Re: [net-next v5 01/15] virtchnl: Extend AVF ops

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 10 Sep 2020 21:06:05 +0000 Brady, Alan wrote:
> > It seems like these are triggering on old messages too, curious why this wasn't
> > caught sooner.  Will fix, thanks.
> > 
> I managed to get a 32-bit build environment setup and found that we
> do indeed have alignment issues there on 32 bit systems for some of
> the new ops we added with the series.  However, I think I'm still
> missing something as it looks like you have errors triggering on much
> more than I found and I'm suspecting there might be a compile option
> I'm missing or perhaps my GCC version is older than yours.  E.g., I
> found issues in virtchnl_txq_info_v2, virtchnl_rxq_info_v2,
> virtchnl_config_rx_queues, and virtchnl_rss_hash.  It appears you
> have compile issues in virtchnl_get_capabilities (among others)
> however which did not trigger on mine.  Manual inspection indicates
> that it _should_ be triggering a failure and that your setup is more
> correct than mine.  I'm guessing some extra padding is getting
> included in some places and causing a false positive on the other
> alignment issues.  Are there any hints you can provide me that might
> help me more accurately reproduce this?

Hm. I build like this:

make CC="ccache gcc" O=build32/ ARCH=i386 allmodconfig
make CC="ccache gcc" O=build32/ ARCH=i386 -j 64 W=1 C=1

My GCC is:
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-10.1.0/configure --enable-languages=c,c++
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 10.1.0 (GCC)