[dpdk-dev] [PATCH v2 2/2] lib/lpm:fix an initialization issue of valid_group in the delete_depth_small()

[Liu, Jijiang]

> -----Original Message-----
> From: Richardson, Bruce
> Sent: Friday, October 30, 2015 10:22 PM
> To: Liu, Jijiang
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v2 2/2] lib/lpm:fix an initialization issue of
> valid_group in the delete_depth_small()
> 
> On Fri, Oct 30, 2015 at 09:14:39PM +0800, Jijiang Liu wrote:
> 
> Title can be shortened to: "lpm: fix initialization of valid_group field"
Ok
> > Fixes an initialization issue of 'valid_group' in the delete_depth_small
> 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.
> >
> 
> Not sure this message is entirely clear.
> How about:
>   When adding an entry to a tbl8, the .valid_group field should always be set,
>   so that future adds do not accidently find and use this table, thinking it is
>   currently invalid, i.e. unused, and thereby overwrite existing entries.
It is ok for me. 
Nana, what do you think?
> > Signed-off-by: NaNa <nana.nn at alibaba-inc.com>
> >
> > ---
> >  lib/librte_lpm/rte_lpm.c |    1 +
> >  1 files changed, 1 insertions(+), 0 deletions(-)
> >
> > diff --git a/lib/librte_lpm/rte_lpm.c b/lib/librte_lpm/rte_lpm.c index
> > 57ec2f0..3981452 100644
> > --- a/lib/librte_lpm/rte_lpm.c
> > +++ b/lib/librte_lpm/rte_lpm.c
> > @@ -769,6 +769,7 @@ delete_depth_small(struct rte_lpm *lpm, uint32_t
> > ip_masked,
> >
> >  		struct rte_lpm_tbl8_entry new_tbl8_entry = {
> >  			.valid = VALID,
> > +			.valid_group = VALID,
> >  			.depth = sub_rule_depth,
> >  			.next_hop = lpm->rules_tbl
> >  			[sub_rule_index].next_hop,
> > --
> > 1.7.7.6
> >