tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (C) 2013 Altera Corporation
3 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
4 * Copyright (C) 2009 Wind River Systems Inc
5 * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
6 * Copyright (C) 2004 Microtronix Datacom Ltd
7 *
8 * based on arch/m68k/mm/init.c
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file "COPYING" in the main directory of this archive
12 * for more details.
13 */
14
15#include <linux/signal.h>
16#include <linux/sched.h>
17#include <linux/kernel.h>
18#include <linux/errno.h>
19#include <linux/string.h>
20#include <linux/types.h>
21#include <linux/ptrace.h>
22#include <linux/mman.h>
23#include <linux/mm.h>
24#include <linux/init.h>
25#include <linux/pagemap.h>
26#include <linux/memblock.h>
27#include <linux/slab.h>
28#include <linux/binfmts.h>
29#include <linux/execmem.h>
30
31#include <asm/setup.h>
32#include <asm/page.h>
33#include <asm/sections.h>
34#include <asm/tlb.h>
35#include <asm/mmu_context.h>
36#include <asm/cpuinfo.h>
37#include <asm/processor.h>
38
39pgd_t *pgd_current;
40
41/*
42 * paging_init() continues the virtual memory environment setup which
43 * was begun by the code in arch/head.S.
44 * The parameters are pointers to where to stick the starting and ending
45 * addresses of available kernel virtual memory.
46 */
47void __init paging_init(void)
48{
49 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
50
51 pagetable_init();
52 pgd_current = swapper_pg_dir;
53
54 max_zone_pfn[ZONE_NORMAL] = max_mapnr;
55
56 /* pass the memory from the bootmem allocator to the main allocator */
57 free_area_init(max_zone_pfn);
58
59 flush_dcache_range((unsigned long)empty_zero_page,
60 (unsigned long)empty_zero_page + PAGE_SIZE);
61}
62
63void __init mem_init(void)
64{
65 unsigned long end_mem = memory_end; /* this must not include
66 kernel stack at top */
67
68 pr_debug("mem_init: start=%lx, end=%lx\n", memory_start, memory_end);
69
70 end_mem &= PAGE_MASK;
71 high_memory = __va(end_mem);
72
73 /* this will put all memory onto the freelists */
74 memblock_free_all();
75}
76
77void __init mmu_init(void)
78{
79 flush_tlb_all();
80}
81
82pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
83pte_t invalid_pte_table[PTRS_PER_PTE] __aligned(PAGE_SIZE);
84static struct page *kuser_page[1];
85static struct vm_special_mapping vdso_mapping = {
86 .name = "[vdso]",
87 .pages = kuser_page,
88};
89
90static int alloc_kuser_page(void)
91{
92 extern char __kuser_helper_start[], __kuser_helper_end[];
93 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
94 unsigned long vpage;
95
96 vpage = get_zeroed_page(GFP_ATOMIC);
97 if (!vpage)
98 return -ENOMEM;
99
100 /* Copy kuser helpers */
101 memcpy((void *)vpage, __kuser_helper_start, kuser_sz);
102
103 flush_icache_range(vpage, vpage + KUSER_SIZE);
104 kuser_page[0] = virt_to_page(vpage);
105
106 return 0;
107}
108arch_initcall(alloc_kuser_page);
109
110int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
111{
112 struct mm_struct *mm = current->mm;
113 struct vm_area_struct *vma;
114
115 mmap_write_lock(mm);
116
117 /* Map kuser helpers to user space address */
118 vma = _install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
119 VM_READ | VM_EXEC | VM_MAYREAD |
120 VM_MAYEXEC, &vdso_mapping);
121
122 mmap_write_unlock(mm);
123
124 return IS_ERR(vma) ? PTR_ERR(vma) : 0;
125}
126
127const char *arch_vma_name(struct vm_area_struct *vma)
128{
129 return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
130}
131
132static const pgprot_t protection_map[16] = {
133 [VM_NONE] = MKP(0, 0, 0),
134 [VM_READ] = MKP(0, 0, 1),
135 [VM_WRITE] = MKP(0, 0, 0),
136 [VM_WRITE | VM_READ] = MKP(0, 0, 1),
137 [VM_EXEC] = MKP(1, 0, 0),
138 [VM_EXEC | VM_READ] = MKP(1, 0, 1),
139 [VM_EXEC | VM_WRITE] = MKP(1, 0, 0),
140 [VM_EXEC | VM_WRITE | VM_READ] = MKP(1, 0, 1),
141 [VM_SHARED] = MKP(0, 0, 0),
142 [VM_SHARED | VM_READ] = MKP(0, 0, 1),
143 [VM_SHARED | VM_WRITE] = MKP(0, 1, 0),
144 [VM_SHARED | VM_WRITE | VM_READ] = MKP(0, 1, 1),
145 [VM_SHARED | VM_EXEC] = MKP(1, 0, 0),
146 [VM_SHARED | VM_EXEC | VM_READ] = MKP(1, 0, 1),
147 [VM_SHARED | VM_EXEC | VM_WRITE] = MKP(1, 1, 0),
148 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = MKP(1, 1, 1)
149};
150DECLARE_VM_GET_PAGE_PROT
151
152#ifdef CONFIG_EXECMEM
153static struct execmem_info execmem_info __ro_after_init;
154
155struct execmem_info __init *execmem_arch_setup(void)
156{
157 execmem_info = (struct execmem_info){
158 .ranges = {
159 [EXECMEM_DEFAULT] = {
160 .start = MODULES_VADDR,
161 .end = MODULES_END,
162 .pgprot = PAGE_KERNEL_EXEC,
163 .alignment = 1,
164 },
165 },
166 };
167
168 return &execmem_info;
169}
170#endif /* CONFIG_EXECMEM */