arch/x86/kernel/vsyscall_32.lds.S

   1 /*
   2  * Linker script for vsyscall DSO.  The vsyscall page is an ELF shared
   3  * object prelinked to its virtual address, and with only one read-only
   4  * segment (that fits in one page).  This script controls its layout.
   5  */
   6 #include <asm/asm-offsets.h>
   7
   8 SECTIONS
   9 {
  10   . = VDSO_PRELINK_asm + SIZEOF_HEADERS;
  11
  12   .hash           : { *(.hash) }                :text
  13   .gnu.hash       : { *(.gnu.hash) }
  14   .dynsym         : { *(.dynsym) }
  15   .dynstr         : { *(.dynstr) }
  16   .gnu.version    : { *(.gnu.version) }
  17   .gnu.version_d  : { *(.gnu.version_d) }
  18   .gnu.version_r  : { *(.gnu.version_r) }
  19
  20   /* This linker script is used both with -r and with -shared.
  21      For the layouts to match, we need to skip more than enough
  22      space for the dynamic symbol table et al.  If this amount
  23      is insufficient, ld -shared will barf.  Just increase it here.  */
  24   . = VDSO_PRELINK_asm + 0x400;
  25
  26   .text           : { *(.text) }                :text =0x90909090
  27   .note           : { *(.note.*) }              :text :note
  28   .eh_frame_hdr   : { *(.eh_frame_hdr) }        :text :eh_frame_hdr
  29   .eh_frame       : { KEEP (*(.eh_frame)) }     :text
  30   .dynamic        : { *(.dynamic) }             :text :dynamic
  31   .useless        : {
  32         *(.got.plt) *(.got)
  33         *(.data .data.* .gnu.linkonce.d.*)
  34         *(.dynbss)
  35         *(.bss .bss.* .gnu.linkonce.b.*)
  36   }                                             :text
  37 }
  38
  39 /*
  40  * We must supply the ELF program headers explicitly to get just one
  41  * PT_LOAD segment, and set the flags explicitly to make segments read-only.
  42  */
  43 PHDRS
  44 {
  45   text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
  46   dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
  47   note PT_NOTE FLAGS(4); /* PF_R */
  48   eh_frame_hdr 0x6474e550; /* PT_GNU_EH_FRAME, but ld doesn't match the name */
  49 }
  50
  51 /*
  52  * This controls what symbols we export from the DSO.
  53  */
  54 VERSION
  55 {
  56   LINUX_2.5 {
  57     global:
  58         __kernel_vsyscall;
  59         __kernel_sigreturn;
  60         __kernel_rt_sigreturn;
  61
  62     local: *;
  63   };
  64 }
  65
  66 /* The ELF entry point can be used to set the AT_SYSINFO value.  */
  67 ENTRY(__kernel_vsyscall);