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1 // SPDX-License-Identifier: LGPL-2.1
2 #define _GNU_SOURCE
3 #include <assert.h>
4 #include <linux/membarrier.h>
5 #include <pthread.h>
6 #include <sched.h>
7 #include <stdatomic.h>
8 #include <stdint.h>
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <syscall.h>
13 #include <unistd.h>
14 #include <poll.h>
15 #include <sys/types.h>
16 #include <signal.h>
17 #include <errno.h>
18 #include <stddef.h>
19 
rseq_gettid(void)20 static inline pid_t rseq_gettid(void)
21 {
22 	return syscall(__NR_gettid);
23 }
24 
25 #define NR_INJECT	9
26 static int loop_cnt[NR_INJECT + 1];
27 
28 static int loop_cnt_1 asm("asm_loop_cnt_1") __attribute__((used));
29 static int loop_cnt_2 asm("asm_loop_cnt_2") __attribute__((used));
30 static int loop_cnt_3 asm("asm_loop_cnt_3") __attribute__((used));
31 static int loop_cnt_4 asm("asm_loop_cnt_4") __attribute__((used));
32 static int loop_cnt_5 asm("asm_loop_cnt_5") __attribute__((used));
33 static int loop_cnt_6 asm("asm_loop_cnt_6") __attribute__((used));
34 
35 static int opt_modulo, verbose;
36 
37 static int opt_yield, opt_signal, opt_sleep,
38 		opt_disable_rseq, opt_threads = 200,
39 		opt_disable_mod = 0, opt_test = 's', opt_mb = 0;
40 
41 #ifndef RSEQ_SKIP_FASTPATH
42 static long long opt_reps = 5000;
43 #else
44 static long long opt_reps = 100;
45 #endif
46 
47 static __thread __attribute__((tls_model("initial-exec")))
48 unsigned int signals_delivered;
49 
50 #ifndef BENCHMARK
51 
52 static __thread __attribute__((tls_model("initial-exec"), unused))
53 unsigned int yield_mod_cnt, nr_abort;
54 
55 #define printf_verbose(fmt, ...)			\
56 	do {						\
57 		if (verbose)				\
58 			printf(fmt, ## __VA_ARGS__);	\
59 	} while (0)
60 
61 #ifdef __i386__
62 
63 #define INJECT_ASM_REG	"eax"
64 
65 #define RSEQ_INJECT_CLOBBER \
66 	, INJECT_ASM_REG
67 
68 #define RSEQ_INJECT_ASM(n) \
69 	"mov asm_loop_cnt_" #n ", %%" INJECT_ASM_REG "\n\t" \
70 	"test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
71 	"jz 333f\n\t" \
72 	"222:\n\t" \
73 	"dec %%" INJECT_ASM_REG "\n\t" \
74 	"jnz 222b\n\t" \
75 	"333:\n\t"
76 
77 #elif defined(__x86_64__)
78 
79 #define INJECT_ASM_REG_P	"rax"
80 #define INJECT_ASM_REG		"eax"
81 
82 #define RSEQ_INJECT_CLOBBER \
83 	, INJECT_ASM_REG_P \
84 	, INJECT_ASM_REG
85 
86 #define RSEQ_INJECT_ASM(n) \
87 	"lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG_P "\n\t" \
88 	"mov (%%" INJECT_ASM_REG_P "), %%" INJECT_ASM_REG "\n\t" \
89 	"test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
90 	"jz 333f\n\t" \
91 	"222:\n\t" \
92 	"dec %%" INJECT_ASM_REG "\n\t" \
93 	"jnz 222b\n\t" \
94 	"333:\n\t"
95 
96 #elif defined(__s390__)
97 
98 #define RSEQ_INJECT_INPUT \
99 	, [loop_cnt_1]"m"(loop_cnt[1]) \
100 	, [loop_cnt_2]"m"(loop_cnt[2]) \
101 	, [loop_cnt_3]"m"(loop_cnt[3]) \
102 	, [loop_cnt_4]"m"(loop_cnt[4]) \
103 	, [loop_cnt_5]"m"(loop_cnt[5]) \
104 	, [loop_cnt_6]"m"(loop_cnt[6])
105 
106 #define INJECT_ASM_REG	"r12"
107 
108 #define RSEQ_INJECT_CLOBBER \
109 	, INJECT_ASM_REG
110 
111 #define RSEQ_INJECT_ASM(n) \
112 	"l %%" INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
113 	"ltr %%" INJECT_ASM_REG ", %%" INJECT_ASM_REG "\n\t" \
114 	"je 333f\n\t" \
115 	"222:\n\t" \
116 	"ahi %%" INJECT_ASM_REG ", -1\n\t" \
117 	"jnz 222b\n\t" \
118 	"333:\n\t"
119 
120 #elif defined(__ARMEL__)
121 
122 #define RSEQ_INJECT_INPUT \
123 	, [loop_cnt_1]"m"(loop_cnt[1]) \
124 	, [loop_cnt_2]"m"(loop_cnt[2]) \
125 	, [loop_cnt_3]"m"(loop_cnt[3]) \
126 	, [loop_cnt_4]"m"(loop_cnt[4]) \
127 	, [loop_cnt_5]"m"(loop_cnt[5]) \
128 	, [loop_cnt_6]"m"(loop_cnt[6])
129 
130 #define INJECT_ASM_REG	"r4"
131 
132 #define RSEQ_INJECT_CLOBBER \
133 	, INJECT_ASM_REG
134 
135 #define RSEQ_INJECT_ASM(n) \
136 	"ldr " INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
137 	"cmp " INJECT_ASM_REG ", #0\n\t" \
138 	"beq 333f\n\t" \
139 	"222:\n\t" \
140 	"subs " INJECT_ASM_REG ", #1\n\t" \
141 	"bne 222b\n\t" \
142 	"333:\n\t"
143 
144 #elif defined(__AARCH64EL__)
145 
146 #define RSEQ_INJECT_INPUT \
147 	, [loop_cnt_1] "Qo" (loop_cnt[1]) \
148 	, [loop_cnt_2] "Qo" (loop_cnt[2]) \
149 	, [loop_cnt_3] "Qo" (loop_cnt[3]) \
150 	, [loop_cnt_4] "Qo" (loop_cnt[4]) \
151 	, [loop_cnt_5] "Qo" (loop_cnt[5]) \
152 	, [loop_cnt_6] "Qo" (loop_cnt[6])
153 
154 #define INJECT_ASM_REG	RSEQ_ASM_TMP_REG32
155 
156 #define RSEQ_INJECT_ASM(n) \
157 	"	ldr	" INJECT_ASM_REG ", %[loop_cnt_" #n "]\n"	\
158 	"	cbz	" INJECT_ASM_REG ", 333f\n"			\
159 	"222:\n"							\
160 	"	sub	" INJECT_ASM_REG ", " INJECT_ASM_REG ", #1\n"	\
161 	"	cbnz	" INJECT_ASM_REG ", 222b\n"			\
162 	"333:\n"
163 
164 #elif defined(__PPC__)
165 
166 #define RSEQ_INJECT_INPUT \
