5b93049337
This patch adds a new way of extracting symbols from the built vDSO image. This is much simpler and less fragile than using ld -R; it removes the need to control the DSO layout quite so exactly. I was clearly unduly distracted by clever ld uses when I did the original vDSO implementation. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
89 lines
2.3 KiB
ArmAsm
89 lines
2.3 KiB
ArmAsm
/*
|
|
* Linker script for vsyscall DSO. The vsyscall page is an ELF shared
|
|
* object prelinked to its virtual address, and with only one read-only
|
|
* segment (that fits in one page). This script controls its layout.
|
|
*/
|
|
#include <asm/asm-offsets.h>
|
|
#include "voffset.h"
|
|
|
|
#define VDSO_PRELINK 0xffffffffff700000
|
|
|
|
/*
|
|
* Symbols we define here called VDSO* get their values into vdso-syms.lds
|
|
* and become visible to the kernel itself.
|
|
*/
|
|
VDSO64_PRELINK = VDSO_PRELINK;
|
|
|
|
#define VEXTERN(x) VDSO64_ ## x = vdso_ ## x;
|
|
#include "vextern.h"
|
|
#undef VEXTERN
|
|
|
|
SECTIONS
|
|
{
|
|
. = VDSO_PRELINK + SIZEOF_HEADERS;
|
|
|
|
.hash : { *(.hash) } :text
|
|
.gnu.hash : { *(.gnu.hash) }
|
|
.dynsym : { *(.dynsym) }
|
|
.dynstr : { *(.dynstr) }
|
|
.gnu.version : { *(.gnu.version) }
|
|
.gnu.version_d : { *(.gnu.version_d) }
|
|
.gnu.version_r : { *(.gnu.version_r) }
|
|
|
|
/* This linker script is used both with -r and with -shared.
|
|
For the layouts to match, we need to skip more than enough
|
|
space for the dynamic symbol table et al. If this amount
|
|
is insufficient, ld -shared will barf. Just increase it here. */
|
|
. = VDSO_PRELINK + VDSO_TEXT_OFFSET;
|
|
|
|
.text : { *(.text*) } :text
|
|
.rodata : { *(.rodata*) } :text
|
|
.data : {
|
|
*(.data*)
|
|
*(.sdata*)
|
|
*(.bss*)
|
|
*(.dynbss*)
|
|
} :text
|
|
|
|
.altinstructions : { *(.altinstructions) } :text
|
|
.altinstr_replacement : { *(.altinstr_replacement) } :text
|
|
|
|
.note : { *(.note.*) } :text :note
|
|
.eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
|
|
.eh_frame : { KEEP (*(.eh_frame)) } :text
|
|
.dynamic : { *(.dynamic) } :text :dynamic
|
|
.useless : {
|
|
*(.got.plt) *(.got)
|
|
*(.gnu.linkonce.d.*)
|
|
*(.gnu.linkonce.b.*)
|
|
} :text
|
|
}
|
|
|
|
/*
|
|
* We must supply the ELF program headers explicitly to get just one
|
|
* PT_LOAD segment, and set the flags explicitly to make segments read-only.
|
|
*/
|
|
PHDRS
|
|
{
|
|
text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
|
|
dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
|
|
note PT_NOTE FLAGS(4); /* PF_R */
|
|
eh_frame_hdr 0x6474e550; /* PT_GNU_EH_FRAME, but ld doesn't match the name */
|
|
}
|
|
|
|
/*
|
|
* This controls what symbols we export from the DSO.
|
|
*/
|
|
VERSION
|
|
{
|
|
LINUX_2.6 {
|
|
global:
|
|
clock_gettime;
|
|
__vdso_clock_gettime;
|
|
gettimeofday;
|
|
__vdso_gettimeofday;
|
|
getcpu;
|
|
__vdso_getcpu;
|
|
local: *;
|
|
};
|
|
}
|