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Date: Mon, 13 May 2019 14:04:35 +0200
From: Christoph Hellwig <hch@lst.de>
To: Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [PATCH, RFC] byteorder: sanity check toolchain vs kernel endianess
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On Mon, May 13, 2019 at 01:50:19PM +0200, Dmitry Vyukov wrote:
> > We did have some bugs in the past (~1-2 y/ago) but AFAIK they are all
> > fixed now. These days I build most of my kernels with a bi-endian 64-bit
> > toolchain, and switching endian without running `make clean` also works.
> 
> For the record, yes, it turn out to be a problem in our code (a latent
> bug). We actually used host (x86) gcc to build as-if ppc code that can
> run on the host, so it defined neither LE no BE macros. It just
> happened to work in the past :)

So Nick was right and these checks actually are useful..