Re: [PATCH net-next] net: ethernet: rmnet: Restructure if checks to avoid uninitialized warning

subashab
2021-06-04T05:15:14Z

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.