summaryrefslogtreecommitdiff
path: root/arch/riscv/mm/kasan_init.c
blob: 8fc0efcf905c9717f38d014d3b08bd965480f354 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2019 Andes Technology Corporation

#include <linux/pfn.h>
#include <linux/init_task.h>
#include <linux/kasan.h>
#include <linux/kernel.h>
#include <linux/memblock.h>
#include <linux/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/fixmap.h>
#include <asm/pgalloc.h>

/*
 * Kasan shadow region must lie at a fixed address across sv39, sv48 and sv57
 * which is right before the kernel.
 *
 * For sv39, the region is aligned on PGDIR_SIZE so we only need to populate
 * the page global directory with kasan_early_shadow_pmd.
 *
 * For sv48 and sv57, the region start is aligned on PGDIR_SIZE whereas the end
 * region is not and then we have to go down to the PUD level.
 */

extern pgd_t early_pg_dir[PTRS_PER_PGD];
pgd_t tmp_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
p4d_t tmp_p4d[PTRS_PER_P4D] __page_aligned_bss;
pud_t tmp_pud[PTRS_PER_PUD] __page_aligned_bss;

static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned long end)
{
	phys_addr_t phys_addr;
	pte_t *ptep, *p;

	if (pmd_none(*pmd)) {
		p = memblock_alloc(PTRS_PER_PTE * sizeof(pte_t), PAGE_SIZE);
		set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(p)), PAGE_TABLE));
	}

	ptep = pte_offset_kernel(pmd, vaddr);

	do {
		if (pte_none(*ptep)) {
			phys_addr = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
			set_pte(ptep, pfn_pte(PFN_DOWN(phys_addr), PAGE_KERNEL));
			memset(__va(phys_addr), KASAN_SHADOW_INIT, PAGE_SIZE);
		}
	} while (ptep++, vaddr += PAGE_SIZE, vaddr != end);
}

static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned long end)
{
	phys_addr_t phys_addr;
	pmd_t *pmdp, *p;
	unsigned long next;

	if (pud_none(*pud)) {
		p = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE);
		set_pud(pud, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE));
	}

	pmdp = pmd_offset(pud, vaddr);

	do {
		next = pmd_addr_end(vaddr, end);

		if (pmd_none(*pmdp) && IS_ALIGNED(vaddr, PMD_SIZE) && (next - vaddr) >= PMD_SIZE) {
			phys_addr = memblock_phys_alloc(PMD_SIZE, PMD_SIZE);
			if (phys_addr) {
				set_pmd(pmdp, pfn_pmd(PFN_DOWN(phys_addr), PAGE_KERNEL));
				memset(__va(phys_addr), KASAN_SHADOW_INIT, PMD_SIZE);
				continue;
			}
		}

		kasan_populate_pte(pmdp, vaddr, next);
	} while (pmdp++, vaddr = next, vaddr != end);
}

static void __init kasan_populate_pud(p4d_t *p4d,
				      unsigned long vaddr, unsigned long end)
{
	phys_addr_t phys_addr;
	pud_t *pudp, *p;
	unsigned long next;

	if (p4d_none(*p4d)) {
		p = memblock_alloc(PTRS_PER_PUD * sizeof(pud_t), PAGE_SIZE);
		set_p4d(p4d, pfn_p4d(PFN_DOWN(__pa(p)), PAGE_TABLE));
	}

	pudp = pud_offset(p4d, vaddr);

	do {
		next = pud_addr_end(vaddr, end);

		if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) {
			phys_addr = memblock_phys_alloc(PUD_SIZE, PUD_SIZE);
			if (phys_addr) {
				set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_KERNEL));
				memset(__va(phys_addr), KASAN_SHADOW_INIT, PUD_SIZE);
				continue;
			}
		}

		kasan_populate_pmd(pudp, vaddr, next);
	} while (pudp++, vaddr = next, vaddr != end);
}

static void __init kasan_populate_p4d(pgd_t *pgd,
				      unsigned long vaddr, unsigned long end)
{
	phys_addr_t phys_addr;
	p4d_t *p4dp, *p;
	unsigned long next;

	if (pgd_none(*pgd)) {
		p = memblock_alloc(PTRS_PER_P4D * sizeof(p4d_t), PAGE_SIZE);
		set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE));
	}

	p4dp = p4d_offset(pgd, vaddr);

	do {
		next = p4d_addr_end(vaddr, end);

