Re: [gentoo-embedded] Tool for eliminating non used code or symbols?

[Christopher Friedt]

-Wunused -Werror


On Mon, May 27, 2013 at 9:09 AM, Bertrand Jacquin <beber@××××××××.net>wrote:

> Hi,
>
> Finally, two months after your mail, I remembered a project I saw last
> year (or so) that might stick your need.
>
> http://anonscm.debian.org/**gitweb/?p=d-i/mklibs.git<http://anonscm.debian.org/gitweb/?p=d-i/mklibs.git>
> http://anonscm.debian.org/**gitweb/?p=d-i/mklibs.git;a=**
> blob_plain;f=src/mklibs;h=**216b34c1cb221458cd0d26c6bd5c71**
> 9c3bf94ab2;hb=HEAD<http://anonscm.debian.org/gitweb/?p=d-i/mklibs.git;a=blob_plain;f=src/mklibs;h=216b34c1cb221458cd0d26c6bd5c719c3bf94ab2;hb=HEAD>
>
> As describe, this tool :
>
> - Gather all unresolved symbols and libraries needed by the programs
>   and reduced libraries
> - Gather all symbols provided by the already reduced libraries
>   (none on the first pass)
> - If all symbols are provided we are done
> - go through all libraries and remember what symbols they provide
> - go through all unresolved/needed symbols and mark them as used
> - for each library:
>   - find pic file (if not present copy and strip the so)
>   - compile in only used symbols
>   - strip
> - back to the top
>
> Beber
>
>
> On 2013-03-25 08:01, Kfir Lavi wrote:
>
>> Hi,
>> I'm looking for a way to reduce glibc code size.
>> It can be a way to make system smaller and minimize the impact
>> of attack vectors in glibc, as in return-to-libc attack.
>>
>> Lets say I'm deleting the program 'mkdir', and mkdir uses a function
>> in glibc that non of the other parts of the system uses.
>> Then I want to eliminate this function from glibc. This leads to smaller
>> code and if this function is used in some attack scenario, maybe prevent
>> it.
>>
>> Is there a way to do it?
>> Can you help me think how to build a tool like this? or, integrate
>> with existing tools.
>>
>> Thanks,
>> Kfir
>>
>
>