Re: determining the stack bounds

[Bruno Haible]

Eric Blake wrote:
> user_context->uc_stack.ss_sp contains the location 
> of the currently running (alternate) stack, not the stack where the fault 
> occurred.   ... find out where the _original_ stack ended
> ...
> I haven't looked at how libsigsegv handles this situation

libsigsegv has a solution that works for most platforms, distributed over
several files:

  File                 platforms              uses

  stackvma-linux.c     Linux                  /proc/self/maps, mincore()
  stackvma-freebsd.c   FreeBSD                /proc/curproc/map, mincore()
  stackvma-mincore.c   OpenBSD, NetBSD        mincore()
  stackvma-mach.c      MacOS X                vm_region()
  stackvma-procfs.c    IRIX, OSF/1, Solaris   ioctl(PIOCMAP)
  stackvma-beos.c      BeOS                   get_next_area_info()

Would help to move this code to gnulib? Are there other uses of the stack VMA?
(Conservative garbage-collectors and Scheme interpreters only need to know
the current stack pointer and the stack top, AFAIK, not the stack bottom.)

Bruno