[Crash-utility] crash failed to get backtrace in module on powerpc target(e500v2)

[Liu, Jianbo (James)]

Hi. Dave:

Got it,  thanks very much for your updates!



Best regards!
James

> 在 2015年12月12日，上午4:11，Dave Anderson <anderson at redhat.com> 写道：
> 
> 
> 
> ----- Original Message -----
>> 
>> Hi Experts:
>> 
>> I met a issue when try to analysis vmcore which was triggered by a error in module on powerpc target. 
>> 
>> BG:
>> Crash version is 6.1.4, I cross build it with powerpc toolchain, and run it on p2020(e500v2) target directly.
>> 
>> 
>> It show the following error:
>> /*************************************************************************/
>> crash> bt 
>> PID: 588    TASK: eed6e880  CPU: 1   COMMAND: "insmod" 
>> R0:  c0097cfc   R1:  eed81e80   R2:  eed6e880   R3:  eed81db8    
>> R4:  00021000   R5:  c07955df   R6:  000025d1   R7:  c0793bb0    
>> R8:  00001a2f   R9:  00000000   R10: 00000020   R11: eed80000    
>> R12: 24000044   R13: 100a73a0   R14: 00000000   R15: 00000000    
>> R16: 00000000   R17: 00000000   R18: 00000000   R19: 00000000    
>> R20: 00000000   R21: 00000000   R22: 00000000   R23: 00000000    
>> R24: 00000000   R25: 00000000   R26: 00028b70   R27: f23ea000    
>> R28: 00000000   R29: eed81db8   R30: c0753178   R31: c0790000    
>> NIP: c05c7e9c   MSR: 00021000   OR3: eed81e48   CTR: 00000001 
>> LR:  c05c7e9c   XER: 20000000   CCR: 24000042   MQ:  c0007fdc 
>> DAR: 00000000 DSISR: 00000000        Syscall Result: 00000000 
>> NIP [00000000c05c7e9c] panic 
>> LR  [00000000c05c7e9c] panic 
>> #0 [eed81e80] panic at c05c7e9c 
>> bt: ppc_back_trace hit unknown symbol (f23e70b4). 
>> /*************************************************************************/
>> 
>> I doubt if the crash can not worked well on e500v2 target for the moment?
>> 
>> BTW, In my module, module_init will call a function, that function will call panic and cause kdump, but from the log when issue happen, looks it did not show the right call trace:
>> /*************************************************************************/
>> [eed81e80] [c05c7e94] panic+0x12c/0x1ac                                        
>> [eed81ed0] [f23e70b4] dummy_cleanup_module+0x0/0x44 [dummy]                    
>> [eed81ee0] [f23ea030] dummy_init_module+0x30/0x68 [dummy]                      
>> [eed81ef0] [c0002124] do_one_initcall+0x3c/0x1e0                               
>> [eed81f20] [c008e698] sys_init_module+0xf8/0x21c 
>> /*************************************************************************/
>> Do you have some comments on this kind of secne?
>> 
>> Thanks a lot for your valuable time!
> 
> Hello James,
> 
> I believe that this error is due to the fact that the dummy module's
> symbols have not been registered with the kernel, because the module 
> forced the panic too early.  If you do a "sym -M", you probably will
> not see the "dummy" module's symbols, and therefore crash cannot resolve
> the f23e70b4 address.
> 
> After do_one_initcall() is called normally, there is still a lot of further
> module initialization to be accomplished.  In this case, it is not being done,
> and the dummy module's "module" structure has not been fully initialization. 
> 
> Dave
> 
> 
> 
>> Best Regards,
>> James
>> 
>> Liu Jianbo | WIND RIVER | Senior Engineer - Technical Support
>> Tel 86 28 65318098 | Cell 86 13558641588 | Fax 86 28 65319983  
>> 
> 
> --
> Crash-utility mailing list
> Crash-utility at redhat.com
> https://www.redhat.com/mailman/listinfo/crash-utility