[PATCH] ice/base: fix gcc 12 warning stringop-overflow

[Wu, WenxuanX]

Hi all, 

The warning  below gcc 12 :
    inlined from ‘ice_add_adv_recipe’ at ../drivers/net/ice/base/ice_switch.c:7951:11,
    inlined from ‘ice_add_adv_rule’ at ../drivers/net/ice/base/ice_switch.c:8911:11:
../drivers/net/ice/base/ice_switch.c:7220:61: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
 7220 |                         buf[recps].content.lkup_indx[i + 1] = entry->fv_idx[i];
      |                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
In file included from ../drivers/net/ice/base/ice_controlq.h:8,
                 from ../drivers/net/ice/base/ice_type.h:54,
                 from ../drivers/net/ice/base/ice_common.h:8,
                 from ../drivers/net/ice/base/ice_switch.h:8,
                 from ../drivers/net/ice/base/ice_switch.c:5:
../drivers/net/ice/base/ice_adminq_cmd.h: In function ‘ice_add_adv_rule’:
../drivers/net/ice/base/ice_adminq_cmd.h:744:12: note: at offset 5 into destination object ‘lkup_indx’ of size 5
  744 |         u8 lkup_indx[5];
      |            ^~~~~~~~~
In function ‘ice_add_sw_recipe’,
    inlined from ‘ice_add_adv_recipe’ at ../drivers/net/ice/base/ice_switch.c:7951:11,
    inlined from ‘ice_add_adv_rule’ at ../drivers/net/ice/base/ice_switch.c:8911:11:
../drivers/net/ice/base/ice_switch.c:7220:61: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
 7220 |                         buf[recps].content.lkup_indx[i + 1] = entry->fv_idx[i];
      |                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
../drivers/net/ice/base/ice_adminq_cmd.h: In function ‘ice_add_adv_rule’:
../drivers/net/ice/base/ice_adminq_cmd.h:744:12: note: at offset [6, 254] into destination object ‘lkup_indx’ of size 5
  744 |         u8 lkup_indx[5];
      |            ^~~~~~~~~
In function ‘ice_add_sw_recipe’,
    inlined from ‘ice_add_adv_recipe’ at ../drivers/net/ice/base/ice_switch.c:7951:11,
    inlined from ‘ice_add_adv_rule’ at ../drivers/net/ice/base/ice_switch.c:8911:11:
../drivers/net/ice/base/ice_switch.c:7220:61: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
 7220 |                         buf[recps].content.lkup_indx[i + 1] = entry->fv_idx[i];
      |                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
../drivers/net/ice/base/ice_adminq_cmd.h: In function ‘ice_add_adv_rule’:
../drivers/net/ice/base/ice_adminq_cmd.h:744:12: note: at offset [7, 255] into destination object ‘lkup_indx’ of size 5
  744 |         u8 lkup_indx[5];
      |            ^~~~~~~~~
cc1: all warnings being treated as errors

Thanks 
Wenxuan

> -----Original Message-----
> From: Zhang, Qi Z <qi.z.zhang at intel.com>
> Sent: 2022年6月19日 20:35
> To: Wu, WenxuanX <wenxuanx.wu at intel.com>; Yang, Qiming
> <qiming.yang at intel.com>; dev at dpdk.org; thomas at monjalon.net
> Cc: stephen at networkplumber.org; stable at dpdk.org
> Subject: RE: [PATCH] ice/base: fix gcc 12 warning stringop-overflow
> 
> 
> 
> > -----Original Message-----
> > From: Wu, WenxuanX <wenxuanx.wu at intel.com>
> > Sent: Thursday, June 16, 2022 6:33 PM
> > To: Yang, Qiming <qiming.yang at intel.com>; Zhang, Qi Z
> > <qi.z.zhang at intel.com>; dev at dpdk.org; thomas at monjalon.net
> > Cc: stephen at networkplumber.org; Wu, WenxuanX
> <wenxuanx.wu at intel.com>;
> > stable at dpdk.org
> > Subject: [PATCH] ice/base: fix gcc 12 warning stringop-overflow
> >
> > From: Wenxuan Wu <wenxuanx.wu at intel.com>
> >
> > Gcc with -O2 flag, would retrieve the value in one time.
> > This patch changed the type of fv_idx in struct ice_recp_grp_entry to
> > align with its callers which is also u8 type.
> >
> > When u8 idx[5] = a value u16 index[4], gcc12 would give this warning,
> > because it is not big enough to store the bytes(bigger than 5 bytes)
> > in one time (-O2 would do it in this way).
> >
> > Fixes: 04b8ec1ea807 ("net/ice/base: add protocol structures and
> > defines")
> > Cc: stable at dpdk.org
> > Signed-off-by: Wenxuan Wu <wenxuanx.wu at intel.com>
> > ---
> >  drivers/net/ice/base/ice_protocol_type.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ice/base/ice_protocol_type.h
> > b/drivers/net/ice/base/ice_protocol_type.h
> > index 0e6e5990be..cfe3b62630 100644
> > --- a/drivers/net/ice/base/ice_protocol_type.h
> > +++ b/drivers/net/ice/base/ice_protocol_type.h
> > @@ -421,7 +421,7 @@ struct ice_recp_grp_entry {  #define
> > ICE_INVAL_CHAIN_IND 0xFF
> >  	u16 rid;
> >  	u8 chain_idx;
> > -	u16 fv_idx[ICE_NUM_WORDS_RECIPE];
> > +	u8 fv_idx[ICE_NUM_WORDS_RECIPE];
> 
> If you change the data type from u16 to u8 for the FV index, you'd better also
> change the type of all the symbols to store the same thing.  e.g. the
> parameter "fv_idx" of ice_find_prot_off.
> So, what's exactly the issue that GCC 12 reported? can we fix it from the
> other side without changing a type in the base code?
> 
> 
> >  	u16 fv_mask[ICE_NUM_WORDS_RECIPE];
> >  	struct ice_pref_recipe_group r_group;  };
> > --
> > 2.25.1