Date: Tue, 31 May 2022 22:29:08 +0200 From: Mateusz Guzik <mjguzik@gmail.com> To: "Alexander V. Chernikov" <melifaro@ipfw.ru> Cc: "Alexander V. Chernikov" <melifaro@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org>, "dev-commits-src-all@freebsd.org" <dev-commits-src-all@freebsd.org>, "dev-commits-src-main@freebsd.org" <dev-commits-src-main@freebsd.org> Subject: Re: git: 8c0d1eca7834 - main - sockbuf: retain backward compatibility with userland after d59bc188d652 Message-ID: <CAGudoHEsdu84krtXXCq4Tam7sOV=AYjeF50Ak76sw7_YDO26Hg@mail.gmail.com> In-Reply-To: <5A6DF60F-9584-43D4-BBF8-18634742A7C3@ipfw.ru> References: <202205301510.24UFAxvj014259@gitrepo.freebsd.org> <CAGudoHGptA4h2Nvb06WCTP7iXbWMNGgcUgiCeaFL0cXz=7TGnw@mail.gmail.com> <8909171653936542@iva6-17bf07036239.qloud-c.yandex.net> <CAGudoHG1v1f86v8mGjs7W5hq1ibrjKaJ4fZTyxAfAufuYD6A0A@mail.gmail.com> <5A6DF60F-9584-43D4-BBF8-18634742A7C3@ipfw.ru>
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On 5/31/22, Alexander V. Chernikov <melifaro@ipfw.ru> wrote:
>
>
>> On 31 May 2022, at 15:33, Mateusz Guzik <mjguzik@gmail.com> wrote:
>>
>> On 5/30/22, Alexander V. Chernikov <melifaro@ipfw.ru> wrote:
>>>
>>>
>>> 30.05.2022, 16:18, "Mateusz Guzik" <mjguzik@gmail.com>:
>>>>
>>>> should probably CTASSERT on size then
>>>
>>> Sorry, I=E2=80=99m afraid I don=E2=80=99t get it. Could you please clar=
ify?
>>>>
>>
>> diff --git a/sys/sys/socketvar.h b/sys/sys/socketvar.h
>> index 249e0800f915..5fc21206b1bf 100644
>> --- a/sys/sys/socketvar.h
>> +++ b/sys/sys/socketvar.h
>> @@ -586,6 +586,14 @@ struct xsocket {
>> } so_rcv, so_snd;
>> };
>>
>> +#if _LP64
>> +_Static_assert(sizeof(struct xsocket) =3D=3D 240, "bad=E2=80=9D)
> Ah, got it!
> Well, the rationale for the commit was not to absolutely prevent structur=
e
> size changes - there may be many perfectly valid reasons to do so.
> IIRC policy suggests it acceptable between the major revisions.
> In the case of original change - removal of mbuf counters - backward
> compatibility (e.g. keeping structure size the same) does not cost us
> anything.
> sockstat(1) from 13 will work on 14 (at least for now).
>
it will prevent accidental changes
>> +#elsif _LP32
>> +....
>> +#else
>> +#error "port me"
>> +#endif
>> +
>> #ifdef _KERNEL
>> void sotoxsocket(struct socket *so, struct xsocket *xso);
>> void sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb);
>>
>>>> On 5/30/22, Alexander V. Chernikov <melifaro@freebsd.org> wrote:
>>>>>
>>>>> The branch main has been updated by melifaro:
>>>>>
>>>>> URL:
>>>>> https://cgit.FreeBSD.org/src/commit/?id=3D8c0d1eca7834bfd5a05c86bf20a=
7600917057492
>>>>>
>>>>> commit 8c0d1eca7834bfd5a05c86bf20a7600917057492
>>>>> Author: Alexander V. Chernikov <melifaro@FreeBSD.org>
>>>>> AuthorDate: 2022-05-30 14:56:25 +0000
>>>>> Commit: Alexander V. Chernikov <melifaro@FreeBSD.org>
>>>>> CommitDate: 2022-05-30 15:10:53 +0000
>>>>>
>>>>> sockbuf: retain backward compatibility with userland after
>>>>> d59bc188d652
>>>>>
>>>>> Add spare fields to xsockbuf in place of sb_mcnt / sb_ccnt to
>>>>> avoid
>>>>> rebuilding userland binaries like sockstat(1).
>>>>>
>>>>> Reviewed by: glebius
>>>>> ---
>>>>> sys/sys/socketvar.h | 2 ++
>>>>> 1 file changed, 2 insertions(+)
>>>>>
>>>>> diff --git a/sys/sys/socketvar.h b/sys/sys/socketvar.h
>>>>> index 52b9376f0559..249e0800f915 100644
>>>>> --- a/sys/sys/socketvar.h
>>>>> +++ b/sys/sys/socketvar.h
>>>>> @@ -577,6 +577,8 @@ struct xsocket {
>>>>> uint32_t sb_cc;
>>>>> uint32_t sb_hiwat;
>>>>> uint32_t sb_mbcnt;
>>>>> + uint32_t sb_spare0; /* was sb_mcnt */
>>>>> + uint32_t sb_spare1; /* was sb_ccnt */
>>>>> uint32_t sb_mbmax;
>>>>> int32_t sb_lowat;
>>>>> int32_t sb_timeo;
>>>>>
>>>>
>>>>
>>>> --
>>>> Mateusz Guzik <mjguzik gmail.com>
>>>
>>
>>
>> --
>> Mateusz Guzik <mjguzik gmail.com>
>
>
--=20
Mateusz Guzik <mjguzik gmail.com>
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