From 9c5e5e91d0c984929dad72e526c9c65175d0b55a Mon Sep 17 00:00:00 2001
From: pjht <terppa05@gmail.com>
Date: Mon, 11 Feb 2019 14:13:49 -0600
Subject: [PATCH] Clear interrupt stack in yield sycall

---
 cpu/i386/gdt.c | 4 ++++
 cpu/i386/gdt.h | 1 +
 cpu/i386/isr.c | 2 ++
 3 files changed, 7 insertions(+)

diff --git a/cpu/i386/gdt.c b/cpu/i386/gdt.c
index 093645b..a7c1057 100644
--- a/cpu/i386/gdt.c
+++ b/cpu/i386/gdt.c
@@ -70,6 +70,10 @@ void gdt_init() {
   ");
 }
 
+void tss_stack_reset() {
+  tss.esp0=int_stack_top+0xC0000000;
+}
+
 void set_entry(int i,uint32_t base,uint32_t limit,uint8_t access) {
   gdt[i].limit_low16=limit&0xFFFF;
   gdt[i].base_low16=base&0xFFFFF;
diff --git a/cpu/i386/gdt.h b/cpu/i386/gdt.h
index 2c244f0..fabba0b 100644
--- a/cpu/i386/gdt.h
+++ b/cpu/i386/gdt.h
@@ -2,5 +2,6 @@
 #define GDT_H
 
 void gdt_init();
+void tss_stack_reset();
 
 #endif
diff --git a/cpu/i386/isr.c b/cpu/i386/isr.c
index af95687..33abed8 100644
--- a/cpu/i386/isr.c
+++ b/cpu/i386/isr.c
@@ -1,5 +1,6 @@
 #include "isr.h"
 #include "idt.h"
+#include "gdt.h"
 #include "ports.h"
 #include "../halt.h"
 #include "../drivers/vga.h"
@@ -166,6 +167,7 @@ void isr_handler(registers_t r) {
       break;
     case 80:
       if (r.eax==1) {
+        tss_stack_reset();
         tasking_yield();
       } else if (r.eax==2) {
         tasking_createTask((void*)r.ebx);