xref: /linux/lib/kunit_iov_iter.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* I/O iterator tests.  This can only test kernel-backed iterator types.
3  *
4  * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/module.h>
11 #include <linux/vmalloc.h>
12 #include <linux/mm.h>
13 #include <linux/uio.h>
14 #include <linux/bvec.h>
15 #include <linux/folio_queue.h>
16 #include <kunit/test.h>
17 
18 MODULE_DESCRIPTION("iov_iter testing");
19 MODULE_AUTHOR("David Howells <dhowells@redhat.com>");
20 MODULE_LICENSE("GPL");
21 
22 struct kvec_test_range {
23 	int	from, to;
24 };
25 
26 static const struct kvec_test_range kvec_test_ranges[] = {
27 	{ 0x00002, 0x00002 },
28 	{ 0x00027, 0x03000 },
29 	{ 0x05193, 0x18794 },
30 	{ 0x20000, 0x20000 },
31 	{ 0x20000, 0x24000 },
32 	{ 0x24000, 0x27001 },
33 	{ 0x29000, 0xffffb },
34 	{ 0xffffd, 0xffffe },
35 	{ -1 }
36 };
37 
38 static inline u8 pattern(unsigned long x)
39 {
40 	return x & 0xff;
41 }
42 
43 static void iov_kunit_unmap(void *data)
44 {
45 	vunmap(data);
46 }
47 
48 static void *__init iov_kunit_create_buffer(struct kunit *test,
49 					    struct page ***ppages,
50 					    size_t npages)
51 {
52 	struct page **pages;
53 	unsigned long got;
54 	void *buffer;
55 
56 	pages = kunit_kcalloc(test, npages, sizeof(struct page *), GFP_KERNEL);
57         KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pages);
58 	*ppages = pages;
59 
60 	got = alloc_pages_bulk_array(GFP_KERNEL, npages, pages);
61 	if (got != npages) {
62 		release_pages(pages, got);
63 		KUNIT_ASSERT_EQ(test, got, npages);
64 	}
65 
66 	for (int i = 0; i < npages; i++)
67 		pages[i]->index = i;
68 
69 	buffer = vmap(pages, npages, VM_MAP | VM_MAP_PUT_PAGES, PAGE_KERNEL);
70         KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buffer);
71 
72 	kunit_add_action_or_reset(test, iov_kunit_unmap, buffer);
73 	return buffer;
74 }
75 
76 static void __init iov_kunit_load_kvec(struct kunit *test,
77 				       struct iov_iter *iter, int dir,
78 				       struct kvec *kvec, unsigned int kvmax,
79 				       void *buffer, size_t bufsize,
80 				       const struct kvec_test_range *pr)
81 {
82 	size_t size = 0;
83 	int i;
84 
85 	for (i = 0; i < kvmax; i++, pr++) {
86 		if (pr->from < 0)
87 			break;
88 		KUNIT_ASSERT_GE(test, pr->to, pr->from);
89 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
90 		kvec[i].iov_base = buffer + pr->from;
91 		kvec[i].iov_len = pr->to - pr->from;
92 		size += pr->to - pr->from;
93 	}
94 	KUNIT_ASSERT_LE(test, size, bufsize);
95 
96 	iov_iter_kvec(iter, dir, kvec, i, size);
97 }
98 
99 /*
100  * Test copying to a ITER_KVEC-type iterator.
101  */
102 static void __init iov_kunit_copy_to_kvec(struct kunit *test)
103 {
104 	const struct kvec_test_range *pr;
105 	struct iov_iter iter;
106 	struct page **spages, **bpages;
107 	struct kvec kvec[8];
108 	u8 *scratch, *buffer;
109 	size_t bufsize, npages, size, copied;
110 	int i, patt;
111 
112 	bufsize = 0x100000;
113 	npages = bufsize / PAGE_SIZE;
114 
115 	scratch = iov_kunit_create_buffer(test, &spages, npages);
116 	for (i = 0; i < bufsize; i++)
117 		scratch[i] = pattern(i);
118 
119 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
120 	memset(buffer, 0, bufsize);
121 
122 	iov_kunit_load_kvec(test, &iter, READ, kvec, ARRAY_SIZE(kvec),
123 			    buffer, bufsize, kvec_test_ranges);
124 	size = iter.count;
125 
126 	copied = copy_to_iter(scratch, size, &iter);
127 
128 	KUNIT_EXPECT_EQ(test, copied, size);
129 	KUNIT_EXPECT_EQ(test, iter.count, 0);
130 	KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
131 
132 	/* Build the expected image in the scratch buffer. */
133 	patt = 0;
134 	memset(scratch, 0, bufsize);
135 	for (pr = kvec_test_ranges; pr->from >= 0; pr++)
136 		for (i = pr->from; i < pr->to; i++)
137 			scratch[i] = pattern(patt++);
138 
139 	/* Compare the images */
140 	for (i = 0; i < bufsize; i++) {
141 		KUNIT_EXPECT_EQ_MSG(test, buffer[i], scratch[i], "at i=%x", i);
142 		if (buffer[i] != scratch[i])
143 			return;
144 	}
145 
146 	KUNIT_SUCCEED(test);
147 }
148 
149 /*
150  * Test copying from a ITER_KVEC-type iterator.
