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-rw-r--r--arch/x86_64/ia32/vsyscall-syscall.S68
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/x86_64/ia32/vsyscall-syscall.S b/arch/x86_64/ia32/vsyscall-syscall.S
new file mode 100644
index 000000000000..e2aaf3de8a42
--- /dev/null
+++ b/arch/x86_64/ia32/vsyscall-syscall.S
@@ -0,0 +1,68 @@
+/*
+ * Code for the vsyscall page. This version uses the syscall instruction.
+ */
+
+#include <asm/ia32_unistd.h>
+#include <asm/offset.h>
+#include <asm/segment.h>
+
+ .text
+ .section .text.vsyscall,"ax"
+ .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:
+
+#define SYSCALL_ENTER_KERNEL syscall
+#include "vsyscall-sigreturn.S"