arch/i386/kernel/vsyscall.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   . = VSYSCALL_BASE + SIZEOF_HEADERS;
  11
  12   .hash           : { *(.hash) }                :text
  13   .dynsym         : { *(.dynsym) }
  14   .dynstr         : { *(.dynstr) }
  15   .gnu.version    : { *(.gnu.version) }
  16   .gnu.version_d  : { *(.gnu.version_d) }
  17   .gnu.version_r  : { *(.gnu.version_r) }
  18
  19   /* This linker script is used both with -r and with -shared.
  20      For the layouts to match, we need to skip more than enough
  21      space for the dynamic symbol table et al.  If this amount
  22      is insufficient, ld -shared will barf.  Just increase it here.  */
  23   . = VSYSCALL_BASE + 0x400;
  24
  25   .text           : { *(.text) }                :text =0x90909090
  26
  27   .eh_frame_hdr   : { *(.eh_frame_hdr) }        :text :eh_frame_hdr
  28   .eh_frame       : { KEEP (*(.eh_frame)) }     :text
  29   .dynamic        : { *(.dynamic) }             :text :dynamic
  30   .useless        : {
  31         *(.got.plt) *(.got)
  32         *(.data .data.* .gnu.linkonce.d.*)
  33         *(.dynbss)
  34         *(.bss .bss.* .gnu.linkonce.b.*)
  35   }                                             :text
  36 }
  37
  38 /*
  39  * We must supply the ELF program headers explicitly to get just one
  40  * PT_LOAD segment, and set the flags explicitly to make segments read-only.
  41  */
  42 PHDRS
  43 {
  44   text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
  45   dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
  46   eh_frame_hdr 0x6474e550; /* PT_GNU_EH_FRAME, but ld doesn't match the name */
  47 }
  48
  49 /*
  50  * This controls what symbols we export from the DSO.
  51  */
  52 VERSION
  53 {
  54   LINUX_2.5 {
  55     global:
  56         __kernel_vsyscall;
  57         __kernel_sigreturn;
  58         __kernel_rt_sigreturn;
  59
  60     local: *;
  61   };
  62 }
  63
  64 /* The ELF entry point can be used to set the AT_SYSINFO value.  */
  65 ENTRY(__kernel_vsyscall);