aboutsummaryrefslogtreecommitdiff
path: root/arch/x86_64/ia32/vsyscall-sysenter.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86_64/ia32/vsyscall-sysenter.S')
-rw-r--r--arch/x86_64/ia32/vsyscall-sysenter.S94
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/x86_64/ia32/vsyscall-sysenter.S b/arch/x86_64/ia32/vsyscall-sysenter.S
new file mode 100644
index 000000000000..8fb8e0ff3afa
--- /dev/null
+++ b/arch/x86_64/ia32/vsyscall-sysenter.S
@@ -0,0 +1,94 @@
+/*
+ * Code for the vsyscall page. This version uses the sysenter instruction.
+ */
+
+#include <asm/ia32_unistd.h>
+#include <asm/offset.h>
+
+ .text
+ .section .text.vsyscall,"ax"
+ .globl __kernel_vsyscall
+ .type __kernel_vsyscall,@function
+__kernel_vsyscall:
+.LSTART_vsyscall:
+ push %ecx
+.Lpush_ecx:
+ push %edx
+.Lpush_edx:
+ push %ebp
+.Lenter_kernel:
+ movl %esp,%ebp
+ sysenter
+ .space 7,0x90
+ jmp .Lenter_kernel
+ /* 16: System call normal return point is here! */
+ pop %ebp
+.Lpop_ebp:
+ pop %edx
+.Lpop_edx:
+ pop %ecx
+.Lpop_ecx:
+ 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 0x04 /* DW_CFA_advance_loc4 */
+ .long .Lpush_ecx-.LSTART_vsyscall
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x08 /* RA at offset 8 now */
+ .byte 0x04 /* DW_CFA_advance_loc4 */
+ .long .Lpush_edx-.Lpush_ecx
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x0c /* RA at offset 12 now */
+ .byte 0x04 /* DW_CFA_advance_loc4 */
+ .long .Lenter_kernel-.Lpush_edx
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x10 /* RA at offset 16 now */
+ .byte 0x85, 0x04 /* DW_CFA_offset %ebp -16 */
+ /* Finally the epilogue. */
+ .byte 0x04 /* DW_CFA_advance_loc4 */
+ .long .Lpop_ebp-.Lenter_kernel
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x12 /* RA at offset 12 now */
+ .byte 0xc5 /* DW_CFA_restore %ebp */
+ .byte 0x04 /* DW_CFA_advance_loc4 */
+ .long .Lpop_edx-.Lpop_ebp
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x08 /* RA at offset 8 now */
+ .byte 0x04 /* DW_CFA_advance_loc4 */
+ .long .Lpop_ecx-.Lpop_edx
+ .byte 0x0e /* DW_CFA_def_cfa_offset */
+ .byte 0x04 /* RA at offset 4 now */
+ .align 4
+.LENDFDE1:
+
+#define SYSCALL_ENTER_KERNEL int $0x80
+#include "vsyscall-sigreturn.S"