }
83}
84
85static void sig_handler(int signum __maybe_unused,
86 siginfo_t *oh __maybe_unused,
87 void *uc __maybe_unused)
88{
89 overflows++;
90
91 if (overflows > 10) {
92 /*
93 * This should be executed only once during
94 * this test, if we are here for the 10th
95 * time, consider this the recursive issue.
96 *
97 * We can get out of here by disable events,
98 * so no new SIGIO is delivered.
99 */
100 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
101 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
102 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
103 }
104}
105
106static int __event(bool is_x, void *addr, int sig)
107{
108 struct perf_event_attr pe;
109 int fd;
110
111 memset(&pe, 0, sizeof(struct perf_event_attr));
112 pe.type = PERF_TYPE_BREAKPOINT;
113 pe.size = sizeof(struct perf_event_attr);
114
115 pe.config = 0;
116 pe.bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
117 pe.bp_addr = (unsigned long) addr;
118 pe.bp_len = sizeof(long);
119
120 pe.sample_period = 1;
121 pe.sample_type = PERF_SAMPLE_IP;
122 pe.wakeup_events = 1;
123
124 pe.disabled = 1;
125 pe.exclude_kernel = 1;
126 pe.exclude_hv = 1;
127
128 fd = sys_perf_event_open(&pe, 0, -1, -1,
129 perf_event_open_cloexec_flag());
130 if (fd < 0) {
131 pr_debug("failed opening event %llx\n", pe.config);
132 return TEST_FAIL;
133 }
134
135 fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
136 fcntl(fd, F_SETSIG, sig);
137 fcntl(fd, F_SETOWN, getpid());
138
139 ioctl(fd, PERF_EVENT_IOC_RESET, 0);
140
141 return fd;
142}
143
144static int bp_event(void *addr, int sig)
145{
146 return __event(true, addr, sig);
147}
148
149static int wp_event(void *addr, int sig)
150{
151 return __event(false, addr, sig);
152}
153
154static long long bp_count(int fd)
155{
156 long long count;
157 int ret;
158
159 ret = read(fd, &count, sizeof(long long));
160 if (ret != sizeof(long long)) {
161 pr_debug("failed to read: %d\n", ret);
162 return TEST_FAIL;
163 }
164
165 return count;
166}
167
168int test__bp_signal(int subtest __maybe_unused)
169{
170 struct sigaction sa;
171 long long count1, count2, count3;
172
173 /* setup SIGIO signal handler */
174 memset(&sa, 0, sizeof(struct sigaction));
175 sa.sa_sigaction = (void *) sig_handler;
176 sa.sa_flags = SA_SIGINFO;
177
178 if (sigaction(SIGIO, &sa, NULL) < 0) {
179 pr_debug("failed setting up signal handler\n");
180 return TEST_FAIL;
181 }
182
183 sa.sa_sigaction = (void *) sig_handler_2;
184 if (sigaction(SIGUSR1, &sa, NULL) < 0) {
185 pr_debug("failed setting up signal handler 2\n");
186 return TEST_FAIL;
187 }
188
189 /*
190 * We create following events:
191 *
192 * fd1 - breakpoint event on __test_function with SIGIO
193 * signal configured. We should get signal
194 * notification each time the breakpoint is hit
195 *
196 * fd2 - breakpoint event on sig_handler with SIGUSR1
197 * configured. We should get SIGUSR1 each time when
198 * breakpoint is hit
199 *
200 * fd3 - watchpoint event on __test_function with SIGIO
201 * configured.
202 *
203 * Following processing should happen:
204 * Exec: Action: Result:
205 * incq (%rdi) - fd1 event breakpoint hit -> count1 == 1
206 * - SIGIO is delivered
207 * sig_handler - fd2 event breakpoint hit -> count2 == 1
208 * - SIGUSR1 is delivered
209 * sig_handler_2 -> overflows_2 == 1 (nested signal)
210 * sys_rt_sigreturn - return from sig_handler_2
211 * overflows++ -> overflows = 1
212 * sys_rt_sigreturn - return from sig_handler
213 * incq (%rdi) - fd3 event watchpoint hit -> count3 == 1 (wp and bp in one insn)
214 * - SIGIO is delivered
215 * sig_handler - fd2 event breakpoint hit -> count2 == 2
216 * - SIGUSR1 is delivered
217 * sig_handler_2 -> overflows_2 == 2 (nested signal)
218 * sys_rt_sigreturn - return from sig_handler_2
219 * overflows++ -> overflows = 2
220 * sys_rt_sigreturn - return from sig_handler
221 * the_var++ - fd3 event watchpoint hit -> count3 == 2 (standalone watchpoint)
222 * - SIGIO is delivered
223 * sig_handler - fd2 event breakpoint hit -> count2 == 3
224 * - SIGUSR1 is delivered
225 * sig_handler_2 -> overflows_2 == 3 (nested signal)
226 * sys_rt_sigreturn - return from sig_handler_2
227 * overflows++ -> overflows == 3
228 * sys_rt_sigreturn - return from sig_handler
229 *
230 * The test case check following error conditions:
231 * - we get stuck in signal handler because of debug
232 * exception being triggered receursively due to
233 * the wrong RF EFLAG management
234 *
235 * - we never trigger the sig_handler breakpoint due
236 * to the rong RF EFLAG management
237 *
238 */
239
240 fd1 = bp_event(__test_function, SIGIO);
241 fd2 = bp_event(sig_handler, SIGUSR1);
242 fd3 = wp_event((void *)&the_var, SIGIO);
243
244 ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0);
245 ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0);
246 ioctl(fd3, PERF_EVENT_IOC_ENABLE, 0);
247
248 /*
249 * Kick off the test by trigering 'fd1'
250 * breakpoint.
251 */
252 test_function();
253
254 ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
255 ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
256 ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
257
258 count1 = bp_count(fd1);
259 count2 = bp_count(fd2);
260 count3 = bp_count(fd3);
261
262 close(fd1);
263 close(fd2);
264 close(fd3);
265
266 pr_debug("count1 %lld, count2 %lld, count3 %lld, overflow %d, overflows_2 %d\n",
267 count1, count2, count3, overflows, overflows_2);
268
269 if (count1 != 1) {
270 if (count1 == 11)
271 pr_debug("failed: RF EFLAG recursion issue detected\n");
272 else
273 pr_debug("failed: wrong count for bp1%lld\n", count1);
274 }
275
276 if (overflows != 3)
277 pr_debug("failed: wrong overflow hit\n");
278
279 if (overflows_2 != 3)
280 pr_debug("failed: wrong overflow_2 hit\n");
281
282 if (count2 != 3)
283 pr_debug("failed: wrong count for bp2\n");
284
285 if (count3 != 2)
286 pr_debug("failed: wrong count for bp3\n");
287
288 return count1 == 1 && overflows == 3 && count2 == 3 && overflows_2 == 3 && count3 == 2 ?
289 TEST_OK : TEST_FAIL;
290}