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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6#include <linux/stddef.h>
7#include <linux/module.h>
8#include <linux/memblock.h>
9#include <linux/mm.h>
10#include <linux/swap.h>
11#include <linux/slab.h>
12#include <asm/fixmap.h>
13#include <asm/page.h>
14#include <asm/pgalloc.h>
15#include <as-layout.h>
16#include <init.h>
17#include <kern.h>
18#include <kern_util.h>
19#include <mem_user.h>
20#include <os.h>
21#include <um_malloc.h>
22#include <linux/sched/task.h>
23
24#ifdef CONFIG_KASAN
25int kasan_um_is_ready;
26void kasan_init(void)
27{
28 /*
29 * kasan_map_memory will map all of the required address space and
30 * the host machine will allocate physical memory as necessary.
31 */
32 kasan_map_memory((void *)KASAN_SHADOW_START, KASAN_SHADOW_SIZE);
33 init_task.kasan_depth = 0;
34 kasan_um_is_ready = true;
35}
36
37static void (*kasan_init_ptr)(void)
38__section(".kasan_init") __used
39= kasan_init;
40#endif
41
42/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
43unsigned long *empty_zero_page = NULL;
44EXPORT_SYMBOL(empty_zero_page);
45
46/*
47 * Initialized during boot, and readonly for initializing page tables
48 * afterwards
49 */
50pgd_t swapper_pg_dir[PTRS_PER_PGD];
51
52/* Initialized at boot time, and readonly after that */
53int kmalloc_ok = 0;
54
55/* Used during early boot */
56static unsigned long brk_end;
57
58void __init mem_init(void)
59{
60 /* clear the zero-page */
61 memset(empty_zero_page, 0, PAGE_SIZE);
62
63 /* Map in the area just after the brk now that kmalloc is about
64 * to be turned on.
65 */
66 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
67 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
68 memblock_free((void *)brk_end, uml_reserved - brk_end);
69 uml_reserved = brk_end;
70
71 /* this will put all low memory onto the freelists */
72 memblock_free_all();
73 max_pfn = max_low_pfn;
74 kmalloc_ok = 1;
75}
76
77/*
78 * Create a page table and place a pointer to it in a middle page
79 * directory entry.
80 */
81static void __init one_page_table_init(pmd_t *pmd)
82{
83 if (pmd_none(*pmd)) {
84 pte_t *pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
85 PAGE_SIZE);
86 if (!pte)
87 panic("%s: Failed to allocate %lu bytes align=%lx\n",
88 __func__, PAGE_SIZE, PAGE_SIZE);
89
90 set_pmd(pmd, __pmd(_KERNPG_TABLE +
91 (unsigned long) __pa(pte)));
92 BUG_ON(pte != pte_offset_kernel(pmd, 0));
93 }
94}
95
96static void __init one_md_table_init(pud_t *pud)
97{
98#if CONFIG_PGTABLE_LEVELS > 2
99 pmd_t *pmd_table = (pmd_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
100 if (!pmd_table)
101 panic("%s: Failed to allocate %lu bytes align=%lx\n",
102 __func__, PAGE_SIZE, PAGE_SIZE);
103
104 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
105 BUG_ON(pmd_table != pmd_offset(pud, 0));
106#endif
107}
108
109static void __init one_ud_table_init(p4d_t *p4d)
110{
111#if CONFIG_PGTABLE_LEVELS > 3
112 pud_t *pud_table = (pud_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
113 if (!pud_table)
114 panic("%s: Failed to allocate %lu bytes align=%lx\n",
115 __func__, PAGE_SIZE, PAGE_SIZE);
116
117 set_p4d(p4d, __p4d(_KERNPG_TABLE + (unsigned long) __pa(pud_table)));
118 BUG_ON(pud_table != pud_offset(p4d, 0));
119#endif
120}
121
122static void __init fixrange_init(unsigned long start, unsigned long end,
123 pgd_t *pgd_base)
124{
125 pgd_t *pgd;
126 p4d_t *p4d;
127 pud_t *pud;
128 pmd_t *pmd;
129 int i, j;
130 unsigned long vaddr;
131
132 vaddr = start;
133 i = pgd_index(vaddr);
134 j = pmd_index(vaddr);
135 pgd = pgd_base + i;
136