151  */
152 static void __init iov_kunit_copy_from_kvec(struct kunit *test)
153 {
154 	const struct kvec_test_range *pr;
155 	struct iov_iter iter;
156 	struct page **spages, **bpages;
157 	struct kvec kvec[8];
158 	u8 *scratch, *buffer;
159 	size_t bufsize, npages, size, copied;
160 	int i, j;
161 
162 	bufsize = 0x100000;
163 	npages = bufsize / PAGE_SIZE;
164 
165 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
166 	for (i = 0; i < bufsize; i++)
167 		buffer[i] = pattern(i);
168 
169 	scratch = iov_kunit_create_buffer(test, &spages, npages);
170 	memset(scratch, 0, bufsize);
171 
172 	iov_kunit_load_kvec(test, &iter, WRITE, kvec, ARRAY_SIZE(kvec),
173 			    buffer, bufsize, kvec_test_ranges);
174 	size = min(iter.count, bufsize);
175 
176 	copied = copy_from_iter(scratch, size, &iter);
177 
178 	KUNIT_EXPECT_EQ(test, copied, size);
179 	KUNIT_EXPECT_EQ(test, iter.count, 0);
180 	KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
181 
182 	/* Build the expected image in the main buffer. */
183 	i = 0;
184 	memset(buffer, 0, bufsize);
185 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
186 		for (j = pr->from; j < pr->to; j++) {
187 			buffer[i++] = pattern(j);
188 			if (i >= bufsize)
189 				goto stop;
190 		}
191 	}
192 stop:
193 
194 	/* Compare the images */
195 	for (i = 0; i < bufsize; i++) {
196 		KUNIT_EXPECT_EQ_MSG(test, scratch[i], buffer[i], "at i=%x", i);
197 		if (scratch[i] != buffer[i])
198 			return;
199 	}
200 
201 	KUNIT_SUCCEED(test);
202 }
203 
204 struct bvec_test_range {
205 	int	page, from, to;
206 };
207 
208 static const struct bvec_test_range bvec_test_ranges[] = {
209 	{ 0, 0x0002, 0x0002 },
210 	{ 1, 0x0027, 0x0893 },
211 	{ 2, 0x0193, 0x0794 },
212 	{ 3, 0x0000, 0x1000 },
213 	{ 4, 0x0000, 0x1000 },
214 	{ 5, 0x0000, 0x1000 },
215 	{ 6, 0x0000, 0x0ffb },
216 	{ 6, 0x0ffd, 0x0ffe },
217 	{ -1, -1, -1 }
218 };
219 
220 static void __init iov_kunit_load_bvec(struct kunit *test,
221 				       struct iov_iter *iter, int dir,
222 				       struct bio_vec *bvec, unsigned int bvmax,
223 				       struct page **pages, size_t npages,
224 				       size_t bufsize,
225 				       const struct bvec_test_range *pr)
226 {
227 	struct page *can_merge = NULL, *page;
228 	size_t size = 0;
229 	int i;
230 
231 	for (i = 0; i < bvmax; i++, pr++) {
232 		if (pr->from < 0)
233 			break;
234 		KUNIT_ASSERT_LT(test, pr->page, npages);
235 		KUNIT_ASSERT_LT(test, pr->page * PAGE_SIZE, bufsize);
236 		KUNIT_ASSERT_GE(test, pr->from, 0);
237 		KUNIT_ASSERT_GE(test, pr->to, pr->from);
238 		KUNIT_ASSERT_LE(test, pr->to, PAGE_SIZE);
239 
240 		page = pages[pr->page];
241 		if (pr->from == 0 && pr->from != pr->to && page == can_merge) {
242 			i--;
243 			bvec[i].bv_len += pr->to;
244 		} else {
245 			bvec_set_page(&bvec[i], page, pr->to - pr->from, pr->from);
246 		}
247 
248 		size += pr->to - pr->from;
249 		if ((pr->to & ~PAGE_MASK) == 0)
250 			can_merge = page + pr->to / PAGE_SIZE;
251 		else
252 			can_merge = NULL;
253 	}
254 
255 	iov_iter_bvec(iter, dir, bvec, i, size);
256 }
257 
258 /*
259  * Test copying to a ITER_BVEC-type iterator.
