Re: [2.6 patch] make UNIX a bool

From: Adrian Bunk
Date: Fri Mar 03 2006 - 10:08:09 EST


On Fri, Mar 03, 2006 at 09:48:46AM -0500, James C. Georgas wrote:
> On Fri, 2006-03-03 at 12:46 +0100, Adrian Bunk wrote:
> > On Thu, Mar 02, 2006 at 11:44:57PM -0500, James C. Georgas wrote:
> > > On Thu, 2006-02-03 at 22:44 +0100, Adrian Bunk wrote:
> > >
> > > > > >
> > > > > > We do not have to export symbols we don't want to export to modules but
> > > > > > needed by CONFIG_UNIX.
> > > > >
> > > > > Sorry, I must just be dense, or something.
> > > > >
> > > > > Is not the only difference between a modular driver and a built in
> > > > > driver supposed to be the initialization and cleanup functions?
> > > > >
> > > > > I don't see why you would have to expose any additional symbols, over
> > > > > and above the existing required symbols, to load your module.
> > > >
> > > > Every kernel symbol a module uses must be explicitely exported with
> > > > EXPORT_SYMBOL.
> > >
> > > Yes, I understand that I need to export symbols to define the interface
> > > to my driver. whether its a module or compiled in. This is how other
> > > systems interact with my driver, right?
> >
> > EXPORT_SYMBOL is only required for modules.
> >
> > > > CONFIG_UNIX uses symbols that are neither used by any other in-kernel
> > > > modules nor should be exported.
> > >
> > > Are you saying that AF_UNIX has to export symbols for its own private
> > > functions in order to call them? I guess I don't understand this. Why
> > > not just call them. They're in scope within the driver code, aren't
> > > they?
> >
> > No, this is about functions defined in other parts of the kernel.
> >
>
> Ok, if I understand you correctly now, there is a function defined in
> another part of the kernel, which is _called_ by AF_UNIX, and it is for
> this function that the other part of the kernel must export a symbol?
>
> But you only need to do this so that modules can use the function,
> because if, instead, the driver is built in, then the function is
> directly in scope, and can be called explicitly?

Correct.

> James C. Georgas <jgeorgas@xxxxxxxxxx>

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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