137 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
138 p4d = p4d_offset(pgd, vaddr);
139 if (p4d_none(*p4d))
140 one_ud_table_init(p4d);
141 pud = pud_offset(p4d, vaddr);
142 if (pud_none(*pud))
143 one_md_table_init(pud);
144 pmd = pmd_offset(pud, vaddr);
145 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
146 one_page_table_init(pmd);
147 vaddr += PMD_SIZE;
148 }
149 j = 0;
150 }
151}
152
153static void __init fixaddr_user_init( void)
154{
155#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
156 long size = FIXADDR_USER_END - FIXADDR_USER_START;
157 pte_t *pte;
158 phys_t p;
159 unsigned long v, vaddr = FIXADDR_USER_START;
160
161 if (!size)
162 return;
163
164 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
165 v = (unsigned long) memblock_alloc_low(size, PAGE_SIZE);
166 if (!v)
167 panic("%s: Failed to allocate %lu bytes align=%lx\n",
168 __func__, size, PAGE_SIZE);
169
170 memcpy((void *) v , (void *) FIXADDR_USER_START, size);
171 p = __pa(v);
172 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
173 p += PAGE_SIZE) {
174 pte = virt_to_kpte(vaddr);
175 pte_set_val(*pte, p, PAGE_READONLY);
176 }
177#endif
178}
179
180void __init paging_init(void)
181{
182 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
183 unsigned long vaddr;
184
185 empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,
186 PAGE_SIZE);
187 if (!empty_zero_page)
188 panic("%s: Failed to allocate %lu bytes align=%lx\n",
189 __func__, PAGE_SIZE, PAGE_SIZE);
190
191 max_zone_pfn[ZONE_NORMAL] = end_iomem >> PAGE_SHIFT;
192 free_area_init(max_zone_pfn);
193
194 /*
195 * Fixed mappings, only the page table structure has to be
196 * created - mappings will be set by set_fixmap():
197 */
198 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
199 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
200
201 fixaddr_user_init();
202}
203
204/*
205 * This can't do anything because nothing in the kernel image can be freed
206 * since it's not in kernel physical memory.
207 */
208
209void free_initmem(void)
210{
211}
212
213/* Allocate and free page tables. */
214
215pgd_t *pgd_alloc(struct mm_struct *mm)
216{
217 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
218
219 if (pgd) {
220 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
221 memcpy(pgd + USER_PTRS_PER_PGD,
222 swapper_pg_dir + USER_PTRS_PER_PGD,
223 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
224 }
225 return pgd;
226}
227
228void *uml_kmalloc(int size, int flags)
229{
230 return kmalloc(size, flags);
231}
232
233static const pgprot_t protection_map[16] = {
234 [VM_NONE] = PAGE_NONE,
235 [VM_READ] = PAGE_READONLY,
236 [VM_WRITE] = PAGE_COPY,
237 [VM_WRITE | VM_READ] = PAGE_COPY,
238 [VM_EXEC] = PAGE_READONLY,
239 [VM_EXEC | VM_READ] = PAGE_READONLY,
240 [VM_EXEC | VM_WRITE] = PAGE_COPY,
241 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY,
242 [VM_SHARED] = PAGE_NONE,
243 [VM_SHARED | VM_READ] = PAGE_READONLY,
244 [VM_SHARED | VM_WRITE] = PAGE_SHARED,
245 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
246 [VM_SHARED | VM_EXEC] = PAGE_READONLY,
247 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY,
248 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED,
249 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED
250};
251DECLARE_VM_GET_PAGE_PROT
1/*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <linux/stddef.h>
7#include <linux/module.h>
8#include <linux/bootmem.h>
9#include <linux/highmem.h>
10#include <linux/mm.h>
11#include <linux/swap.h>
12#include <linux/slab.h>
13#include <asm/fixmap.h>
14#include <asm/page.h>
15#include <as-layout.h>