260  */
261 static void __init iov_kunit_copy_to_bvec(struct kunit *test)
262 {
263 	const struct bvec_test_range *pr;
264 	struct iov_iter iter;
265 	struct bio_vec bvec[8];
266 	struct page **spages, **bpages;
267 	u8 *scratch, *buffer;
268 	size_t bufsize, npages, size, copied;
269 	int i, b, patt;
270 
271 	bufsize = 0x100000;
272 	npages = bufsize / PAGE_SIZE;
273 
274 	scratch = iov_kunit_create_buffer(test, &spages, npages);
275 	for (i = 0; i < bufsize; i++)
276 		scratch[i] = pattern(i);
277 
278 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
279 	memset(buffer, 0, bufsize);
280 
281 	iov_kunit_load_bvec(test, &iter, READ, bvec, ARRAY_SIZE(bvec),
282 			    bpages, npages, bufsize, bvec_test_ranges);
283 	size = iter.count;
284 
285 	copied = copy_to_iter(scratch, size, &iter);
286 
287 	KUNIT_EXPECT_EQ(test, copied, size);
288 	KUNIT_EXPECT_EQ(test, iter.count, 0);
289 	KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
290 
291 	/* Build the expected image in the scratch buffer. */
292 	b = 0;
293 	patt = 0;
294 	memset(scratch, 0, bufsize);
295 	for (pr = bvec_test_ranges; pr->from >= 0; pr++, b++) {
296 		u8 *p = scratch + pr->page * PAGE_SIZE;
297 
298 		for (i = pr->from; i < pr->to; i++)
299 			p[i] = pattern(patt++);
300 	}
301 
302 	/* Compare the images */
303 	for (i = 0; i < bufsize; i++) {
304 		KUNIT_EXPECT_EQ_MSG(test, buffer[i], scratch[i], "at i=%x", i);
305 		if (buffer[i] != scratch[i])
306 			return;
307 	}
308 
309 	KUNIT_SUCCEED(test);
310 }
311 
312 /*
313  * Test copying from a ITER_BVEC-type iterator.
314  */
315 static void __init iov_kunit_copy_from_bvec(struct kunit *test)
316 {
317 	const struct bvec_test_range *pr;
318 	struct iov_iter iter;
319 	struct bio_vec bvec[8];
320 	struct page **spages, **bpages;
321 	u8 *scratch, *buffer;
322 	size_t bufsize, npages, size, copied;
323 	int i, j;
324 
325 	bufsize = 0x100000;
326 	npages = bufsize / PAGE_SIZE;
327 
328 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
329 	for (i = 0; i < bufsize; i++)
330 		buffer[i] = pattern(i);
331 
332 	scratch = iov_kunit_create_buffer(test, &spages, npages);
333 	memset(scratch, 0, bufsize);
334 
335 	iov_kunit_load_bvec(test, &iter, WRITE, bvec, ARRAY_SIZE(bvec),
336 			    bpages, npages, bufsize, bvec_test_ranges);
337 	size = iter.count;
338 
339 	copied = copy_from_iter(scratch, size, &iter);
340 
341 	KUNIT_EXPECT_EQ(test, copied, size);
342 	KUNIT_EXPECT_EQ(test, iter.count, 0);
343 	KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
344 
345 	/* Build the expected image in the main buffer. */
346 	i = 0;
347 	memset(buffer, 0, bufsize);
348 	for (pr = bvec_test_ranges; pr->from >= 0; pr++) {
349 		size_t patt = pr->page * PAGE_SIZE;
350 
351 		for (j = pr->from; j < pr->to; j++) {
352 			buffer[i++] = pattern(patt + j);
353 			if (i >= bufsize)
354 				goto stop;
355 		}
356 	}
357 stop:
358 
359 	/* Compare the images */
360 	for (i = 0; i < bufsize; i++) {
361 		KUNIT_EXPECT_EQ_MSG(test, scratch[i], buffer[i], "at i=%x", i);
362 		if (scratch[i] != buffer[i])
363 			return;
364 	}
365 
366 	KUNIT_SUCCEED(test);
367 }
368 
369 static void iov_kunit_destroy_folioq(void *data)
370 {
371 	struct folio_queue *folioq, *next;
372 
373 	for (folioq = data; folioq; folioq = next) {
374 		next = folioq->next;
375 		for (int i = 0; i < folioq_nr_slots(folioq); i++)
376 			if (folioq_folio(folioq, i))
377 				folio_put(folioq_folio(folioq, i));
378 		kfree(folioq);
379 	}
380 }
381 
382 static void __init iov_kunit_load_folioq(struct kunit *test,
383 					struct iov_iter *iter, int dir,
384 					struct folio_queue *folioq,
385 					struct page **pages, size_t npages)
386 {
387 	struct folio_queue *p = folioq;
388 	size_t size = 0;
389 	int i;
390 
391 	for (i = 0; i < npages; i++) {
392 		if (folioq_full(p)) {
393 			p->next = kzalloc(sizeof(struct folio_queue), GFP_KERNEL);
394 			KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p->next);
395 			folioq_init(p->next);
396 			p->next->prev = p;
397 			p = p->next;
398 		}
399 		folioq_append(p, page_folio(pages[i]));
400 		size += PAGE_SIZE;
401 	}
402 	iov_iter_folio_queue(iter, dir, folioq, 0, 0, size);
403 }
404 
405 static struct folio_queue *iov_kunit_create_folioq(struct kunit *test)
406 {
407 	struct folio_queue *folioq;
408 
409 	folioq = kzalloc(sizeof(struct folio_queue), GFP_KERNEL);
410 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, folioq);
411 	kunit_add_action_or_reset(test, iov_kunit_destroy_folioq, folioq);
412 	folioq_init(folioq);
413 	return folioq;
414 }
415 
416 /*
417  * Test copying to a ITER_FOLIOQ-type iterator.
