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Date:   Fri, 6 Oct 2023 13:56:59 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Alex Williamson <alex.williamson@redhat.com>
Cc:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        liucong2@kylinos.cn, yishaih@nvidia.com, brett.creeley@amd.com
Subject: Re: [PATCH] vfio: Fix smatch errors in vfio_combine_iova_ranges()
Message-ID: <20231006165659.GX13795@ziepe.ca>
References: <20230920095532.88135-1-liucong2@kylinos.cn>
 <20231002224325.3150842-1-alex.williamson@redhat.com>
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On Mon, Oct 02, 2023 at 04:43:25PM -0600, Alex Williamson wrote:
> smatch reports:
> 
> vfio_combine_iova_ranges() error: uninitialized symbol 'last'.
> vfio_combine_iova_ranges() error: potentially dereferencing uninitialized 'comb_end'.
> vfio_combine_iova_ranges() error: potentially dereferencing uninitialized 'comb_start'.
> 
> These errors are only reachable via invalid input, in the case of
> @last when we receive an empty rb-tree or for @comb_{start,end} if the
> rb-tree is empty or otherwise fails to produce a second node that
> reduces the gap.  Add tests with warnings for these cases.
> 
> Reported-by: Cong Liu <liucong2@kylinos.cn>
> Link: https://lore.kernel.org/all/20230920095532.88135-1-liucong2@kylinos.cn
> Cc: Yishai Hadas <yishaih@nvidia.com>
> Cc: Brett Creeley <brett.creeley@amd.com>
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> ---
>  drivers/vfio/vfio_main.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)

Yeah, this is much clearer

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Thanks,
Jason