Hi, I am doing some testing on IBM Lanstreamer MCA tokenring adapter on IBM PS/2 server-9595. Inserting the driver ( as module) it is perfect. But when I do an ifconfig tr0 up then I get an kernel panic and Oops message is printed out . It occures when the function interruptible_sleep_on_timeout() is called within the device driver .. . I am using kernel-2.4.0 with redhat -7 installation. Same effect was also there on 2.4.2 .But I didn't had any problem when the driver is compiled and run on 2.2.x version . Can anyone help me to resolve the problem. . The following is the output of ksymoops < oops.txt message. Unable to handle kernel NULL pointer dereference at virtual address 00000004 c0111720 *pde = 00000000 Oops: 0002 CPU: 0 EIP: 0010:[<c0111720>] Using defaults from ksymoops -t elf32-i386 -a i386 EFLAGS: 00010086 eax: 00000000 ebx: 00000086 ecx: c0d08c1c edx: c0b9ddc8 esi: c0d08c18 edi: 000001f4 ebp: c0b9dddc esp: c0b9ddc0 ds: 0018 es: 0018 ss: 0018 Process ifconfig (pid: 651, stackpage=c0b9d000) Stack: 00000000 c0b9c000 00000001 ffffffff c0b9c000 00001c68 000007ce c0d08c00 c2810add c0b9ddf8 1c681c62 00000001 00000202 1c0073e0 00000002 40017000 00000246 00000000 00000246 00000000 c0b9f6f4 00000246 00000000 00000246 Call Trace: [<c2810add>] [<c012926c>] [<c01223b0>] [<c014239f>] [<c01232eb>] [<c01202bf>] [<c0120411>] [<c01416f0>] [<c01407b9>] [<c01e9402>] [<c01ea142>] [<c020d7b7>] [<c01e52e0>] [<c013cab7>] [<c0108fe3>] Code: 89 50 04 89 45 ec 89 4d f0 89 56 04 89 f8 e8 ed f7 ff ff 89 >>EIP; c0111720 <interruptible_sleep_on_timeout+30/60> <===== Trace; c2810add <[lanstreamer]streamer_open+2cd/8f0> Trace; c012926c <inactive_shortage+2c/40> Trace; c01223b0 <__find_get_page+30/70> Trace; c014239f <get_new_inode+df/160> Trace; c01232eb <filemap_nopage+cb/440> Trace; c01202bf <do_no_page+4f/c0> Trace; c0120411 <handle_mm_fault+e1/160> Trace; c01416f0 <destroy_inode+30/40> Trace; c01407b9 <dput+129/150> Trace; c01e9402 <dev_open+42/a0> Trace; c01ea142 <dev_change_flags+52/f0> Trace; c020d7b7 <devinet_ioctl+2d7/640> Trace; c01e52e0 <sock_ioctl+20/30> Trace; c013cab7 <sys_ioctl+187/1a0> Trace; c0108fe3 <system_call+33/40> Code; c0111720 <interruptible_sleep_on_timeout+30/60> 00000000 <_EIP>: Code; c0111720 <interruptible_sleep_on_timeout+30/60> <===== 0: 89 50 04 mov %edx,0x4(%eax) <===== Code; c0111723 <interruptible_sleep_on_timeout+33/60> 3: 89 45 ec mov %eax,0xffffffec(%ebp) Code; c0111726 <interruptible_sleep_on_timeout+36/60> 6: 89 4d f0 mov %ecx,0xfffffff0(%ebp) Code; c0111729 <interruptible_sleep_on_timeout+39/60> 9: 89 56 04 mov %edx,0x4(%esi) Code; c011172c <interruptible_sleep_on_timeout+3c/60> c: 89 f8 mov %edi,%eax Code; c011172e <interruptible_sleep_on_timeout+3e/60> e: e8 ed f7 ff ff call fffff800 <_EIP+0xfffff800> c0110f20 <schedule_timeout+0/a0> Code; c0111733 <interruptible_sleep_on_timeout+43/60> 13: 89 00 mov %eax,(%eax) Thanks & Regards Shiju Shiju A Mathew Software Engineer IBM Global Services Golden Enclave,Bangalore Tel:91-80-5262355 Extn.:2862 - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org