Re: [dpdk-dev] [PATCH] lib/lpm:fix two issues in the delete_depth_small()

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Oct 29, 2015 at 10:41:45AM +0800, nana.nn wrote:
> Hi Bruce:
> 	Should I send the test unit as a DPDK patch, or just the program for you to demonstrate the bugs? 
>         
> 	
> 	Thank you very much!
> 
> 
> Regards
> 
> Na Na
> 

A patch to add a unit test for the bug would be best.
/Bruce

> 
> 
> 
> On Oct 28, 2015, at 10:40 PM, Bruce Richardson <bruce.richardson@intel.com> wrote:
> 
> > On Wed, Oct 28, 2015 at 11:44:15AM +0800, Jijiang Liu wrote:
> >> Fix two issues in the delete_depth_small() function.
> >> 
> >> 1> The control is not strict in this function.
> >> 
> >> In the following structure,
> >> struct rte_lpm_tbl24_entry {
> >>        union {
> >>                uint8_t next_hop;
> >>                uint8_t tbl8_gindex;
> >>        };
> >>     uint8_t ext_entry :1;
> >> }
> >> 
> >> When ext_entry = 0, use next_hop.only to process rte_lpm_tbl24_entry.
> >> 
> >> When ext_entry = 1, use tbl8_gindex to process the rte_lpm_tbl8_entry.
> >> 
> >> When using LPM24 + 8 algorithm, it will use ext_entry to decide to process rte_lpm_tbl24_entry structure or rte_lpm_tbl8_entry structure. 
> >> If a route is deleted, the prefix of previous route is used to override the deleted route. when (lpm->tbl24[i].ext_entry == 0 && lpm->tbl24[i].depth > depth) 
> >> it should be ignored, but due to the incorrect logic, the next_hop is used as tbl8_gindex and will process the rte_lpm_tbl8_entry.
> >> 
> >> 2> Initialization of rte_lpm_tbl8_entry is incorrect in this function 
> >> 
> >> In this function, use new rte_lpm_tbl8_entry we call A to replace the old rte_lpm_tbl8_entry. But the valid_group do not set VALID, so it will be INVALID.
> >> Then when adding a new route which depth is > 24,the tbl8_alloc() function will search the rte_lpm_tbl8_entrys to find INVALID valid_group, 
> >> and it will return the A to the add_depth_big function, so A's data is overridden.
> >> 
> >> Signed-off-by: NaNa <nana.nn@alibaba-inc.com>
> >> 
> > 
> > Hi NaNa, Jijiang,
> > 
> > since this patch contains two separate fixes, it would be better split into
> > two separate patches, one for each fix. Also, please add a "Fixes" line to
> > the commit log.
> > 
> > Are there still plans for a unit test to demonstrate the bug(s) and make it easy
> > for us to verify the fix?
> > 
> > Regards,
> > /Bruce
>