diff options
Diffstat (limited to 'arch/x86/um/mem_32.c')
-rw-r--r-- | arch/x86/um/mem_32.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/x86/um/mem_32.c b/arch/x86/um/mem_32.c new file mode 100644 index 000000000000..639900a6fde9 --- /dev/null +++ b/arch/x86/um/mem_32.c | |||
@@ -0,0 +1,62 @@ | |||
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 | } | ||