Re: [PATCH v11 net-next 11/12] net: filter: move eBPF instruction macros

[Alexei Starovoitov]

On Wed, Sep 10, 2014 at 4:24 AM, Daniel Borkmann <dborkman@xxxxxxxxxx> wrote:
> On 09/10/2014 07:10 AM, Alexei Starovoitov wrote:
>>
>> move instruction macros (like BPF_MOV64_REG or BPF_ALU32_IMM)
>> from linux/filter.h into uapi/linux/bpf.h
>> so that userspace programs can use them.
>>
>> verifier testsuite (in later patches) will be using them.
>>
>> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxxxx>
>
>
> I don't think we need this commit at all. These macros are not really
> part of the ABI and we should expose __as less as possible__, otherwise
> we won't be able to alter them anymore. Plus, based on your previous
> argumentation regarding the header file expose, we also won't be able
> to add any new macros anymore since you could run into name collisions.
>
> Anyway, I don't see a reason why a e.g. central user space eBPF library
> cannot live with, for example, a private copy of these helper macros or
> whatever it wants to define by itself.
>
> I know in classic BPF there's BPF_STMT() and BPF_JUMP() but it's much
> less complicated than eBPF and less likely to changes.

Interesting idea. Are you saying just copy paste these
226 lines into user libbpf.h for now to use them in testsuite
and examples ? Hmm.
Indeed the less lines we add to uapi the better. I'll do that.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/