[Crash-utility] debug 3th part module which oops the system
Dave Anderson
anderson at redhat.com
Wed Jul 3 13:04:50 UTC 2013
----- Original Message -----
> Hey there,
>
> I'm trying to analyse the vmcore come from an oops caused by a module. The
> module
> comes from here:
>
> http://www.linuxforu.com/2011/01/understanding-a-kernel-oops
>
> This web page wants to teach how to analyse kernel oops. It provided a
> module named 'oops', which triggers a NULL pointer dereference in its
> init function.
>
> The problem is I cannot figure out how to use crash to analyse vmcore:
>
> GNU gdb (GDB) 7.0
> Copyright (C) 2009 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law. Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "powerpc64-unknown-linux-gnu"...
>
> KERNEL: /usr/lib/debug/lib/modules/2.6.18-348.el5/vmlinux
> DUMPFILE: /var/crash/127.0.0.1-2013-07-01-04:43/vmcore
> CPUS: 20
> DATE: Mon Jul 1 04:38:49 2013
> UPTIME: 00:33:44
> LOAD AVERAGE: 0.22, 0.18, 0.07
> TASKS: 482
> NODENAME: lawlp3.upt.austin.ibm.com
> RELEASE: 2.6.18-348.el5
> VERSION: #1 SMP Wed Nov 28 21:23:52 EST 2012
> MACHINE: ppc64 (3550 Mhz)
> MEMORY: 3.2 GB
> PANIC: "Oops: Kernel access of bad area, sig: 11 [#1]" (check log for
> details)
> PID: 5402
> COMMAND: "insmod"
> TASK: c0000000cfa35150 [THREAD_INFO: c0000000ce5d0000]
> CPU: 15
> STATE: TASK_RUNNING (PANIC)
>
> crash> log
> ... ....
> oops: module license 'unspecified' taints kernel.
> oops from the module
> Unable to handle kernel paging request for data at address 0x00000000
> Faulting instruction address: 0xd000000001460060
> Oops: Kernel access of bad area, sig: 11 [#1]
> SMP NR_CPUS=128 NUMA
> Modules linked in: oops(PU) nfsd exportfs auth_rpcgss autofs4 hidp nfs
> nfs_acl rfcomm l2cap bluetooth lockd sunrpc ip6t_REJECT xt_tcpudp
> ip6table_filter ip6_tables x_tables be2iscsi ib_iser rdma_cm ib_addr ib_cm
> ib_sa ib_mad iw_cm iscsi_tcp bnx2i cnic ipv6 xfrm_nalgo crypto_api uio
> cxgb3i libcxgbi libiscsi_tcp libiscsi2 scsi_transport_iscsi2
> scsi_transport_iscsi dm_multipath scsi_dh snd_powermac snd_seq_dummy
> snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss
> snd_mixer_oss snd_pcm snd_page_alloc snd_timer snd soundcore i2c_core
> parport_pc lp parport sg iw_cxgb3 ib_core cxgb3 ibmveth 8021q dm_raid45
> dm_message dm_region_hash dm_mem_cache dm_snapshot dm_zero dm_mirror dm_log
> dm_mod lpfc ibmvfc scsi_transport_fc ibmvscsic sd_mod scsi_mod ext3 jbd
> uhci_hcd ohci_hcd ehci_hcd
> NIP: D000000001460060 LR: D000000001460050 CTR: 0000000000000004
> REGS: c0000000ce5d39b0 TRAP: 0300 Tainted: P ---- (2.6.18-348.el5)
> MSR: 8000000000009032 <EE,ME,IR,DR> CR: 24022482 XER: 00000006
> DAR: 0000000000000000, DSISR: 0000000042000000
> TASK = c0000000cfa35150[5402] 'insmod' THREAD: c0000000ce5d0000 CPU: 15
> GPR00: D000000001460050 C0000000CE5D3C30 D00000000146C930 0000000000000000
> GPR04: 8000000000001032 0000000000000000 0000000000000000 0000000000000000
> GPR08: 0000000000000000 0000000000000000 C0000000015FBB68 0000000000000000
> GPR12: 0000000000000000 C000000000570B80 0000000000000000 D0000000012B1850
> GPR16: D0000000012B1810 D0000000014601B0 0000000000000000 0000000000000000
> GPR20: 0000000000000028 D0000000012B0CE9 C0000000005A12E8 0000000000000029
> GPR24: D0000000012A0000 000000000000002A C0000000CD6F5A80 C0000000CD6F5AB0
> GPR28: C0000000005A18C8 D000000001460680 D00000000146C900 D000000001460680
> NIP [D000000001460060] .my_oops_init+0x2c/0xd4 [oops]
> LR [D000000001460050] .my_oops_init+0x1c/0xd4 [oops]
> Call Trace:
> [C0000000CE5D3C30] [C000000000098944] .sys_init_module+0x1a88/0x1d18
> (unreliable)
> [C0000000CE5D3E30] [C0000000000086A4] syscall_exit+0x0/0x40
> Instruction dump:
> 4e800020 7c0802a6 fbc1fff0 ebc28000 f8010010 f821ff81 e87e8008 4800002d
> e8410028 39200000 38210080 38600000 <91290000> e8010010 ebc1fff0 7c0803a6
> <0>Sending IPI to other cpus...
