1/* SPDX-License-Identifier: GPL-2.0 */
2#include <asm/vdso.h>
3
4/*
5 * Linker script for vDSO. This is an ELF shared object prelinked to
6 * its virtual address, and with only one read-only segment.
7 * This script controls its layout.
8 */
9
10SECTIONS
11{
12 /*
13 * User/kernel shared data is before the vDSO. This may be a little
14 * uglier than putting it after the vDSO, but it avoids issues with
15 * non-allocatable things that dangle past the end of the PT_LOAD
16 * segment.
17 */
18
19 vvar_start = . - 4 * PAGE_SIZE;
20 vvar_page = vvar_start;
21
22 /* Place all vvars at the offsets in asm/vvar.h. */
23#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
24#include <asm/vvar.h>
25#undef EMIT_VVAR
26
27 pvclock_page = vvar_start + PAGE_SIZE;
28 hvclock_page = vvar_start + 2 * PAGE_SIZE;
29 timens_page = vvar_start + 3 * PAGE_SIZE;
30
31#undef _ASM_X86_VVAR_H
32 /* Place all vvars in timens too at the offsets in asm/vvar.h. */
33#define EMIT_VVAR(name, offset) timens_ ## name = timens_page + offset;
34#include <asm/vvar.h>
35#undef EMIT_VVAR
36
37 . = SIZEOF_HEADERS;
38
39 .hash : { *(.hash) } :text
40 .gnu.hash : { *(.gnu.hash) }
41 .dynsym : { *(.dynsym) }
42 .dynstr : { *(.dynstr) }
43 .gnu.version : { *(.gnu.version) }
44 .gnu.version_d : { *(.gnu.version_d) }
45 .gnu.version_r : { *(.gnu.version_r) }
46
47 .dynamic : { *(.dynamic) } :text :dynamic
48
49 .rodata : {
50 *(.rodata*)
51 *(.data*)
52 *(.sdata*)
53 *(.got.plt) *(.got)
54 *(.gnu.linkonce.d.*)
55 *(.bss*)
56 *(.dynbss*)
57 *(.gnu.linkonce.b.*)
58 } :text
59
60 /*
61 * Discard .note.gnu.property sections which are unused and have
62 * different alignment requirement from vDSO note sections.
63 */
64 /DISCARD/ : {
65 *(.note.gnu.property)
66 }
67 .note : { *(.note.*) } :text :note
68
69 .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
70 .eh_frame : { KEEP (*(.eh_frame)) } :text
71
72
73 /*
74 * Text is well-separated from actual data: there's plenty of
75 * stuff that isn't used at runtime in between.
76 */
77
78 .text : {
79 *(.text*)
80 } :text =0x90909090,
81
82
83
84 .altinstructions : { *(.altinstructions) } :text
85 .altinstr_replacement : { *(.altinstr_replacement) } :text
86
87 __ex_table : { *(__ex_table) } :text
88
89 /DISCARD/ : {
90 *(.discard)
91 *(.discard.*)
92 *(__bug_table)
93 }
94}
95
96/*
97 * Very old versions of ld do not recognize this name token; use the constant.
98 */
99#define PT_GNU_EH_FRAME 0x6474e550
100
101/*
102 * We must supply the ELF program headers explicitly to get just one
103 * PT_LOAD segment, and set the flags explicitly to make segments read-only.
104 */
105PHDRS
106{
107 text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
108 dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
109 note PT_NOTE FLAGS(4); /* PF_R */
110 eh_frame_hdr PT_GNU_EH_FRAME;
111}
112

source code of linux/arch/x86/entry/vdso/vdso-layout.lds.S