Merge pull request #38 from Frost-Wing/codex/fix-os-userland-return-crash-and-tty-buffer-issue

Allow userland to request return-to-kernel and flush TTY input before exec

Author: pradosh-arduino

source/kernel/C/interrupts/syscalls-x86_64.asm

@@ -28,7 +28,7 @@ syscall_entry:
     mov [rel saved_user_rsp], rsp
 
     ; Switch to kernel stack
-    mov rsp, kernel_stack_top
+    mov rsp, [rel kernel_stack_top]
 
     ; Build FULL iret frame manually
     push 0x23        ; SS (user data)