		if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) && (next - vaddr) >= P4D_SIZE) {
			phys_addr = memblock_phys_alloc(P4D_SIZE, P4D_SIZE);
			if (phys_addr) {
				set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_KERNEL));
				memset(__va(phys_addr), KASAN_SHADOW_INIT, P4D_SIZE);
				continue;
			}
		}

		kasan_populate_pud(p4dp, vaddr, next);
	} while (p4dp++, vaddr = next, vaddr != end);
}

static void __init kasan_populate_pgd(pgd_t *pgdp,
				      unsigned long vaddr, unsigned long end)
{
	phys_addr_t phys_addr;
	unsigned long next;

	do {
		next = pgd_addr_end(vaddr, end);

		if (pgd_none(*pgdp) && IS_ALIGNED(vaddr, PGDIR_SIZE) &&
		    (next - vaddr) >= PGDIR_SIZE) {
			phys_addr = memblock_phys_alloc(PGDIR_SIZE, PGDIR_SIZE);
			if (phys_addr) {
				set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_KERNEL));
				memset(__va(phys_addr), KASAN_SHADOW_INIT, PGDIR_SIZE);
				continue;
			}
		}

		kasan_populate_p4d(pgdp, vaddr, next);
	} while (pgdp++, vaddr = next, vaddr != end);
}

static void __init kasan_early_clear_pud(p4d_t *p4dp,
					 unsigned long vaddr, unsigned long end)
{
	pud_t *pudp, *base_pud;
	unsigned long next;

	if (!pgtable_l4_enabled) {
		pudp = (pud_t *)p4dp;
	} else {
		base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(*p4dp)));
		pudp = base_pud + pud_index(vaddr);
	}

	do {
		next = pud_addr_end(vaddr, end);

		if (IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) {
			pud_clear(pudp);
			continue;
		}

		BUG();
	} while (pudp++, vaddr = next, vaddr != end);
}

static void __init kasan_early_clear_p4d(pgd_t *pgdp,
					 unsigned long vaddr, unsigned long end)
{
	p4d_t *p4dp, *base_p4d;
	unsigned long next;

	if (!pgtable_l5_enabled) {
		p4dp = (p4d_t *)pgdp;
	} else {
		base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgdp)));
		p4dp = base_p4d + p4d_index(vaddr);
	}

	do {
		next = p4d_addr_end(vaddr, end);

		if (pgtable_l4_enabled && IS_ALIGNED(vaddr, P4D_SIZE) &&
		    (next - vaddr) >= P4D_SIZE) {
			p4d_clear(p4dp);
			continue;
		}

		kasan_early_clear_pud(p4dp, vaddr, next);
	} while (p4dp++, vaddr = next, vaddr != end);
}

static void __init kasan_early_clear_pgd(pgd_t *pgdp,
					 unsigned long vaddr, unsigned long end)
{
	unsigned long next;

	do {
		next = pgd_addr_end(vaddr, end);

		if (pgtable_l5_enabled && IS_ALIGNED(vaddr, PGDIR_SIZE) &&
		    (next - vaddr) >= PGDIR_SIZE) {
			pgd_clear(pgdp);
			continue;
		}

		kasan_early_clear_p4d(pgdp, vaddr, next);
	} while (pgdp++, vaddr = next, vaddr != end);
}

static void __init kasan_early_populate_pud(p4d_t *p4dp,
					    unsigned long vaddr,
					    unsigned long end)
{
	pud_t *pudp, *base_pud;
	phys_addr_t phys_addr;
	unsigned long next;

	if (!pgtable_l4_enabled) {
		pudp = (pud_t *)p4dp;
	} else {
		base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(*p4dp)));
		pudp = base_pud + pud_index(vaddr);
	}

	do {
		next = pud_addr_end(vaddr, end);

		if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) &&
		    (next - vaddr) >= PUD_SIZE) {
			phys_addr = __pa((uintptr_t)kasan_early_shadow_pmd);
			set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_TABLE));
			continue;
		}

		BUG();
	} while (pudp++, vaddr = next, vaddr != end);
}

static void __init kasan_early_populate_p4d(pgd_t *pgdp,
					    unsigned long vaddr,
					    unsigned long end)
{
	p4d_t *p4dp, *base_p4d;
	phys_addr_t phys_addr;
	unsigned long next;