> crash> whatis my_oops_init
> whatis: gdb request failed: whatis my_oops_init
> crash> mod -s oops
> MODULE NAME SIZE OBJECT FILE
> d000000001460680 oops 18752 /lib/modules/2.6.18-348.el5/kernel/oops.ko
> crash> whatis my_oops_init
> int my_oops_init(void);
> crash> dis -l .my_oops_init
> <nothing outputed>
> crash> sym -m oops
> d000000001460000 MODULE START: oops
> d000000001460000 (t) .my_oops_exit
> d000000001460000 (t) .cleanup_module
> d000000001460034 (t) .my_oops_init
> d000000001460034 (t) .init_module
> d000000001460130 (r) ____versions
> d000000001460130 (r) __versions
> d000000001460680 (D) __this_module
> d000000001464910 (D) cleanup_module
> d000000001464910 (d) my_oops_exit
> d000000001464920 (D) init_module
> d000000001464920 (d) my_oops_init
> d000000001464940 MODULE END: oops
> crash> bt
> PID: 5402 TASK: c0000000cfa35150 CPU: 15 COMMAND: "insmod"
>
> R0: d000000001460050 R1: c0000000ce5d3c30 R2: d00000000146c930
> R3: 0000000000000000 R4: 8000000000001032 R5: 0000000000000000
> R6: 0000000000000000 R7: 0000000000000000 R8: 0000000000000000
> R9: 0000000000000000 R10: c0000000015fbb68 R11: 0000000000000000
> R12: 0000000000000000 R13: c000000000570b80 R14: 0000000000000000
> R15: d0000000012b1850 R16: d0000000012b1810 R17: d0000000014601b0
> R18: 0000000000000000 R19: 0000000000000000 R20: 0000000000000028
> R21: d0000000012b0ce9 R22: c0000000005a12e8 R23: 0000000000000029
> R24: d0000000012a0000 R25: 000000000000002a R26: c0000000cd6f5a80
> R27: c0000000cd6f5ab0 R28: c0000000005a18c8 R29: d000000001460680
> R30: d00000000146c900 R31: d000000001460680
> NIP: d000000001460060 MSR: 8000000000009032 OR3: c0000000005a13c0
> CTR: 0000000000000004 LR: d000000001460050 XER: 0000000000000006
> CCR: 0000000024022482 MQ: c0000000cd6f5ab0 DAR: 0000000000000000
> DSISR: 0000000042000000 Syscall Result: 0000000000000000
> NIP [d000000001460060] .init_module
> LR [d000000001460050] .init_module
>
> #0 [c0000000ce5d3c30] .sys_init_module at c000000000098944
> #1 [c0000000ce5d3e30] syscall_exit at c0000000000086a4
> syscall [c00] exception frame:
> R0: 0000000000000080 R1: 00000000ff91fb60 R2: 000000000fff8eb0
> R3: 0000000010020028 R4: 000000000001caf8 R5: 0000000010020018
> R6: 000000000000002d R7: fffffffffeff0000 R8: 000000000002ffe0
> R9: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000
> R12: 0000000000000000 R13: 000000001001959c R14: 0000000000000000
> R15: 0000000000000000 R16: 0000000000000000 R17: 0000000000000000
> R18: 0000000000000000 R19: 0000000000000000 R20: 0000000000000000
> R21: 0000000000000000 R22: 0000000000000000 R23: 0000000000000000
> R24: 000000000ffbf280 R25: 00000000ff91fdf0 R26: 0000000010020018
> R27: 00000000ff91ff05 R28: 0000000000020000 R29: 000000000001caf8
> R30: 0000000010020028 R31: 0000000000000003
> NIP: 000000000ff0496c MSR: 000000000000d032 OR3: 0000000010020028
> CTR: 000000000ff04964 LR: 0000000010000bf8 XER: 0000000000000000
> CCR: 0000000044000484 MQ: 0000000002756c28 DAR: 000000001004002c
> DSISR: 0000000042000000 Syscall Result: 0000000000000000
>
> crash>
>
> as you can see, the 'bt' command says the problem is at '.init_module',
> but in fact it should come from '.my_oops_init'. But 'dis -l
> .my_oops_init' shows nothing. I cannot use crash to figure out which line
> of source code caused the oops. But using gdb as being stated in the web page
> I
> can find the code line easily.
>
> Please help. Thanks.
I'm not well-versed in ppc64, but the issue seems to be related
to the fact that .my_oops_init and .init_module are both being
assigned the same virtual address:
d000000001460034 (t) .my_oops_init
d000000001460034 (t) .init_module
If you do an "nm -Bn" on the oops.ko file, do they show the same
offset value?
Dave
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