[dm-devel] [Report] crash tool cannot resolve struct dm_table properly

[Eric Ren]

Hi Steffen,

On 04/13/17 18:22, Steffen Maier wrote:
> On 04/13/2017 04:01 AM, Eric Ren wrote:
>> Hi Mikulas,
>>
>> When inspecting on coredump with crash tool, I find that 'dm_table'
>> cannot be resolved properly as follows:
>>
>> ===
>> crash> struct dm_table
>> struct dm_table {
>>     int undefined__;
>> }
>> SIZE: 4
>> ===
>>
>> Looks this issue is introduced by 83d5e5b (dm: optimize use SRCU and
>> RCU) with this code:
>> ===
>> +/*
>> + * A dummy definition to make RCU happy.
>> + * struct dm_table should never be dereferenced in this file.
>>  + */ +struct dm_table {
>> + int undefined__;
>> +};
>> +
>> ===
>>
>> It stops me from looking into dm_table when analyzing coredump. Is there
>> any workaround?
>> or can be fixed somehow?
>
> Does this help somewhat?:
>
> https://www.redhat.com/archives/dm-devel/2015-December/msg00042.html
>
> As workaround for eppic scripts in crash, we currently re-define struct dm_table in eppic 
> scripts, because "set scope dm_table_create" has not always worked as we liked. Sometimes 
> "whatis dm_table_create" and again "set scope dm_table_create" worked and we put this in 
> .crashrc, but eventually gave up and kept our struct re-define.

Yes, playing with "set" or "gdb ptype" commands doesn't always work. Could you please share 
your eppic scripts and steps how to use it?

Thanks in advance,
Eric