16#include <init.h>
17#include <kern.h>
18#include <kern_util.h>
19#include <mem_user.h>
20#include <os.h>
21
22/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
23unsigned long *empty_zero_page = NULL;
24EXPORT_SYMBOL(empty_zero_page);
25/* allocated in paging_init and unchanged thereafter */
26static unsigned long *empty_bad_page = NULL;
27
28/*
29 * Initialized during boot, and readonly for initializing page tables
30 * afterwards
31 */
32pgd_t swapper_pg_dir[PTRS_PER_PGD];
33
34/* Initialized at boot time, and readonly after that */
35unsigned long long highmem;
36int kmalloc_ok = 0;
37
38/* Used during early boot */
39static unsigned long brk_end;
40
41#ifdef CONFIG_HIGHMEM
42static void setup_highmem(unsigned long highmem_start,
43 unsigned long highmem_len)
44{
45 unsigned long highmem_pfn;
46 int i;
47
48 highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT;
49 for (i = 0; i < highmem_len >> PAGE_SHIFT; i++)
50 free_highmem_page(&mem_map[highmem_pfn + i]);
51}
52#endif
53
54void __init mem_init(void)
55{
56 /* clear the zero-page */
57 memset(empty_zero_page, 0, PAGE_SIZE);
58
59 /* Map in the area just after the brk now that kmalloc is about
60 * to be turned on.
61 */
62 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
63 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
64 free_bootmem(__pa(brk_end), uml_reserved - brk_end);
65 uml_reserved = brk_end;
66
67 /* this will put all low memory onto the freelists */
68 free_all_bootmem();
69 max_low_pfn = totalram_pages;
70#ifdef CONFIG_HIGHMEM
71 setup_highmem(end_iomem, highmem);
72#endif
73 max_pfn = totalram_pages;
74 mem_init_print_info(NULL);
75 kmalloc_ok = 1;
76}
77
78/*
79 * Create a page table and place a pointer to it in a middle page
80 * directory entry.
81 */
82static void __init one_page_table_init(pmd_t *pmd)
83{
84 if (pmd_none(*pmd)) {
85 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
86 set_pmd(pmd, __pmd(_KERNPG_TABLE +
87 (unsigned long) __pa(pte)));
88 if (pte != pte_offset_kernel(pmd, 0))
89 BUG();
90 }
91}
92
93static void __init one_md_table_init(pud_t *pud)
94{
95#ifdef CONFIG_3_LEVEL_PGTABLES
96 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
97 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
98 if (pmd_table != pmd_offset(pud, 0))
99 BUG();
100#endif
101}
102
103static void __init fixrange_init(unsigned long start, unsigned long end,
104 pgd_t *pgd_base)
105{
106 pgd_t *pgd;
107 pud_t *pud;
108 pmd_t *pmd;
109 int i, j;
110 unsigned long vaddr;
111
112 vaddr = start;
113 i = pgd_index(vaddr);
114 j = pmd_index(vaddr);
115 pgd = pgd_base + i;
116
117 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
118 pud = pud_offset(pgd, vaddr);
119 if (pud_none(*pud))
120 one_md_table_init(pud);
121 pmd = pmd_offset(pud, vaddr);
122 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
123 one_page_table_init(pmd);
124 vaddr += PMD_SIZE;
125 }
126 j = 0;
127 }
128}
129
130#ifdef CONFIG_HIGHMEM
131pte_t *kmap_pte;
132pgprot_t kmap_prot;
133
134#define kmap_get_fixmap_pte(vaddr) \
135 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
136 (vaddr)), (vaddr))
137
138static void __init kmap_init(void)
139{
140 unsigned long kmap_vstart;
141
142 /* cache the first kmap pte */
143 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
144 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
145
146 kmap_prot = PAGE_KERNEL;
147}
148
149static void __init init_highmem(void)
150{
151 pgd_t *pgd;
152 pud_t *pud;
153 pmd_t *pmd;
154 pte_t *pte;
155 unsigned long vaddr;
156
157 /*
158 * Permanent kmaps:
159 */
160 vaddr = PKMAP_BASE;
