dynamically written code problem

[Tolga Dalman]

hi,

On Mon, 11 Oct 2004 10:10:43 +0200 Paolo Bonzini <paolo.bonzini@polimi.it>
wrote:

> > > on my system, mmap is allocating in the 0x40000000 range, and malloc 
> > > is allocating at the brk (around 0x08000000).  Is this different when 
> > > exec-shield is activated?
> > 
> > Yes.  mmap with PROT_EXEC set attempts to allocate as low as possible,
> > usually below the executable.
> > mmap without PROT_EXEC allocates as high as possible, below the stack.
> 
> So at least my function does not lose execute protection if mmap was 
> used with PROT_EXEC.  Thank you very much,

the mprotect man-page says:

" POSIX.1b says  that  mprotect  can  be  used  only on regions of memory
obtained from mmap(2)."

is there a way to set the PROT_EXEC flag on arbitrary malloc'ed space ? at
least, using mprotect is (currently) not POSIX conforming. 

regards, 
Tolga Dalman