[Wine] Want to use Digital Oszilloscope DSO-2100 at parport LPT1

Gert van den Berg wine-users at mohag.net
Sun Feb 7 06:22:32 CST 2010


On Sun, Feb 7, 2010 at 02:56, oiaohm <wineforum-user at winehq.org> wrote:
> Gert van den Berg.  Ring 0 by default has io permissions.
>
> IOPL is a independent value to rings.  To be correct it assigns what IO permission rings has.  Basically from ring 0-3 call can be assigned IO permissions if you want.  Even that they have related kinds of numbers.  And that it is assigned to the ring running the application for it to work.
>
> http://wiki.osdev.org/Security#I.2FO_Privilege_Level
>
(My assembler books are a few hundred km's away and the Intel
documentation is spread between 10's of PDFs...)

Ah, ok, so it looks like the IOPL is a flag value determining for
which rings the port permissions (settable with ioperm on Linux) is
checked?

> Now issue here we really don't want to have to grant this to anything non native.  Even granting this to X11 risks big problems.
>
Direct I/O is dangerous.... (Even when ignoring the problems that
multitasking causes...) Which is why I started my first reply with a
rant on ehy it should never be done...

> Really is a last resort option to enable iopl since it grants way too much access and can cause the kernel to die.   ioperm maybe.   But it can also have bad effects.
>
ioperm with all ports aren't much better....

> Also any code using ioperm or iopl is Linux only.   Must always be kept in mind that it is such.

I was under the impression that BSD also have a iopl call, but it
seems that I am wrong...



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