linux/net/dsa
Vladimir Oltean 1f778d500d net: mscc: ocelot: avoid type promotion when calling ocelot_ifh_set_dest
Smatch is confused by the fact that a 32-bit BIT(port) macro is passed
as argument to the ocelot_ifh_set_dest function and warns:

ocelot_xmit() warn: should '(((1))) << (dp->index)' be a 64 bit type?
seville_xmit() warn: should '(((1))) << (dp->index)' be a 64 bit type?

The destination port mask is copied into a 12-bit field of the packet,
starting at bit offset 67 and ending at 56.

So this DSA tagging protocol supports at most 12 bits, which is clearly
less than 32. Attempting to send to a port number > 12 will cause the
packing() call to truncate way before there will be 32-bit truncation
due to type promotion of the BIT(port) argument towards u64.

Therefore, smatch's fears that BIT(port) will do the wrong thing and
cause unexpected truncation for "port" values >= 32 are unfounded.
Nonetheless, let's silence the warning by explicitly passing an u64
value to ocelot_ifh_set_dest, such that the compiler does not need to do
a questionable type promotion.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-15 12:42:19 -08:00
..
dsa.c net: dsa: allow changing the tag protocol via the "tagging" device attribute 2021-01-29 21:24:39 -08:00
dsa2.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-02-10 13:30:12 -08:00
dsa_priv.h net: dsa: propagate extack to .port_vlan_filtering 2021-02-14 17:38:12 -08:00
Kconfig net: dsa: add a second tagger for Ocelot switches based on tag_8021q 2021-01-29 21:25:27 -08:00
Makefile net: dsa: add a second tagger for Ocelot switches based on tag_8021q 2021-01-29 21:25:27 -08:00
master.c net: dsa: allow changing the tag protocol via the "tagging" device attribute 2021-01-29 21:24:39 -08:00
port.c net: dsa: propagate extack to .port_vlan_filtering 2021-02-14 17:38:12 -08:00
slave.c net: dsa: propagate extack to .port_vlan_filtering 2021-02-14 17:38:12 -08:00
switch.c net: dsa: propagate extack to .port_vlan_filtering 2021-02-14 17:38:12 -08:00
tag_8021q.c net: dsa: tag_8021q: add helpers to deduce whether a VLAN ID is RX or TX VLAN 2021-01-29 21:24:30 -08:00
tag_ar9331.c net: dsa: tag_ar9331: let DSA core deal with TX reallocation 2020-11-02 17:41:17 -08:00
tag_brcm.c net: dsa: move the Broadcom tag information in a separate header file 2021-01-07 15:42:07 -08:00
tag_dsa.c net: dsa: tag_dsa: Support reception of packets from LAG devices 2021-01-14 17:11:56 -08:00
tag_gswip.c net: dsa: tag_gswip: let DSA core deal with TX reallocation 2020-11-02 17:41:16 -08:00
tag_hellcreek.c net: dsa: tag_hellcreek: Cleanup includes 2020-11-23 16:57:21 -08:00
tag_ksz.c net: dsa: tag_ksz: don't allocate additional memory for padding/tagging 2020-11-02 17:41:16 -08:00
tag_lan9303.c net: dsa: tag_lan9303: let DSA core deal with TX reallocation 2020-11-02 17:41:16 -08:00
tag_mtk.c net: dsa: tag_mtk: let DSA core deal with TX reallocation 2020-11-02 17:41:16 -08:00
tag_ocelot.c net: mscc: ocelot: avoid type promotion when calling ocelot_ifh_set_dest 2021-02-15 12:42:19 -08:00
tag_ocelot_8021q.c net: dsa: tag_ocelot_8021q: add support for PTP timestamping 2021-02-14 17:31:44 -08:00
tag_qca.c net: dsa: tag_qca: let DSA core deal with TX reallocation 2020-11-02 17:41:16 -08:00
tag_rtl4_a.c net: dsa: tag_rtl4_a: use the generic flow dissector procedure 2020-09-26 14:17:59 -07:00
tag_sja1105.c net: dsa: tag_sja1105: use a custom flow dissector procedure 2020-09-26 14:17:59 -07:00
tag_trailer.c net: dsa: trailer: don't allocate additional memory for padding/tagging 2020-11-02 17:41:16 -08:00
tag_xrs700x.c net: dsa: xrs700x: add HSR offloading support 2021-02-11 13:24:45 -08:00