by entering a system call, we need also to push the segment descriptor on the stack

arch/x86/kernel/entry.asm

@@ -145,7 +145,6 @@ global isr29
 global isr30
 global isr31
 global isrsyscall
-global jump_to_child
 
 ;  0: Divide By Zero Exception
 isr0:
@@ -433,6 +432,10 @@ extern syscall_handler
 
 ; used to realize system calls
 isrsyscall:
+    push ds
+    push fs
+    push gs
+    push es
     push ebp
     push edi
     push esi
@@ -449,17 +452,10 @@ isrsyscall:
     pop esi
     pop edi
     pop ebp
-    iret
-
-jump_to_child:
-    add esp, 4
-    mov eax, 0 ; child got always zero as return value
-    pop ebx
-    pop ecx
-    pop edx
-    pop esi
-    pop edi
-    pop ebp
+    pop es
+    pop gs
+    pop fs
+    pop ds
     iret
 
 global irq0