167 	, [loop_cnt_1]"m"(loop_cnt[1]) \
168 	, [loop_cnt_2]"m"(loop_cnt[2]) \
169 	, [loop_cnt_3]"m"(loop_cnt[3]) \
170 	, [loop_cnt_4]"m"(loop_cnt[4]) \
171 	, [loop_cnt_5]"m"(loop_cnt[5]) \
172 	, [loop_cnt_6]"m"(loop_cnt[6])
173 
174 #define INJECT_ASM_REG	"r18"
175 
176 #define RSEQ_INJECT_CLOBBER \
177 	, INJECT_ASM_REG
178 
179 #define RSEQ_INJECT_ASM(n) \
180 	"lwz %%" INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
181 	"cmpwi %%" INJECT_ASM_REG ", 0\n\t" \
182 	"beq 333f\n\t" \
183 	"222:\n\t" \
184 	"subic. %%" INJECT_ASM_REG ", %%" INJECT_ASM_REG ", 1\n\t" \
185 	"bne 222b\n\t" \
186 	"333:\n\t"
187 
188 #elif defined(__mips__)
189 
190 #define RSEQ_INJECT_INPUT \
191 	, [loop_cnt_1]"m"(loop_cnt[1]) \
192 	, [loop_cnt_2]"m"(loop_cnt[2]) \
193 	, [loop_cnt_3]"m"(loop_cnt[3]) \
194 	, [loop_cnt_4]"m"(loop_cnt[4]) \
195 	, [loop_cnt_5]"m"(loop_cnt[5]) \
196 	, [loop_cnt_6]"m"(loop_cnt[6])
197 
198 #define INJECT_ASM_REG	"$5"
199 
200 #define RSEQ_INJECT_CLOBBER \
201 	, INJECT_ASM_REG
202 
203 #define RSEQ_INJECT_ASM(n) \
204 	"lw " INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
205 	"beqz " INJECT_ASM_REG ", 333f\n\t" \
206 	"222:\n\t" \
207 	"addiu " INJECT_ASM_REG ", -1\n\t" \
208 	"bnez " INJECT_ASM_REG ", 222b\n\t" \
209 	"333:\n\t"
210 
211 #else
212 #error unsupported target
213 #endif
214 
215 #define RSEQ_INJECT_FAILED \
216 	nr_abort++;
217 
218 #define RSEQ_INJECT_C(n) \
219 { \
220 	int loc_i, loc_nr_loops = loop_cnt[n]; \
221 	\
222 	for (loc_i = 0; loc_i < loc_nr_loops; loc_i++) { \
223 		rseq_barrier(); \
224 	} \
225 	if (loc_nr_loops == -1 && opt_modulo) { \
226 		if (yield_mod_cnt == opt_modulo - 1) { \
227 			if (opt_sleep > 0) \
228 				poll(NULL, 0, opt_sleep); \
229 			if (opt_yield) \
230 				sched_yield(); \
231 			if (opt_signal) \
232 				raise(SIGUSR1); \
233 			yield_mod_cnt = 0; \
234 		} else { \
235 			yield_mod_cnt++; \
236 		} \
237 	} \
238 }
239 
240 #else
241 
242 #define printf_verbose(fmt, ...)
243 
244 #endif /* BENCHMARK */
245 
246 #include "rseq.h"
247 
248 struct percpu_lock_entry {
249 	intptr_t v;
250 } __attribute__((aligned(128)));
251 
252 struct percpu_lock {
253 	struct percpu_lock_entry c[CPU_SETSIZE];
254 };
255 
256 struct test_data_entry {
257 	intptr_t count;
258 } __attribute__((aligned(128)));
259 
260 struct spinlock_test_data {
261 	struct percpu_lock lock;
262 	struct test_data_entry c[CPU_SETSIZE];
263 };
264 
265 struct spinlock_thread_test_data {
266 	struct spinlock_test_data *data;
267 	long long reps;
268 	int reg;
269 };
270 
271 struct inc_test_data {
272 	struct test_data_entry c[CPU_SETSIZE];
273 };
274 
275 struct inc_thread_test_data {
276 	struct inc_test_data *data;
277 	long long reps;
278 	int reg;
279 };
280 
281 struct percpu_list_node {
282 	intptr_t data;
283 	struct percpu_list_node *next;
284 };
285 
286 struct percpu_list_entry {
287 	struct percpu_list_node *head;
288 } __attribute__((aligned(128)));
289 
290 struct percpu_list {
291 	struct percpu_list_entry c[CPU_SETSIZE];
292 };
293 
294 #define BUFFER_ITEM_PER_CPU	100
295 
296 struct percpu_buffer_node {
297 	intptr_t data;
298 };
299 
300 struct percpu_buffer_entry {
301 	intptr_t offset;
302 	intptr_t buflen;
303 	struct percpu_buffer_node **array;
304 } __attribute__((aligned(128)));
305 
306 struct percpu_buffer {
307 	struct percpu_buffer_entry c[CPU_SETSIZE];
308 };
309 
310 #define MEMCPY_BUFFER_ITEM_PER_CPU	100
311 
312 struct percpu_memcpy_buffer_node {
313 	intptr_t data1;
314 	uint64_t data2;
315 };
316 
317 struct percpu_memcpy_buffer_entry {
318 	intptr_t offset;
319 	intptr_t buflen;
320 	struct percpu_memcpy_buffer_node *array;
321 } __attribute__((aligned(128)));
322 
323 struct percpu_memcpy_buffer {
324 	struct percpu_memcpy_buffer_entry c[CPU_SETSIZE];
325 };
326 
327 /* A simple percpu spinlock. Grabs lock on current cpu. */
rseq_this_cpu_lock(struct percpu_lock * lock)328 static int rseq_this_cpu_lock(struct percpu_lock *lock)
329 {
330 	int cpu;
331 
332 	for (;;) {
333 		int ret;
334 
335 		cpu = rseq_cpu_start();
336 		ret = rseq_cmpeqv_storev(&lock->c[cpu].v,
337 					 0, 1, cpu);
338 		if (rseq_likely(!ret))
339 			break;
340 		/* Retry if comparison fails or rseq aborts. */
341 	}
342 	/*
343 	 * Acquire semantic when taking lock after control dependency.
344 	 * Matches rseq_smp_store_release().
345 	 */
346 	rseq_smp_acquire__after_ctrl_dep();
347 	return cpu;
348 }
349 
rseq_percpu_unlock(struct percpu_lock * lock,int cpu)350 static void rseq_percpu_unlock(struct percpu_lock *lock, int cpu)
351 {
352 	assert(lock->c[cpu].v == 1);
353 	/*
354 	 * Release lock, with release semantic. Matches
355 	 * rseq_smp_acquire__after_ctrl_dep().