418  */
419 static void __init iov_kunit_copy_to_folioq(struct kunit *test)
420 {
421 	const struct kvec_test_range *pr;
422 	struct iov_iter iter;
423 	struct folio_queue *folioq;
424 	struct page **spages, **bpages;
425 	u8 *scratch, *buffer;
426 	size_t bufsize, npages, size, copied;
427 	int i, patt;
428 
429 	bufsize = 0x100000;
430 	npages = bufsize / PAGE_SIZE;
431 
432 	folioq = iov_kunit_create_folioq(test);
433 
434 	scratch = iov_kunit_create_buffer(test, &spages, npages);
435 	for (i = 0; i < bufsize; i++)
436 		scratch[i] = pattern(i);
437 
438 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
439 	memset(buffer, 0, bufsize);
440 
441 	iov_kunit_load_folioq(test, &iter, READ, folioq, bpages, npages);
442 
443 	i = 0;
444 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
445 		size = pr->to - pr->from;
446 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
447 
448 		iov_iter_folio_queue(&iter, READ, folioq, 0, 0, pr->to);
449 		iov_iter_advance(&iter, pr->from);
450 		copied = copy_to_iter(scratch + i, size, &iter);
451 
452 		KUNIT_EXPECT_EQ(test, copied, size);
453 		KUNIT_EXPECT_EQ(test, iter.count, 0);
454 		KUNIT_EXPECT_EQ(test, iter.iov_offset, pr->to % PAGE_SIZE);
455 		i += size;
456 		if (test->status == KUNIT_FAILURE)
457 			goto stop;
458 	}
459 
460 	/* Build the expected image in the scratch buffer. */
461 	patt = 0;
462 	memset(scratch, 0, bufsize);
463 	for (pr = kvec_test_ranges; pr->from >= 0; pr++)
464 		for (i = pr->from; i < pr->to; i++)
465 			scratch[i] = pattern(patt++);
466 
467 	/* Compare the images */
468 	for (i = 0; i < bufsize; i++) {
469 		KUNIT_EXPECT_EQ_MSG(test, buffer[i], scratch[i], "at i=%x", i);
470 		if (buffer[i] != scratch[i])
471 			return;
472 	}
473 
474 stop:
475 	KUNIT_SUCCEED(test);
476 }
477 
478 /*
479  * Test copying from a ITER_FOLIOQ-type iterator.
480  */
481 static void __init iov_kunit_copy_from_folioq(struct kunit *test)
482 {
483 	const struct kvec_test_range *pr;
484 	struct iov_iter iter;
485 	struct folio_queue *folioq;
486 	struct page **spages, **bpages;
487 	u8 *scratch, *buffer;
488 	size_t bufsize, npages, size, copied;
489 	int i, j;
490 
491 	bufsize = 0x100000;
492 	npages = bufsize / PAGE_SIZE;
493 
494 	folioq = iov_kunit_create_folioq(test);
495 
496 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
497 	for (i = 0; i < bufsize; i++)
498 		buffer[i] = pattern(i);
499 
500 	scratch = iov_kunit_create_buffer(test, &spages, npages);
501 	memset(scratch, 0, bufsize);
502 
503 	iov_kunit_load_folioq(test, &iter, READ, folioq, bpages, npages);
504 
505 	i = 0;
506 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
507 		size = pr->to - pr->from;
508 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
509 
510 		iov_iter_folio_queue(&iter, WRITE, folioq, 0, 0, pr->to);
511 		iov_iter_advance(&iter, pr->from);
512 		copied = copy_from_iter(scratch + i, size, &iter);
513 
514 		KUNIT_EXPECT_EQ(test, copied, size);
515 		KUNIT_EXPECT_EQ(test, iter.count, 0);
516 		KUNIT_EXPECT_EQ(test, iter.iov_offset, pr->to % PAGE_SIZE);
517 		i += size;
518 	}
519 
520 	/* Build the expected image in the main buffer. */
521 	i = 0;
522 	memset(buffer, 0, bufsize);
523 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
524 		for (j = pr->from; j < pr->to; j++) {
525 			buffer[i++] = pattern(j);
526 			if (i >= bufsize)
527 				goto stop;
528 		}
529 	}
530 stop:
531 
532 	/* Compare the images */
533 	for (i = 0; i < bufsize; i++) {
534 		KUNIT_EXPECT_EQ_MSG(test, scratch[i], buffer[i], "at i=%x", i);
535 		if (scratch[i] != buffer[i])
536 			return;
537 	}
538 
539 	KUNIT_SUCCEED(test);
540 }
541 
542 static void iov_kunit_destroy_xarray(void *data)
543 {
544 	struct xarray *xarray = data;
545 
546 	xa_destroy(xarray);
547 	kfree(xarray);
548 }
549 
550 static void __init iov_kunit_load_xarray(struct kunit *test,
551 					 struct iov_iter *iter, int dir,
552 					 struct xarray *xarray,
553 					 struct page **pages, size_t npages)
554 {
555 	size_t size = 0;
556 	int i;
557 
558 	for (i = 0; i < npages; i++) {
559 		void *x = xa_store(xarray, i, pages[i], GFP_KERNEL);
560 
561 		KUNIT_ASSERT_FALSE(test, xa_is_err(x));
562 		size += PAGE_SIZE;
563 	}
564 	iov_iter_xarray(iter, dir, xarray, 0, size);
565 }
566 
567 static struct xarray *iov_kunit_create_xarray(struct kunit *test)
568 {
569 	struct xarray *xarray;
570 
571 	xarray = kzalloc(sizeof(struct xarray), GFP_KERNEL);
572 	xa_init(xarray);
573 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xarray);
574 	kunit_add_action_or_reset(test, iov_kunit_destroy_xarray, xarray);
575 	return xarray;
576 }
577 
578 /*
579  * Test copying to a ITER_XARRAY-type iterator.
