xref: /OK3568_Linux_fs/kernel/arch/x86/entry/vdso/vdso-layout.lds.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun#include <asm/vdso.h>
3*4882a593Smuzhiyun
4*4882a593Smuzhiyun/*
5*4882a593Smuzhiyun * Linker script for vDSO.  This is an ELF shared object prelinked to
6*4882a593Smuzhiyun * its virtual address, and with only one read-only segment.
7*4882a593Smuzhiyun * This script controls its layout.
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593SmuzhiyunSECTIONS
11*4882a593Smuzhiyun{
12*4882a593Smuzhiyun	/*
13*4882a593Smuzhiyun	 * User/kernel shared data is before the vDSO.  This may be a little
14*4882a593Smuzhiyun	 * uglier than putting it after the vDSO, but it avoids issues with
15*4882a593Smuzhiyun	 * non-allocatable things that dangle past the end of the PT_LOAD
16*4882a593Smuzhiyun	 * segment.
17*4882a593Smuzhiyun	 */
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun	vvar_start = . - 4 * PAGE_SIZE;
20*4882a593Smuzhiyun	vvar_page  = vvar_start;
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun	/* Place all vvars at the offsets in asm/vvar.h. */
23*4882a593Smuzhiyun#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
24*4882a593Smuzhiyun#include <asm/vvar.h>
25*4882a593Smuzhiyun#undef EMIT_VVAR
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun	pvclock_page = vvar_start + PAGE_SIZE;
28*4882a593Smuzhiyun	hvclock_page = vvar_start + 2 * PAGE_SIZE;
29*4882a593Smuzhiyun	timens_page  = vvar_start + 3 * PAGE_SIZE;
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun#undef _ASM_X86_VVAR_H
32*4882a593Smuzhiyun	/* Place all vvars in timens too at the offsets in asm/vvar.h. */
33*4882a593Smuzhiyun#define EMIT_VVAR(name, offset) timens_ ## name = timens_page + offset;
34*4882a593Smuzhiyun#include <asm/vvar.h>
35*4882a593Smuzhiyun#undef EMIT_VVAR
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun	. = SIZEOF_HEADERS;
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun	.hash		: { *(.hash) }			:text
40*4882a593Smuzhiyun	.gnu.hash	: { *(.gnu.hash) }
41*4882a593Smuzhiyun	.dynsym		: { *(.dynsym) }
42*4882a593Smuzhiyun	.dynstr		: { *(.dynstr) }
43*4882a593Smuzhiyun	.gnu.version	: { *(.gnu.version) }
44*4882a593Smuzhiyun	.gnu.version_d	: { *(.gnu.version_d) }
45*4882a593Smuzhiyun	.gnu.version_r	: { *(.gnu.version_r) }
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun	.dynamic	: { *(.dynamic) }		:text	:dynamic
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun	.rodata		: {
50*4882a593Smuzhiyun		*(.rodata*)
51*4882a593Smuzhiyun		*(.data*)
52*4882a593Smuzhiyun		*(.sdata*)
53*4882a593Smuzhiyun		*(.got.plt) *(.got)
54*4882a593Smuzhiyun		*(.gnu.linkonce.d.*)
55*4882a593Smuzhiyun		*(.bss*)
56*4882a593Smuzhiyun		*(.dynbss*)
57*4882a593Smuzhiyun		*(.gnu.linkonce.b.*)
58*4882a593Smuzhiyun	}						:text
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun	/*
61*4882a593Smuzhiyun	 * Discard .note.gnu.property sections which are unused and have
62*4882a593Smuzhiyun	 * different alignment requirement from vDSO note sections.
63*4882a593Smuzhiyun	 */
64*4882a593Smuzhiyun	/DISCARD/ : {
65*4882a593Smuzhiyun		*(.note.gnu.property)
66*4882a593Smuzhiyun	}
67*4882a593Smuzhiyun	.note		: { *(.note.*) }		:text	:note
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun	.eh_frame_hdr	: { *(.eh_frame_hdr) }		:text	:eh_frame_hdr
70*4882a593Smuzhiyun	.eh_frame	: { KEEP (*(.eh_frame)) }	:text
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun	/*
74*4882a593Smuzhiyun	 * Text is well-separated from actual data: there's plenty of
75*4882a593Smuzhiyun	 * stuff that isn't used at runtime in between.
76*4882a593Smuzhiyun	 */
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun	.text		: { *(.text*) }			:text	=0x90909090,
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun	.altinstructions	: { *(.altinstructions) }	:text
81*4882a593Smuzhiyun	.altinstr_replacement	: { *(.altinstr_replacement) }	:text
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun	/DISCARD/ : {
84*4882a593Smuzhiyun		*(.discard)
85*4882a593Smuzhiyun		*(.discard.*)
86*4882a593Smuzhiyun		*(__bug_table)
87*4882a593Smuzhiyun	}
88*4882a593Smuzhiyun}
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun/*
91*4882a593Smuzhiyun * Very old versions of ld do not recognize this name token; use the constant.
92*4882a593Smuzhiyun */
93*4882a593Smuzhiyun#define PT_GNU_EH_FRAME	0x6474e550
94*4882a593Smuzhiyun
95*4882a593Smuzhiyun/*
96*4882a593Smuzhiyun * We must supply the ELF program headers explicitly to get just one
97*4882a593Smuzhiyun * PT_LOAD segment, and set the flags explicitly to make segments read-only.
98*4882a593Smuzhiyun */
99*4882a593SmuzhiyunPHDRS
100*4882a593Smuzhiyun{
101*4882a593Smuzhiyun	text		PT_LOAD		FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
102*4882a593Smuzhiyun	dynamic		PT_DYNAMIC	FLAGS(4);		/* PF_R */
103*4882a593Smuzhiyun	note		PT_NOTE		FLAGS(4);		/* PF_R */
104*4882a593Smuzhiyun	eh_frame_hdr	PT_GNU_EH_FRAME;
105*4882a593Smuzhiyun}
106