356 	 */
357 	rseq_smp_store_release(&lock->c[cpu].v, 0);
358 }
359 
test_percpu_spinlock_thread(void * arg)360 void *test_percpu_spinlock_thread(void *arg)
361 {
362 	struct spinlock_thread_test_data *thread_data = arg;
363 	struct spinlock_test_data *data = thread_data->data;
364 	long long i, reps;
365 
366 	if (!opt_disable_rseq && thread_data->reg &&
367 	    rseq_register_current_thread())
368 		abort();
369 	reps = thread_data->reps;
370 	for (i = 0; i < reps; i++) {
371 		int cpu = rseq_this_cpu_lock(&data->lock);
372 		data->c[cpu].count++;
373 		rseq_percpu_unlock(&data->lock, cpu);
374 #ifndef BENCHMARK
375 		if (i != 0 && !(i % (reps / 10)))
376 			printf_verbose("tid %d: count %lld\n",
377 				       (int) rseq_gettid(), i);
378 #endif
379 	}
380 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
381 		       (int) rseq_gettid(), nr_abort, signals_delivered);
382 	if (!opt_disable_rseq && thread_data->reg &&
383 	    rseq_unregister_current_thread())
384 		abort();
385 	return NULL;
386 }
387 
388 /*
389  * A simple test which implements a sharded counter using a per-cpu
390  * lock.  Obviously real applications might prefer to simply use a
391  * per-cpu increment; however, this is reasonable for a test and the
392  * lock can be extended to synchronize more complicated operations.
393  */
test_percpu_spinlock(void)394 void test_percpu_spinlock(void)
395 {
396 	const int num_threads = opt_threads;
397 	int i, ret;
398 	uint64_t sum;
399 	pthread_t test_threads[num_threads];
400 	struct spinlock_test_data data;
401 	struct spinlock_thread_test_data thread_data[num_threads];
402 
403 	memset(&data, 0, sizeof(data));
404 	for (i = 0; i < num_threads; i++) {
405 		thread_data[i].reps = opt_reps;
406 		if (opt_disable_mod <= 0 || (i % opt_disable_mod))
407 			thread_data[i].reg = 1;
408 		else
409 			thread_data[i].reg = 0;
410 		thread_data[i].data = &data;
411 		ret = pthread_create(&test_threads[i], NULL,
412 				     test_percpu_spinlock_thread,
413 				     &thread_data[i]);
414 		if (ret) {
415 			errno = ret;
416 			perror("pthread_create");
417 			abort();
418 		}
419 	}
420 
421 	for (i = 0; i < num_threads; i++) {
422 		ret = pthread_join(test_threads[i], NULL);
423 		if (ret) {
424 			errno = ret;
425 			perror("pthread_join");
426 			abort();
427 		}
428 	}
429 
430 	sum = 0;
431 	for (i = 0; i < CPU_SETSIZE; i++)
432 		sum += data.c[i].count;
433 
434 	assert(sum == (uint64_t)opt_reps * num_threads);
435 }
436 
test_percpu_inc_thread(void * arg)437 void *test_percpu_inc_thread(void *arg)
438 {
439 	struct inc_thread_test_data *thread_data = arg;
440 	struct inc_test_data *data = thread_data->data;
441 	long long i, reps;
442 
443 	if (!opt_disable_rseq && thread_data->reg &&
444 	    rseq_register_current_thread())
445 		abort();
446 	reps = thread_data->reps;
447 	for (i = 0; i < reps; i++) {
448 		int ret;
449 
450 		do {
451 			int cpu;
452 
453 			cpu = rseq_cpu_start();
454 			ret = rseq_addv(&data->c[cpu].count, 1, cpu);
455 		} while (rseq_unlikely(ret));
456 #ifndef BENCHMARK
457 		if (i != 0 && !(i % (reps / 10)))
458 			printf_verbose("tid %d: count %lld\n",
459 				       (int) rseq_gettid(), i);
460 #endif
461 	}
462 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
463 		       (int) rseq_gettid(), nr_abort, signals_delivered);
464 	if (!opt_disable_rseq && thread_data->reg &&
465 	    rseq_unregister_current_thread())
466 		abort();
467 	return NULL;
468 }
469 
test_percpu_inc(void)470 void test_percpu_inc(void)
471 {
472 	const int num_threads = opt_threads;
473 	int i, ret;
474 	uint64_t sum;
475 	pthread_t test_threads[num_threads];
476 	struct inc_test_data data;
477 	struct inc_thread_test_data thread_data[num_threads];
478 
479 	memset(&data, 0, sizeof(data));
480 	for (i = 0; i < num_threads; i++) {
481 		thread_data[i].reps = opt_reps;
482 		if (opt_disable_mod <= 0 || (i % opt_disable_mod))
483 			thread_data[i].reg = 1;
484 		else
485 			thread_data[i].reg = 0;
486 		thread_data[i].data = &data;
487 		ret = pthread_create(&test_threads[i], NULL,
488 				     test_percpu_inc_thread,
489 				     &thread_data[i]);
490 		if (ret) {
491 			errno = ret;
492 			perror("pthread_create");
493 			abort();
494 		}
495 	}
496 
497 	for (i = 0; i < num_threads; i++) {
498 		ret = pthread_join(test_threads[i], NULL);
499 		if (ret) {
500 			errno = ret;
501 			perror("pthread_join");
502 			abort();
503 		}
504 	}
505 
506 	sum = 0;
507 	for (i = 0; i < CPU_SETSIZE; i++)
508 		sum += data.c[i].count;
509 
510 	assert(sum == (uint64_t)opt_reps * num_threads);
511 }
512 
this_cpu_list_push(struct percpu_list * list,struct percpu_list_node * node,int * _cpu)513 void this_cpu_list_push(struct percpu_list *list,
514 			struct percpu_list_node *node,
515 			int *_cpu)
516 {
517 	int cpu;
518 
519 	for (;;) {
520 		intptr_t *targetptr, newval, expect;
521 		int ret;
522 
523 		cpu = rseq_cpu_start();
524 		/* Load list->c[cpu].head with single-copy atomicity. */
525 		expect = (intptr_t)RSEQ_READ_ONCE(list->c[cpu].head);
526 		newval = (intptr_t)node;
527 		targetptr = (intptr_t *)&list->c[cpu].head;
528 		node->next = (struct percpu_list_node *)expect;
529 		ret = rseq_cmpeqv_storev(targetptr, expect, newval, cpu);
530 		if (rseq_likely(!ret))
531 			break;
532 		/* Retry if comparison fails or rseq aborts. */
533 	}
534 	if (_cpu)
535 		*_cpu = cpu;
536 }
537 
538 /*
539  * Unlike a traditional lock-less linked list; the availability of a
540  * rseq primitive allows us to implement pop without concerns over
541  * ABA-type races.
542  */
this_cpu_list_pop(struct percpu_list * list,int * _cpu)543 struct percpu_list_node *this_cpu_list_pop(struct percpu_list *list,
544 					   int *_cpu)
545 {
546 	struct percpu_list_node *node = NULL;
547 	int cpu;
548 
549 	for (;;) {
550 		struct percpu_list_node *head;
551 		intptr_t *targetptr, expectnot, *load;
552 		long offset;
553 		int ret;
554 
555 		cpu = rseq_cpu_start();
556 		targetptr = (intptr_t *)&list->c[cpu].head;
557 		expectnot = (intptr_t)NULL;
558 		offset = offsetof(struct percpu_list_node, next);
559 		load = (intptr_t *)&head;
560 		ret = rseq_cmpnev_storeoffp_load(targetptr, expectnot,
561 						   offset, load, cpu);
562 		if (rseq_likely(!ret)) {
563 			node = head;
564 			break;
565 		}
566 		if (ret > 0)
567 			break;
568 		/* Retry if rseq aborts. */
569 	}
570 	if (_cpu)
571 		*_cpu = cpu;
572 	return node;
573 }
574 
575 /*
576  * __percpu_list_pop is not safe against concurrent accesses. Should
577  * only be used on lists that are not concurrently modified.
