[lvm-devel] [PATCH 17/23] Add check for dm_snprintf result

[Zdenek Kabelac]

Dne 21.12.2010 18:38, Milan Broz napsal(a):
>>  		/* If the VG name is empty then lock the unused PVs */
>> -		if (is_orphan_vg(resource) || is_global_vg(resource) || (flags & LCK_CACHE))
>> -			dm_snprintf(lockname, sizeof(lockname), "P_%s",
>> -				    resource);
>> -		else
>> -			dm_snprintf(lockname, sizeof(lockname), "V_%s",
>> -				    resource);
>> +		if (dm_snprintf(lockname, sizeof(lockname), "%c_%s",
>> +				(is_orphan_vg(resource) ||
>> +				 is_global_vg(resource) ||
>> +				 (flags & LCK_CACHE)) ?  'P' : 'V',
>> +				resource)  < 0) {
>> +			log_error("Locking resource %s too long.", resource);
>> +			return 0;
>> +		}
> 
> I cannot imagine how this can happen. First parm is fixed char, second is resource string
> with exact length. And char lockname[PATH_MAX];

One shiny afternoon day someone could think about using 256byte long VG and LV
uuids and it will nicely fail ;)

So take this just like an assert.

> 
> Should we check for glibc and clompiler bugs also? :)
> 
> Well, isn't return_0 here enough?
> 

First trace is supposed to be always some 'log_error'
If you print only 'stack' without log_error - internal error is generated.
(Thought we have it wrong on many places in the code...)

Zdenek