OSDev.org

Posted: **Tue Mar 03, 2026 10:32 am**

Hi,
I'm currently developing a hobby OS in Rust for x86_64.

The local APIC timer has been setup, and successfully sends an interrupt.
However the handler for this interrupt always results in a double fault once it completes.
The fault occurs even if there is no code in the handler.

Repo: https://github.com/darrkenn/os

Any help would be greatly appreciated :)

Posted: **Tue Mar 03, 2026 10:52 am**

What does your virtual machine say about the double fault? (Since you're using QEMU, add "-d int" to the command line.)

Posted: **Tue Mar 03, 2026 11:29 am**

Thanks for the quick reply and pointing me in the correct direction.
The double fault is not occurring any more. Setting the DS, SS and ES GDT registers correctly after boot fixed the issue.

OSDev.org

Double fault occurs after local APIC timer interrupt handler finishes.

Double fault occurs after local APIC timer interrupt handler finishes.

Re: Double fault occurs after local APIC timer interrupt handler finishes.

Re: Double fault occurs after local APIC timer interrupt handler finishes.