1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
4 * <benh@kernel.crashing.org>
5 * Copyright (C) 2012 ARM Limited
6 * Copyright (C) 2015 Regents of the University of California
10 #include <linux/slab.h>
11 #include <linux/binfmts.h>
12 #include <linux/err.h>
16 extern char vdso_start[], vdso_end[];
18 static unsigned int vdso_pages;
19 static struct page **vdso_pagelist;
25 struct vdso_data data;
27 } vdso_data_store __page_aligned_data;
28 struct vdso_data *vdso_data = &vdso_data_store.data;
30 static int __init vdso_init(void)
34 vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
36 kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL);
37 if (unlikely(vdso_pagelist == NULL)) {
38 pr_err("vdso: pagelist allocation failed\n");
42 for (i = 0; i < vdso_pages; i++) {
45 pg = virt_to_page(vdso_start + (i << PAGE_SHIFT));
46 vdso_pagelist[i] = pg;
48 vdso_pagelist[i] = virt_to_page(vdso_data);
52 arch_initcall(vdso_init);
54 int arch_setup_additional_pages(struct linux_binprm *bprm,
57 struct mm_struct *mm = current->mm;
58 unsigned long vdso_base, vdso_len;
61 vdso_len = (vdso_pages + 1) << PAGE_SHIFT;
63 down_write(&mm->mmap_sem);
64 vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0);
65 if (IS_ERR_VALUE(vdso_base)) {
71 * Put vDSO base into mm struct. We need to do this before calling
72 * install_special_mapping or the perf counter mmap tracking code
73 * will fail to recognise it as a vDSO (since arch_vma_name fails).
75 mm->context.vdso = (void *)vdso_base;
77 ret = install_special_mapping(mm, vdso_base, vdso_len,
78 (VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
82 mm->context.vdso = NULL;
85 up_write(&mm->mmap_sem);
89 const char *arch_vma_name(struct vm_area_struct *vma)
91 if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso))
97 * Function stubs to prevent linker errors when AT_SYSINFO_EHDR is defined
100 int in_gate_area_no_mm(unsigned long addr)
105 int in_gate_area(struct mm_struct *mm, unsigned long addr)
110 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)