578  */
__percpu_list_pop(struct percpu_list * list,int cpu)579 struct percpu_list_node *__percpu_list_pop(struct percpu_list *list, int cpu)
580 {
581 	struct percpu_list_node *node;
582 
583 	node = list->c[cpu].head;
584 	if (!node)
585 		return NULL;
586 	list->c[cpu].head = node->next;
587 	return node;
588 }
589 
test_percpu_list_thread(void * arg)590 void *test_percpu_list_thread(void *arg)
591 {
592 	long long i, reps;
593 	struct percpu_list *list = (struct percpu_list *)arg;
594 
595 	if (!opt_disable_rseq && rseq_register_current_thread())
596 		abort();
597 
598 	reps = opt_reps;
599 	for (i = 0; i < reps; i++) {
600 		struct percpu_list_node *node;
601 
602 		node = this_cpu_list_pop(list, NULL);
603 		if (opt_yield)
604 			sched_yield();  /* encourage shuffling */
605 		if (node)
606 			this_cpu_list_push(list, node, NULL);
607 	}
608 
609 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
610 		       (int) rseq_gettid(), nr_abort, signals_delivered);
611 	if (!opt_disable_rseq && rseq_unregister_current_thread())
612 		abort();
613 
614 	return NULL;
615 }
616 
617 /* Simultaneous modification to a per-cpu linked list from many threads.  */
test_percpu_list(void)618 void test_percpu_list(void)
619 {
620 	const int num_threads = opt_threads;
621 	int i, j, ret;
622 	uint64_t sum = 0, expected_sum = 0;
623 	struct percpu_list list;
624 	pthread_t test_threads[num_threads];
625 	cpu_set_t allowed_cpus;
626 
627 	memset(&list, 0, sizeof(list));
628 
629 	/* Generate list entries for every usable cpu. */
630 	sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
631 	for (i = 0; i < CPU_SETSIZE; i++) {
632 		if (!CPU_ISSET(i, &allowed_cpus))
633 			continue;
634 		for (j = 1; j <= 100; j++) {
635 			struct percpu_list_node *node;
636 
637 			expected_sum += j;
638 
639 			node = malloc(sizeof(*node));
640 			assert(node);
641 			node->data = j;
642 			node->next = list.c[i].head;
643 			list.c[i].head = node;
644 		}
645 	}
646 
647 	for (i = 0; i < num_threads; i++) {
648 		ret = pthread_create(&test_threads[i], NULL,
649 				     test_percpu_list_thread, &list);
650 		if (ret) {
651 			errno = ret;
652 			perror("pthread_create");
653 			abort();
654 		}
655 	}
656 
657 	for (i = 0; i < num_threads; i++) {
658 		ret = pthread_join(test_threads[i], NULL);
659 		if (ret) {
660 			errno = ret;
661 			perror("pthread_join");
662 			abort();
663 		}
664 	}
665 
666 	for (i = 0; i < CPU_SETSIZE; i++) {
667 		struct percpu_list_node *node;
668 
669 		if (!CPU_ISSET(i, &allowed_cpus))
670 			continue;
671 
672 		while ((node = __percpu_list_pop(&list, i))) {
673 			sum += node->data;
674 			free(node);
675 		}
676 	}
677 
678 	/*
679 	 * All entries should now be accounted for (unless some external
680 	 * actor is interfering with our allowed affinity while this
681 	 * test is running).
682 	 */
683 	assert(sum == expected_sum);
684 }
685 
this_cpu_buffer_push(struct percpu_buffer * buffer,struct percpu_buffer_node * node,int * _cpu)686 bool this_cpu_buffer_push(struct percpu_buffer *buffer,
687 			  struct percpu_buffer_node *node,
688 			  int *_cpu)
689 {
690 	bool result = false;
691 	int cpu;
692 
693 	for (;;) {
694 		intptr_t *targetptr_spec, newval_spec;
695 		intptr_t *targetptr_final, newval_final;
696 		intptr_t offset;
697 		int ret;
698 
699 		cpu = rseq_cpu_start();
700 		offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
701 		if (offset == buffer->c[cpu].buflen)
702 			break;
703 		newval_spec = (intptr_t)node;
704 		targetptr_spec = (intptr_t *)&buffer->c[cpu].array[offset];
705 		newval_final = offset + 1;
706 		targetptr_final = &buffer->c[cpu].offset;
707 		if (opt_mb)
708 			ret = rseq_cmpeqv_trystorev_storev_release(
709 				targetptr_final, offset, targetptr_spec,
710 				newval_spec, newval_final, cpu);
711 		else
712 			ret = rseq_cmpeqv_trystorev_storev(targetptr_final,
713 				offset, targetptr_spec, newval_spec,
714 				newval_final, cpu);
715 		if (rseq_likely(!ret)) {
716 			result = true;
717 			break;
718 		}
719 		/* Retry if comparison fails or rseq aborts. */
720 	}
721 	if (_cpu)
722 		*_cpu = cpu;
723 	return result;
724 }
725 
this_cpu_buffer_pop(struct percpu_buffer * buffer,int * _cpu)726 struct percpu_buffer_node *this_cpu_buffer_pop(struct percpu_buffer *buffer,
727 					       int *_cpu)
728 {
729 	struct percpu_buffer_node *head;
730 	int cpu;
731 
732 	for (;;) {
733 		intptr_t *targetptr, newval;
734 		intptr_t offset;
735 		int ret;
736 
737 		cpu = rseq_cpu_start();
738 		/* Load offset with single-copy atomicity. */
739 		offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
740 		if (offset == 0) {
741 			head = NULL;
742 			break;
743 		}
744 		head = RSEQ_READ_ONCE(buffer->c[cpu].array[offset - 1]);
745 		newval = offset - 1;
746 		targetptr = (intptr_t *)&buffer->c[cpu].offset;
747 		ret = rseq_cmpeqv_cmpeqv_storev(targetptr, offset,
748 			(intptr_t *)&buffer->c[cpu].array[offset - 1],
749 			(intptr_t)head, newval, cpu);
750 		if (rseq_likely(!ret))
751 			break;
752 		/* Retry if comparison fails or rseq aborts. */
753 	}
754 	if (_cpu)
755 		*_cpu = cpu;
756 	return head;
757 }
758 
759 /*
760  * __percpu_buffer_pop is not safe against concurrent accesses. Should
761  * only be used on buffers that are not concurrently modified.
