xref: /linux/tools/testing/selftests/mm/mremap_test.c (revision 01a620d491592ead12eca039fe1c9e74908c35cf)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2020 Google LLC
4  */
5 #define _GNU_SOURCE
6 
7 #include <errno.h>
8 #include <stdlib.h>
9 #include <stdio.h>
10 #include <string.h>
11 #include <sys/mman.h>
12 #include <time.h>
13 #include <stdbool.h>
14 
15 #include "../kselftest.h"
16 
17 #define EXPECT_SUCCESS 0
18 #define EXPECT_FAILURE 1
19 #define NON_OVERLAPPING 0
20 #define OVERLAPPING 1
21 #define NS_PER_SEC 1000000000ULL
22 #define VALIDATION_DEFAULT_THRESHOLD 4	/* 4MB */
23 #define VALIDATION_NO_THRESHOLD 0	/* Verify the entire region */
24 
25 #ifndef MIN
26 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
27 #define MAX(X, Y) ((X) > (Y) ? (X) : (Y))
28 #endif
29 #define SIZE_MB(m) ((size_t)m * (1024 * 1024))
30 #define SIZE_KB(k) ((size_t)k * 1024)
31 
32 struct config {
33 	unsigned long long src_alignment;
34 	unsigned long long dest_alignment;
35 	unsigned long long region_size;
36 	int overlapping;
37 	int dest_preamble_size;
38 };
39 
40 struct test {
41 	const char *name;
42 	struct config config;
43 	int expect_failure;
44 };
45 
46 enum {
47 	_1KB = 1ULL << 10,	/* 1KB -> not page aligned */
48 	_4KB = 4ULL << 10,
49 	_8KB = 8ULL << 10,
50 	_1MB = 1ULL << 20,
51 	_2MB = 2ULL << 20,
52 	_4MB = 4ULL << 20,
53 	_5MB = 5ULL << 20,
54 	_1GB = 1ULL << 30,
55 	_2GB = 2ULL << 30,
56 	PMD = _2MB,
57 	PUD = _1GB,
58 };
59 
60 #define PTE page_size
61 
62 #define MAKE_TEST(source_align, destination_align, size,	\
63 		  overlaps, should_fail, test_name)		\
64 (struct test){							\
65 	.name = test_name,					\
66 	.config = {						\
67 		.src_alignment = source_align,			\
68 		.dest_alignment = destination_align,		\
69 		.region_size = size,				\
70 		.overlapping = overlaps,			\
71 	},							\
72 	.expect_failure = should_fail				\
73 }
74 
75 /* compute square root using binary search */
get_sqrt(unsigned long val)76 static unsigned long get_sqrt(unsigned long val)
77 {
78 	unsigned long low = 1;
79 
80 	/* assuming rand_size is less than 1TB */
81 	unsigned long high = (1UL << 20);
82 
83 	while (low <= high) {
84 		unsigned long mid = low + (high - low) / 2;
85 		unsigned long temp = mid * mid;
86 
87 		if (temp == val)
88 			return mid;
89 		if (temp < val)
90 			low = mid + 1;
91 		high = mid - 1;
92 	}
93 	return low;
94 }
95 
96 /*
97  * Returns false if the requested remap region overlaps with an
98  * existing mapping (e.g text, stack) else returns true.
99  */
is_remap_region_valid(void * addr,unsigned long long size)100 static bool is_remap_region_valid(void *addr, unsigned long long size)
101 {
102 	void *remap_addr = NULL;
103 	bool ret = true;
104 
105 	/* Use MAP_FIXED_NOREPLACE flag to ensure region is not mapped */
106 	remap_addr = mmap(addr, size, PROT_READ | PROT_WRITE,
107 					 MAP_FIXED_NOREPLACE | MAP_ANONYMOUS | MAP_SHARED,
108 					 -1, 0);
109 
110 	if (remap_addr == MAP_FAILED) {
111 		if (errno == EEXIST)
112 			ret = false;
113 	} else {
114 		munmap(remap_addr, size);
115 	}
116 
117 	return ret;
118 }
119 
120 /* Returns mmap_min_addr sysctl tunable from procfs */
get_mmap_min_addr(void)121 static unsigned long long get_mmap_min_addr(void)
122 {
123 	FILE *fp;
124 	int n_matched;
125 	static unsigned long long addr;
126 
127 	if (addr)
128 		return addr;
129 
130 	fp = fopen("/proc/sys/vm/mmap_min_addr", "r");
131 	if (fp == NULL) {
132 		ksft_print_msg("Failed to open /proc/sys/vm/mmap_min_addr: %s\n",
133 			strerror(errno));
134 		exit(KSFT_SKIP);
135 	}
136 
137 	n_matched = fscanf(fp, "%llu", &addr);
138 	if (n_matched != 1) {
139 		ksft_print_msg("Failed to read /proc/sys/vm/mmap_min_addr: %s\n",
140 			strerror(errno));
141 		fclose(fp);
142 		exit(KSFT_SKIP);
143 	}
144 
145 	fclose(fp);
146 	return addr;
147 }
148 
149 /*
150  * Using /proc/self/maps, assert that the specified address range is contained
151  * within a single mapping.
