Why do some kernels need "-DMODVERSIONS -include linux/modversions.h" ?

Timur Tabi <timur.tabi@xxxxxxxxxxx> · Tue, 16 Nov 2004 15:11:52 -0600

I have a driver that compiles under several different 2.4 and 2.6 
kernels.  It uses a number of tricks (mostly in the makefile) to 
determine what code to compile.

One particular kernel has me confused, however.  This is a customized 
kernel from a particular vendor, and I think it's based on Red Hat 8.0 
or something equally old.  The kernel version is 2.4.25-14.

The problem I'm having is that in order to insmod my driver, I need to 
specify "-DMODVERSIONS -include linux/modversions.h" on the gcc command 
line.

So I have two questions:

1) What is it about this particular kernel that requires modversion.h 
included?

2) Is there any characteristic of any of the kernel header or source 
files that I can scan for to allow me to know in advance whether I need

modversions.h?

--
Timur Tabi
Staff Software Engineer
timur.tabi@xxxxxxxxxxx

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