Re: [PATCH] kernel: bpf: remove dead code

[Gustavo A. R. Silva]

Hi David,

Quoting David Miller <davem@xxxxxxxxxxxxx>:

> From: "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx>
> Date: Mon, 22 May 2017 09:07:46 -0500
>
> > Execution cannot reach NET_IP_ALIGN inside the following statement:
> > ip_align = strict ? 2 : NET_IP_ALIGN
> >
> > Addresses-Coverity-ID: 1409762
> > Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
> > ---
> > NOTE: variable ip_align could also be removed and use value 2 directly.
>
> Incorrect.
>
> Some platforms define NET_IP_ALIGN to zero, so the code must remain
> as is.

The following piece of code at kernel/bpf/verifier.c:798 is preventing  
value NET_IP_ALIGN to be stored in variable ip_align when _strict_ is  
false:

798        if (!strict || size == 1)
799                return 0;


Thanks
--
Gustavo A. R. Silva