linux-kernel - Re: x86/fpu: Don't export __kernel_fpu

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Message-ID: <20190109165235.GA8151@kroah.com>
Date:   Wed, 9 Jan 2019 17:52:35 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Cc:     Marc Dionne <marc.c.dionne@...il.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        x86@...nel.org
Subject: Re: x86/fpu: Don't export __kernel_fpu_{begin,end}()

On Wed, Jan 09, 2019 at 12:19:52PM +0100, Sebastian Andrzej Siewior wrote:
> On 2019-01-07 18:08:26 [-0400], Marc Dionne wrote:
> > On Thu, Dec 27, 2018 at 11:20 AM Linux Kernel Mailing List
> > <linux-kernel@...r.kernel.org> wrote:
> > >
> > > Commit:     12209993e98c5fa1855c467f22a24e3d5b8be205
> > >     x86/fpu: Don't export __kernel_fpu_{begin,end}()
> > >
> …
> > >     With EFI gone as the last user of __kernel_fpu_{begin|end}(), both can
> > >     be made static and not exported anymore.
> > >
> > This commit removes an exported function pair that is currently used
> > by out of tree modules, while the replacement pair
> > (kernel_fpu_begin/end) is EXPORT_SYMBOL_GPL.  So this is making
> > existing functionality GPL only, which will probably be an issue for
> > several out of tree modules that use the fpu.
> > 
> > Could kernel_fpu_begin/end be made plain EXPORT_SYMBOL?
> 
> It can be used by OOT modules as long as they are not under a
> proprietary license. The change here is not for me to decide, I added
> the x86 maintainers to make their decision. I can make a patch if they
> say so.

If there are no in-kernel users, the symbols should not be exported
anymore.  That's nothing new, we have always done this.

> On the other hand could we just drop EXPORT_SYMBOL_GPL? I doubt this
> helps in any way yet please correct me if I am wrong. 

Yes, it helps, please leave it as-is.

thanks,

greg k-h