Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: subashab=codeaurora.org@mg.codeaurora.org
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII;
 format=flowed
Content-Transfer-Encoding: 7bit
Date:   Thu, 03 Jun 2021 23:15:10 -0600
From:   subashab@codeaurora.org
To:     patchwork-bot+netdevbpf@kernel.org
Cc:     Nathan Chancellor <nathan@kernel.org>, stranche@codeaurora.org,
        davem@davemloft.net, kuba@kernel.org, ndesaulniers@google.com,
        sharathv@codeaurora.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: Re: [PATCH net-next] net: ethernet: rmnet: Restructure if checks to
 avoid uninitialized warning
In-Reply-To: <162276000605.13062.14467575723320615318.git-patchwork-notify@kernel.org>
References: <20210603173410.310362-1-nathan@kernel.org>
 <162276000605.13062.14467575723320615318.git-patchwork-notify@kernel.org>
Message-ID: <1f6f8246f0cd477c0b1e2b88b4ec825a@codeaurora.org>
User-Agent: Roundcube Webmail/1.3.9
Precedence: bulk

On 2021-06-03 16:40, patchwork-bot+netdevbpf@kernel.org wrote:
> Hello:
> 
> This patch was applied to netdev/net-next.git (refs/heads/master):
> 
> On Thu,  3 Jun 2021 10:34:10 -0700 you wrote:
>> Clang warns that proto in rmnet_map_v5_checksum_uplink_packet() might 
>> be
>> used uninitialized:
>> 
>> drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:283:14: warning:
>> variable 'proto' is used uninitialized whenever 'if' condition is 
>> false
>> [-Wsometimes-uninitialized]
>>                 } else if (skb->protocol == htons(ETH_P_IPV6)) {
>>                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:295:36: note:
>> uninitialized use occurs here
>>                 check = rmnet_map_get_csum_field(proto, trans);
>>                                                  ^~~~~
>> drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:283:10: note:
>> remove the 'if' if its condition is always true
>>                 } else if (skb->protocol == htons(ETH_P_IPV6)) {
>>                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:270:11: note:
>> initialize the variable 'proto' to silence this warning
>>                 u8 proto;
>>                         ^
>>                          = '\0'
>> 1 warning generated.
>> 
>> [...]
> 
> Here is the summary with links:
>   - [net-next] net: ethernet: rmnet: Restructure if checks to avoid
> uninitialized warning
>     https://git.kernel.org/netdev/net-next/c/118de6106735
> 
> You are awesome, thank you!
> --
> Deet-doot-dot, I am a bot.
> https://korg.docs.kernel.org/patchwork/pwbot.html

Hi Nathan

Can you tell why CLANG detected this error.
Does it require a bug fix.