This source file includes following definitions.
- vdso_init
- arch_setup_additional_pages
- arch_vma_name
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9 #include <linux/elf.h>
10 #include <linux/mm.h>
11 #include <linux/slab.h>
12 #include <linux/binfmts.h>
13 #include <linux/err.h>
14
15 #include <asm/vdso.h>
16
17 extern char vdso_start[], vdso_end[];
18
19 static unsigned int vdso_pages;
20 static struct page **vdso_pagelist;
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22
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24
25 static union {
26 struct vdso_data data;
27 u8 page[PAGE_SIZE];
28 } vdso_data_store __page_aligned_data;
29 static struct vdso_data *vdso_data = &vdso_data_store.data;
30
31 static int __init vdso_init(void)
32 {
33 unsigned int i;
34
35 vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
36 vdso_pagelist =
37 kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL);
38 if (unlikely(vdso_pagelist == NULL)) {
39 pr_err("vdso: pagelist allocation failed\n");
40 return -ENOMEM;
41 }
42
43 for (i = 0; i < vdso_pages; i++) {
44 struct page *pg;
45
46 pg = virt_to_page(vdso_start + (i << PAGE_SHIFT));
47 vdso_pagelist[i] = pg;
48 }
49 vdso_pagelist[i] = virt_to_page(vdso_data);
50
51 return 0;
52 }
53 arch_initcall(vdso_init);
54
55 int arch_setup_additional_pages(struct linux_binprm *bprm,
56 int uses_interp)
57 {
58 struct mm_struct *mm = current->mm;
59 unsigned long vdso_base, vdso_len;
60 int ret;
61
62 vdso_len = (vdso_pages + 1) << PAGE_SHIFT;
63
64 down_write(&mm->mmap_sem);
65 vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0);
66 if (IS_ERR_VALUE(vdso_base)) {
67 ret = vdso_base;
68 goto end;
69 }
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76 mm->context.vdso = (void *)vdso_base;
77
78 ret = install_special_mapping(mm, vdso_base, vdso_len,
79 (VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
80 vdso_pagelist);
81
82 if (unlikely(ret))
83 mm->context.vdso = NULL;
84
85 end:
86 up_write(&mm->mmap_sem);
87 return ret;
88 }
89
90 const char *arch_vma_name(struct vm_area_struct *vma)
91 {
92 if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso))
93 return "[vdso]";
94 return NULL;
95 }