762  */
__percpu_buffer_pop(struct percpu_buffer * buffer,int cpu)763 struct percpu_buffer_node *__percpu_buffer_pop(struct percpu_buffer *buffer,
764 					       int cpu)
765 {
766 	struct percpu_buffer_node *head;
767 	intptr_t offset;
768 
769 	offset = buffer->c[cpu].offset;
770 	if (offset == 0)
771 		return NULL;
772 	head = buffer->c[cpu].array[offset - 1];
773 	buffer->c[cpu].offset = offset - 1;
774 	return head;
775 }
776 
test_percpu_buffer_thread(void * arg)777 void *test_percpu_buffer_thread(void *arg)
778 {
779 	long long i, reps;
780 	struct percpu_buffer *buffer = (struct percpu_buffer *)arg;
781 
782 	if (!opt_disable_rseq && rseq_register_current_thread())
783 		abort();
784 
785 	reps = opt_reps;
786 	for (i = 0; i < reps; i++) {
787 		struct percpu_buffer_node *node;
788 
789 		node = this_cpu_buffer_pop(buffer, NULL);
790 		if (opt_yield)
791 			sched_yield();  /* encourage shuffling */
792 		if (node) {
793 			if (!this_cpu_buffer_push(buffer, node, NULL)) {
794 				/* Should increase buffer size. */
795 				abort();
796 			}
797 		}
798 	}
799 
800 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
801 		       (int) rseq_gettid(), nr_abort, signals_delivered);
802 	if (!opt_disable_rseq && rseq_unregister_current_thread())
803 		abort();
804 
805 	return NULL;
806 }
807 
808 /* Simultaneous modification to a per-cpu buffer from many threads.  */
test_percpu_buffer(void)809 void test_percpu_buffer(void)
810 {
811 	const int num_threads = opt_threads;
812 	int i, j, ret;
813 	uint64_t sum = 0, expected_sum = 0;
814 	struct percpu_buffer buffer;
815 	pthread_t test_threads[num_threads];
816 	cpu_set_t allowed_cpus;
817 
818 	memset(&buffer, 0, sizeof(buffer));
819 
820 	/* Generate list entries for every usable cpu. */
821 	sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
822 	for (i = 0; i < CPU_SETSIZE; i++) {
823 		if (!CPU_ISSET(i, &allowed_cpus))
824 			continue;
825 		/* Worse-case is every item in same CPU. */
826 		buffer.c[i].array =
827 			malloc(sizeof(*buffer.c[i].array) * CPU_SETSIZE *
828 			       BUFFER_ITEM_PER_CPU);
829 		assert(buffer.c[i].array);
830 		buffer.c[i].buflen = CPU_SETSIZE * BUFFER_ITEM_PER_CPU;
831 		for (j = 1; j <= BUFFER_ITEM_PER_CPU; j++) {
832 			struct percpu_buffer_node *node;
833 
834 			expected_sum += j;
835 
836 			/*
837 			 * We could theoretically put the word-sized
838 			 * "data" directly in the buffer. However, we
839 			 * want to model objects that would not fit
840 			 * within a single word, so allocate an object
841 			 * for each node.
842 			 */
843 			node = malloc(sizeof(*node));
844 			assert(node);
845 			node->data = j;
846 			buffer.c[i].array[j - 1] = node;
847 			buffer.c[i].offset++;
848 		}
849 	}
850 
851 	for (i = 0; i < num_threads; i++) {
852 		ret = pthread_create(&test_threads[i], NULL,
853 				     test_percpu_buffer_thread, &buffer);
854 		if (ret) {
855 			errno = ret;
856 			perror("pthread_create");
857 			abort();
858 		}
859 	}
860 
861 	for (i = 0; i < num_threads; i++) {
862 		ret = pthread_join(test_threads[i], NULL);
863 		if (ret) {
864 			errno = ret;
865 			perror("pthread_join");
866 			abort();
867 		}
868 	}
869 
870 	for (i = 0; i < CPU_SETSIZE; i++) {
871 		struct percpu_buffer_node *node;
872 
873 		if (!CPU_ISSET(i, &allowed_cpus))
874 			continue;
875 
876 		while ((node = __percpu_buffer_pop(&buffer, i))) {
877 			sum += node->data;
878 			free(node);
879 		}
880 		free(buffer.c[i].array);
881 	}
882 
883 	/*
884 	 * All entries should now be accounted for (unless some external
885 	 * actor is interfering with our allowed affinity while this
886 	 * test is running).
887 	 */
888 	assert(sum == expected_sum);
889 }
890 
this_cpu_memcpy_buffer_push(struct percpu_memcpy_buffer * buffer,struct percpu_memcpy_buffer_node item,int * _cpu)891 bool this_cpu_memcpy_buffer_push(struct percpu_memcpy_buffer *buffer,
892 				 struct percpu_memcpy_buffer_node item,
893 				 int *_cpu)
894 {
895 	bool result = false;
896 	int cpu;
897 
898 	for (;;) {
899 		intptr_t *targetptr_final, newval_final, offset;
900 		char *destptr, *srcptr;
901 		size_t copylen;
902 		int ret;
903 
904 		cpu = rseq_cpu_start();
905 		/* Load offset with single-copy atomicity. */
906 		offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
907 		if (offset == buffer->c[cpu].buflen)
908 			break;
909 		destptr = (char *)&buffer->c[cpu].array[offset];
910 		srcptr = (char *)&item;
911 		/* copylen must be <= 4kB. */
912 		copylen = sizeof(item);
913 		newval_final = offset + 1;
914 		targetptr_final = &buffer->c[cpu].offset;
915 		if (opt_mb)
916 			ret = rseq_cmpeqv_trymemcpy_storev_release(
917 				targetptr_final, offset,
918 				destptr, srcptr, copylen,
919 				newval_final, cpu);
920 		else
921 			ret = rseq_cmpeqv_trymemcpy_storev(targetptr_final,
922 				offset, destptr, srcptr, copylen,
923 				newval_final, cpu);
924 		if (rseq_likely(!ret)) {
925 			result = true;
926 			break;
927 		}
928 		/* Retry if comparison fails or rseq aborts. */
929 	}
930 	if (_cpu)
931 		*_cpu = cpu;
932 	return result;
933 }
934 
this_cpu_memcpy_buffer_pop(struct percpu_memcpy_buffer * buffer,struct percpu_memcpy_buffer_node * item,int * _cpu)935 bool this_cpu_memcpy_buffer_pop(struct percpu_memcpy_buffer *buffer,
936 				struct percpu_memcpy_buffer_node *item,
937 				int *_cpu)
938 {
939 	bool result = false;
940 	int cpu;
941 
942 	for (;;) {
943 		intptr_t *targetptr_final, newval_final, offset;
944 		char *destptr, *srcptr;
945 		size_t copylen;
946 		int ret;
947 
948 		cpu = rseq_cpu_start();
949 		/* Load offset with single-copy atomicity. */
950 		offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
951 		if (offset == 0)
952 			break;
953 		destptr = (char *)item;
954 		srcptr = (char *)&buffer->c[cpu].array[offset - 1];
955 		/* copylen must be <= 4kB. */
956 		copylen = sizeof(*item);
957 		newval_final = offset - 1;
958 		targetptr_final = &buffer->c[cpu].offset;
959 		ret = rseq_cmpeqv_trymemcpy_storev(targetptr_final,
960 			offset, destptr, srcptr, copylen,
961 			newval_final, cpu);
962 		if (rseq_likely(!ret)) {
963 			result = true;
964 			break;
965 		}
966 		/* Retry if comparison fails or rseq aborts. */
967 	}
968 	if (_cpu)
969 		*_cpu = cpu;
970 	return result;
971 }
972 
973 /*
974  * __percpu_memcpy_buffer_pop is not safe against concurrent accesses. Should
975  * only be used on buffers that are not concurrently modified.
