Guest Additions build error

[mcockerell]

I have been using Linux for many years and have recently installed VirtualBox 4.0.8 on a Windows Vista laptop to allow me to support a couple of old Linux releases that I occasionally run to support some old appliances running embedded Linux (previously these releases were dual-booted on an old desktop PC that I wish to dispose of). The Linux releases were specifically chosen so that the kernel source and headers are the correct level for the cross-compilation that I need to do for the embedded systems, SuSE 10 (kernel 2.6.13) and Red Hat 9 (kernel 2.4.20).

I decided to install Guest Additions into each to allow me to have Shared Folder support. Absolutely no problems with the SuSE 10 system, installed and works like a dream; not quite so straightforward with the Red Hat 9 system, but I now have them working.

I chose to install Guest Additions on RH9 without DKMS, but although everything compiled cleanly the vboxguest kernel module failed to load with an unresolved symbol error for 'vunmap'; the 'vunmap' function is not available in a 2.4.20 kernel. I have tracked this problem to one particular source code files.

In memobj-r0drv-linux.c:
'vunmap' is potentially called in several places; in two of them a conditional compile directive replaces the 'vunmap' call with alternate code, however there are two places where it is called within rtR0MemObjNativeFree - I 'fixed' this problem by commenting these lines out in the source code.

Having done this I can successfully load the kernel module, start the additions and access my shared folder. I will raise a bug with the developers.

I have now confirmed that the same problem exists with version 4.0.10.

Regards,
Martin