/dev/hello_world: A Simple Introduction to Device Drivers under Linux
Subject:   Error during insmod hello_proc
Date:   2007-11-30 04:03:54
From:   georgeneil
When i try to insmod hello_proc the following error occurs

[root@localhost hello_dev]# ls
hello_dev.c hello.rules Makefile

[root@localhost hello_dev]# make
make -C /lib/modules/2.6.21-1.3194.fc7/build M=/root/Download/hello_dev modules
make[1]: Entering directory `/usr/src/kernels/'
CC [M] /root/Download/hello_dev/hello_dev.o
Building modules, stage 2.
MODPOST 1 modules
CC /root/Download/hello_dev/hello_dev.mod.o
LD [M] /root/Download/hello_dev/hello_dev.ko
make[1]: Leaving directory `/usr/src/kernels/'

[root@localhost hello_dev]# ls
hello_dev.c hello_dev.ko hello_dev.mod.c hello_dev.mod.o hello_dev.o hello.rules Makefile Module.symvers

[root@localhost hello_dev]# insmod ./hello_dev.ko
insmod: error inserting './hello_dev.ko': -1 Unknown symbol in module

what may be the problems...??