Commit 7f3646aa authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar
Browse files

x86 vDSO: use vdso-syms.lds 



This patch changes the kernel's references to addresses in the vDSO image
to be based on the symbols defined by vdso-syms.lds instead of the old
vdso-syms.o symbols.  This is all wrapped up in a macro defined by the new
asm-x86/vdso.h header; that's the only place in the kernel source that has
to know the details of the scheme for getting vDSO symbol values.

Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 5b930493

arch/x86/vdso/Makefile

+1 −2
Original line number Diff line number Diff line
@@ -3,8 +3,7 @@ 
#



# files to link into the vdso

# vdso-start.o has to be first

vobjs-y := vdso-start.o vdso-note.o vclock_gettime.o vgetcpu.o vvar.o

vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vvar.o



# files to link into kernel

obj-y := vma.o vdso.o vdso-syms.o

arch/x86/vdso/vdso-start.S

deleted100644 → 0
+0 −2
Original line number Diff line number Diff line 
	.globl vdso_kernel_start

vdso_kernel_start:

arch/x86/vdso/vma.c

+7 −11
Original line number Diff line number Diff line
@@ -11,23 +11,20 @@ 
#include <asm/vsyscall.h>

#include <asm/vgtod.h>

#include <asm/proto.h>

#include "voffset.h"

#include <asm/vdso.h>



int vdso_enabled = 1;



#define VEXTERN(x) extern typeof(__ ## x) *vdso_ ## x;

#include "vextern.h"

#include "vextern.h"		/* Just for VMAGIC.  */

#undef VEXTERN



extern char vdso_kernel_start[], vdso_start[], vdso_end[];

int vdso_enabled = 1;



extern char vdso_start[], vdso_end[];

extern unsigned short vdso_sync_cpuid;



struct page **vdso_pages;



static inline void *var_ref(void *vbase, char *var, char *name)

static inline void *var_ref(void *p, char *name)

{

	unsigned offset = var - &vdso_kernel_start[0] + VDSO_TEXT_OFFSET;

	void *p = vbase + offset;

	if (*(void **)p != (void *)VMAGIC) {

		printk("VDSO: variable %s broken\n", name);

		vdso_enabled = 0;
@@ -62,9 +59,8 @@ static int __init init_vdso_vars(void) 
		vdso_enabled = 0;

	}



#define V(x) *(typeof(x) *) var_ref(vbase, (char *)RELOC_HIDE(&x, 0), #x)

#define VEXTERN(x) \

	V(vdso_ ## x) = &__ ## x;

	*(typeof(__ ## x) **) var_ref(VDSO64_SYMBOL(vbase, x), #x) = &__ ## x;

#include "vextern.h"

#undef VEXTERN

	return 0;

include/asm-x86/vdso.h

0 → 100644
+14 −0
Original line number Diff line number Diff line 
#ifndef _ASM_X86_VDSO_H

#define _ASM_X86_VDSO_H	1



extern const char VDSO64_PRELINK[];



/*

 * Given a pointer to the vDSO image, find the pointer to VDSO64_name

 * as that symbol is defined in the vDSO sources or linker script.

 */

#define VDSO64_SYMBOL(base, name) ({		\

	extern const char VDSO64_##name[];	\

	(void *) (VDSO64_##name - VDSO64_PRELINK + (unsigned long) (base)); })



#endif	/* asm-x86/vdso.h */

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