580  */
581 static void __init iov_kunit_copy_to_xarray(struct kunit *test)
582 {
583 	const struct kvec_test_range *pr;
584 	struct iov_iter iter;
585 	struct xarray *xarray;
586 	struct page **spages, **bpages;
587 	u8 *scratch, *buffer;
588 	size_t bufsize, npages, size, copied;
589 	int i, patt;
590 
591 	bufsize = 0x100000;
592 	npages = bufsize / PAGE_SIZE;
593 
594 	xarray = iov_kunit_create_xarray(test);
595 
596 	scratch = iov_kunit_create_buffer(test, &spages, npages);
597 	for (i = 0; i < bufsize; i++)
598 		scratch[i] = pattern(i);
599 
600 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
601 	memset(buffer, 0, bufsize);
602 
603 	iov_kunit_load_xarray(test, &iter, READ, xarray, bpages, npages);
604 
605 	i = 0;
606 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
607 		size = pr->to - pr->from;
608 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
609 
610 		iov_iter_xarray(&iter, READ, xarray, pr->from, size);
611 		copied = copy_to_iter(scratch + i, size, &iter);
612 
613 		KUNIT_EXPECT_EQ(test, copied, size);
614 		KUNIT_EXPECT_EQ(test, iter.count, 0);
615 		KUNIT_EXPECT_EQ(test, iter.iov_offset, size);
616 		i += size;
617 	}
618 
619 	/* Build the expected image in the scratch buffer. */
620 	patt = 0;
621 	memset(scratch, 0, bufsize);
622 	for (pr = kvec_test_ranges; pr->from >= 0; pr++)
623 		for (i = pr->from; i < pr->to; i++)
624 			scratch[i] = pattern(patt++);
625 
626 	/* Compare the images */
627 	for (i = 0; i < bufsize; i++) {
628 		KUNIT_EXPECT_EQ_MSG(test, buffer[i], scratch[i], "at i=%x", i);
629 		if (buffer[i] != scratch[i])
630 			return;
631 	}
632 
633 	KUNIT_SUCCEED(test);
634 }
635 
636 /*
637  * Test copying from a ITER_XARRAY-type iterator.
638  */
639 static void __init iov_kunit_copy_from_xarray(struct kunit *test)
640 {
641 	const struct kvec_test_range *pr;
642 	struct iov_iter iter;
643 	struct xarray *xarray;
644 	struct page **spages, **bpages;
645 	u8 *scratch, *buffer;
646 	size_t bufsize, npages, size, copied;
647 	int i, j;
648 
649 	bufsize = 0x100000;
650 	npages = bufsize / PAGE_SIZE;
651 
652 	xarray = iov_kunit_create_xarray(test);
653 
654 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
655 	for (i = 0; i < bufsize; i++)
656 		buffer[i] = pattern(i);
657 
658 	scratch = iov_kunit_create_buffer(test, &spages, npages);
659 	memset(scratch, 0, bufsize);
660 
661 	iov_kunit_load_xarray(test, &iter, READ, xarray, bpages, npages);
662 
663 	i = 0;
664 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
665 		size = pr->to - pr->from;
666 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
667 
668 		iov_iter_xarray(&iter, WRITE, xarray, pr->from, size);
669 		copied = copy_from_iter(scratch + i, size, &iter);
670 
671 		KUNIT_EXPECT_EQ(test, copied, size);
672 		KUNIT_EXPECT_EQ(test, iter.count, 0);
673 		KUNIT_EXPECT_EQ(test, iter.iov_offset, size);
674 		i += size;
675 	}
676 
677 	/* Build the expected image in the main buffer. */
678 	i = 0;
679 	memset(buffer, 0, bufsize);
680 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
681 		for (j = pr->from; j < pr->to; j++) {
682 			buffer[i++] = pattern(j);
683 			if (i >= bufsize)
684 				goto stop;
685 		}
686 	}
687 stop:
688 
689 	/* Compare the images */
690 	for (i = 0; i < bufsize; i++) {
691 		KUNIT_EXPECT_EQ_MSG(test, scratch[i], buffer[i], "at i=%x", i);
692 		if (scratch[i] != buffer[i])
693 			return;
694 	}
695 
696 	KUNIT_SUCCEED(test);
697 }
698 
699 /*
700  * Test the extraction of ITER_KVEC-type iterators.
