From: Alexei Starovoitov <ast@plumgrid.com>
To: Daniel Borkmann <daniel@iogearbox.net>,
"David S. Miller" <davem@davemloft.net>
Cc: Thomas Graf <tgraf@suug.ch>,
linux-api@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 net-next 1/2] bpf: allow extended BPF programs access skb fields
Date: Fri, 13 Mar 2015 21:59:43 -0700 [thread overview]
Message-ID: <5503C03F.8020903@plumgrid.com> (raw)
In-Reply-To: <55039C9D.6010602@plumgrid.com>
On 3/13/15 7:27 PM, Alexei Starovoitov wrote:
> On 3/13/15 7:16 PM, Daniel Borkmann wrote:
>> On 03/14/2015 03:08 AM, Alexei Starovoitov wrote:
>>> On 3/13/15 7:06 PM, Daniel Borkmann wrote:
>>>> On 03/14/2015 02:46 AM, Daniel Borkmann wrote:
>>>> ...
>>>>> Previously, it was much more consistent, which I like better. And only
>>>>> because of the simple BUILD_BUG_ON()? :/
>>>>
>>>> Alternative is to move all of them into a central place, something like
>>>> in twsk_build_assert() or __mld2_query_bugs[].
>>>
>>> nope. that defeats the purpose of bug_on.
>>
>> Well, it doesn't. ;) It throws a build error thus the user is forced to
>> investigate that further.
>
> according to this distorted logic all build_bug_on can be in one file
> across the whole tree, since 'user is forced to investigate' ?!
also note that this case and twsk_build_assert are different.
twsk_build_assert has no other choice then to have one function
that covers logic in the whole file, whereas in this patch:
+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
+ *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
+ offsetof(struct sk_buff, mark));
the build_bug_on protect the line directly below.
Separating them just doesn't make sense at all.
next prev parent reply other threads:[~2015-03-14 4:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-13 18:57 [PATCH v2 net-next 0/2] bpf: allow eBPF access skb fields Alexei Starovoitov
2015-03-13 18:57 ` [PATCH v2 net-next 1/2] bpf: allow extended BPF programs " Alexei Starovoitov
2015-03-14 1:46 ` Daniel Borkmann
2015-03-14 2:06 ` Daniel Borkmann
2015-03-14 2:08 ` Alexei Starovoitov
2015-03-14 2:16 ` Daniel Borkmann
2015-03-14 2:27 ` Alexei Starovoitov
2015-03-14 4:59 ` Alexei Starovoitov [this message]
2015-03-14 9:35 ` Daniel Borkmann
2015-03-14 15:55 ` Alexei Starovoitov
2015-03-14 23:51 ` Daniel Borkmann
2015-03-15 2:02 ` Alexei Starovoitov
2015-03-14 2:07 ` Alexei Starovoitov
2015-03-13 18:57 ` [PATCH v2 net-next 2/2] samples: bpf: add skb->field examples and tests Alexei Starovoitov
2015-03-16 2:03 ` [PATCH v2 net-next 0/2] bpf: allow eBPF access skb fields David Miller
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