linux-kernel - Re: [PATCH v1] uml: remove support for CONFIG_STATIC_LINK

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Date:   Tue, 10 Dec 2019 08:54:45 +0000
From:   Anton Ivanov <anton.ivanov@...bridgegreys.com>
To:     Johannes Berg <johannes@...solutions.net>,
        Richard Weinberger <richard@....at>,
        Brendan Higgins <brendanhiggins@...gle.com>
Cc:     Jeff Dike <jdike@...toit.com>,
        linux-um <linux-um@...ts.infradead.org>,
        linux-kernel <linux-kernel@...r.kernel.org>, davidgow@...gle.com
Subject: Re: [PATCH v1] uml: remove support for CONFIG_STATIC_LINK

On 10/12/2019 08:28, Johannes Berg wrote:
> On Tue, 2019-12-10 at 07:34 +0000, Anton Ivanov wrote:
> 
>>> Further to this - any properly written piece of networking code which
>>> uses the newer functions for name/service resolution will have the same
>>> problem. You can be static only if you do everything "manually" the old
>>> way.
>>
>> The offending piece of code is the glibc implementation of getaddrinfo().
>>
>> If you use it and link static the resulting binary is not really static.
> 
> However, this (getaddrinfo) really only applies if you use the vector
> network driver, if you e.g. use only virtio then this particular problem
> isn't present.
> 
> Note sure if we implicitly call getaddrinfo from libpcap, but again,
> that's just a single driver.
> 
> IOW, we could just make CONFIG_STATIC_LINK depend on !VECTOR && !PCAP?

+1

We also need to add VDE (wonder if anyone still uses that).

We will need to add XDP when I finish it. If memory servces me right, 
libelf or libbpf has the same lovely features as NSS.

This is not just NSS - it is creeping in with a lot of new libraries. 
Sometimes the libc guys fix that. For example, librt was like that when 
I started working on epoll and vector IO.

Sometimes (as in the NSS case) they don't. So the static build 
containing those will be broken and we are better off making it conflict 
for those options.

> 
> johannes
> 
> 
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> 

-- 
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/

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