976  */
__percpu_memcpy_buffer_pop(struct percpu_memcpy_buffer * buffer,struct percpu_memcpy_buffer_node * item,int cpu)977 bool __percpu_memcpy_buffer_pop(struct percpu_memcpy_buffer *buffer,
978 				struct percpu_memcpy_buffer_node *item,
979 				int cpu)
980 {
981 	intptr_t offset;
982 
983 	offset = buffer->c[cpu].offset;
984 	if (offset == 0)
985 		return false;
986 	memcpy(item, &buffer->c[cpu].array[offset - 1], sizeof(*item));
987 	buffer->c[cpu].offset = offset - 1;
988 	return true;
989 }
990 
test_percpu_memcpy_buffer_thread(void * arg)991 void *test_percpu_memcpy_buffer_thread(void *arg)
992 {
993 	long long i, reps;
994 	struct percpu_memcpy_buffer *buffer = (struct percpu_memcpy_buffer *)arg;
995 
996 	if (!opt_disable_rseq && rseq_register_current_thread())
997 		abort();
998 
999 	reps = opt_reps;
1000 	for (i = 0; i < reps; i++) {
1001 		struct percpu_memcpy_buffer_node item;
1002 		bool result;
1003 
1004 		result = this_cpu_memcpy_buffer_pop(buffer, &item, NULL);
1005 		if (opt_yield)
1006 			sched_yield();  /* encourage shuffling */
1007 		if (result) {
1008 			if (!this_cpu_memcpy_buffer_push(buffer, item, NULL)) {
1009 				/* Should increase buffer size. */
1010 				abort();
1011 			}
1012 		}
1013 	}
1014 
1015 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
1016 		       (int) rseq_gettid(), nr_abort, signals_delivered);
1017 	if (!opt_disable_rseq && rseq_unregister_current_thread())
1018 		abort();
1019 
1020 	return NULL;
1021 }
1022 
1023 /* Simultaneous modification to a per-cpu buffer from many threads.  */
test_percpu_memcpy_buffer(void)1024 void test_percpu_memcpy_buffer(void)
1025 {
1026 	const int num_threads = opt_threads;
1027 	int i, j, ret;
1028 	uint64_t sum = 0, expected_sum = 0;
1029 	struct percpu_memcpy_buffer buffer;
1030 	pthread_t test_threads[num_threads];
1031 	cpu_set_t allowed_cpus;
1032 
1033 	memset(&buffer, 0, sizeof(buffer));
1034 
1035 	/* Generate list entries for every usable cpu. */
1036 	sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
1037 	for (i = 0; i < CPU_SETSIZE; i++) {
1038 		if (!CPU_ISSET(i, &allowed_cpus))
1039 			continue;
1040 		/* Worse-case is every item in same CPU. */
1041 		buffer.c[i].array =
1042 			malloc(sizeof(*buffer.c[i].array) * CPU_SETSIZE *
1043 			       MEMCPY_BUFFER_ITEM_PER_CPU);
1044 		assert(buffer.c[i].array);
1045 		buffer.c[i].buflen = CPU_SETSIZE * MEMCPY_BUFFER_ITEM_PER_CPU;
1046 		for (j = 1; j <= MEMCPY_BUFFER_ITEM_PER_CPU; j++) {
1047 			expected_sum += 2 * j + 1;
1048 
1049 			/*
1050 			 * We could theoretically put the word-sized
1051 			 * "data" directly in the buffer. However, we
1052 			 * want to model objects that would not fit
1053 			 * within a single word, so allocate an object
1054 			 * for each node.
1055 			 */
1056 			buffer.c[i].array[j - 1].data1 = j;
1057 			buffer.c[i].array[j - 1].data2 = j + 1;
1058 			buffer.c[i].offset++;
1059 		}
1060 	}
1061 
1062 	for (i = 0; i < num_threads; i++) {
1063 		ret = pthread_create(&test_threads[i], NULL,
1064 				     test_percpu_memcpy_buffer_thread,
1065 				     &buffer);
1066 		if (ret) {
1067 			errno = ret;
1068 			perror("pthread_create");
1069 			abort();
1070 		}
1071 	}
1072 
1073 	for (i = 0; i < num_threads; i++) {
1074 		ret = pthread_join(test_threads[i], NULL);
1075 		if (ret) {
1076 			errno = ret;
1077 			perror("pthread_join");
1078 			abort();
1079 		}
1080 	}
1081 
1082 	for (i = 0; i < CPU_SETSIZE; i++) {
1083 		struct percpu_memcpy_buffer_node item;
1084 
1085 		if (!CPU_ISSET(i, &allowed_cpus))
1086 			continue;
1087 
1088 		while (__percpu_memcpy_buffer_pop(&buffer, &item, i)) {
1089 			sum += item.data1;
1090 			sum += item.data2;
1091 		}
1092 		free(buffer.c[i].array);
1093 	}
1094 
1095 	/*
1096 	 * All entries should now be accounted for (unless some external
1097 	 * actor is interfering with our allowed affinity while this
1098 	 * test is running).
1099 	 */
1100 	assert(sum == expected_sum);
1101 }
1102 
test_signal_interrupt_handler(int signo)1103 static void test_signal_interrupt_handler(int signo)
1104 {
1105 	signals_delivered++;
1106 }
1107 
set_signal_handler(void)1108 static int set_signal_handler(void)
1109 {
1110 	int ret = 0;
1111 	struct sigaction sa;
1112 	sigset_t sigset;
1113 
1114 	ret = sigemptyset(&sigset);
1115 	if (ret < 0) {
1116 		perror("sigemptyset");
1117 		return ret;
1118 	}
1119 
1120 	sa.sa_handler = test_signal_interrupt_handler;
1121 	sa.sa_mask = sigset;
1122 	sa.sa_flags = 0;
1123 	ret = sigaction(SIGUSR1, &sa, NULL);
1124 	if (ret < 0) {
1125 		perror("sigaction");
1126 		return ret;
1127 	}
1128 
1129 	printf_verbose("Signal handler set for SIGUSR1\n");
1130 
1131 	return ret;
1132 }
1133 
1134 struct test_membarrier_thread_args {
1135 	int stop;
1136 	intptr_t percpu_list_ptr;
1137 };
1138 
1139 /* Worker threads modify data in their "active" percpu lists. */
test_membarrier_worker_thread(void * arg)1140 void *test_membarrier_worker_thread(void *arg)
1141 {
1142 	struct test_membarrier_thread_args *args =
1143 		(struct test_membarrier_thread_args *)arg;
1144 	const int iters = opt_reps;
1145 	int i;
1146 
1147 	if (rseq_register_current_thread()) {
1148 		fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
1149 			errno, strerror(errno));
1150 		abort();
1151 	}
1152 
1153 	/* Wait for initialization. */
1154 	while (!atomic_load(&args->percpu_list_ptr)) {}
1155 
1156 	for (i = 0; i < iters; ++i) {
1157 		int ret;
1158 
1159 		do {
1160 			int cpu = rseq_cpu_start();
1161 
1162 			ret = rseq_offset_deref_addv(&args->percpu_list_ptr,
1163 				sizeof(struct percpu_list_entry) * cpu, 1, cpu);
1164 		} while (rseq_unlikely(ret));
1165 	}
1166 
1167 	if (rseq_unregister_current_thread()) {
1168 		fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
1169 			errno, strerror(errno));
1170 		abort();
1171 	}
1172 	return NULL;
1173 }
1174 
test_membarrier_init_percpu_list(struct percpu_list * list)1175 void test_membarrier_init_percpu_list(struct percpu_list *list)
1176 {
1177 	int i;
1178 
1179 	memset(list, 0, sizeof(*list));
1180 	for (i = 0; i < CPU_SETSIZE; i++) {
1181 		struct percpu_list_node *node;
1182 
1183 		node = malloc(sizeof(*node));
1184 		assert(node);
1185 		node->data = 0;
1186 		node->next = NULL;
1187 		list->c[i].head = node;
1188 	}
1189 }
1190 
test_membarrier_free_percpu_list(struct percpu_list * list)1191 void test_membarrier_free_percpu_list(struct percpu_list *list)
1192 {
1193 	int i;
1194 
1195 	for (i = 0; i < CPU_SETSIZE; i++)
1196 		free(list->c[i].head);
1197 }
1198 
sys_membarrier(int cmd,int flags,int cpu_id)1199 static int sys_membarrier(int cmd, int flags, int cpu_id)
1200 {
1201 	return syscall(__NR_membarrier, cmd, flags, cpu_id);
1202 }
1203 
1204 /*
1205  * The manager thread swaps per-cpu lists that worker threads see,
1206  * and validates that there are no unexpected modifications.
