netdev - Re: [PATCH net-next 1/2] samples/bpf: fix sockex2 example

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Message-ID: <58356844.4030700@iogearbox.net>
Date:   Wed, 23 Nov 2016 10:58:28 +0100
From:   Daniel Borkmann <daniel@...earbox.net>
To:     Alexei Starovoitov <ast@...com>,
        "David S . Miller" <davem@...emloft.net>
CC:     netdev@...r.kernel.org
Subject: Re: [PATCH net-next 1/2] samples/bpf: fix sockex2 example

On 11/23/2016 01:52 AM, Alexei Starovoitov wrote:
> since llvm commit "Do not expand UNDEF SDNode during insn selection lowering"
> llvm will generate code that uses uninitialized registers for cases
> where C code is actually uses uninitialized data.
> So this sockex2 example is technically broken.
> Fix it by initializing on the stack variable fully.
> Also increase verifier buffer limit, since verifier output
> may not fit in 64k for this sockex2 code depending on llvm version.
>
> Signed-off-by: Alexei Starovoitov <ast@...nel.org>

Acked-by: Daniel Borkmann <daniel@...earbox.net>