	/*
	 * We can't use pgd_page_vaddr here as it would return a linear
	 * mapping address but it is not mapped yet, but when populating
	 * early_pg_dir, we need the physical address and when populating
	 * swapper_pg_dir, we need the kernel virtual address so use
	 * pt_ops facility.
	 * Note that this test is then completely equivalent to
	 * p4dp = p4d_offset(pgdp, vaddr)
	 */
	if (!pgtable_l5_enabled) {
		p4dp = (p4d_t *)pgdp;
	} else {
		base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgdp)));
		p4dp = base_p4d + p4d_index(vaddr);
	}

	do {
		next = p4d_addr_end(vaddr, end);

		if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) &&
		    (next - vaddr) >= P4D_SIZE) {
			phys_addr = __pa((uintptr_t)kasan_early_shadow_pud);
			set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_TABLE));
			continue;
		}

		kasan_early_populate_pud(p4dp, vaddr, next);
	} while (p4dp++, vaddr = next, vaddr != end);
}

static void __init kasan_early_populate_pgd(pgd_t *pgdp,
					    unsigned long vaddr,
					    unsigned long end)
{
	phys_addr_t phys_addr;
	unsigned long next;

	do {
		next = pgd_addr_end(vaddr, end);

		if (pgd_none(*pgdp) && IS_ALIGNED(vaddr, PGDIR_SIZE) &&
		    (next - vaddr) >= PGDIR_SIZE) {
			phys_addr = __pa((uintptr_t)kasan_early_shadow_p4d);
			set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_TABLE));
			continue;
		}

		kasan_early_populate_p4d(pgdp, vaddr, next);
	} while (pgdp++, vaddr = next, vaddr != end);
}

asmlinkage void __init kasan_early_init(void)
{
	uintptr_t i;

	BUILD_BUG_ON(KASAN_SHADOW_OFFSET !=
		KASAN_SHADOW_END - (1UL << (64 - KASAN_SHADOW_SCALE_SHIFT)));

	for (i = 0; i < PTRS_PER_PTE; ++i)
		set_pte(kasan_early_shadow_pte + i,
			pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL));

	for (i = 0; i < PTRS_PER_PMD; ++i)
		set_pmd(kasan_early_shadow_pmd + i,
			pfn_pmd(PFN_DOWN
				(__pa((uintptr_t)kasan_early_shadow_pte)),
				PAGE_TABLE));

	if (pgtable_l4_enabled) {
		for (i = 0; i < PTRS_PER_PUD; ++i)
			set_pud(kasan_early_shadow_pud + i,
				pfn_pud(PFN_DOWN
					(__pa(((uintptr_t)kasan_early_shadow_pmd))),
					PAGE_TABLE));
	}

	if (pgtable_l5_enabled) {
		for (i = 0; i < PTRS_PER_P4D; ++i)
			set_p4d(kasan_early_shadow_p4d + i,
				pfn_p4d(PFN_DOWN
					(__pa(((uintptr_t)kasan_early_shadow_pud))),
					PAGE_TABLE));
	}

	kasan_early_populate_pgd(early_pg_dir + pgd_index(KASAN_SHADOW_START),
				 KASAN_SHADOW_START, KASAN_SHADOW_END);

	local_flush_tlb_all();
}

void __init kasan_swapper_init(void)
{
	kasan_early_populate_pgd(pgd_offset_k(KASAN_SHADOW_START),
				 KASAN_SHADOW_START, KASAN_SHADOW_END);

	local_flush_tlb_all();
}

static void __init kasan_populate(void *start, void *end)
{
	unsigned long vaddr = (unsigned long)start & PAGE_MASK;
	unsigned long vend = PAGE_ALIGN((unsigned long)end);

	kasan_populate_pgd(pgd_offset_k(vaddr), vaddr, vend);
}

static void __init kasan_shallow_populate_pud(p4d_t *p4d,
					      unsigned long vaddr, unsigned long end)
{
	unsigned long next;
	void *p;
	pud_t *pud_k = pud_offset(p4d, vaddr);

	do {
		next = pud_addr_end(vaddr, end);

		if (pud_none(*pud_k)) {
			p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
			set_pud(pud_k, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE));
			continue;
		}