152  */
is_range_mapped(FILE * maps_fp,unsigned long start,unsigned long end)153 static bool is_range_mapped(FILE *maps_fp, unsigned long start,
154 			    unsigned long end)
155 {
156 	char *line = NULL;
157 	size_t len = 0;
158 	bool success = false;
159 	unsigned long first_val, second_val;
160 
161 	rewind(maps_fp);
162 
163 	while (getline(&line, &len, maps_fp) != -1) {
164 		if (sscanf(line, "%lx-%lx", &first_val, &second_val) != 2) {
165 			ksft_exit_fail_msg("cannot parse /proc/self/maps\n");
166 			break;
167 		}
168 
169 		if (first_val <= start && second_val >= end) {
170 			success = true;
171 			break;
172 		}
173 	}
174 
175 	return success;
176 }
177 
178 /*
179  * Returns the start address of the mapping on success, else returns
180  * NULL on failure.
181  */
get_source_mapping(struct config c)182 static void *get_source_mapping(struct config c)
183 {
184 	unsigned long long addr = 0ULL;
185 	void *src_addr = NULL;
186 	unsigned long long mmap_min_addr;
187 
188 	mmap_min_addr = get_mmap_min_addr();
189 	/*
190 	 * For some tests, we need to not have any mappings below the
191 	 * source mapping. Add some headroom to mmap_min_addr for this.
192 	 */
193 	mmap_min_addr += 10 * _4MB;
194 
195 retry:
196 	addr += c.src_alignment;
197 	if (addr < mmap_min_addr)
198 		goto retry;
199 
200 	src_addr = mmap((void *) addr, c.region_size, PROT_READ | PROT_WRITE,
201 					MAP_FIXED_NOREPLACE | MAP_ANONYMOUS | MAP_SHARED,
202 					-1, 0);
203 	if (src_addr == MAP_FAILED) {
204 		if (errno == EPERM || errno == EEXIST)
205 			goto retry;
206 		goto error;
207 	}
208 	/*
209 	 * Check that the address is aligned to the specified alignment.
210 	 * Addresses which have alignments that are multiples of that
211 	 * specified are not considered valid. For instance, 1GB address is
212 	 * 2MB-aligned, however it will not be considered valid for a
213 	 * requested alignment of 2MB. This is done to reduce coincidental
214 	 * alignment in the tests.
215 	 */
216 	if (((unsigned long long) src_addr & (c.src_alignment - 1)) ||
217 			!((unsigned long long) src_addr & c.src_alignment)) {
218 		munmap(src_addr, c.region_size);
219 		goto retry;
220 	}
221 
222 	if (!src_addr)
223 		goto error;
224 
225 	return src_addr;
226 error:
227 	ksft_print_msg("Failed to map source region: %s\n",
228 			strerror(errno));
229 	return NULL;
230 }
231 
232 /*
233  * This test validates that merge is called when expanding a mapping.
234  * Mapping containing three pages is created, middle page is unmapped
235  * and then the mapping containing the first page is expanded so that
236  * it fills the created hole. The two parts should merge creating
237  * single mapping with three pages.
238  */
mremap_expand_merge(FILE * maps_fp,unsigned long page_size)239 static void mremap_expand_merge(FILE *maps_fp, unsigned long page_size)
240 {
241 	char *test_name = "mremap expand merge";
242 	bool success = false;
243 	char *remap, *start;
244 
245 	start = mmap(NULL, 3 * page_size, PROT_READ | PROT_WRITE,
246 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
247 
248 	if (start == MAP_FAILED) {
249 		ksft_print_msg("mmap failed: %s\n", strerror(errno));
250 		goto out;
251 	}
252 
253 	munmap(start + page_size, page_size);
254 	remap = mremap(start, page_size, 2 * page_size, 0);
255 	if (remap == MAP_FAILED) {
256 		ksft_print_msg("mremap failed: %s\n", strerror(errno));
257 		munmap(start, page_size);
258 		munmap(start + 2 * page_size, page_size);
259 		goto out;
260 	}
261 
262 	success = is_range_mapped(maps_fp, (unsigned long)start,
263 				  (unsigned long)(start + 3 * page_size));
264 	munmap(start, 3 * page_size);
265 
266 out:
267 	if (success)
268 		ksft_test_result_pass("%s\n", test_name);
269 	else
270 		ksft_test_result_fail("%s\n", test_name);
271 }
272 
273 /*
274  * Similar to mremap_expand_merge() except instead of removing the middle page,
275  * we remove the last then attempt to remap offset from the second page. This
276  * should result in the mapping being restored to its former state.
