If vmplayer fails to compile on your 2.6.20 kernel with the following error

Extracting the sources of the vmmon module.

Building the vmmon module.

Building for VMware Player 1.0.2 or 1.0.3 or VMware Workstation 5.5.2 or 5.5.3.
Using 2.6.x kernel build system.
make: Entering directory `/tmp/vmware-config1/vmmon-only'
make -C /lib/modules/2.6.20-gentoo-r6/build/include/.. SUBDIRS=$PWD SRCROOT=$PWD/. modules
make[1]: Entering directory `/usr/src/linux-2.6.20-gentoo-r6'
CC [M]  /tmp/vmware-config1/vmmon-only/linux/driver.o
In file included from /tmp/vmware-config1/vmmon-only/linux/driver.c:85:
/tmp/vmware-config1/vmmon-only/./include/compat_kernel.h:21: error: expected declaration specifiers or ‘...’ before ‘compat_exit’
/tmp/vmware-config1/vmmon-only/./include/compat_kernel.h:21: error: expected declaration specifiers or ‘...’ before ‘exit_code’
/tmp/vmware-config1/vmmon-only/./include/compat_kernel.h:21: warning: type defaults to ‘int’ in declaration of ‘_syscall1’
make[2]: *** [/tmp/vmware-config1/vmmon-only/linux/driver.o] Error 1
make[1]: *** [_module_/tmp/vmware-config1/vmmon-only] Error 2
make[1]: Leaving directory `/usr/src/linux-2.6.20-gentoo-r6'
make: *** [vmmon.ko] Error 2
make: Leaving directory `/tmp/vmware-config1/vmmon-only'
Unable to build the vmmon module.

change dir to /opt/vmware/player/lib/modules/source and untar vmmon.tar

# cd /opt/vmware/player/lib/modules/source/
# tar xvf vmmon.tar
vmmon-only/
vmmon-only/autoconf/
vmmon-only/autoconf/geninclude.c
vmmon-only/autoconf/epoll.c
...

next, edit the file vmmon-only/include/compat_kernel.h and add the following preprocessor statements (in bold font)

/*
* compat_exit() provides an access to the exit() function. It must
* be named compat_exit(), as exit() (with different signature) is
* provided by x86-64, arm and other (but not by i386).
*/
#define __NR_compat_exit __NR_exit
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
static inline _syscall1(int, compat_exit, int, exit_code);
#endif

save, exit the editor, rename the original tarball and create an updated vmmon.tar tarball:

# mv vmmon.tar vmmon.orig.tar
# tar cvf vmmon.tar vmmon-only

now run vmware-config.pl again

# /opt/vmware/player/bin/vmware-config.pl
...
The configuration of VMware Player 1.0.3 build-34682 for Linux for this running
kernel completed successfully.

You can now run VMware Player by invoking the following command:
"/opt/vmware/player/bin/vmplayer".

Enjoy,

--the VMware team