difference between compiling Kernel modules for linux 2.4 with gcc 3.4 rather than 3.3

[Åke Forslund <aforslund at lasermaxroll dot se>]

Hello,

My question is about differences between gcc-3.3 and gcc-3.4 and is asked mostly because of curiosity since I've got a working solution.

We have an old x86-based product that uses RTL on Linux 2.4 and to build it we use a virtual Mandrake machine from way back. Earlier this week I got fed up with the old build system and started migrating to a more modern distro (Debian Squeeze). gcc-4.4 showed lots of warnings and in the end no object file was created. 

I downgraded to gcc-3.4 and managed to get module compiled but for some reason modinfo doesn't output anything and when installing the module in our target system we get 

???????????????????????????? uw.o: couldn't find the kernel version the module was compiled for

After testing switching to older version of libraries and what not to no avail I installed gcc-3.3 (the version used on the old build machine), and with after compiling with this version modinfo shows:

Filename:???????? ???????????????????????????? uw.o
kernel_version:????????????????????????? 2.4.21
kernel_version:????????????????????????? 2.4.21
kernel_version:????????????????????????? 2.4.21
etc.

and the module works fine when installed.

What is different between the gcc-versions 3.3 and 3.4 that can cause this behavior or is there some quirky behavior of the Linux-headers?

Flags used for the project:
-D__KERNEL__ -Wall -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common \
??? -pipe -mpreferred-stack-boundary=2 -march=i586 -DMODULE -fomit-frame-pointer \
??? -D__RTL__ -D_LOOSE_KERNEL_NAMES -O2 \
??? -I$(RTL_DIR)/linux/include \
??? -I$(RTL_DIR)/include \
??? -I$(RTL_DIR)/include/compat \
??? -I$(RTL_DIR)/include/posix \


Best regards
/ Åke Forslund

Åke Forslund
Lasermax Roll Systems
Tel: +46 (0) 372-25639