projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| f1c2bb8b RW |
1 | /* |
| 2 | * Copyright (C) 2011 Richard Weinberger <richrd@nod.at> | |
| 3 | * | |
| 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. | |
| 7 | */ | |
| 8 | ||
| 9 | #include <linux/slab.h> | |
| 10 | #include <linux/sched.h> | |
| 11 | #include <linux/mm.h> | |
| 12 | #include <asm/page.h> | |
| 9b46e212 | 13 | #include <asm/elf.h> |
| f1c2bb8b RW |
14 | #include <linux/init.h> |
| 15 | ||
| 3d7ee969 | 16 | static unsigned int __read_mostly vdso_enabled = 1; |
| f1c2bb8b RW |
17 | unsigned long um_vdso_addr; |
| 18 | ||
| 19 | extern unsigned long task_size; | |
| 20 | extern char vdso_start[], vdso_end[]; | |
| 21 | ||
| 22 | static struct page **vdsop; | |
| 23 | ||
| 24 | static int __init init_vdso(void) | |
| 25 | { | |
| 26 | struct page *um_vdso; | |
| 27 | ||
| 28 | BUG_ON(vdso_end - vdso_start > PAGE_SIZE); | |
| 29 | ||
| 30 | um_vdso_addr = task_size - PAGE_SIZE; | |
| 31 | ||
| 0d65ede0 | 32 | vdsop = kmalloc(sizeof(struct page *), GFP_KERNEL); |
| f1c2bb8b RW |
33 | if (!vdsop) |
| 34 | goto oom; | |
| 35 | ||
| 36 | um_vdso = alloc_page(GFP_KERNEL); | |
| 37 | if (!um_vdso) { | |
| 38 | kfree(vdsop); | |
| 39 | ||
| 40 | goto oom; | |
| 41 | } | |
| 42 | ||
| 43 | copy_page(page_address(um_vdso), vdso_start); | |
| 44 | *vdsop = um_vdso; | |
| 45 | ||
| 46 | return 0; | |
| 47 | ||
| 48 | oom: | |
| 49 | printk(KERN_ERR "Cannot allocate vdso\n"); | |
| 50 | vdso_enabled = 0; | |
| 51 | ||
| 52 | return -ENOMEM; | |
| 53 | } | |
| 54 | subsys_initcall(init_vdso); | |
| 55 | ||
| 56 | int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) | |
| 57 | { | |
| 58 | int err; | |
| 59 | struct mm_struct *mm = current->mm; | |
| 60 | ||
| 61 | if (!vdso_enabled) | |
| 62 | return 0; | |
| 63 | ||
| 69048176 MH |
64 | if (down_write_killable(&mm->mmap_sem)) |
| 65 | return -EINTR; | |
| f1c2bb8b RW |
66 | |
| 67 | err = install_special_mapping(mm, um_vdso_addr, PAGE_SIZE, | |
| 68 | VM_READ|VM_EXEC| | |
| 909af768 | 69 | VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, |
| f1c2bb8b RW |
70 | vdsop); |
| 71 | ||
| 72 | up_write(&mm->mmap_sem); | |
| 73 | ||
| 74 | return err; | |
| 75 | } |