Re: Non-static variables and nested function pointers [bug #28392]

[Seth Goldberg]

Quoting Grégoire Sutre, who wrote the following on Thu, 24 Dec 2009:

> Seth Goldberg wrote:
>
> >  Exactly -- the presence of the execstack attribute in the segment is 
> > merely a request -- the kernel is free to discard it, and many OSes do, as 
> > you've found :).
>
> The problem is more complex: I tried a simple example with a pointer to a 
> nested function, and it runs without any segfault on NetBSD/i386.
> This would suggest that, by default, the stack is executable -- at least if 
> trampolines are used?

  I forgot to add: the NX bit is only supported when PAE mode is enabled on a 
32-bit kernel, so if NetBSD/i386 isn't using PAE mode (for whatever reason), 
the NX bit won't be supported.

 --S