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review.evervolv.com / android_kernel_htc_msm8960 / 937cdb9db7f59278d0cb1582e6e64e3dfd73b4fc / . / arch / x86 / vdso / vdso32 / syscall.S
blob: 5415b5613d5545b68dc88ee08de03f1061c48f8c [file] [log] [blame]
Roland McGrath00f8b1b2008-01-30 13:30:43 +0100[diff] [blame]1/*
Roland McGrath69d06272008-01-30 13:30:44 +0100[diff] [blame]2 * Code for the vDSO. This version uses the syscall instruction.
3 *
4 * First get the common code for the sigreturn entry points.
5 * This must come first.
Roland McGrath00f8b1b2008-01-30 13:30:43 +0100[diff] [blame]6 */
Roland McGrath69d06272008-01-30 13:30:44 +0100[diff] [blame]7#define SYSCALL_ENTER_KERNEL syscall
8#include "sigreturn.S"
Roland McGrath00f8b1b2008-01-30 13:30:43 +0100[diff] [blame]9
Roland McGrath00f8b1b2008-01-30 13:30:43 +0100[diff] [blame]10#include <asm/segment.h>
11
12 .text
13 .globl __kernel_vsyscall
14 .type __kernel_vsyscall,@function
Roland McGrath69d06272008-01-30 13:30:44 +0100[diff] [blame]15 ALIGN
Roland McGrath00f8b1b2008-01-30 13:30:43 +0100[diff] [blame]16__kernel_vsyscall:
17.LSTART_vsyscall:
18 push %ebp
19.Lpush_ebp:
20 movl %ecx, %ebp
21 syscall
22 movl $__USER32_DS, %ecx
23 movl %ecx, %ss
24 movl %ebp, %ecx
25 popl %ebp
26.Lpop_ebp:
27 ret
28.LEND_vsyscall:
29 .size __kernel_vsyscall,.-.LSTART_vsyscall
30
31 .section .eh_frame,"a",@progbits
32.LSTARTFRAME:
33 .long .LENDCIE-.LSTARTCIE
34.LSTARTCIE:
35 .long 0 /* CIE ID */
36 .byte 1 /* Version number */
37 .string "zR" /* NUL-terminated augmentation string */
38 .uleb128 1 /* Code alignment factor */
39 .sleb128 -4 /* Data alignment factor */
40 .byte 8 /* Return address register column */
41 .uleb128 1 /* Augmentation value length */
42 .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
43 .byte 0x0c /* DW_CFA_def_cfa */
44 .uleb128 4
45 .uleb128 4
46 .byte 0x88 /* DW_CFA_offset, column 0x8 */
47 .uleb128 1
48 .align 4
49.LENDCIE:
50
51 .long .LENDFDE1-.LSTARTFDE1 /* Length FDE */
52.LSTARTFDE1:
53 .long .LSTARTFDE1-.LSTARTFRAME /* CIE pointer */
54 .long .LSTART_vsyscall-. /* PC-relative start address */
55 .long .LEND_vsyscall-.LSTART_vsyscall
56 .uleb128 0 /* Augmentation length */
57 /* What follows are the instructions for the table generation.
58 We have to record all changes of the stack pointer. */
59 .byte 0x40 + .Lpush_ebp-.LSTART_vsyscall /* DW_CFA_advance_loc */
60 .byte 0x0e /* DW_CFA_def_cfa_offset */
61 .uleb128 8
62 .byte 0x85, 0x02 /* DW_CFA_offset %ebp -8 */
63 .byte 0x40 + .Lpop_ebp-.Lpush_ebp /* DW_CFA_advance_loc */
64 .byte 0xc5 /* DW_CFA_restore %ebp */
65 .byte 0x0e /* DW_CFA_def_cfa_offset */
66 .uleb128 4
67 .align 4
68.LENDFDE1:
Roland McGrath69d06272008-01-30 13:30:44 +0100[diff] [blame]69 .previous
Roland McGrath00f8b1b2008-01-30 13:30:43 +0100[diff] [blame]70
Roland McGrath69d06272008-01-30 13:30:44 +0100[diff] [blame]71 /*
72 * Pad out the segment to match the size of the sysenter.S version.
73 */
Roland McGrathcadd5162008-01-30 13:30:44 +0100[diff] [blame]74VDSO32_vsyscall_eh_frame_size = 0x40
Roland McGrath69d06272008-01-30 13:30:44 +0100[diff] [blame]75 .section .data,"aw",@progbits
76 .space VDSO32_vsyscall_eh_frame_size-(.LENDFDE1-.LSTARTFRAME), 0
77 .previous