Patch "ethernet: ice: avoid gcc-9 integer overflow warning" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ethernet: ice: avoid gcc-9 integer overflow warning

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ethernet-ice-avoid-gcc-9-integer-overflow-warning.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c99de60c032bba6fae728709e15487a0b7ac46a7
Author: Arnd Bergmann <arnd@xxxxxxxx>
Date:   Tue Feb 14 16:25:36 2023 +0100

    ethernet: ice: avoid gcc-9 integer overflow warning
    
    [ Upstream commit 8f5c5a790e3025d6eca96bf7ee5e3873dc92373f ]
    
    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@xxxxxxxxx>
    Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
    Reviewed-by: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx>
    Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@xxxxxxxxx>
    Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/intel/ice/ice_tc_lib.c b/drivers/net/ethernet/intel/ice/ice_tc_lib.c
index f68c555be4e9a..71cb15fcf63b9 100644
--- a/drivers/net/ethernet/intel/ice/ice_tc_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_tc_lib.c
@@ -1322,8 +1322,8 @@ 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)
@@ -1356,8 +1356,8 @@ 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);
 		}
 	}