277  */
mremap_expand_merge_offset(FILE * maps_fp,unsigned long page_size)278 static void mremap_expand_merge_offset(FILE *maps_fp, unsigned long page_size)
279 {
280 
281 	char *test_name = "mremap expand merge offset";
282 	bool success = false;
283 	char *remap, *start;
284 
285 	start = mmap(NULL, 3 * page_size, PROT_READ | PROT_WRITE,
286 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
287 
288 	if (start == MAP_FAILED) {
289 		ksft_print_msg("mmap failed: %s\n", strerror(errno));
290 		goto out;
291 	}
292 
293 	/* Unmap final page to ensure we have space to expand. */
294 	munmap(start + 2 * page_size, page_size);
295 	remap = mremap(start + page_size, page_size, 2 * page_size, 0);
296 	if (remap == MAP_FAILED) {
297 		ksft_print_msg("mremap failed: %s\n", strerror(errno));
298 		munmap(start, 2 * page_size);
299 		goto out;
300 	}
301 
302 	success = is_range_mapped(maps_fp, (unsigned long)start,
303 				  (unsigned long)(start + 3 * page_size));
304 	munmap(start, 3 * page_size);
305 
306 out:
307 	if (success)
308 		ksft_test_result_pass("%s\n", test_name);
309 	else
310 		ksft_test_result_fail("%s\n", test_name);
311 }
312 
313 /*
314  * Verify that an mremap within a range does not cause corruption
315  * of unrelated part of range.
316  *
317  * Consider the following range which is 2MB aligned and is
318  * a part of a larger 20MB range which is not shown. Each
319  * character is 256KB below making the source and destination
320  * 2MB each. The lower case letters are moved (s to d) and the
321  * upper case letters are not moved. The below test verifies
322  * that the upper case S letters are not corrupted by the
323  * adjacent mremap.
324  *
325  * |DDDDddddSSSSssss|
326  */
mremap_move_within_range(unsigned int pattern_seed,char * rand_addr)327 static void mremap_move_within_range(unsigned int pattern_seed, char *rand_addr)
328 {
329 	char *test_name = "mremap mremap move within range";
330 	void *src, *dest;
331 	int i, success = 1;
332 
333 	size_t size = SIZE_MB(20);
334 	void *ptr = mmap(NULL, size, PROT_READ | PROT_WRITE,
335 			 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
336 	if (ptr == MAP_FAILED) {
337 		perror("mmap");
338 		success = 0;
339 		goto out;
340 	}
341 	memset(ptr, 0, size);
342 
343 	src = ptr + SIZE_MB(6);
344 	src = (void *)((unsigned long)src & ~(SIZE_MB(2) - 1));
345 
346 	/* Set byte pattern for source block. */
347 	memcpy(src, rand_addr, SIZE_MB(2));
348 
349 	dest = src - SIZE_MB(2);
350 
351 	void *new_ptr = mremap(src + SIZE_MB(1), SIZE_MB(1), SIZE_MB(1),
352 						   MREMAP_MAYMOVE | MREMAP_FIXED, dest + SIZE_MB(1));
353 	if (new_ptr == MAP_FAILED) {
354 		perror("mremap");
355 		success = 0;
356 		goto out;
357 	}
358 
359 	/* Verify byte pattern after remapping */
360 	srand(pattern_seed);
361 	for (i = 0; i < SIZE_MB(1); i++) {
362 		char c = (char) rand();
363 
364 		if (((char *)src)[i] != c) {
365 			ksft_print_msg("Data at src at %d got corrupted due to unrelated mremap\n",
366 				       i);
367 			ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff,
368 					((char *) src)[i] & 0xff);
369 			success = 0;
370 		}
371 	}
372 
373 out:
374 	if (munmap(ptr, size) == -1)
375 		perror("munmap");
376 
377 	if (success)
