Re: [Xen-devel] [PATCH v2 1/1] tools/ocaml: Re-introduce Xenctrl.with_intf wrapper [and 1 more messages]

[Ian Jackson <ian.jackson@xxxxxxxxxx>]

Christian Lindig writes ("Re: [PATCH v2 1/1] tools/ocaml: Re-introduce 
Xenctrl.with_intf wrapper [and 1 more messages]"):
> On 31/10/18 15:41, Ian Jackson wrote:
> > this needs a stronger warning against anyone ever calling it, or a
> > clearer explanation of the consquences (whose scope is very broad).
> 
> The consequence is that the global handle is closed but it would be 
> opened again if
> one called with_intf again. So I'm not sure that this would be 
> dangerous. Maybe a warning
> that is should be if at all called before process termination? I'm hapy 
> to make such a change.

 with_intf
    do some stuff with get_handle (1)
    spong
    do some stuff with get_handle (2)

 let spong = with_intf
    do some stuff with handle
    close_handle

(forgive my syntax but I hope you get the idea).  This will crash in
(2)'s call to get_handle.

IMO the bug is that spong calls close_handle which has a distant
destructive action, without being able to know that it is safe to do
so.

Ian.

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