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Date:   Thu, 10 Jan 2019 19:07:52 +0100
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     "Hutter, Tony" <hutter2@llnl.gov>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Marc Dionne <marc.c.dionne@gmail.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "x86@kernel.org" <x86@kernel.org>
Subject: Re: x86/fpu: Don't export __kernel_fpu_{begin,end}()
Message-ID: <20190110180752.f4cnunadzzkev24m@linutronix.de>
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On 2019-01-10 17:32:58 [+0000], Hutter, Tony wrote:
> > But since when did out-of-tree modules use __kernel_fpu_begin?  It's an
> > x86-only thing, and shouldn't really be used by anyone, right?
> 
> ZFS on Linux uses it for checksums.  Its removal is currently breaking ZFS builds against 5.0:

So btrfs uses crc32c() / kernel's crypto API for that and ZFS can't?
Well the crypto API is GPL only exported so that won't work. crc32c() is
EXPORT_SYMBOL() so it would work.
On the other hand it does not look right to provide a EXPORT_SYMBOL
wrapper around a GPL only interface…

Sebastian