tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: f7efed9f38f886edb450041b82a6f15d663c98f8 commit: 7e5e7d800011adf4aeda615f8a1bc31c0c1e2bb9 [8122/10546] sfc: neighbour lookup for TC encap action offload config: x86_64-buildonly-randconfig-r003-20230618 (https://download.01.org/0day-ci/archive/20230618/202306180235.N2G6clyj-lkp@xxxxxxxxx/config) compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a) reproduce: (https://download.01.org/0day-ci/archive/20230618/202306180235.N2G6clyj-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202306180235.N2G6clyj-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> drivers/net/ethernet/sfc/tc_encap_actions.c:144:7: warning: variable 'n' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (encap->type & EFX_ENCAP_FLAG_IPV6) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/sfc/tc_encap_actions.c:184:8: note: uninitialized use occurs here if (!n) { ^ drivers/net/ethernet/sfc/tc_encap_actions.c:144:3: note: remove the 'if' if its condition is always false if (encap->type & EFX_ENCAP_FLAG_IPV6) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/sfc/tc_encap_actions.c:141:22: note: initialize the variable 'n' to silence this warning struct neighbour *n; ^ = NULL 1 warning generated. vim +144 drivers/net/ethernet/sfc/tc_encap_actions.c 83 84 static int efx_bind_neigh(struct efx_nic *efx, 85 struct efx_tc_encap_action *encap, struct net *net, 86 struct netlink_ext_ack *extack) 87 { 88 struct efx_neigh_binder *neigh, *old; 89 struct flowi6 flow6 = {}; 90 struct flowi4 flow4 = {}; 91 int rc; 92 93 /* GCC stupidly thinks that only values explicitly listed in the enum 94 * definition can _possibly_ be sensible case values, so without this 95 * cast it complains about the IPv6 versions. 96 */ 97 switch ((int)encap->type) { 98 case EFX_ENCAP_TYPE_VXLAN: 99 case EFX_ENCAP_TYPE_GENEVE: 100 flow4.flowi4_proto = IPPROTO_UDP; 101 flow4.fl4_dport = encap->key.tp_dst; 102 flow4.flowi4_tos = encap->key.tos; 103 flow4.daddr = encap->key.u.ipv4.dst; 104 flow4.saddr = encap->key.u.ipv4.src; 105 break; 106 case EFX_ENCAP_TYPE_VXLAN | EFX_ENCAP_FLAG_IPV6: 107 case EFX_ENCAP_TYPE_GENEVE | EFX_ENCAP_FLAG_IPV6: 108 flow6.flowi6_proto = IPPROTO_UDP; 109 flow6.fl6_dport = encap->key.tp_dst; 110 flow6.flowlabel = ip6_make_flowinfo(encap->key.tos, 111 encap->key.label); 112 flow6.daddr = encap->key.u.ipv6.dst; 113 flow6.saddr = encap->key.u.ipv6.src; 114 break; 115 default: 116 NL_SET_ERR_MSG_FMT_MOD(extack, "Unsupported encap type %d", 117 (int)encap->type); 118 return -EOPNOTSUPP; 119 } 120 121 neigh = kzalloc(sizeof(*neigh), GFP_KERNEL_ACCOUNT); 122 if (!neigh) 123 return -ENOMEM; 124 neigh->net = get_net_track(net, &neigh->ns_tracker, GFP_KERNEL_ACCOUNT); 125 neigh->dst_ip = flow4.daddr; 126 neigh->dst_ip6 = flow6.daddr; 127 128 old = rhashtable_lookup_get_insert_fast(&efx->tc->neigh_ht, 129 &neigh->linkage, 130 efx_neigh_ht_params); 131 if (old) { 132 /* don't need our new entry */ 133 put_net_track(neigh->net, &neigh->ns_tracker); 134 kfree(neigh); 135 if (!refcount_inc_not_zero(&old->ref)) 136 return -EAGAIN; 137 /* existing entry found, ref taken */ 138 neigh = old; 139 } else { 140 /* New entry. We need to initiate a lookup */ 141 struct neighbour *n; 142 struct rtable *rt; 143 > 144 if (encap->type & EFX_ENCAP_FLAG_IPV6) { 145 #if IS_ENABLED(CONFIG_IPV6) 146 struct dst_entry *dst; 147 148 dst = ipv6_stub->ipv6_dst_lookup_flow(net, NULL, &flow6, 149 NULL); 150 rc = PTR_ERR_OR_ZERO(dst); 151 if (rc) { 152 NL_SET_ERR_MSG_MOD(extack, "Failed to lookup route for IPv6 encap"); 153 goto out_free; 154 } 155 neigh->egdev = dst->dev; 156 netdev_hold(neigh->egdev, &neigh->dev_tracker, 157 GFP_KERNEL_ACCOUNT); 158 neigh->ttl = ip6_dst_hoplimit(dst); 159 n = dst_neigh_lookup(dst, &flow6.daddr); 160 dst_release(dst); 161 #else 162 /* We shouldn't ever get here, because if IPv6 isn't 163 * enabled how did someone create an IPv6 tunnel_key? 164 */ 165 rc = -EOPNOTSUPP; 166 NL_SET_ERR_MSG_MOD(extack, "No IPv6 support (neigh bind)"); 167 #endif 168 } else { 169 rt = ip_route_output_key(net, &flow4); 170 if (IS_ERR_OR_NULL(rt)) { 171 rc = PTR_ERR_OR_ZERO(rt); 172 if (!rc) 173 rc = -EIO; 174 NL_SET_ERR_MSG_MOD(extack, "Failed to lookup route for encap"); 175 goto out_free; 176 } 177 neigh->egdev = rt->dst.dev; 178 netdev_hold(neigh->egdev, &neigh->dev_tracker, 179 GFP_KERNEL_ACCOUNT); 180 neigh->ttl = ip4_dst_hoplimit(&rt->dst); 181 n = dst_neigh_lookup(&rt->dst, &flow4.daddr); 182 ip_rt_put(rt); 183 } 184 if (!n) { 185 rc = -ENETUNREACH; 186 NL_SET_ERR_MSG_MOD(extack, "Failed to lookup neighbour for encap"); 187 netdev_put(neigh->egdev, &neigh->dev_tracker); 188 goto out_free; 189 } 190 refcount_set(&neigh->ref, 1); 191 INIT_LIST_HEAD(&neigh->users); 192 read_lock_bh(&n->lock); 193 ether_addr_copy(neigh->ha, n->ha); 194 neigh->n_valid = n->nud_state & NUD_VALID; 195 read_unlock_bh(&n->lock); 196 rwlock_init(&neigh->lock); 197 INIT_WORK(&neigh->work, efx_neigh_update); 198 neigh->efx = efx; 199 neigh->used = jiffies; 200 if (!neigh->n_valid) 201 /* Prod ARP to find us a neighbour */ 202 neigh_event_send(n, NULL); 203 neigh_release(n); 204 } 205 /* Add us to this neigh */ 206 encap->neigh = neigh; 207 list_add_tail(&encap->list, &neigh->users); 208 return 0; 209 210 out_free: 211 /* cleanup common to several error paths */ 212 rhashtable_remove_fast(&efx->tc->neigh_ht, &neigh->linkage, 213 efx_neigh_ht_params); 214 synchronize_rcu(); 215 put_net_track(net, &neigh->ns_tracker); 216 kfree(neigh); 217 return rc; 218 } 219 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