378 		ksft_test_result_pass("%s\n", test_name);
379 	else
380 		ksft_test_result_fail("%s\n", test_name);
381 }
382 
383 /* Returns the time taken for the remap on success else returns -1. */
remap_region(struct config c,unsigned int threshold_mb,char * rand_addr)384 static long long remap_region(struct config c, unsigned int threshold_mb,
385 			      char *rand_addr)
386 {
387 	void *addr, *src_addr, *dest_addr, *dest_preamble_addr;
388 	unsigned long long t, d;
389 	struct timespec t_start = {0, 0}, t_end = {0, 0};
390 	long long  start_ns, end_ns, align_mask, ret, offset;
391 	unsigned long long threshold;
392 	unsigned long num_chunks;
393 
394 	if (threshold_mb == VALIDATION_NO_THRESHOLD)
395 		threshold = c.region_size;
396 	else
397 		threshold = MIN(threshold_mb * _1MB, c.region_size);
398 
399 	src_addr = get_source_mapping(c);
400 	if (!src_addr) {
401 		ret = -1;
402 		goto out;
403 	}
404 
405 	/* Set byte pattern for source block. */
406 	memcpy(src_addr, rand_addr, threshold);
407 
408 	/* Mask to zero out lower bits of address for alignment */
409 	align_mask = ~(c.dest_alignment - 1);
410 	/* Offset of destination address from the end of the source region */
411 	offset = (c.overlapping) ? -c.dest_alignment : c.dest_alignment;
412 	addr = (void *) (((unsigned long long) src_addr + c.region_size
413 			  + offset) & align_mask);
414 
415 	/* Remap after the destination block preamble. */
416 	addr += c.dest_preamble_size;
417 
418 	/* See comment in get_source_mapping() */
419 	if (!((unsigned long long) addr & c.dest_alignment))
420 		addr = (void *) ((unsigned long long) addr | c.dest_alignment);
421 
422 	/* Don't destroy existing mappings unless expected to overlap */
423 	while (!is_remap_region_valid(addr, c.region_size) && !c.overlapping) {
424 		/* Check for unsigned overflow */
425 		if (addr + c.dest_alignment < addr) {
426 			ksft_print_msg("Couldn't find a valid region to remap to\n");
427 			ret = -1;
428 			goto clean_up_src;
429 		}
430 		addr += c.dest_alignment;
431 	}
432 
433 	if (c.dest_preamble_size) {
434 		dest_preamble_addr = mmap((void *) addr - c.dest_preamble_size, c.dest_preamble_size,
435 					  PROT_READ | PROT_WRITE,
436 					  MAP_FIXED_NOREPLACE | MAP_ANONYMOUS | MAP_SHARED,
437 							-1, 0);
438 		if (dest_preamble_addr == MAP_FAILED) {
439 			ksft_print_msg("Failed to map dest preamble region: %s\n",
440 					strerror(errno));
441 			ret = -1;
442 			goto clean_up_src;
443 		}
444 
445 		/* Set byte pattern for the dest preamble block. */
446 		memcpy(dest_preamble_addr, rand_addr, c.dest_preamble_size);
447 	}
448 
449 	clock_gettime(CLOCK_MONOTONIC, &t_start);
450 	dest_addr = mremap(src_addr, c.region_size, c.region_size,
451 					  MREMAP_MAYMOVE|MREMAP_FIXED, (char *) addr);
452 	clock_gettime(CLOCK_MONOTONIC, &t_end);
453 
454 	if (dest_addr == MAP_FAILED) {
455 		ksft_print_msg("mremap failed: %s\n", strerror(errno));
456 		ret = -1;
457 		goto clean_up_dest_preamble;
458 	}
459 
460 	/*
461 	 * Verify byte pattern after remapping. Employ an algorithm with a
462 	 * square root time complexity in threshold: divide the range into
463 	 * chunks, if memcmp() returns non-zero, only then perform an
464 	 * iteration in that chunk to find the mismatch index.