161 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
162
163 pgd = swapper_pg_dir + pgd_index(vaddr);
164 pud = pud_offset(pgd, vaddr);
165 pmd = pmd_offset(pud, vaddr);
166 pte = pte_offset_kernel(pmd, vaddr);
167 pkmap_page_table = pte;
168
169 kmap_init();
170}
171#endif /* CONFIG_HIGHMEM */
172
173static void __init fixaddr_user_init( void)
174{
175#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
176 long size = FIXADDR_USER_END - FIXADDR_USER_START;
177 pgd_t *pgd;
178 pud_t *pud;
179 pmd_t *pmd;
180 pte_t *pte;
181 phys_t p;
182 unsigned long v, vaddr = FIXADDR_USER_START;
183
184 if (!size)
185 return;
186
187 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
188 v = (unsigned long) alloc_bootmem_low_pages(size);
189 memcpy((void *) v , (void *) FIXADDR_USER_START, size);
190 p = __pa(v);
191 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
192 p += PAGE_SIZE) {
193 pgd = swapper_pg_dir + pgd_index(vaddr);
194 pud = pud_offset(pgd, vaddr);
195 pmd = pmd_offset(pud, vaddr);
196 pte = pte_offset_kernel(pmd, vaddr);
197 pte_set_val(*pte, p, PAGE_READONLY);
198 }
199#endif
200}
201
202void __init paging_init(void)
203{
204 unsigned long zones_size[MAX_NR_ZONES], vaddr;
205 int i;
206
207 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
208 empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
209 for (i = 0; i < ARRAY_SIZE(zones_size); i++)
210 zones_size[i] = 0;
211
212 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
213 (uml_physmem >> PAGE_SHIFT);
214#ifdef CONFIG_HIGHMEM
215 zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT;
216#endif
217 free_area_init(zones_size);
218
219 /*
220 * Fixed mappings, only the page table structure has to be
221 * created - mappings will be set by set_fixmap():
222 */
223 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
224 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
225
226 fixaddr_user_init();
227
228#ifdef CONFIG_HIGHMEM
229 init_highmem();
230#endif
231}
232
233/*
234 * This can't do anything because nothing in the kernel image can be freed
235 * since it's not in kernel physical memory.
236 */
237
238void free_initmem(void)
239{
240}
241
242#ifdef CONFIG_BLK_DEV_INITRD
243void free_initrd_mem(unsigned long start, unsigned long end)
244{
245 free_reserved_area((void *)start, (void *)end, -1, "initrd");
246}
247#endif
248
249/* Allocate and free page tables. */
250
251pgd_t *pgd_alloc(struct mm_struct *mm)
252{
253 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
254
255 if (pgd) {
256 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
257 memcpy(pgd + USER_PTRS_PER_PGD,
258 swapper_pg_dir + USER_PTRS_PER_PGD,
259 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
260 }
261 return pgd;
262}
263
264void pgd_free(struct mm_struct *mm, pgd_t *pgd)
265{
266 free_page((unsigned long) pgd);
267}
268
269pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
270{
271 pte_t *pte;
272
273 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
274 return pte;
275}
276
277pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
278{
279 struct page *pte;
280
281 pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
282 if (!pte)
283 return NULL;
284 if (!pgtable_page_ctor(pte)) {
285 __free_page(pte);
286 return NULL;
287 }
288 return pte;
289}
290
291#ifdef CONFIG_3_LEVEL_PGTABLES
292pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
293{
294 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
295
296 if (pmd)
297 memset(pmd, 0, PAGE_SIZE);
298
299 return pmd;
300}
301#endif
302
303void *uml_kmalloc(int size, int flags)
304{
305 return kmalloc(size, flags);
306}