701  */
702 static void __init iov_kunit_extract_pages_kvec(struct kunit *test)
703 {
704 	const struct kvec_test_range *pr;
705 	struct iov_iter iter;
706 	struct page **bpages, *pagelist[8], **pages = pagelist;
707 	struct kvec kvec[8];
708 	u8 *buffer;
709 	ssize_t len;
710 	size_t bufsize, size = 0, npages;
711 	int i, from;
712 
713 	bufsize = 0x100000;
714 	npages = bufsize / PAGE_SIZE;
715 
716 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
717 
718 	iov_kunit_load_kvec(test, &iter, READ, kvec, ARRAY_SIZE(kvec),
719 			    buffer, bufsize, kvec_test_ranges);
720 	size = iter.count;
721 
722 	pr = kvec_test_ranges;
723 	from = pr->from;
724 	do {
725 		size_t offset0 = LONG_MAX;
726 
727 		for (i = 0; i < ARRAY_SIZE(pagelist); i++)
728 			pagelist[i] = (void *)(unsigned long)0xaa55aa55aa55aa55ULL;
729 
730 		len = iov_iter_extract_pages(&iter, &pages, 100 * 1024,
731 					     ARRAY_SIZE(pagelist), 0, &offset0);
732 		KUNIT_EXPECT_GE(test, len, 0);
733 		if (len < 0)
734 			break;
735 		KUNIT_EXPECT_GE(test, (ssize_t)offset0, 0);
736 		KUNIT_EXPECT_LT(test, offset0, PAGE_SIZE);
737 		KUNIT_EXPECT_LE(test, len, size);
738 		KUNIT_EXPECT_EQ(test, iter.count, size - len);
739 		size -= len;
740 
741 		if (len == 0)
742 			break;
743 
744 		for (i = 0; i < ARRAY_SIZE(pagelist); i++) {
745 			struct page *p;
746 			ssize_t part = min_t(ssize_t, len, PAGE_SIZE - offset0);
747 			int ix;
748 
749 			KUNIT_ASSERT_GE(test, part, 0);
750 			while (from == pr->to) {
751 				pr++;
752 				from = pr->from;
753 				if (from < 0)
754 					goto stop;
755 			}
756 			ix = from / PAGE_SIZE;
757 			KUNIT_ASSERT_LT(test, ix, npages);
758 			p = bpages[ix];
759 			KUNIT_EXPECT_PTR_EQ(test, pagelist[i], p);
760 			KUNIT_EXPECT_EQ(test, offset0, from % PAGE_SIZE);
761 			from += part;
762 			len -= part;
763 			KUNIT_ASSERT_GE(test, len, 0);
764 			if (len == 0)
765 				break;
766 			offset0 = 0;
767 		}
768 
769 		if (test->status == KUNIT_FAILURE)
770 			break;
771 	} while (iov_iter_count(&iter) > 0);
772 
773 stop:
774 	KUNIT_EXPECT_EQ(test, size, 0);
775 	KUNIT_EXPECT_EQ(test, iter.count, 0);
776 	KUNIT_SUCCEED(test);
777 }
778 
779 /*
780  * Test the extraction of ITER_BVEC-type iterators.