465 	 */
466 	num_chunks = get_sqrt(threshold);
467 	for (unsigned long i = 0; i < num_chunks; ++i) {
468 		size_t chunk_size = threshold / num_chunks;
469 		unsigned long shift = i * chunk_size;
470 
471 		if (!memcmp(dest_addr + shift, rand_addr + shift, chunk_size))
472 			continue;
473 
474 		/* brute force iteration only over mismatch segment */
475 		for (t = shift; t < shift + chunk_size; ++t) {
476 			if (((char *) dest_addr)[t] != rand_addr[t]) {
477 				ksft_print_msg("Data after remap doesn't match at offset %llu\n",
478 						t);
479 				ksft_print_msg("Expected: %#x\t Got: %#x\n", rand_addr[t] & 0xff,
480 						((char *) dest_addr)[t] & 0xff);
481 				ret = -1;
482 				goto clean_up_dest;
483 			}
484 		}
485 	}
486 
487 	/*
488 	 * if threshold is not divisible by num_chunks, then check the
489 	 * last chunk
490 	 */
491 	for (t = num_chunks * (threshold / num_chunks); t < threshold; ++t) {
492 		if (((char *) dest_addr)[t] != rand_addr[t]) {
493 			ksft_print_msg("Data after remap doesn't match at offset %llu\n",
494 					t);
495 			ksft_print_msg("Expected: %#x\t Got: %#x\n", rand_addr[t] & 0xff,
496 					((char *) dest_addr)[t] & 0xff);
497 			ret = -1;
498 			goto clean_up_dest;
499 		}
500 	}
501 
502 	/* Verify the dest preamble byte pattern after remapping */
503 	if (!c.dest_preamble_size)
504 		goto no_preamble;
505 
506 	num_chunks = get_sqrt(c.dest_preamble_size);
507 
508 	for (unsigned long i = 0; i < num_chunks; ++i) {
509 		size_t chunk_size = c.dest_preamble_size / num_chunks;
510 		unsigned long shift = i * chunk_size;
511 
512 		if (!memcmp(dest_preamble_addr + shift, rand_addr + shift,
513 			    chunk_size))
514 			continue;
515 
516 		/* brute force iteration only over mismatched segment */
517 		for (d = shift; d < shift + chunk_size; ++d) {
518 			if (((char *) dest_preamble_addr)[d] != rand_addr[d]) {
519 				ksft_print_msg("Preamble data after remap doesn't match at offset %llu\n",
520 						d);
521 				ksft_print_msg("Expected: %#x\t Got: %#x\n", rand_addr[d] & 0xff,
522 						((char *) dest_preamble_addr)[d] & 0xff);
523 				ret = -1;
524 				goto clean_up_dest;
525 			}
526 		}
527 	}
528 
529 	for (d = num_chunks * (c.dest_preamble_size / num_chunks); d < c.dest_preamble_size; ++d) {
530 		if (((char *) dest_preamble_addr)[d] != rand_addr[d]) {
531 			ksft_print_msg("Preamble data after remap doesn't match at offset %llu\n",
532 					d);
533 			ksft_print_msg("Expected: %#x\t Got: %#x\n", rand_addr[d] & 0xff,
534 					((char *) dest_preamble_addr)[d] & 0xff);
535 			ret = -1;
536 			goto clean_up_dest;
537 		}
538 	}
539 
540 no_preamble:
541 	start_ns = t_start.tv_sec * NS_PER_SEC + t_start.tv_nsec;
542 	end_ns = t_end.tv_sec * NS_PER_SEC + t_end.tv_nsec;
543 	ret = end_ns - start_ns;
544 
545 /*
546  * Since the destination address is specified using MREMAP_FIXED, subsequent
547  * mremap will unmap any previous mapping at the address range specified by
548  * dest_addr and region_size. This significantly affects the remap time of
549  * subsequent tests. So we clean up mappings after each test.
550  */
551 clean_up_dest:
552 	munmap(dest_addr, c.region_size);
553 clean_up_dest_preamble:
554 	if (c.dest_preamble_size && dest_preamble_addr)
555 		munmap(dest_preamble_addr, c.dest_preamble_size);
556 clean_up_src:
557 	munmap(src_addr, c.region_size);
558 out:
559 	return ret;
560 }
561 
562 /*
563  * Verify that an mremap aligning down does not destroy
564  * the beginning of the mapping just because the aligned
565  * down address landed on a mapping that maybe does not exist.
566  */
mremap_move_1mb_from_start(unsigned int pattern_seed,char * rand_addr)567 static void mremap_move_1mb_from_start(unsigned int pattern_seed,
568 				       char *rand_addr)
569 {
570 	char *test_name = "mremap move 1mb from start at 1MB+256KB aligned src";
571 	void *src = NULL, *dest = NULL;
572 	int i, success = 1;
573 
574 	/* Config to reuse get_source_mapping() to do an aligned mmap. */
575 	struct config c = {
576 		.src_alignment = SIZE_MB(1) + SIZE_KB(256),
577 		.region_size = SIZE_MB(6)
578 	};
579 
580 	src = get_source_mapping(c);
581 	if (!src) {
582 		success = 0;
583 		goto out;
584 	}
585 
586 	c.src_alignment = SIZE_MB(1) + SIZE_KB(256);
587 	dest = get_source_mapping(c);
588 	if (!dest) {
589 		success = 0;
590 		goto out;
591 	}
592 
593 	/* Set byte pattern for source block. */
594 	memcpy(src, rand_addr, SIZE_MB(2));
595 
596 	/*
597 	 * Unmap the beginning of dest so that the aligned address
598 	 * falls on no mapping.
