| Richard Weinberger | 548f0a4 | 2011-07-25 17:12:53 -0700 | [diff] [blame] | 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/mm.h> |
| 10 | #include <asm/page.h> |
| 11 | #include <asm/mman.h> |
| 12 | |
| 13 | static struct vm_area_struct gate_vma; |
| 14 | |
| 15 | static int __init gate_vma_init(void) |
| 16 | { |
| 17 | if (!FIXADDR_USER_START) |
| 18 | return 0; |
| 19 | |
| 20 | gate_vma.vm_mm = NULL; |
| 21 | gate_vma.vm_start = FIXADDR_USER_START; |
| 22 | gate_vma.vm_end = FIXADDR_USER_END; |
| 23 | gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC; |
| 24 | gate_vma.vm_page_prot = __P101; |
| 25 | |
| 26 | /* |
| 27 | * Make sure the vDSO gets into every core dump. |
| 28 | * Dumping its contents makes post-mortem fully interpretable later |
| 29 | * without matching up the same kernel and hardware config to see |
| 30 | * what PC values meant. |
| 31 | */ |
| 32 | gate_vma.vm_flags |= VM_ALWAYSDUMP; |
| 33 | |
| 34 | return 0; |
| 35 | } |
| 36 | __initcall(gate_vma_init); |
| 37 | |
| 38 | struct vm_area_struct *get_gate_vma(struct mm_struct *mm) |
| 39 | { |
| 40 | return FIXADDR_USER_START ? &gate_vma : NULL; |
| 41 | } |
| 42 | |
| 43 | int in_gate_area_no_mm(unsigned long addr) |
| 44 | { |
| 45 | if (!FIXADDR_USER_START) |
| 46 | return 0; |
| 47 | |
| 48 | if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END)) |
| 49 | return 1; |
| 50 | |
| 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | int in_gate_area(struct mm_struct *mm, unsigned long addr) |
| 55 | { |
| 56 | struct vm_area_struct *vma = get_gate_vma(mm); |
| 57 | |
| 58 | if (!vma) |
| 59 | return 0; |
| 60 | |
| 61 | return (addr >= vma->vm_start) && (addr < vma->vm_end); |
| 62 | } |