From 3b8e6791ee47d6210870515de58b95ca87e700d5 Mon Sep 17 00:00:00 2001
From: Stefan Lankes <slankes@eonerc.rwth-aachen.de>
Date: Sun, 20 Aug 2017 10:51:52 +0200
Subject: [PATCH] create valid pseudo interrupt to set cs

---
 arch/x86/kernel/entry.asm | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/entry.asm b/arch/x86/kernel/entry.asm
index 022f0209c..5775dfbcc 100644
--- a/arch/x86/kernel/entry.asm
+++ b/arch/x86/kernel/entry.asm
@@ -273,11 +273,13 @@ gdt_flush:
     mov fs, eax
     mov gs, eax
     ; create pseudo interrupt to set cs
-    push 0x08
-    push flush2
+    push QWORD 0x10             ; SS
+    push rsp                    ; RSP
+    add QWORD [rsp], 0x08       ; => value of rsp before the creation of a pseudo interrupt
+    pushfq                      ; RFLAGS
+    push QWORD 0x08             ; CS
+    push QWORD rollback         ; RIP
     iretq
-flush2:
-    ret
 
 ; The first 32 interrupt service routines (ISR) entries correspond to exceptions.
 ; Some exceptions will push an error code onto the stack which is specific to