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
|
// SPDX-License-Identifier: GPL-2.0
/*
* Author: Huacai Chen <chenhuacai@loongson.cn>
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <linux/binfmts.h>
#include <linux/elf.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/timekeeper_internal.h>
#include <asm/page.h>
#include <asm/vdso.h>
#include <vdso/helpers.h>
#include <vdso/vsyscall.h>
#include <generated/vdso-offsets.h>
extern char vdso_start[], vdso_end[];
/* Kernel-provided data used by the VDSO. */
static union loongarch_vdso_data {
u8 page[PAGE_SIZE];
struct vdso_data data[CS_BASES];
} loongarch_vdso_data __page_aligned_data;
struct vdso_data *vdso_data = loongarch_vdso_data.data;
static struct page *vdso_pages[] = { NULL };
static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)
{
current->mm->context.vdso = (void *)(new_vma->vm_start);
return 0;
}
struct loongarch_vdso_info vdso_info = {
.vdso = vdso_start,
.size = PAGE_SIZE,
.code_mapping = {
.name = "[vdso]",
.pages = vdso_pages,
.mremap = vdso_mremap,
},
.data_mapping = {
.name = "[vvar]",
},
.offset_sigreturn = vdso_offset_sigreturn,
};
static int __init init_vdso(void)
{
unsigned long i, pfn;
BUG_ON(!PAGE_ALIGNED(vdso_info.vdso));
BUG_ON(!PAGE_ALIGNED(vdso_info.size));
pfn = __phys_to_pfn(__pa_symbol(vdso_info.vdso));
for (i = 0; i < vdso_info.size / PAGE_SIZE; i++)
vdso_info.code_mapping.pages[i] = pfn_to_page(pfn + i);
return 0;
}
subsys_initcall(init_vdso);
static unsigned long vdso_base(void)
{
unsigned long base = STACK_TOP;
if (current->flags & PF_RANDOMIZE) {
base += get_random_int() & (VDSO_RANDOMIZE_SIZE - 1);
base = PAGE_ALIGN(base);
}
return base;
}
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
int ret;
unsigned long vvar_size, size, data_addr, vdso_addr;
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
struct loongarch_vdso_info *info = current->thread.vdso;
if (mmap_write_lock_killable(mm))
return -EINTR;
/*
* Determine total area size. This includes the VDSO data itself
* and the data page.
*/
vvar_size = PAGE_SIZE;
size = vvar_size + info->size;
data_addr = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
if (IS_ERR_VALUE(data_addr)) {
ret = data_addr;
goto out;
}
vdso_addr = data_addr + PAGE_SIZE;
vma = _install_special_mapping(mm, data_addr, vvar_size,
VM_READ | VM_MAYREAD,
&info->data_mapping);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto out;
}
/* Map VDSO data page. */
ret = remap_pfn_range(vma, data_addr,
virt_to_phys(vdso_data) >> PAGE_SHIFT,
PAGE_SIZE, PAGE_READONLY);
if (ret)
goto out;
/* Map VDSO code page. */
vma = _install_special_mapping(mm, vdso_addr, info->size,
VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
&info->code_mapping);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto out;
}
mm->context.vdso = (void *)vdso_addr;
ret = 0;
out:
mmap_write_unlock(mm);
return ret;
}
|
