1 files changed, 104 insertions, 0 deletions
diff --git a/arch/i386/kernel/vsyscall-sysenter.S b/arch/i386/kernel/vsyscall-sysenter.S
new file mode 100644
index 0000000..4daefb2
--- /dev/null
+++ b/arch/i386/kernel/vsyscall-sysenter.S
@@ -0,0 +1,104 @@
+/*
+ * Code for the vsyscall page.  This version uses the sysenter instruction.
+ *
+ * NOTE:
+ * 1) __kernel_vsyscall _must_ be first in this page.
+ * 2) there are alignment constraints on this stub, see vsyscall-sigreturn.S
+ *    for details.
+ */
+
+	.text
+	.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
+
+	/* 7: align return point with nop's to make disassembly easier */
+	.space 7,0x90
+
+	/* 14: System call restart point is here! (SYSENTER_RETURN - 2) */
+	jmp .Lenter_kernel
+	/* 16: System call normal return point is here! */
+	.globl SYSENTER_RETURN	/* Symbol used by entry.S.  */
+SYSENTER_RETURN:
+	pop %ebp
+.Lpop_ebp:
+	pop %edx
+.Lpop_edx:
+	pop %ecx
+.Lpop_ecx:
+	ret
+.LEND_vsyscall:
+	.size __kernel_vsyscall,.-.LSTART_vsyscall
+	.previous
+
+	.section .eh_frame,"a",@progbits
+.LSTARTFRAMEDLSI:
+	.long .LENDCIEDLSI-.LSTARTCIEDLSI
+.LSTARTCIEDLSI:
+	.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
+.LENDCIEDLSI:
+	.long .LENDFDEDLSI-.LSTARTFDEDLSI /* Length FDE */
+.LSTARTFDEDLSI:
+	.long .LSTARTFDEDLSI-.LSTARTFRAMEDLSI /* CIE pointer */
+	.long .LSTART_vsyscall-.	/* PC-relative start address */
+	.long .LEND_vsyscall-.LSTART_vsyscall
+	.uleb128 0
+	/* 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 0x0c		/* 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
+.LENDFDEDLSI:
+	.previous
+
+/*
+ * Get the common code for the sigreturn entry points.
+ */
+#include "vsyscall-sigreturn.S"