2 * Code for the vsyscall page. This version uses the sysenter instruction.
5 * 1) __kernel_vsyscall _must_ be first in this page.
6 * 2) there are alignment constraints on this stub, see vsyscall-sigreturn.S
11 .globl __kernel_vsyscall
12 .type __kernel_vsyscall,@function
29 /* 7: align return point with nop's to make disassembly easier */
32 /* 14: System call restart point is here! (SYSENTER_RETURN_OFFSET-2) */
34 /* 16: System call normal return point is here! */
35 .globl SYSENTER_RETURN_OFFSET /* Symbol used by sysenter.c */
36 SYSENTER_RETURN_OFFSET:
45 .size __kernel_vsyscall,.-.LSTART_vsyscall
48 .section .eh_frame,"a",@progbits
50 .long .LENDCIEDLSI-.LSTARTCIEDLSI
53 .byte 1 /* Version number */
54 .string "zR" /* NUL-terminated augmentation string */
55 .uleb128 1 /* Code alignment factor */
56 .sleb128 -4 /* Data alignment factor */
57 .byte 8 /* Return address register column */
58 .uleb128 1 /* Augmentation value length */
59 .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
60 .byte 0x0c /* DW_CFA_def_cfa */
63 .byte 0x88 /* DW_CFA_offset, column 0x8 */
67 .long .LENDFDEDLSI-.LSTARTFDEDLSI /* Length FDE */
69 .long .LSTARTFDEDLSI-.LSTARTFRAMEDLSI /* CIE pointer */
70 .long .LSTART_vsyscall-. /* PC-relative start address */
71 .long .LEND_vsyscall-.LSTART_vsyscall
73 /* What follows are the instructions for the table generation.
74 We have to record all changes of the stack pointer. */
75 .byte 0x04 /* DW_CFA_advance_loc4 */
76 .long .Lpush_ecx-.LSTART_vsyscall
77 .byte 0x0e /* DW_CFA_def_cfa_offset */
78 .byte 0x08 /* RA at offset 8 now */
79 .byte 0x04 /* DW_CFA_advance_loc4 */
80 .long .Lpush_edx-.Lpush_ecx
81 .byte 0x0e /* DW_CFA_def_cfa_offset */
82 .byte 0x0c /* RA at offset 12 now */
83 .byte 0x04 /* DW_CFA_advance_loc4 */
84 .long .Lenter_kernel-.Lpush_edx
85 .byte 0x0e /* DW_CFA_def_cfa_offset */
86 .byte 0x10 /* RA at offset 16 now */
87 .byte 0x85, 0x04 /* DW_CFA_offset %ebp -16 */
88 /* Finally the epilogue. */
89 .byte 0x04 /* DW_CFA_advance_loc4 */
90 .long .Lpop_ebp-.Lenter_kernel
91 .byte 0x0e /* DW_CFA_def_cfa_offset */
92 .byte 0x12 /* RA at offset 12 now */
93 .byte 0xc5 /* DW_CFA_restore %ebp */
94 .byte 0x04 /* DW_CFA_advance_loc4 */
95 .long .Lpop_edx-.Lpop_ebp
96 .byte 0x0e /* DW_CFA_def_cfa_offset */
97 .byte 0x08 /* RA at offset 8 now */
98 .byte 0x04 /* DW_CFA_advance_loc4 */
99 .long .Lpop_ecx-.Lpop_edx
100 .byte 0x0e /* DW_CFA_def_cfa_offset */
101 .byte 0x04 /* RA at offset 4 now */
107 * Get the common code for the sigreturn entry points.
109 #include "vsyscall-sigreturn.S"