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authorRoland McGrath <roland@redhat.com>2008-01-30 15:30:43 +0300
committerIngo Molnar <mingo@elte.hu>2008-01-30 15:30:43 +0300
commit00f8b1bc0e44ba94fb33e1fbd8ac82841d7cc570 (patch)
tree40921e3470a9ebbeb799939f03137af91987ac19 /arch/x86/vdso/vdso32/syscall.S
parent36197c92a20c142fc2a068e0366053d770fa0096 (diff)
downloadlinux-00f8b1bc0e44ba94fb33e1fbd8ac82841d7cc570.tar.xz
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 <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>
Diffstat (limited to 'arch/x86/vdso/vdso32/syscall.S')
-rw-r--r--arch/x86/vdso/vdso32/syscall.S69
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/x86/vdso/vdso32/syscall.S b/arch/x86/vdso/vdso32/syscall.S
new file mode 100644
index 000000000000..333bfb552c88
--- /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 <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"