xref: /linux/arch/x86/entry/vdso/vdso-layout.lds.S (revision 63307d015b91e626c97bb82e88054af3d0b74643)
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 = . - 3 * 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#define __VVAR_KERNEL_LDS
25#include <asm/vvar.h>
26#undef __VVAR_KERNEL_LDS
27#undef EMIT_VVAR
28
29	pvclock_page = vvar_start + PAGE_SIZE;
30	hvclock_page = vvar_start + 2 * PAGE_SIZE;
31
32	. = SIZEOF_HEADERS;
33
34	.hash		: { *(.hash) }			:text
35	.gnu.hash	: { *(.gnu.hash) }
36	.dynsym		: { *(.dynsym) }
37	.dynstr		: { *(.dynstr) }
38	.gnu.version	: { *(.gnu.version) }
39	.gnu.version_d	: { *(.gnu.version_d) }
40	.gnu.version_r	: { *(.gnu.version_r) }
41
42	.dynamic	: { *(.dynamic) }		:text	:dynamic
43
44	.rodata		: {
45		*(.rodata*)
46		*(.data*)
47		*(.sdata*)
48		*(.got.plt) *(.got)
49		*(.gnu.linkonce.d.*)
50		*(.bss*)
51		*(.dynbss*)
52		*(.gnu.linkonce.b.*)
53	}						:text
54
55	.note		: { *(.note.*) }		:text	:note
56
57	.eh_frame_hdr	: { *(.eh_frame_hdr) }		:text	:eh_frame_hdr
58	.eh_frame	: { KEEP (*(.eh_frame)) }	:text
59
60
61	/*
62	 * Text is well-separated from actual data: there's plenty of
63	 * stuff that isn't used at runtime in between.
64	 */
65
66	.text		: { *(.text*) }			:text	=0x90909090,
67
68	.altinstructions	: { *(.altinstructions) }	:text
69	.altinstr_replacement	: { *(.altinstr_replacement) }	:text
70
71	/DISCARD/ : {
72		*(.discard)
73		*(.discard.*)
74		*(__bug_table)
75	}
76}
77
78/*
79 * Very old versions of ld do not recognize this name token; use the constant.
80 */
81#define PT_GNU_EH_FRAME	0x6474e550
82
83/*
84 * We must supply the ELF program headers explicitly to get just one
85 * PT_LOAD segment, and set the flags explicitly to make segments read-only.
86 */
87PHDRS
88{
89	text		PT_LOAD		FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
90	dynamic		PT_DYNAMIC	FLAGS(4);		/* PF_R */
91	note		PT_NOTE		FLAGS(4);		/* PF_R */
92	eh_frame_hdr	PT_GNU_EH_FRAME;
93}
94