Hi, I am using the following makefile and the .c file to generate a kernel module. I can load this module without error and warning. But when I call ioctl() from user application to run this module it gets kernel panic! I am using redhat 9.0 and kernel 2.4.20-8. testmngmnt.c: ============= This file has been attached with this mail. Makefile: ========= # set the approriate value for additional cflags GCC_VER := $(strip $(shell gcc -dumpversion)) XTRA_CFLAGS = ifeq ($(GCC_VER), 3.2.2) XTRA_CFLAGS = -DRH_9_0 endif # GCC_VER ifeq ($(GCC_VER), 3.2.3) XTRA_CFLAGS = -DRH_9_0 endif # GCC_VER CC = gcc LD = ld LDFLAG = -r LINUX_VERSION = linux-$(shell uname -r) CFLAGS = -g -Wall -DMODULE -O2 -D__KERNEL__ $(XTRA_CFLAGS) -DLINK_ETHERNET \ -I/usr/src/$(LINUX_VERSION)/include -I${INCLUDE} -D__DEBUG__ dvr_objs = testmngmnt.o test.o: ${dvr_objs} ld -X -r -o test.o ${dvr_objs} ; \ testmngmnt.o: testmngmnt.c ${CC} ${CFLAGS} -c testmngmnt.c clean: rm -f *.o *~ include/*~ all: test.o Kernel panic dump: ================== Unable to handle kernel NULL pointer dereference at virtual address 00000005 printing eip: c0118ffd *pde = 00000000 Oops: 0002 test soundcore ide-cd cdrom i830 agpgart parport_pc lp parport cisco_ipsec autofs 8139too mii keybdev mousedev hid input usb-uhci ehci-hcd usbcore ext3 jbd CPU: 0 EIP: 0060:[] Tainted: P EFLAGS: 00210086 EIP is at interruptible_sleep_on_timeout [kernel] 0x2d (2.4.20-8) eax: f4f31f78 ebx: 00200286 ecx: f4f31f50 edx: 00000001 esi: 00000002 edi: f5050300 ebp: f4f31f60 esp: f4f31f48 ds: 0068 es: 0068 ss: 0068 Process vnicClientMirro (pid: 4971, stackpage=f4f31000) Stack: 00000000 f4f30000 f5113980 f5113980 0000001d 00000000 f4f31f90 f8fe60b8 f8fe615c 0000001d f5113fa4 f5113700 00000001 f4f31f7c f4f31f7c 00000000 00000002 ffffffe7 00000003 c01566e9 bfffd880 f5050300 00000000 bfffd880 Call Trace: [] VNICClientStart [test] 0x58 (0xf4f31f64)) [] .rodata.str1.1 [test] 0x2c (0xf4f31f68)) [] sys_ioctl [kernel] 0xc9 (0xf4f31f94)) [] system_call [kernel] 0x33 (0xf4f31fc0)) Code: 89 4a 04 89 55 f0 89 45 f4 89 08 89 f0 e8 a1 cb 00 00 89 c6 Could you please give some light on this issue? Regards, Manomugdhab Manomugdha Biswas _______________________________________________________ Too much spam in your inbox? Yahoo! Mail gives you the best spam protection for FREE! http://in.mail.yahoo.com