Intended Security Hole?

[Justin Whear]

On Wednesday, 24 October 2012 at 21:07:28 UTC, Manfred Nowak 
wrote:
> Chris Cain wrote:
>
>> So, no, the implementation wouldn't be changed during runtime 
>> since it must be provided when linking.
>
> Thats an expressed intent only. Reason: the linker does not 
> know any
> thing about the language; the linker would be satisfied if there
> exists any function the linker can link to ... but the linker 
> would
> not prohibit any replacement of that function during runtime.

If the code in question is statically linked, this is not a 
problem.  If it's a shared library which is linked at runtime, 
then this is actually intended behavior and is used to create 
library shims.  Here's an introduction to the technique: 
http://www.linuxjournal.com/article/7795