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Commit 00f8b1bc authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar
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x86 vDSO: ia32 vdso32-syscall build 



This puts the syscall version of the 32-bit vDSO in arch/x86/vdso/vdso32/
for 64-bit IA32 support.  This is not used yet, but it paves the way for
consolidating the 32-bit vDSO source and build logic all in one place.

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 36197c92

arch/x86/vdso/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE 
#

obj-$(VDSO32-y)			+= vdso32-syms.lds

vdso32.so-$(CONFIG_X86_32)	+= int80

vdso32.so-$(CONFIG_COMPAT)	+= syscall

vdso32.so-$(VDSO32-y)		+= sysenter



CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)

arch/x86/vdso/vdso32/sigreturn.S

+6 −3
Original line number Diff line number Diff line
@@ -6,9 +6,12 @@ 
 * routines are constant for all vsyscall implementations.

 */



#include <asm/unistd.h>

#include <asm/unistd_32.h>

#include <asm/asm-offsets.h>



#ifndef SYSCALL_ENTER_KERNEL

#define	SYSCALL_ENTER_KERNEL	int $0x80

#endif



/* XXX

   Should these be named "_sigtramp" or something?
@@ -22,7 +25,7 @@ __kernel_sigreturn: 
.LSTART_sigreturn:

	popl %eax		/* XXX does this mean it needs unwind info? */

	movl $__NR_sigreturn, %eax

	int $0x80

	SYSCALL_ENTER_KERNEL

.LEND_sigreturn:

	.size __kernel_sigreturn,.-.LSTART_sigreturn
@@ -32,7 +35,7 @@ __kernel_sigreturn: 
__kernel_rt_sigreturn:

.LSTART_rt_sigreturn:

	movl $__NR_rt_sigreturn, %eax

	int $0x80

	SYSCALL_ENTER_KERNEL

.LEND_rt_sigreturn:

	.size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn

	.balign 32

arch/x86/vdso/vdso32/syscall.S

0 → 100644
+69 −0
Original line number Diff line number Diff line 
/*

 * Code for the vsyscall page.  This version uses the syscall instruction.

 */



#include <asm/asm-offsets.h>

#include <asm/segment.h>



	.text

	.globl __kernel_vsyscall

	.type __kernel_vsyscall,@function

__kernel_vsyscall:

.LSTART_vsyscall:

	push	%ebp

.Lpush_ebp:

	movl	%ecx, %ebp

	syscall

	movl	$__USER32_DS, %ecx

	movl	%ecx, %ss

	movl	%ebp, %ecx

	popl	%ebp

.Lpop_ebp:

	ret

.LEND_vsyscall:

	.size __kernel_vsyscall,.-.LSTART_vsyscall



	.section .eh_frame,"a",@progbits

.LSTARTFRAME:

	.long .LENDCIE-.LSTARTCIE

.LSTARTCIE:

	.long 0			/* CIE ID */

	.byte 1			/* Version number */

	.string "zR"		/* NUL-terminated augmentation string */

	.uleb128 1		/* Code alignment factor */

	.sleb128 -4		/* Data alignment factor */

	.byte 8			/* Return address register column */

	.uleb128 1		/* Augmentation value length */

	.byte 0x1b		/* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */

	.byte 0x0c		/* DW_CFA_def_cfa */

	.uleb128 4

	.uleb128 4

	.byte 0x88		/* DW_CFA_offset, column 0x8 */

	.uleb128 1

	.align 4

.LENDCIE:



	.long .LENDFDE1-.LSTARTFDE1	/* Length FDE */

.LSTARTFDE1:

	.long .LSTARTFDE1-.LSTARTFRAME	/* CIE pointer */

	.long .LSTART_vsyscall-.	/* PC-relative start address */

	.long .LEND_vsyscall-.LSTART_vsyscall

	.uleb128 0			/* Augmentation length */

	/* What follows are the instructions for the table generation.

	   We have to record all changes of the stack pointer.  */

	.byte 0x40 + .Lpush_ebp-.LSTART_vsyscall /* DW_CFA_advance_loc */

	.byte 0x0e		/* DW_CFA_def_cfa_offset */

	.uleb128 8

	.byte 0x85, 0x02	/* DW_CFA_offset %ebp -8 */

	.byte 0x40 + .Lpop_ebp-.Lpush_ebp /* DW_CFA_advance_loc */

	.byte 0xc5		/* DW_CFA_restore %ebp */

	.byte 0x0e		/* DW_CFA_def_cfa_offset */

	.uleb128 4

	.align 4

.LENDFDE1:



/*

 * Get the common code for the sigreturn entry points.

 */

#define SYSCALL_ENTER_KERNEL	syscall

#include "sigreturn.S"