599 	 */
600 	munmap(dest, SIZE_MB(1));
601 
602 	void *new_ptr = mremap(src + SIZE_MB(1), SIZE_MB(1), SIZE_MB(1),
603 						   MREMAP_MAYMOVE | MREMAP_FIXED, dest + SIZE_MB(1));
604 	if (new_ptr == MAP_FAILED) {
605 		perror("mremap");
606 		success = 0;
607 		goto out;
608 	}
609 
610 	/* Verify byte pattern after remapping */
611 	srand(pattern_seed);
612 	for (i = 0; i < SIZE_MB(1); i++) {
613 		char c = (char) rand();
614 
615 		if (((char *)src)[i] != c) {
616 			ksft_print_msg("Data at src at %d got corrupted due to unrelated mremap\n",
617 				       i);
618 			ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff,
619 					((char *) src)[i] & 0xff);
620 			success = 0;
621 		}
622 	}
623 
624 out:
625 	if (src && munmap(src, c.region_size) == -1)
626 		perror("munmap src");
627 
628 	if (dest && munmap(dest, c.region_size) == -1)
629 		perror("munmap dest");
630 
631 	if (success)
632 		ksft_test_result_pass("%s\n", test_name);
633 	else
634 		ksft_test_result_fail("%s\n", test_name);
635 }
636 
run_mremap_test_case(struct test test_case,int * failures,unsigned int threshold_mb,unsigned int pattern_seed,char * rand_addr)637 static void run_mremap_test_case(struct test test_case, int *failures,
638 				 unsigned int threshold_mb,
639 				 unsigned int pattern_seed, char *rand_addr)
640 {
641 	long long remap_time = remap_region(test_case.config, threshold_mb,
642 					    rand_addr);
643 
644 	if (remap_time < 0) {
645 		if (test_case.expect_failure)
646 			ksft_test_result_xfail("%s\n\tExpected mremap failure\n",
647 					      test_case.name);
648 		else {
649 			ksft_test_result_fail("%s\n", test_case.name);
650 			*failures += 1;
651 		}
652 	} else {
653 		/*
654 		 * Comparing mremap time is only applicable if entire region
655 		 * was faulted in.
656 		 */
657 		if (threshold_mb == VALIDATION_NO_THRESHOLD ||
658 		    test_case.config.region_size <= threshold_mb * _1MB)
659 			ksft_test_result_pass("%s\n\tmremap time: %12lldns\n",
660 					      test_case.name, remap_time);
661 		else
662 			ksft_test_result_pass("%s\n", test_case.name);
663 	}
664 }
665 
usage(const char * cmd)666 static void usage(const char *cmd)
667 {
668 	fprintf(stderr,
669 		"Usage: %s [[-t <threshold_mb>] [-p <pattern_seed>]]\n"
670 		"-t\t only validate threshold_mb of the remapped region\n"
671 		"  \t if 0 is supplied no threshold is used; all tests\n"
672 		"  \t are run and remapped regions validated fully.\n"
673 		"  \t The default threshold used is 4MB.\n"
674 		"-p\t provide a seed to generate the random pattern for\n"
675 		"  \t validating the remapped region.\n", cmd);
676 }
677 
parse_args(int argc,char ** argv,unsigned int * threshold_mb,unsigned int * pattern_seed)678 static int parse_args(int argc, char **argv, unsigned int *threshold_mb,
679 		      unsigned int *pattern_seed)
680 {
681 	const char *optstr = "t:p:";
682 	int opt;
683 
684 	while ((opt = getopt(argc, argv, optstr)) != -1) {
685 		switch (opt) {
686 		case 't':
687 			*threshold_mb = atoi(optarg);
688 			break;
689 		case 'p':
690 			*pattern_seed = atoi(optarg);
691 			break;
692 		default:
693 			usage(argv[0]);
694 			return -1;
695 		}
696 	}
697 
698 	if (optind < argc) {
699 		usage(argv[0]);
700 		return -1;
701 	}
702 
703 	return 0;
704 }
705 