781  */
782 static void __init iov_kunit_extract_pages_bvec(struct kunit *test)
783 {
784 	const struct bvec_test_range *pr;
785 	struct iov_iter iter;
786 	struct page **bpages, *pagelist[8], **pages = pagelist;
787 	struct bio_vec bvec[8];
788 	ssize_t len;
789 	size_t bufsize, size = 0, npages;
790 	int i, from;
791 
792 	bufsize = 0x100000;
793 	npages = bufsize / PAGE_SIZE;
794 
795 	iov_kunit_create_buffer(test, &bpages, npages);
796 	iov_kunit_load_bvec(test, &iter, READ, bvec, ARRAY_SIZE(bvec),
797 			    bpages, npages, bufsize, bvec_test_ranges);
798 	size = iter.count;
799 
800 	pr = bvec_test_ranges;
801 	from = pr->from;
802 	do {
803 		size_t offset0 = LONG_MAX;
804 
805 		for (i = 0; i < ARRAY_SIZE(pagelist); i++)
806 			pagelist[i] = (void *)(unsigned long)0xaa55aa55aa55aa55ULL;
807 
808 		len = iov_iter_extract_pages(&iter, &pages, 100 * 1024,
809 					     ARRAY_SIZE(pagelist), 0, &offset0);
810 		KUNIT_EXPECT_GE(test, len, 0);
811 		if (len < 0)
812 			break;
813 		KUNIT_EXPECT_GE(test, (ssize_t)offset0, 0);
814 		KUNIT_EXPECT_LT(test, offset0, PAGE_SIZE);
815 		KUNIT_EXPECT_LE(test, len, size);
816 		KUNIT_EXPECT_EQ(test, iter.count, size - len);
817 		size -= len;
818 
819 		if (len == 0)
820 			break;
821 
822 		for (i = 0; i < ARRAY_SIZE(pagelist); i++) {
823 			struct page *p;
824 			ssize_t part = min_t(ssize_t, len, PAGE_SIZE - offset0);
825 			int ix;
826 
827 			KUNIT_ASSERT_GE(test, part, 0);
828 			while (from == pr->to) {
829 				pr++;
830 				from = pr->from;
831 				if (from < 0)
832 					goto stop;
833 			}
834 			ix = pr->page + from / PAGE_SIZE;
835 			KUNIT_ASSERT_LT(test, ix, npages);
836 			p = bpages[ix];
837 			KUNIT_EXPECT_PTR_EQ(test, pagelist[i], p);
838 			KUNIT_EXPECT_EQ(test, offset0, from % PAGE_SIZE);
839 			from += part;
840 			len -= part;
841 			KUNIT_ASSERT_GE(test, len, 0);
842 			if (len == 0)
843 				break;
844 			offset0 = 0;
845 		}
846 
847 		if (test->status == KUNIT_FAILURE)
848 			break;
849 	} while (iov_iter_count(&iter) > 0);
850 
851 stop:
852 	KUNIT_EXPECT_EQ(test, size, 0);
853 	KUNIT_EXPECT_EQ(test, iter.count, 0);
854 	KUNIT_SUCCEED(test);
855 }
856 
857 /*
858  * Test the extraction of ITER_FOLIOQ-type iterators.
859  */
860 static void __init iov_kunit_extract_pages_folioq(struct kunit *test)
861 {
862 	const struct kvec_test_range *pr;
863 	struct folio_queue *folioq;
864 	struct iov_iter iter;
865 	struct page **bpages, *pagelist[8], **pages = pagelist;
866 	ssize_t len;
867 	size_t bufsize, size = 0, npages;
868 	int i, from;
869 
870 	bufsize = 0x100000;
871 	npages = bufsize / PAGE_SIZE;
872 
873 	folioq = iov_kunit_create_folioq(test);
874 
875 	iov_kunit_create_buffer(test, &bpages, npages);
876 	iov_kunit_load_folioq(test, &iter, READ, folioq, bpages, npages);
877 
878 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
879 		from = pr->from;
880 		size = pr->to - from;
881 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
882 
883 		iov_iter_folio_queue(&iter, WRITE, folioq, 0, 0, pr->to);
884 		iov_iter_advance(&iter, from);
885 
886 		do {
887 			size_t offset0 = LONG_MAX;
888 
889 			for (i = 0; i < ARRAY_SIZE(pagelist); i++)
890 				pagelist[i] = (void *)(unsigned long)0xaa55aa55aa55aa55ULL;
891 
892 			len = iov_iter_extract_pages(&iter, &pages, 100 * 1024,
893 						     ARRAY_SIZE(pagelist), 0, &offset0);
894 			KUNIT_EXPECT_GE(test, len, 0);
895 			if (len < 0)
896 				break;
897 			KUNIT_EXPECT_LE(test, len, size);
898 			KUNIT_EXPECT_EQ(test, iter.count, size - len);
899 			if (len == 0)
900 				break;
901 			size -= len;
902 			KUNIT_EXPECT_GE(test, (ssize_t)offset0, 0);
903 			KUNIT_EXPECT_LT(test, offset0, PAGE_SIZE);
904 
905 			for (i = 0; i < ARRAY_SIZE(pagelist); i++) {
906 				struct page *p;
907 				ssize_t part = min_t(ssize_t, len, PAGE_SIZE - offset0);
908 				int ix;
909 
910 				KUNIT_ASSERT_GE(test, part, 0);
911 				ix = from / PAGE_SIZE;
912 				KUNIT_ASSERT_LT(test, ix, npages);
913 				p = bpages[ix];
914 				KUNIT_EXPECT_PTR_EQ(test, pagelist[i], p);
915 				KUNIT_EXPECT_EQ(test, offset0, from % PAGE_SIZE);
916 				from += part;
917 				len -= part;
918 				KUNIT_ASSERT_GE(test, len, 0);
919 				if (len == 0)
920 					break;
921 				offset0 = 0;
922 			}
923 
924 			if (test->status == KUNIT_FAILURE)
925 				goto stop;
926 		} while (iov_iter_count(&iter) > 0);
927 
928 		KUNIT_EXPECT_EQ(test, size, 0);
929 		KUNIT_EXPECT_EQ(test, iter.count, 0);
930 	}
931 
932 stop:
933 	KUNIT_SUCCEED(test);
934 }
935 
936 /*
937  * Test the extraction of ITER_XARRAY-type iterators.
