Hi to all,
I am writing kernel module for block device driver and I am getting the OOPS message. But I am unable to decode that OOPS message. So Please help me or if there is any link which gives this decoding info of OOPS message, then please forward that link to me.
The OOPS Message is -:
Unable to handle kernel NULL pointer dereference at 0000000000000020 RIP:
<ffffffff802c9954>{blk_do_ordered+24}
PGD 12ab8067 PUD 20b42067 PMD 0
Oops: 0000 [1]
CPU 0
Modules linked in: dbd xt_pkttype ipt_LOG xt_limit af_packet snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device edd button battery ac ip6t_REJECT xt_tcpudp ipt_REJECT xt_state iptable_mangle iptable_nat ip_nat iptable_filter ip6table_mangle ip_conntrack nfnetlink ip_tables ip6table_filter ip6_tables x_tables ipv6 nls_utf8 ntfs nls_iso8859_1 nls_cp437 vfat fat loop dm_mod i2c_nforce2 ohci_hcd i2c_core forcedeth ehci_hcd ide_cd sk98lin cdrom ohci1394 usbcore ieee1394 snd_intel8x0 snd_ac97_codec snd_ac97_bus snd_pcm snd_timer snd soundcore snd_page_alloc parport_pc lp parport reiserfs sg fan thermal processor sata_sil sata_nv libata amd74xx sd_mod scsi_mod ide_disk ide_core
Pid: 4880, comm: a.out Tainted: P R 2.6.17.8-default #1
RIP: 0010:[<ffffffff802c9954>] <ffffffff802c9954>{blk_do_ordered+24}
RSP: 0018:ffff810020b6d8c8 EFLAGS: 00010292
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8043de20
RDX: 0000000000000000 RSI: ffff810020b6d908 RDI: ffff81002ded0cf8
RBP: ffff810020b6d8e8 R08: 0000000000000000 R09: ffff81002ffe4000
R10: ffff81002ffee7a0 R11: 00000000ffffffff R12: ffff81002ded0cf8
R13: ffff810020b6d908 R14: ffff81002ed26cc0 R15: 0000000000000080
FS: 00002ae8ccb7d6d0(0000) GS:ffffffff8052e000(0000) knlGS:00000000f7bd46b0
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000020 CR3: 0000000007132000 CR4: 00000000000006e0
Process a.out (pid: 4880, threadinfo ffff810020b6c000, task ffff81002f5f1550)
Stack: 0000000000000000 0000000000000008 00000000000000ff ffff81002ded0cf8
ffff810020b6d928 ffffffff802c5900 0000001800000000 000000012fd2a018
0000000000000000 0000000000000008
Call Trace: <ffffffff802c5900>{elv_next_request+282}
<ffffffff8830d4cd>{:dbd:dbdd_make_request+473} <ffffffff802c73e7>{generic_make_request+370}
<ffffffff802c903b>{submit_bio+192} <ffffffff80267f90>{submit_bh+259}
<ffffffff8026a7ba>{block_read_full_page+589} <ffffffff8026e0c4>{blkdev_get_block+0}
<ffffffff802db053>{radix_tree_insert+259} <ffffffff8026d247>{blkdev_readpage+19}
<ffffffff8024f46a>{__do_page_cache_readahead+400} <ffffffff80222a8f>{default_wake_function+13}
<ffffffff80236ec0>{autoremove_wake_function+17} <ffffffff80221ffa>{__wake_up_common+60}
<ffffffff8024f54b>{blockable_page_cache_readahead+92}
<ffffffff8024f732>{page_cache_readahead+221} <ffffffff8024991f>{do_generic_mapping_read+344}
<ffffffff8024b8a3>{file_read_actor+0} <ffffffff8024a473>{__generic_file_aio_read+336}
<ffffffff8024b66c>{generic_file_read+198} <ffffffff8026de8c>{blkdev_open+42}
<ffffffff80236eaf>{autoremove_wake_function+0} <ffffffff8024711c>{audit_syscall_entry+316}
<ffffffff80266fdb>{vfs_read+204} <ffffffff80267349>{sys_read+71}
<ffffffff802096f9>{tracesys+209}
Code: 48 8b 43 20 83 e0 50 48 83 f8 50 0f 94 c2 83 bf a0 02 00 00
RIP <ffffffff802c9954>{blk_do_ordered+24} RSP <ffff810020b6d8c8>
CR2: 0000000000000020
Please help me.
Thank you.
Regards,
Vaibhav
