1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* vvar.h: Shared vDSO/kernel variable declarations
* Copyright (c) 2011 Andy Lutomirski
*
* A handful of variables are accessible (read-only) from userspace
* code in the vsyscall page and the vdso. They are declared here.
* Some other file must define them with DEFINE_VVAR.
*
* In normal kernel code, they are used like any other variable.
* In user code, they are accessed through the VVAR macro.
*
* These variables live in a page of kernel data that has an extra RO
* mapping for userspace. Each variable needs a unique offset within
* that page; specify that offset with the DECLARE_VVAR macro. (If
* you mess up, the linker will catch it.)
*/
#ifndef _ASM_X86_VVAR_H
#define _ASM_X86_VVAR_H
#ifdef EMIT_VVAR
/*
* EMIT_VVAR() is used by the kernel linker script to put vvars in the
* right place. Also, it's used by kernel code to import offsets values.
*/
#define DECLARE_VVAR(offset, type, name) \
EMIT_VVAR(name, offset)
#define DECLARE_VVAR_SINGLE(offset, type, name) \
EMIT_VVAR(name, offset)
#else
extern char __vvar_page;
#define DECLARE_VVAR(offset, type, name) \
extern type vvar_ ## name[CS_BASES] \
__attribute__((visibility("hidden"))); \
extern type timens_ ## name[CS_BASES] \
__attribute__((visibility("hidden"))); \
#define DECLARE_VVAR_SINGLE(offset, type, name) \
extern type vvar_ ## name \
__attribute__((visibility("hidden"))); \
#define VVAR(name) (vvar_ ## name)
#define TIMENS(name) (timens_ ## name)
#define DEFINE_VVAR(type, name) \
type name[CS_BASES] \
__attribute__((section(".vvar_" #name), aligned(16))) __visible
#define DEFINE_VVAR_SINGLE(type, name) \
type name \
__attribute__((section(".vvar_" #name), aligned(16))) __visible
#endif
/* DECLARE_VVAR(offset, type, name) */
DECLARE_VVAR(128, struct vdso_data, _vdso_data)
#if !defined(_SINGLE_DATA)
#define _SINGLE_DATA
DECLARE_VVAR_SINGLE(640, struct vdso_rng_data, _vdso_rng_data)
#endif
#undef DECLARE_VVAR
#undef DECLARE_VVAR_SINGLE
#endif
|
