| Message ID | 20230214152548.826703-1-arnd@kernel.org (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v2] ethernet: ice: avoid gcc-9 integer overflow warning | expand |
From: Arnd Bergmann <arnd@kernel.org> Date: Tue, 14 Feb 2023 16:25:36 +0100 > From: Arnd Bergmann <arnd@arndb.de> > > With older compilers like gcc-9, the calculation of the vlan > priority field causes a false-positive warning from the byteswap: > > In file included from drivers/net/ethernet/intel/ice/ice_tc_lib.c:4: > drivers/net/ethernet/intel/ice/ice_tc_lib.c: In function 'ice_parse_cls_flower': > include/uapi/linux/swab.h:15:15: error: integer overflow in expression '(int)(short unsigned int)((int)match.key-><U67c8>.<U6698>.vlan_priority << 13) & 57344 & 255' of type 'int' results in '0' [-Werror=overflow] > 15 | (((__u16)(x) & (__u16)0x00ffU) << 8) | \ > | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ > include/uapi/linux/swab.h:106:2: note: in expansion of macro '___constant_swab16' > 106 | ___constant_swab16(x) : \ > | ^~~~~~~~~~~~~~~~~~ > include/uapi/linux/byteorder/little_endian.h:42:43: note: in expansion of macro '__swab16' > 42 | #define __cpu_to_be16(x) ((__force __be16)__swab16((x))) > | ^~~~~~~~ > include/linux/byteorder/generic.h:96:21: note: in expansion of macro '__cpu_to_be16' > 96 | #define cpu_to_be16 __cpu_to_be16 > | ^~~~~~~~~~~~~ > drivers/net/ethernet/intel/ice/ice_tc_lib.c:1458:5: note: in expansion of macro 'cpu_to_be16' > 1458 | cpu_to_be16((match.key->vlan_priority << > | ^~~~~~~~~~~ > > After a change to be16_encode_bits(), the code becomes more > readable to both people and compilers, which avoids the warning. > > Fixes: 34800178b302 ("ice: Add support for VLAN priority filters in switchdev") > Suggested-by: Alexander Lobakin <alexandr.lobakin@intel.com> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > v2: use be16_encode_bits() instead of a temporary variable. > --- > drivers/net/ethernet/intel/ice/ice_tc_lib.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/ethernet/intel/ice/ice_tc_lib.c b/drivers/net/ethernet/intel/ice/ice_tc_lib.c > index 6b48cbc049c6..76f29a5bf8d7 100644 > --- a/drivers/net/ethernet/intel/ice/ice_tc_lib.c > +++ b/drivers/net/ethernet/intel/ice/ice_tc_lib.c > @@ -1455,8 +1455,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi, > if (match.mask->vlan_priority) { > fltr->flags |= ICE_TC_FLWR_FIELD_VLAN_PRIO; > headers->vlan_hdr.vlan_prio = > - cpu_to_be16((match.key->vlan_priority << > - VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK); > + be16_encode_bits(match.key->vlan_priority, > + VLAN_PRIO_MASK); > } > > if (match.mask->vlan_tpid) > @@ -1489,8 +1489,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi, > if (match.mask->vlan_priority) { > fltr->flags |= ICE_TC_FLWR_FIELD_CVLAN_PRIO; > headers->cvlan_hdr.vlan_prio = > - cpu_to_be16((match.key->vlan_priority << > - VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK); > + be16_encode_bits(match.key->vlan_priority, > + VLAN_PRIO_MASK); Oh, the patch looks great! Both fixes the issue and cleans up the code a little bit. Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> > } > } > Thanks! Olek
> -----Original Message----- > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of > Arnd Bergmann > Sent: Tuesday, February 14, 2023 8:56 PM > To: Brandeburg, Jesse <jesse.brandeburg@intel.com>; Nguyen, Anthony L > <anthony.l.nguyen@intel.com>; David S. Miller <davem@davemloft.net>; > Eric Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; > Paolo Abeni <pabeni@redhat.com>; Martyna Szapar-Mudlaw > <martyna.szapar-mudlaw@linux.intel.com> > Cc: Lu Wei <luwei32@huawei.com>; Arnd Bergmann <arnd@arndb.de>; > netdev@vger.kernel.org; linux-kernel@vger.kernel.org; intel-wired- > lan@lists.osuosl.org > Subject: [Intel-wired-lan] [PATCH] [v2] ethernet: ice: avoid gcc-9 integer > overflow warning > > From: Arnd Bergmann <arnd@arndb.de> > > With older compilers like gcc-9, the calculation of the vlan priority field > causes a false-positive warning from the byteswap: > > In file included from drivers/net/ethernet/intel/ice/ice_tc_lib.c:4: > drivers/net/ethernet/intel/ice/ice_tc_lib.c: In function 'ice_parse_cls_flower': > include/uapi/linux/swab.h:15:15: error: integer overflow in expression > '(int)(short unsigned int)((int)match.key-><U67c8>.<U6698>.vlan_priority << > 13) & 57344 & 255' of type 'int' results in '0' [-Werror=overflow] > 15 | (((__u16)(x) & (__u16)0x00ffU) << 8) | \ > | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ > include/uapi/linux/swab.h:106:2: note: in expansion of macro > '___constant_swab16' > 106 | ___constant_swab16(x) : \ > | ^~~~~~~~~~~~~~~~~~ > include/uapi/linux/byteorder/little_endian.h:42:43: note: in expansion of > macro '__swab16' > 42 | #define __cpu_to_be16(x) ((__force __be16)__swab16((x))) > | ^~~~~~~~ > include/linux/byteorder/generic.h:96:21: note: in expansion of macro > '__cpu_to_be16' > 96 | #define cpu_to_be16 __cpu_to_be16 > | ^~~~~~~~~~~~~ > drivers/net/ethernet/intel/ice/ice_tc_lib.c:1458:5: note: in expansion of > macro 'cpu_to_be16' > 1458 | cpu_to_be16((match.key->vlan_priority << > | ^~~~~~~~~~~ > > After a change to be16_encode_bits(), the code becomes more readable to > both people and compilers, which avoids the warning. > > Fixes: 34800178b302 ("ice: Add support for VLAN priority filters in > switchdev") > Suggested-by: Alexander Lobakin <alexandr.lobakin@intel.com> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > v2: use be16_encode_bits() instead of a temporary variable. > --- > drivers/net/ethernet/intel/ice/ice_tc_lib.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
diff --git a/drivers/net/ethernet/intel/ice/ice_tc_lib.c b/drivers/net/ethernet/intel/ice/ice_tc_lib.c index 6b48cbc049c6..76f29a5bf8d7 100644 --- a/drivers/net/ethernet/intel/ice/ice_tc_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_tc_lib.c @@ -1455,8 +1455,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi, if (match.mask->vlan_priority) { fltr->flags |= ICE_TC_FLWR_FIELD_VLAN_PRIO; headers->vlan_hdr.vlan_prio = - cpu_to_be16((match.key->vlan_priority << - VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK); + be16_encode_bits(match.key->vlan_priority, + VLAN_PRIO_MASK); } if (match.mask->vlan_tpid) @@ -1489,8 +1489,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi, if (match.mask->vlan_priority) { fltr->flags |= ICE_TC_FLWR_FIELD_CVLAN_PRIO; headers->cvlan_hdr.vlan_prio = - cpu_to_be16((match.key->vlan_priority << - VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK); + be16_encode_bits(match.key->vlan_priority, + VLAN_PRIO_MASK); } }