[patch] Adding stack markings to the x86 assembly for not using executable stack

[Tom Rodriguez]

>> Are you sending this patch upstream?  It would be good to have some
>> feedback from the HotSpot developers before we commit this for a
>> release.
>>
>> Does this affect SPARC too?
>
> I'm not familiar with SPARC hardware, but if it supports "execute"  
> memory
> protections, then it is a valuable change there too.  It it doesn't,  
> it
> won't hurt anything, IIUC.

The machinery for this on Solaris is completely different.  On Solaris  
it's done using mapfiles and it wouldn't be a bad idea to request non- 
executable stacks though this brings up a question about how all this  
interacts with shared libraries.  If you have an executable that  
disables execute and it dlopens a library that doesn't, what happens?   
Presumably the executables and libraries have to be in agreement for  
this to really work, right?

tom

>
> -Kees
>
> -- 
> Kees Cook
> Ubuntu Security Team