706 #define MAX_TEST 15
707 #define MAX_PERF_TEST 3
main(int argc,char ** argv)708 int main(int argc, char **argv)
709 {
710 	int failures = 0;
711 	int i, run_perf_tests;
712 	unsigned int threshold_mb = VALIDATION_DEFAULT_THRESHOLD;
713 
714 	/* hard-coded test configs */
715 	size_t max_test_variable_region_size = _2GB;
716 	size_t max_test_constant_region_size = _2MB;
717 	size_t dest_preamble_size = 10 * _4MB;
718 
719 	unsigned int pattern_seed;
720 	char *rand_addr;
721 	size_t rand_size;
722 	int num_expand_tests = 2;
723 	int num_misc_tests = 2;
724 	struct test test_cases[MAX_TEST] = {};
725 	struct test perf_test_cases[MAX_PERF_TEST];
726 	int page_size;
727 	time_t t;
728 	FILE *maps_fp;
729 
730 	pattern_seed = (unsigned int) time(&t);
731 
732 	if (parse_args(argc, argv, &threshold_mb, &pattern_seed) < 0)
733 		exit(EXIT_FAILURE);
734 
735 	ksft_print_msg("Test configs:\n\tthreshold_mb=%u\n\tpattern_seed=%u\n\n",
736 		       threshold_mb, pattern_seed);
737 
738 	/*
739 	 * set preallocated random array according to test configs; see the
740 	 * functions for the logic of setting the size
741 	 */
742 	if (!threshold_mb)
743 		rand_size = MAX(max_test_variable_region_size,
744 				max_test_constant_region_size);
745 	else
746 		rand_size = MAX(MIN(threshold_mb * _1MB,
747 				    max_test_variable_region_size),
748 				max_test_constant_region_size);
749 	rand_size = MAX(dest_preamble_size, rand_size);
750 
751 	rand_addr = (char *)mmap(NULL, rand_size, PROT_READ | PROT_WRITE,
752 				 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
753 	if (rand_addr == MAP_FAILED) {
754 		perror("mmap");
755 		ksft_exit_fail_msg("cannot mmap rand_addr\n");
756 	}
757 
758 	/* fill stream of random bytes */
759 	srand(pattern_seed);
760 	for (unsigned long i = 0; i < rand_size; ++i)
761 		rand_addr[i] = (char) rand();
762 
763 	page_size = sysconf(_SC_PAGESIZE);
764 
765 	/* Expected mremap failures */
766 	test_cases[0] =	MAKE_TEST(page_size, page_size, page_size,
767 				  OVERLAPPING, EXPECT_FAILURE,
768 				  "mremap - Source and Destination Regions Overlapping");
769 
770 	test_cases[1] = MAKE_TEST(page_size, page_size/4, page_size,
771 				  NON_OVERLAPPING, EXPECT_FAILURE,
772 				  "mremap - Destination Address Misaligned (1KB-aligned)");
773 	test_cases[2] = MAKE_TEST(page_size/4, page_size, page_size,
774 				  NON_OVERLAPPING, EXPECT_FAILURE,
775 				  "mremap - Source Address Misaligned (1KB-aligned)");
776 
777 	/* Src addr PTE aligned */
778 	test_cases[3] = MAKE_TEST(PTE, PTE, PTE * 2,
779 				  NON_OVERLAPPING, EXPECT_SUCCESS,
780 				  "8KB mremap - Source PTE-aligned, Destination PTE-aligned");
781 
782 	/* Src addr 1MB aligned */
783 	test_cases[4] = MAKE_TEST(_1MB, PTE, _2MB, NON_OVERLAPPING, EXPECT_SUCCESS,
784 				  "2MB mremap - Source 1MB-aligned, Destination PTE-aligned");
785 	test_cases[5] = MAKE_TEST(_1MB, _1MB, _2MB, NON_OVERLAPPING, EXPECT_SUCCESS,
786 				  "2MB mremap - Source 1MB-aligned, Destination 1MB-aligned");
787 
788 	/* Src addr PMD aligned */
789 	test_cases[6] = MAKE_TEST(PMD, PTE, _4MB, NON_OVERLAPPING, EXPECT_SUCCESS,
790 				  "4MB mremap - Source PMD-aligned, Destination PTE-aligned");
791 	test_cases[7] =	MAKE_TEST(PMD, _1MB, _4MB, NON_OVERLAPPING, EXPECT_SUCCESS,
