Tainted kernels:

With details below, drivers with propietary components set a Tainted
label on kernels. This is only a warning to Users and alerts 
developers/experts that the drivers cannot be fully debugged.
Effects of closed source modules range from minor nuisances to system
crashes, judging from reports to discuss@linmodems.org.

For the Lucent DSP modem drivers, there are three recognized problems: 
1) infrared communications mediated through the irda.o module do not
function after the modem drivers have beem loaded; 
2) On smp ( Symmetric MultiProcessor)  motherboards with supporting smp
kernels, dialout and ppp are intitially achieved.  But ppp subsequently
fails.  This problem can be bypassed, through use of a NOAPIC bootup option;
3) After usage of Hylafax with  FaxGetty, the modem drivers unload with
version 6.00 drivers, but Not with the current 8.26 ltmodem drivers.

From /usr/src/Lnx/linux-2.4.17/Documentation/oops-tracing.txt
-------------------------------------------------------------------------
Some oops reports contain the string 'Tainted: ' after the program
counter, this indicates that the kernel has been tainted by some
mechanism.  The string is followed by a series of position sensitive
characters, each representing a particular tainted value.

  1: 'G' if all modules loaded have a GPL or compatible license, 'P' if
     any proprietary module has been loaded.  Modules without a
     MODULE_LICENSE or with a MODULE_LICENSE that is not recognised by
     insmod as GPL compatible are assumed to be proprietary.

  2: 'F' if any module was force loaded by insmod -f, ' ' if all
     modules were loaded normally.

The primary reason for the 'Tainted: ' string is to tell kernel
debuggers if this is a clean kernel or if anything unusual has
occurred.  Tainting is permanent, even if an offending module is
unloading the tainted value remains to indicate that the kernel is not
trustworthy.


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Last week's Usenix Technical Conference brought together academics, high-end
information technology professionals and old-school UNIX gurus. And
Linus Torvalds.

During the "Birds of a Feather" (BoF) session held on
the evening of June 14 at the Usenix Conference,
  >>   Linus Torvalds <<  took questions about the
present and future of Linux. One question came from
a Linux administrator at a Very Large Company that is
struggling with the issue of making a vendor's
binary-only kernel modules play well with an up-to-date
Linux system. 

"I'm a complete non-believer in binary modules",
Torvalds said, reiterating what has become the
conventional wisdom of the Linux-kernel mailing list
and experienced Linux support people. "Most houses
that use Linux a lot say that they won't support binary
modules because they can't. They may work, but
you're not getting the full advantage of Linux", he
added. On the legal side, there is no specific exception for
binary-only modules. "They're borderline legal. There's
nothing in the license that says you're excused from the GPL", Torvalds said. 