938  */
939 static void __init iov_kunit_extract_pages_xarray(struct kunit *test)
940 {
941 	const struct kvec_test_range *pr;
942 	struct iov_iter iter;
943 	struct xarray *xarray;
944 	struct page **bpages, *pagelist[8], **pages = pagelist;
945 	ssize_t len;
946 	size_t bufsize, size = 0, npages;
947 	int i, from;
948 
949 	bufsize = 0x100000;
950 	npages = bufsize / PAGE_SIZE;
951 
952 	xarray = iov_kunit_create_xarray(test);
953 
954 	iov_kunit_create_buffer(test, &bpages, npages);
955 	iov_kunit_load_xarray(test, &iter, READ, xarray, bpages, npages);
956 
957 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
958 		from = pr->from;
959 		size = pr->to - from;
960 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
961 
962 		iov_iter_xarray(&iter, WRITE, xarray, from, size);
963 
964 		do {
965 			size_t offset0 = LONG_MAX;
966 
967 			for (i = 0; i < ARRAY_SIZE(pagelist); i++)
968 				pagelist[i] = (void *)(unsigned long)0xaa55aa55aa55aa55ULL;
969 
970 			len = iov_iter_extract_pages(&iter, &pages, 100 * 1024,
971 						     ARRAY_SIZE(pagelist), 0, &offset0);
972 			KUNIT_EXPECT_GE(test, len, 0);
973 			if (len < 0)
974 				break;
975 			KUNIT_EXPECT_LE(test, len, size);
976 			KUNIT_EXPECT_EQ(test, iter.count, size - len);
977 			if (len == 0)
978 				break;
979 			size -= len;
980 			KUNIT_EXPECT_GE(test, (ssize_t)offset0, 0);
981 			KUNIT_EXPECT_LT(test, offset0, PAGE_SIZE);
982 
983 			for (i = 0; i < ARRAY_SIZE(pagelist); i++) {
984 				struct page *p;
985 				ssize_t part = min_t(ssize_t, len, PAGE_SIZE - offset0);
986 				int ix;
987 
988 				KUNIT_ASSERT_GE(test, part, 0);
989 				ix = from / PAGE_SIZE;
990 				KUNIT_ASSERT_LT(test, ix, npages);
991 				p = bpages[ix];
992 				KUNIT_EXPECT_PTR_EQ(test, pagelist[i], p);
993 				KUNIT_EXPECT_EQ(test, offset0, from % PAGE_SIZE);
994 				from += part;
995 				len -= part;
996 				KUNIT_ASSERT_GE(test, len, 0);
997 				if (len == 0)
998 					break;
999 				offset0 = 0;
1000 			}
1001 
1002 			if (test->status == KUNIT_FAILURE)
1003 				goto stop;
1004 		} while (iov_iter_count(&iter) > 0);
1005 
1006 		KUNIT_EXPECT_EQ(test, size, 0);
1007 		KUNIT_EXPECT_EQ(test, iter.count, 0);
1008 		KUNIT_EXPECT_EQ(test, iter.iov_offset, pr->to - pr->from);
1009 	}
1010 
1011 stop:
1012 	KUNIT_SUCCEED(test);
1013 }
1014 
1015 static struct kunit_case __refdata iov_kunit_cases[] = {
1016 	KUNIT_CASE(iov_kunit_copy_to_kvec),
1017 	KUNIT_CASE(iov_kunit_copy_from_kvec),
1018 	KUNIT_CASE(iov_kunit_copy_to_bvec),
1019 	KUNIT_CASE(iov_kunit_copy_from_bvec),
1020 	KUNIT_CASE(iov_kunit_copy_to_folioq),
1021 	KUNIT_CASE(iov_kunit_copy_from_folioq),
1022 	KUNIT_CASE(iov_kunit_copy_to_xarray),
1023 	KUNIT_CASE(iov_kunit_copy_from_xarray),
1024 	KUNIT_CASE(iov_kunit_extract_pages_kvec),
1025 	KUNIT_CASE(iov_kunit_extract_pages_bvec),
1026 	KUNIT_CASE(iov_kunit_extract_pages_folioq),
1027 	KUNIT_CASE(iov_kunit_extract_pages_xarray),
1028 	{}
1029 };
1030 
1031 static struct kunit_suite iov_kunit_suite = {
1032 	.name = "iov_iter",
1033 	.test_cases = iov_kunit_cases,
1034 };
1035 
1036 kunit_test_suites(&iov_kunit_suite);
1037