		BUG();
	} while (pud_k++, vaddr = next, vaddr != end);
}

static void __init kasan_shallow_populate_p4d(pgd_t *pgd,
					      unsigned long vaddr, unsigned long end)
{
	unsigned long next;
	void *p;
	p4d_t *p4d_k = p4d_offset(pgd, vaddr);

	do {
		next = p4d_addr_end(vaddr, end);

		if (p4d_none(*p4d_k)) {
			p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
			set_p4d(p4d_k, pfn_p4d(PFN_DOWN(__pa(p)), PAGE_TABLE));
			continue;
		}

		kasan_shallow_populate_pud(p4d_k, vaddr, end);
	} while (p4d_k++, vaddr = next, vaddr != end);
}

static void __init kasan_shallow_populate_pgd(unsigned long vaddr, unsigned long end)
{
	unsigned long next;
	void *p;
	pgd_t *pgd_k = pgd_offset_k(vaddr);

	do {
		next = pgd_addr_end(vaddr, end);

		if (pgd_none(*pgd_k)) {
			p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
			set_pgd(pgd_k, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE));
			continue;
		}

		kasan_shallow_populate_p4d(pgd_k, vaddr, next);
	} while (pgd_k++, vaddr = next, vaddr != end);
}

static void __init kasan_shallow_populate(void *start, void *end)
{
	unsigned long vaddr = (unsigned long)start & PAGE_MASK;
	unsigned long vend = PAGE_ALIGN((unsigned long)end);

	kasan_shallow_populate_pgd(vaddr, vend);
}

static void create_tmp_mapping(void)
{
	void *ptr;
	p4d_t *base_p4d;

	/*
	 * We need to clean the early mapping: this is hard to achieve "in-place",
	 * so install a temporary mapping like arm64 and x86 do.
	 */
	memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(pgd_t) * PTRS_PER_PGD);

	/* Copy the last p4d since it is shared with the kernel mapping. */
	if (pgtable_l5_enabled) {
		ptr = (p4d_t *)pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_END));
		memcpy(tmp_p4d, ptr, sizeof(p4d_t) * PTRS_PER_P4D);
		set_pgd(&tmp_pg_dir[pgd_index(KASAN_SHADOW_END)],
			pfn_pgd(PFN_DOWN(__pa(tmp_p4d)), PAGE_TABLE));
		base_p4d = tmp_p4d;
	} else {
		base_p4d = (p4d_t *)tmp_pg_dir;
	}

	/* Copy the last pud since it is shared with the kernel mapping. */
	if (pgtable_l4_enabled) {
		ptr = (pud_t *)p4d_page_vaddr(*(base_p4d + p4d_index(KASAN_SHADOW_END)));
		memcpy(tmp_pud, ptr, sizeof(pud_t) * PTRS_PER_PUD);
		set_p4d(&base_p4d[p4d_index(KASAN_SHADOW_END)],
			pfn_p4d(PFN_DOWN(__pa(tmp_pud)), PAGE_TABLE));
	}
}

void __init kasan_init(void)
{
	phys_addr_t p_start, p_end;
	u64 i;

	create_tmp_mapping();
	csr_write(CSR_SATP, PFN_DOWN(__pa(tmp_pg_dir)) | satp_mode);

	kasan_early_clear_pgd(pgd_offset_k(KASAN_SHADOW_START),
			      KASAN_SHADOW_START, KASAN_SHADOW_END);

	kasan_populate_early_shadow((void *)kasan_mem_to_shadow((void *)FIXADDR_START),
				    (void *)kasan_mem_to_shadow((void *)VMALLOC_START));

	if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
		kasan_shallow_populate(
			(void *)kasan_mem_to_shadow((void *)VMALLOC_START),
			(void *)kasan_mem_to_shadow((void *)VMALLOC_END));
		/* Shallow populate modules and BPF which are vmalloc-allocated */
		kasan_shallow_populate(
			(void *)kasan_mem_to_shadow((void *)MODULES_VADDR),
			(void *)kasan_mem_to_shadow((void *)MODULES_END));
	} else {
		kasan_populate_early_shadow((void *)kasan_mem_to_shadow((void *)VMALLOC_START),
					    (void *)kasan_mem_to_shadow((void *)VMALLOC_END));
	}

	/* Populate the linear mapping */
	for_each_mem_range(i, &p_start, &p_end) {
		void *start = (void *)__va(p_start);
		void *end = (void *)__va(p_end);

		if (start >= end)
			break;

		kasan_populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end));
	}

	/* Populate kernel */
	kasan_populate(kasan_mem_to_shadow((const void *)MODULES_END),
		       kasan_mem_to_shadow((const void *)MODULES_VADDR + SZ_2G));

	for (i = 0; i < PTRS_PER_PTE; i++)
		set_pte(&kasan_early_shadow_pte[i],
			mk_pte(virt_to_page(kasan_early_shadow_page),
			       __pgprot(_PAGE_PRESENT | _PAGE_READ |
					_PAGE_ACCESSED)));

	memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE);
	init_task.kasan_depth = 0;

	csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | satp_mode);
	local_flush_tlb_all();
}