What is -fPIE (GCC) good for? [Was: Re: strange "Exec format error" (gcc4.2 suspicious)]

[Alex Dupre]

Harald Schmalzbauer ha scritto:
> a quick search told me that pie means Posix Independant Executable.

Position, not Posix.

> Has anybody a link handy where I can find an explanation why one would want to 
> have this?

 From Wikipedia:

Position-independent executables (PIE) are executable binaries made 
entirely from position-independent code. While some systems only run PIC 
executables, there are other reasons they are used. PIE binaries are 
used in some security-focused Linux distributions to allow PaX or Exec 
Shield to use address space layout randomization to prevent attackers 
from knowing where existing executable code is during a security attack 
using exploits that rely on knowing the offset of the executable code in 
the binary, such as return-to-libc attacks.

-- 
Alex Dupre