Re: [RESEND PATCH 2/3] net: hns: avoid gcc-7.0.1 warning for uninitialized data

[David Miller]

From: Arnd Bergmann <arnd@xxxxxxxx>
Date: Fri, 24 Mar 2017 23:02:50 +0100

> hns_dsaf_set_mac_key() calls dsaf_set_field() on an uninitialized field,
> which will then change only a few of its bits, causing a warning with
> the latest gcc:
> 
> hisilicon/hns/hns_dsaf_main.c: In function 'hns_dsaf_set_mac_uc_entry':
> hisilicon/hns/hns_dsaf_reg.h:1046:12: error: 'mac_key.low.bits.port_vlan' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>    (origin) &= (~(mask)); \
>             ^~
> hisilicon/hns/hns_dsaf_main.c: In function 'hns_dsaf_set_mac_mc_entry':
> hisilicon/hns/hns_dsaf_reg.h:1046:12: error: 'mac_key.low.bits.port_vlan' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> hisilicon/hns/hns_dsaf_main.c: In function 'hns_dsaf_add_mac_mc_port':
> hisilicon/hns/hns_dsaf_reg.h:1046:12: error: 'mac_key.low.bits.port_vlan' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> hisilicon/hns/hns_dsaf_main.c: In function 'hns_dsaf_del_mac_entry':
> hisilicon/hns/hns_dsaf_reg.h:1046:12: error: 'mac_key.low.bits.port_vlan' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> hisilicon/hns/hns_dsaf_main.c: In function 'hns_dsaf_rm_mac_addr':
> hisilicon/hns/hns_dsaf_reg.h:1046:12: error: 'mac_key.low.bits.port_vlan' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> hisilicon/hns/hns_dsaf_main.c: In function 'hns_dsaf_del_mac_mc_port':
> hisilicon/hns/hns_dsaf_reg.h:1046:12: error: 'mac_key.low.bits.port_vlan' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> hisilicon/hns/hns_dsaf_main.c: In function 'hns_dsaf_get_mac_uc_entry':
> hisilicon/hns/hns_dsaf_reg.h:1046:12: error: 'mac_key.low.bits.port_vlan' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> hisilicon/hns/hns_dsaf_main.c: In function 'hns_dsaf_get_mac_mc_entry':
> hisilicon/hns/hns_dsaf_reg.h:1046:12: error: 'mac_key.low.bits.port_vlan' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> 
> The code is actually correct since we always set all 16 bits of the
> port_vlan field, but gcc correctly points out that the first
> access does contain uninitialized data.
> 
> This initializes the field to zero first before setting the
> individual bits.
> 
> Fixes: 5483bfcb169c ("net: hns: modify tcam table and set mac key")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Applied.