2 * Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
3 * <benh@kernel.crashing.org>
4 * Copyright (C) 2012 ARM Limited
5 * Copyright (C) 2015 Regents of the University of California
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #include <linux/slab.h>
22 #include <linux/binfmts.h>
23 #include <linux/err.h>
27 extern char vdso_start[], vdso_end[];
29 static unsigned int vdso_pages;
30 static struct page **vdso_pagelist;
36 struct vdso_data data;
38 } vdso_data_store __page_aligned_data;
39 struct vdso_data *vdso_data = &vdso_data_store.data;
41 static int __init vdso_init(void)
45 vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
47 kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL);
48 if (unlikely(vdso_pagelist == NULL)) {
49 pr_err("vdso: pagelist allocation failed\n");
53 for (i = 0; i < vdso_pages; i++) {
56 pg = virt_to_page(vdso_start + (i << PAGE_SHIFT));
57 ClearPageReserved(pg);
58 vdso_pagelist[i] = pg;
60 vdso_pagelist[i] = virt_to_page(vdso_data);
64 arch_initcall(vdso_init);
66 int arch_setup_additional_pages(struct linux_binprm *bprm,
69 struct mm_struct *mm = current->mm;
70 unsigned long vdso_base, vdso_len;
73 vdso_len = (vdso_pages + 1) << PAGE_SHIFT;
75 down_write(&mm->mmap_sem);
76 vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0);
77 if (IS_ERR_VALUE(vdso_base)) {
83 * Put vDSO base into mm struct. We need to do this before calling
84 * install_special_mapping or the perf counter mmap tracking code
85 * will fail to recognise it as a vDSO (since arch_vma_name fails).
87 mm->context.vdso = (void *)vdso_base;
89 ret = install_special_mapping(mm, vdso_base, vdso_len,
90 (VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
94 mm->context.vdso = NULL;
97 up_write(&mm->mmap_sem);
101 const char *arch_vma_name(struct vm_area_struct *vma)
103 if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso))
109 * Function stubs to prevent linker errors when AT_SYSINFO_EHDR is defined
112 int in_gate_area_no_mm(unsigned long addr)
117 int in_gate_area(struct mm_struct *mm, unsigned long addr)
122 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)