Re: [PATCH/RFA] Don't relocate SunOS-style a.out dynamic executables

[Kevin Buettner <kevinb@redhat.com>]

On Sun, 22 Aug 2004 20:56:34 +0200 (CEST)
Mark Kettenis <kettenis@chello.nl> wrote:

> Since I was curious whether our SunOS-style a.out shared library
> support still worked, I fired up my virtual VAX[1] and installed
> NetBSD 1.5.2 on it.  Alas, GDB didn't quite work, and indeed the
> solib-sunos.c code is to blame.  Some debugging revealed that the code
> was relocating the main executable over two bytes.  If you know a bit
> about the VAX and look at the code it is pretty easy to see why.  VAX
> functions start at an offset of two bytes from the function's address.

Those two bytes are a register save mask?  (Not that it matters; just
trying to remember something that I knew a very long time ago.)

> The code in sunos-solib.c:sunos_relocate_main_executable() compares
> the PC with the entry point as recorded in the executable.  Since
> these differ by two bytes, the code relocates the main executable over
> those two bytes.  
> 
> The easiest way to solve the problem would be to rip out the code that
> tries to relocate the executable.  AFAIK SunOS-style a.out executable
> aren't relocatable.  This code is probably just a leftover from when
> the SunOS code was split out of the SVR4 code.  Is that right?

That sounds like a reasonable guess to me.  FWIW, I did test the code
after the split, but I tested it on an old SunOS (sparc architecture)
system.
 
> If so, I'd like to apply the attached patch.

Sure.  It's okay with me.

Kevin