1207  */
test_membarrier_manager_thread(void * arg)1208 void *test_membarrier_manager_thread(void *arg)
1209 {
1210 	struct test_membarrier_thread_args *args =
1211 		(struct test_membarrier_thread_args *)arg;
1212 	struct percpu_list list_a, list_b;
1213 	intptr_t expect_a = 0, expect_b = 0;
1214 	int cpu_a = 0, cpu_b = 0;
1215 
1216 	if (rseq_register_current_thread()) {
1217 		fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
1218 			errno, strerror(errno));
1219 		abort();
1220 	}
1221 
1222 	/* Init lists. */
1223 	test_membarrier_init_percpu_list(&list_a);
1224 	test_membarrier_init_percpu_list(&list_b);
1225 
1226 	atomic_store(&args->percpu_list_ptr, (intptr_t)&list_a);
1227 
1228 	while (!atomic_load(&args->stop)) {
1229 		/* list_a is "active". */
1230 		cpu_a = rand() % CPU_SETSIZE;
1231 		/*
1232 		 * As list_b is "inactive", we should never see changes
1233 		 * to list_b.
1234 		 */
1235 		if (expect_b != atomic_load(&list_b.c[cpu_b].head->data)) {
1236 			fprintf(stderr, "Membarrier test failed\n");
1237 			abort();
1238 		}
1239 
1240 		/* Make list_b "active". */
1241 		atomic_store(&args->percpu_list_ptr, (intptr_t)&list_b);
1242 		if (sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ,
1243 					MEMBARRIER_CMD_FLAG_CPU, cpu_a) &&
1244 				errno != ENXIO /* missing CPU */) {
1245 			perror("sys_membarrier");
1246 			abort();
1247 		}
1248 		/*
1249 		 * Cpu A should now only modify list_b, so the values
1250 		 * in list_a should be stable.
1251 		 */
1252 		expect_a = atomic_load(&list_a.c[cpu_a].head->data);
1253 
1254 		cpu_b = rand() % CPU_SETSIZE;
1255 		/*
1256 		 * As list_a is "inactive", we should never see changes
1257 		 * to list_a.
1258 		 */
1259 		if (expect_a != atomic_load(&list_a.c[cpu_a].head->data)) {
1260 			fprintf(stderr, "Membarrier test failed\n");
1261 			abort();
1262 		}
1263 
1264 		/* Make list_a "active". */
1265 		atomic_store(&args->percpu_list_ptr, (intptr_t)&list_a);
1266 		if (sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ,
1267 					MEMBARRIER_CMD_FLAG_CPU, cpu_b) &&
1268 				errno != ENXIO /* missing CPU*/) {
1269 			perror("sys_membarrier");
1270 			abort();
1271 		}
1272 		/* Remember a value from list_b. */
1273 		expect_b = atomic_load(&list_b.c[cpu_b].head->data);
1274 	}
1275 
1276 	test_membarrier_free_percpu_list(&list_a);
1277 	test_membarrier_free_percpu_list(&list_b);
1278 
1279 	if (rseq_unregister_current_thread()) {
1280 		fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
1281 			errno, strerror(errno));
1282 		abort();
1283 	}
1284 	return NULL;
1285 }
1286 
1287 /* Test MEMBARRIER_CMD_PRIVATE_RESTART_RSEQ_ON_CPU membarrier command. */
1288 #ifdef RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV
test_membarrier(void)1289 void test_membarrier(void)
1290 {
1291 	const int num_threads = opt_threads;
1292 	struct test_membarrier_thread_args thread_args;
1293 	pthread_t worker_threads[num_threads];
1294 	pthread_t manager_thread;
1295 	int i, ret;
1296 
1297 	if (sys_membarrier(MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ, 0, 0)) {
1298 		perror("sys_membarrier");
1299 		abort();
1300 	}
1301 
1302 	thread_args.stop = 0;
1303 	thread_args.percpu_list_ptr = 0;
1304 	ret = pthread_create(&manager_thread, NULL,
1305 			test_membarrier_manager_thread, &thread_args);
1306 	if (ret) {
1307 		errno = ret;
1308 		perror("pthread_create");
1309 		abort();
1310 	}
1311 
1312 	for (i = 0; i < num_threads; i++) {
1313 		ret = pthread_create(&worker_threads[i], NULL,
1314 				test_membarrier_worker_thread, &thread_args);
1315 		if (ret) {
1316 			errno = ret;
1317 			perror("pthread_create");
1318 			abort();
1319 		}
1320 	}
1321 
1322 
1323 	for (i = 0; i < num_threads; i++) {
1324 		ret = pthread_join(worker_threads[i], NULL);
1325 		if (ret) {
1326 			errno = ret;
1327 			perror("pthread_join");
1328 			abort();
1329 		}
1330 	}
1331 
1332 	atomic_store(&thread_args.stop, 1);
1333 	ret = pthread_join(manager_thread, NULL);
1334 	if (ret) {
1335 		errno = ret;
1336 		perror("pthread_join");
1337 		abort();
1338 	}
1339 }
1340 #else /* RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV */
test_membarrier(void)1341 void test_membarrier(void)
1342 {
1343 	fprintf(stderr, "rseq_offset_deref_addv is not implemented on this architecture. "
1344 			"Skipping membarrier test.\n");
1345 }
1346 #endif
1347 
show_usage(int argc,char ** argv)1348 static void show_usage(int argc, char **argv)
1349 {
1350 	printf("Usage : %s <OPTIONS>\n",
1351 		argv[0]);
1352 	printf("OPTIONS:\n");
1353 	printf("	[-1 loops] Number of loops for delay injection 1\n");
1354 	printf("	[-2 loops] Number of loops for delay injection 2\n");
1355 	printf("	[-3 loops] Number of loops for delay injection 3\n");
1356 	printf("	[-4 loops] Number of loops for delay injection 4\n");
1357 	printf("	[-5 loops] Number of loops for delay injection 5\n");
1358 	printf("	[-6 loops] Number of loops for delay injection 6\n");
