From 00f8b1bc0e44ba94fb33e1fbd8ac82841d7cc570 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:30:43 +0100 Subject: [PATCH] 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: Roland McGrath Cc: Andrew Morton Cc: Linus Torvalds Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/vdso/Makefile | 1 + arch/x86/vdso/vdso32/sigreturn.S | 9 +++-- arch/x86/vdso/vdso32/syscall.S | 69 ++++++++++++++++++++++++++++++++ 3 files changed, 76 insertions(+), 3 deletions(-) create mode 100644 arch/x86/vdso/vdso32/syscall.S diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile index 1efe785979a..1127c716df0 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -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) diff --git a/arch/x86/vdso/vdso32/sigreturn.S b/arch/x86/vdso/vdso32/sigreturn.S index 778f4649e32..8d65a0a0eb7 100644 --- a/arch/x86/vdso/vdso32/sigreturn.S +++ b/arch/x86/vdso/vdso32/sigreturn.S @@ -6,9 +6,12 @@ * routines are constant for all vsyscall implementations. */ -#include +#include #include +#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 diff --git a/arch/x86/vdso/vdso32/syscall.S b/arch/x86/vdso/vdso32/syscall.S new file mode 100644 index 00000000000..333bfb552c8 --- /dev/null +++ b/arch/x86/vdso/vdso32/syscall.S @@ -0,0 +1,69 @@ +/* + * Code for the vsyscall page. This version uses the syscall instruction. + */ + +#include +#include + + .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" -- 2.41.1