From 59038fc67c20a1f04e5d2fd5f9a444e707d1d3ea Mon Sep 17 00:00:00 2001
From: Miguel <m.i@gmx.at>
Date: Wed, 22 Aug 2018 00:52:30 +0200
Subject: userspace and kernelspace taskswitching

---
 asm/task.s | 37 +++++++++++++++++++++++++++++++------
 1 file changed, 31 insertions(+), 6 deletions(-)

(limited to 'asm/task.s')

diff --git a/asm/task.s b/asm/task.s
index 7611d4a..c29bdae 100644
--- a/asm/task.s
+++ b/asm/task.s
@@ -2,15 +2,21 @@
 task_pusha:
 
     pushf
-
-    push $0x8
+    push $0x8	   // code segment
     push $userfunc
 
     pusha
+
+    push %ds
+    push %es
+    push %fs
+    push %gs
+
 	/*
+
 	now stack looks like:
 
-	param			 // esp+48
+	param			 // esp+64
 	returnaddy		
 
 	eflags			
@@ -26,9 +32,14 @@ task_pusha:
 	esi			
 	edi			
 
+	ds
+	es
+	fs
+	gs
+
 	*/
 
-    mov 48(%esp),%eax // get address of alternative stack where we want to simulate the pusha
+    mov 64(%esp),%eax // get address of alternative stack where we want to simulate the pusha
 
     mov (%esp),%ecx
     mov %ecx,(%eax)
@@ -66,10 +77,24 @@ task_pusha:
     mov 44(%esp),%ecx
     mov %ecx,44(%eax)
 
+    mov 48(%esp),%ecx
+    mov %ecx,48(%eax)
+
+    mov 52(%esp),%ecx
+    mov %ecx,52(%eax)
+
+    mov 56(%esp),%ecx
+    mov %ecx,56(%eax)
+
+    pop %gs
+    pop %fs
+    pop %es
+    pop %ds
+
+    popa
+
     pop %eax
     pop %eax
     pop %eax
 
-    popa
-
     ret
-- 
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