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Date:   Thu, 18 Oct 2018 09:32:31 +0300
From:   Dan Carpenter <dan.carpenter@oracle.com>
To:     kys@microsoft.com
Cc:     gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
        devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com,
        jasowang@redhat.com, sthemmin@microsoft.com,
        Michael.H.Kelley@microsoft.com, vkuznets@redhat.com,
        Haiyang Zhang <haiyangz@microsoft.com>
Subject: Re: [PATCH V2 5/5] Tools: hv: kvp: Fix a warning of buffer overflow
 with gcc 8.0.1
Message-ID: <20181018063230.v6hp5e3agk62c3s3@mwanda>
References: <20181018050835.27828-1-kys@linuxonhyperv.com>
 <20181018050932.27932-1-kys@linuxonhyperv.com>
 <20181018050932.27932-5-kys@linuxonhyperv.com>
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On Thu, Oct 18, 2018 at 05:09:32AM +0000, kys@linuxonhyperv.com wrote:
> From: Dexuan Cui <decui@microsoft.com>
> 
> The patch fixes:
> 
> hv_kvp_daemon.c: In function 'kvp_set_ip_info':
> hv_kvp_daemon.c:1305:2: note: 'snprintf' output between 41 and 4136 bytes
> into a destination of size 4096
> 
> The "(unsigned int)str_len" is to avoid:
> 
> hv_kvp_daemon.c:1309:30: warning: comparison of integer expressions of
> different signedness: 'int' and 'long unsigned int' [-Wsign-compare]
> 

Ugh...  Any tool with the most basic flow analysis would realize this
was a false positive.  We use at least three static analyzers which
catch signedness bugs.  Can we turn off GCC's warning on this until they
improve it a bit?

regards,
dan carpenter