Re: [PATCH] user-mode linux: use address instead of value as argument in os_free_irq_by_cb

From: Jeff Dike
Date: Mon Sep 24 2007 - 13:02:41 EST

On Sat, Sep 22, 2007 at 12:39:55PM +0800, lepton wrote:
> There is a bug in os_free_irq_by_cb, when the first element
> of active_fds list is free, the value of active_fds is not
> updated, just value in stack is updated.

Man, that sucks.

Nice spotting.

> The intresting thing is that without this patch, a poweroff
> in user mode linux guest will halt the host linux system.It
> seems that after the tracing thread is dead, the syscall to
> sys_reboot of the traced thread is executed by host. I don't
> know if it is another bug.

I would say that you shouldn't be running UMLs as root. However, a
sys_reboot shouldn't escape being ptraced either. This is a bug, but
I don't see any connection between it and ptrace missing a final
system call.


Work email - jdike at linux dot intel dot com
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