792 				  "4MB mremap - Source PMD-aligned, Destination 1MB-aligned");
793 	test_cases[8] = MAKE_TEST(PMD, PMD, _4MB, NON_OVERLAPPING, EXPECT_SUCCESS,
794 				  "4MB mremap - Source PMD-aligned, Destination PMD-aligned");
795 
796 	/* Src addr PUD aligned */
797 	test_cases[9] = MAKE_TEST(PUD, PTE, _2GB, NON_OVERLAPPING, EXPECT_SUCCESS,
798 				  "2GB mremap - Source PUD-aligned, Destination PTE-aligned");
799 	test_cases[10] = MAKE_TEST(PUD, _1MB, _2GB, NON_OVERLAPPING, EXPECT_SUCCESS,
800 				   "2GB mremap - Source PUD-aligned, Destination 1MB-aligned");
801 	test_cases[11] = MAKE_TEST(PUD, PMD, _2GB, NON_OVERLAPPING, EXPECT_SUCCESS,
802 				   "2GB mremap - Source PUD-aligned, Destination PMD-aligned");
803 	test_cases[12] = MAKE_TEST(PUD, PUD, _2GB, NON_OVERLAPPING, EXPECT_SUCCESS,
804 				   "2GB mremap - Source PUD-aligned, Destination PUD-aligned");
805 
806 	/* Src and Dest addr 1MB aligned. 5MB mremap. */
807 	test_cases[13] = MAKE_TEST(_1MB, _1MB, _5MB, NON_OVERLAPPING, EXPECT_SUCCESS,
808 				  "5MB mremap - Source 1MB-aligned, Destination 1MB-aligned");
809 
810 	/* Src and Dest addr 1MB aligned. 5MB mremap. */
811 	test_cases[14] = MAKE_TEST(_1MB, _1MB, _5MB, NON_OVERLAPPING, EXPECT_SUCCESS,
812 				  "5MB mremap - Source 1MB-aligned, Dest 1MB-aligned with 40MB Preamble");
813 	test_cases[14].config.dest_preamble_size = 10 * _4MB;
814 
815 	perf_test_cases[0] =  MAKE_TEST(page_size, page_size, _1GB, NON_OVERLAPPING, EXPECT_SUCCESS,
816 					"1GB mremap - Source PTE-aligned, Destination PTE-aligned");
817 	/*
818 	 * mremap 1GB region - Page table level aligned time
819 	 * comparison.
820 	 */
821 	perf_test_cases[1] = MAKE_TEST(PMD, PMD, _1GB, NON_OVERLAPPING, EXPECT_SUCCESS,
822 				       "1GB mremap - Source PMD-aligned, Destination PMD-aligned");
823 	perf_test_cases[2] = MAKE_TEST(PUD, PUD, _1GB, NON_OVERLAPPING, EXPECT_SUCCESS,
824 				       "1GB mremap - Source PUD-aligned, Destination PUD-aligned");
825 
826 	run_perf_tests =  (threshold_mb == VALIDATION_NO_THRESHOLD) ||
827 				(threshold_mb * _1MB >= _1GB);
828 
829 	ksft_set_plan(ARRAY_SIZE(test_cases) + (run_perf_tests ?
830 		      ARRAY_SIZE(perf_test_cases) : 0) + num_expand_tests + num_misc_tests);
831 
832 	for (i = 0; i < ARRAY_SIZE(test_cases); i++)
833 		run_mremap_test_case(test_cases[i], &failures, threshold_mb,
834 				     pattern_seed, rand_addr);
835 
836 	maps_fp = fopen("/proc/self/maps", "r");
837 
838 	if (maps_fp == NULL) {
839 		munmap(rand_addr, rand_size);
840 		ksft_exit_fail_msg("Failed to read /proc/self/maps: %s\n", strerror(errno));
841 	}
842 
843 	mremap_expand_merge(maps_fp, page_size);
844 	mremap_expand_merge_offset(maps_fp, page_size);
845 
846 	fclose(maps_fp);
847 
848 	mremap_move_within_range(pattern_seed, rand_addr);
849 	mremap_move_1mb_from_start(pattern_seed, rand_addr);
850 
851 	if (run_perf_tests) {
852 		ksft_print_msg("\n%s\n",
853 		 "mremap HAVE_MOVE_PMD/PUD optimization time comparison for 1GB region:");
854 		for (i = 0; i < ARRAY_SIZE(perf_test_cases); i++)
855 			run_mremap_test_case(perf_test_cases[i], &failures,
856 					     threshold_mb, pattern_seed,
857 					     rand_addr);
858 	}
859 
860 	munmap(rand_addr, rand_size);
861 
862 	if (failures > 0)
863 		ksft_exit_fail();
864 	else
865 		ksft_exit_pass();
866 }
867