prelink should not mess with running executables

[Andrew Haley]

On 07/18/2012 02:25 AM, Sam Varshavchik wrote:
> Chris Adams writes:
> 
>> Once upon a time, Sam Varshavchik <mrsam at courier-mta.com> said:
>>> Chris Adams writes:
>>>> Is there any value in this "additional check" (that nobody else
>>>> apparently does)?  Do you not trust the kernel's credential handling?
>>>
>>> I certainly trust it. But just because I trust it, it doesn't mean that any
>>> additional checks have no value.
>>
>> Sure it does.  If the credentials are always correct, additional checks
>> past that are a waste of cycles.
> 
> You feel absolutely confident that just because you can't think of any value  
> of additional checks, there cannot possibly be any.
> 
> You're wrong.
> 
>>                                  I ask again: do you have a legitimate
>> use case?  Is there _any_ case that other checks can succeed that this
>> invented test of yours would catch?
> 
> I already explained what they are.

Not exactly.  You said:

> Can you explain, then, the "correctly" approach by which an
> executable can affirm whether another pid is either running the same
> executable, or the post-prelinked version of the same
> executable. Anyone who suggests readlinking /proc/self/exe, then
> the other /proc/pid/exe, and comparing them sans any hardcoded "
> (deleted)" suffix is going to get only howls of laughter, in
> response.

But that's not a use case.  There's no way to know why you want to do
this: why you care that another process is running the exact same
executable.

Andrew.