1359 	printf("	[-7 loops] Number of loops for delay injection 7 (-1 to enable -m)\n");
1360 	printf("	[-8 loops] Number of loops for delay injection 8 (-1 to enable -m)\n");
1361 	printf("	[-9 loops] Number of loops for delay injection 9 (-1 to enable -m)\n");
1362 	printf("	[-m N] Yield/sleep/kill every modulo N (default 0: disabled) (>= 0)\n");
1363 	printf("	[-y] Yield\n");
1364 	printf("	[-k] Kill thread with signal\n");
1365 	printf("	[-s S] S: =0: disabled (default), >0: sleep time (ms)\n");
1366 	printf("	[-t N] Number of threads (default 200)\n");
1367 	printf("	[-r N] Number of repetitions per thread (default 5000)\n");
1368 	printf("	[-d] Disable rseq system call (no initialization)\n");
1369 	printf("	[-D M] Disable rseq for each M threads\n");
1370 	printf("	[-T test] Choose test: (s)pinlock, (l)ist, (b)uffer, (m)emcpy, (i)ncrement, membarrie(r)\n");
1371 	printf("	[-M] Push into buffer and memcpy buffer with memory barriers.\n");
1372 	printf("	[-v] Verbose output.\n");
1373 	printf("	[-h] Show this help.\n");
1374 	printf("\n");
1375 }
1376 
main(int argc,char ** argv)1377 int main(int argc, char **argv)
1378 {
1379 	int i;
1380 
1381 	for (i = 1; i < argc; i++) {
1382 		if (argv[i][0] != '-')
1383 			continue;
1384 		switch (argv[i][1]) {
1385 		case '1':
1386 		case '2':
1387 		case '3':
1388 		case '4':
1389 		case '5':
1390 		case '6':
1391 		case '7':
1392 		case '8':
1393 		case '9':
1394 			if (argc < i + 2) {
1395 				show_usage(argc, argv);
1396 				goto error;
1397 			}
1398 			loop_cnt[argv[i][1] - '0'] = atol(argv[i + 1]);
1399 			i++;
1400 			break;
1401 		case 'm':
1402 			if (argc < i + 2) {
1403 				show_usage(argc, argv);
1404 				goto error;
1405 			}
1406 			opt_modulo = atol(argv[i + 1]);
1407 			if (opt_modulo < 0) {
1408 				show_usage(argc, argv);
1409 				goto error;
1410 			}
1411 			i++;
1412 			break;
1413 		case 's':
1414 			if (argc < i + 2) {
1415 				show_usage(argc, argv);
1416 				goto error;
1417 			}
1418 			opt_sleep = atol(argv[i + 1]);
1419 			if (opt_sleep < 0) {
1420 				show_usage(argc, argv);
1421 				goto error;
1422 			}
1423 			i++;
1424 			break;
1425 		case 'y':
1426 			opt_yield = 1;
1427 			break;
1428 		case 'k':
1429 			opt_signal = 1;
1430 			break;
1431 		case 'd':
1432 			opt_disable_rseq = 1;
1433 			break;
1434 		case 'D':
1435 			if (argc < i + 2) {
1436 				show_usage(argc, argv);
1437 				goto error;
1438 			}
1439 			opt_disable_mod = atol(argv[i + 1]);
1440 			if (opt_disable_mod < 0) {
1441 				show_usage(argc, argv);
1442 				goto error;
1443 			}
1444 			i++;
1445 			break;
1446 		case 't':
1447 			if (argc < i + 2) {
1448 				show_usage(argc, argv);
1449 				goto error;
1450 			}
1451 			opt_threads = atol(argv[i + 1]);
1452 			if (opt_threads < 0) {
1453 				show_usage(argc, argv);
1454 				goto error;
1455 			}
1456 			i++;
1457 			break;
1458 		case 'r':
1459 			if (argc < i + 2) {
1460 				show_usage(argc, argv);
1461 				goto error;
1462 			}
1463 			opt_reps = atoll(argv[i + 1]);
1464 			if (opt_reps < 0) {
1465 				show_usage(argc, argv);
1466 				goto error;
1467 			}
1468 			i++;
1469 			break;
1470 		case 'h':
1471 			show_usage(argc, argv);
1472 			goto end;
1473 		case 'T':
1474 			if (argc < i + 2) {
1475 				show_usage(argc, argv);
1476 				goto error;
1477 			}
1478 			opt_test = *argv[i + 1];
1479 			switch (opt_test) {
1480 			case 's':
1481 			case 'l':
1482 			case 'i':
1483 			case 'b':
1484 			case 'm':
1485 			case 'r':
1486 				break;
1487 			default:
1488 				show_usage(argc, argv);
1489 				goto error;
1490 			}
1491 			i++;
1492 			break;
1493 		case 'v':
1494 			verbose = 1;
1495 			break;
1496 		case 'M':
1497 			opt_mb = 1;
1498 			break;
1499 		default:
1500 			show_usage(argc, argv);
1501 			goto error;
1502 		}
1503 	}
1504 
1505 	loop_cnt_1 = loop_cnt[1];
1506 	loop_cnt_2 = loop_cnt[2];
1507 	loop_cnt_3 = loop_cnt[3];
1508 	loop_cnt_4 = loop_cnt[4];
1509 	loop_cnt_5 = loop_cnt[5];
1510 	loop_cnt_6 = loop_cnt[6];
1511 
1512 	if (set_signal_handler())
1513 		goto error;
1514 
1515 	if (!opt_disable_rseq && rseq_register_current_thread())
1516 		goto error;
1517 	switch (opt_test) {
1518 	case 's':
1519 		printf_verbose("spinlock\n");
1520 		test_percpu_spinlock();
1521 		break;
1522 	case 'l':
1523 		printf_verbose("linked list\n");
1524 		test_percpu_list();
1525 		break;
1526 	case 'b':
1527 		printf_verbose("buffer\n");
1528 		test_percpu_buffer();
1529 		break;
1530 	case 'm':
1531 		printf_verbose("memcpy buffer\n");
1532 		test_percpu_memcpy_buffer();
1533 		break;
1534 	case 'i':
1535 		printf_verbose("counter increment\n");
1536 		test_percpu_inc();
1537 		break;
1538 	case 'r':
1539 		printf_verbose("membarrier\n");
1540 		test_membarrier();
1541 		break;
1542 	}
1543 	if (!opt_disable_rseq && rseq_unregister_current_thread())
1544 		abort();
1545 end:
1546 	return 0;
1547 
1548 error:
1549 	return -1;
1550 }
1551