2 * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
9 #include <linux/slab.h>
10 #include <linux/sched.h>
13 #include <linux/init.h>
15 unsigned int __read_mostly vdso_enabled
= 1;
16 unsigned long um_vdso_addr
;
18 extern unsigned long task_size
;
19 extern char vdso_start
[], vdso_end
[];
21 static struct page
**vdsop
;
23 static int __init
init_vdso(void)
27 BUG_ON(vdso_end
- vdso_start
> PAGE_SIZE
);
29 um_vdso_addr
= task_size
- PAGE_SIZE
;
31 vdsop
= kmalloc(sizeof(struct page
*), GFP_KERNEL
);
35 um_vdso
= alloc_page(GFP_KERNEL
);
42 copy_page(page_address(um_vdso
), vdso_start
);
48 printk(KERN_ERR
"Cannot allocate vdso\n");
53 subsys_initcall(init_vdso
);
55 int arch_setup_additional_pages(struct linux_binprm
*bprm
, int uses_interp
)
58 struct mm_struct
*mm
= current
->mm
;
63 down_write(&mm
->mmap_sem
);
65 err
= install_special_mapping(mm
, um_vdso_addr
, PAGE_SIZE
,
67 VM_MAYREAD
|VM_MAYWRITE
|VM_MAYEXEC
|
71 up_write(&mm
->mmap_sem
);