LXR linux/arch/x86/entry/vdso/vdso-layout.lds.S

   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