1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
6 #include <linux/slab.h>
7 #include <linux/sched.h>
11 #include <linux/init.h>
13 static unsigned int __read_mostly vdso_enabled = 1;
14 unsigned long um_vdso_addr;
16 extern unsigned long task_size;
17 extern char vdso_start[], vdso_end[];
19 static struct page **vdsop;
21 static int __init init_vdso(void)
25 BUG_ON(vdso_end - vdso_start > PAGE_SIZE);
27 um_vdso_addr = task_size - PAGE_SIZE;
29 vdsop = kmalloc(sizeof(struct page *), GFP_KERNEL);
33 um_vdso = alloc_page(GFP_KERNEL);
40 copy_page(page_address(um_vdso), vdso_start);
46 printk(KERN_ERR "Cannot allocate vdso\n");
51 subsys_initcall(init_vdso);
53 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
56 struct mm_struct *mm = current->mm;
61 if (mmap_write_lock_killable(mm))
64 err = install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
66 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
69 mmap_write_unlock(mm);