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From: Arvind Sankar <nivedita@alum.mit.edu>
Date: Tue, 7 Jul 2020 17:59:25 -0400
Subject: Re: [PATCH v6 2/8] lib: prepare xxhash for preboot environment
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Cc: Borislav Petkov <bp@alien8.de>, Thomas Gleixner <tglx@linutronix.de>, linux-kernel@vger.kernel.org, Chris Mason <clm@fb.com>, linux-kbuild@vger.kernel.org, x86@kernel.org, gregkh@linuxfoundation.org, Petr Malat <oss@malat.biz>, Kees Cook <keescook@chromium.org>, Kernel Team <Kernel-team@fb.com>, Adam Borowski <kilobyte@angband.pl>, Patrick Williams <patrickw3@fb.com>, rmikey@fb.com, mingo@kernel.org, Patrick Williams <patrick@stwcx.xyz>, Sedat Dilek <sedat.dilek@gmail.com>, Norbert Lange <nolange79@gmail.com>, Andrew Morton <akpm@linux-foundation.org>, Nick Terrell <terrelln@fb.com>

On Mon, Jul 06, 2020 at 08:45:58PM -0700, Nick Terrell wrote:
> From: Nick Terrell <terrelln@fb.com>
> 
> Don't export symbols if XXH_PREBOOT is defined.
> 
> This change is necessary to get xxhash to work in a preboot environment,
> which is needed to support zstd-compressed kernels.

The usual way to do it is by adding -D__DISABLE_EXPORTS to the CFLAGS, which will
cause EXPORT_SYMBOL to be stubbed out. Doesn't that work here?