prelink should not mess with running executables

[Bryn M. Reeves]

On 07/17/2012 12:01 PM, Sam Varshavchik wrote:
> Andrew Haley writes:
>> Yes, it's the pathname that started this process.  Yes, that pathname
>> may point to file that no longer exists.  That's UNIX.
> 
> No, that's Linux with prelink installed.

And a number of other common configurations for e.g. a Fedora system set
to automatically apply security updates in the background.

> Perhaps this might be a hard concept to wrap one's brain around, but there's  
> a quite a bit of difference between "this is an exceptional event, and  
> that's what happens when i does", versus "this is now a normal occurence  
> that, with prelink installed, and can happen to any random executable, at  
> any time."
> 
> Across the pond, I believe that there's a word to describe this: "rubbish".  

Throwing pejoratives around doesn't change the situation.

> How presumptious of an executable binary, that's not world-writable, to  
> expect that nobody's going to come around, suddenly, and delete it! What  
> would those kids think of next…

Prelink is not new. I think the fact that it's been in the distro for
many years without breaking other apps that are doing this
read-my-own-binary thing suggests that that is not a common idiom for
UNIX programs (that's not to say it has never caused any problems but
you seem to be questioning the entire design).

> Sure. And since gruesome car wrecks are a normal, everyday occurence,  
> there's no reason to do anything to davoid them. That's how they always  
> work, and anyone will just have to deal with the aftermath, without  
> bothering to take any steps to avoid the situation in the first place, right?

Adding more hyperbole and strawman arguments does not change the fact
that this can and does happen on Linux and UNIX environments and that
programs need to be aware of it and deal with it reasonably when it does
happen.

Ken Thompson once stated that if he wrote UNIX again he would spell
"creat" with an 'e' but nobody is proposing changing that today.

Regards,
Bryn.