From 8f8b46a9b66175280adb4a225050deed2de8fe0a Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Sat, 14 Jan 2017 16:38:33 +0100
Subject: [PATCH] Load null selectors to all data registers

This is required for some instructions such as iretq (ss must be valid or 0).
---
 src/arch/x86_64/long_mode_init.asm | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/arch/x86_64/long_mode_init.asm b/src/arch/x86_64/long_mode_init.asm
index 83fa8f46..79b4c025 100644
--- a/src/arch/x86_64/long_mode_init.asm
+++ b/src/arch/x86_64/long_mode_init.asm
@@ -13,6 +13,14 @@ extern rust_main
 section .text
 bits 64
 long_mode_start:
+    ; load 0 into all data segment registers
+    mov ax, 0
+    mov ss, ax
+    mov ds, ax
+    mov es, ax
+    mov fs, ax
+    mov gs, ax
+
     ; call rust main (with multiboot pointer in rdi)
     call rust_main
 .os_returned: