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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
41void __init mem_init(void)
42{
43 /* clear the zero-page */
44 memset(empty_zero_page, 0, PAGE_SIZE);
45
46 /* Map in the area just after the brk now that kmalloc is about
47 * to be turned on.
48 */
49 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
50 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
51 free_bootmem(__pa(brk_end), uml_reserved - brk_end);
52 uml_reserved = brk_end;
53
54 /* this will put all low memory onto the freelists */
55 free_all_bootmem();
56 max_low_pfn = totalram_pages;
57 max_pfn = totalram_pages;
58 mem_init_print_info(NULL);
59 kmalloc_ok = 1;
60}
61
62/*
63 * Create a page table and place a pointer to it in a middle page
64 * directory entry.
65 */
66static void __init one_page_table_init(pmd_t *pmd)
67{
68 if (pmd_none(*pmd)) {
69 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
70 set_pmd(pmd, __pmd(_KERNPG_TABLE +
71 (unsigned long) __pa(pte)));
72 if (pte != pte_offset_kernel(pmd, 0))
73 BUG();
74 }
75}
76
77static void __init one_md_table_init(pud_t *pud)
78{
79#ifdef CONFIG_3_LEVEL_PGTABLES
80 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
81 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
82 if (pmd_table != pmd_offset(pud, 0))
83 BUG();
84#endif
85}
86
87static void __init fixrange_init(unsigned long start, unsigned long end,
88 pgd_t *pgd_base)
89{
90 pgd_t *pgd;
91 pud_t *pud;
92 pmd_t *pmd;
93 int i, j;
94 unsigned long vaddr;
95
96 vaddr = start;
97 i = pgd_index(vaddr);
98 j = pmd_index(vaddr);
99 pgd = pgd_base + i;
100
101 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
102 pud = pud_offset(pgd, vaddr);
103 if (pud_none(*pud))
104 one_md_table_init(pud);
105 pmd = pmd_offset(pud, vaddr);
106 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
107 one_page_table_init(pmd);
108 vaddr += PMD_SIZE;
109 }
110 j = 0;
111 }
112}
113
114static void __init fixaddr_user_init( void)
115{
116#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
117 long size = FIXADDR_USER_END - FIXADDR_USER_START;
118 pgd_t *pgd;
119 pud_t *pud;
120 pmd_t *pmd;
121 pte_t *pte;
122 phys_t p;
123 unsigned long v, vaddr = FIXADDR_USER_START;
124
125 if (!size)
126 return;
127
128 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
129 v = (unsigned long) alloc_bootmem_low_pages(size);
130 memcpy((void *) v , (void *) FIXADDR_USER_START, size);
131 p = __pa(v);
132 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
133 p += PAGE_SIZE) {
134 pgd = swapper_pg_dir + pgd_index(vaddr);
135 pud = pud_offset(pgd, vaddr);
136 pmd = pmd_offset(pud, vaddr);
137 pte = pte_offset_kernel(pmd, vaddr);
138 pte_set_val(*pte, p, PAGE_READONLY);
139 }
140#endif
141}
142
143void __init paging_init(void)
144{
145 unsigned long zones_size[MAX_NR_ZONES], vaddr;
146 int i;
147
148 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
149 empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
150 for (i = 0; i < ARRAY_SIZE(zones_size); i++)
151 zones_size[i] = 0;
152
153 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
154 (uml_physmem >> PAGE_SHIFT);
155 free_area_init(zones_size);
156
157 /*
158 * Fixed mappings, only the page table structure has to be
159 * created - mappings will be set by set_fixmap():
160 */
161 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
162 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
163
164 fixaddr_user_init();
165}
166
167/*
168 * This can't do anything because nothing in the kernel image can be freed
169 * since it's not in kernel physical memory.
170 */
171
172void free_initmem(void)
173{
174}
175
176#ifdef CONFIG_BLK_DEV_INITRD
177void free_initrd_mem(unsigned long start, unsigned long end)
178{
179 free_reserved_area((void *)start, (void *)end, -1, "initrd");
180}
181#endif
182
183/* Allocate and free page tables. */
184
185pgd_t *pgd_alloc(struct mm_struct *mm)
186{
187 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
188
189 if (pgd) {
190 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
191 memcpy(pgd + USER_PTRS_PER_PGD,
192 swapper_pg_dir + USER_PTRS_PER_PGD,
193 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
194 }
195 return pgd;
196}
197
198void pgd_free(struct mm_struct *mm, pgd_t *pgd)
199{
200 free_page((unsigned long) pgd);
201}
202
203pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
204{
205 pte_t *pte;
206
207 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
208 return pte;
209}
210
211pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
212{
213 struct page *pte;
214
215 pte = alloc_page(GFP_KERNEL|__GFP_ZERO);
216 if (!pte)
217 return NULL;
218 if (!pgtable_page_ctor(pte)) {
219 __free_page(pte);
220 return NULL;
221 }
222 return pte;
223}
224
225#ifdef CONFIG_3_LEVEL_PGTABLES
226pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
227{
228 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
229
230 if (pmd)
231 memset(pmd, 0, PAGE_SIZE);
232
233 return pmd;
234}
235#endif
236
237void *uml_kmalloc(int size, int flags)
238{
239 return kmalloc(size, flags);
240}