[kbuild-all] drivers/net/macsec.c:905:22: warning: Variable 'recovered_pn.lower' is assigned a value that is never used. [unreadVariable]

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 8f3d9f354286745c751374f5f1fcafee6b3f3136 commit: a21ecf0e033807b976967286e6c392f48ee2049f macsec: Support XPN frame handling - IEEE 802.1AEbw date: 4 weeks ago If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; cppcheck warnings: (new ones prefixed by >>) drivers/net/macsec.c:3550:7: warning: Local variable 'ret' shadows outer variable [shadowVariable] int ret; ^ drivers/net/macsec.c:3525:6: note: Shadowed declaration int ret; ^ drivers/net/macsec.c:3550:7: note: Shadow variable int ret; ^ drivers/net/macsec.c:3298:56: warning: Clarify calculation precedence for '&' and '?'. [clarifyCalculation] dev_set_allmulti(real_dev, dev->flags & IFF_ALLMULTI ? 1 : -1); ^ drivers/net/macsec.c:3302:34: warning: Clarify calculation precedence for '&' and '?'. [clarifyCalculation] dev->flags & IFF_PROMISC ? 1 : -1); ^ drivers/net/macsec.c:571:30: warning: 'tmp' is of type 'void *'. When using void pointers in calculations, the behaviour is undefined. [arithOperationsOnVoidPointer] *iv = (unsigned char *)(tmp + iv_offset); ^ drivers/net/macsec.c:572:35: warning: 'tmp' is of type 'void *'. When using void pointers in calculations, the behaviour is undefined. [arithOperationsOnVoidPointer] *sg = (struct scatterlist *)(tmp + sg_offset); ^ recovered_pn.lower = hdr_pn; ^ recovered_pn.upper++; ^ drivers/net/macsec.c:2195:10: warning: Variable 'ret' is assigned a value that is never used. [unreadVariable] int ret = 0; ^ drivers/net/macsec.c:2278:10: warning: Variable 'ret' is assigned a value that is never used. [unreadVariable] int ret = 0; ^ vim +905 drivers/net/macsec.c 867 868 static struct sk_buff *macsec_decrypt(struct sk_buff *skb, 869 struct net_device *dev, 870 struct macsec_rx_sa *rx_sa, 871 sci_t sci, 872 struct macsec_secy *secy) 873 { 874 int ret; 875 struct scatterlist *sg; 876 struct sk_buff *trailer; 877 unsigned char *iv; 878 struct aead_request *req; 879 struct macsec_eth_header *hdr; 880 u32 hdr_pn; 881 u16 icv_len = secy->icv_len; 882 883 macsec_skb_cb(skb)->valid = false; 884 skb = skb_share_check(skb, GFP_ATOMIC); 885 if (!skb) 886 return ERR_PTR(-ENOMEM); 887 888 ret = skb_cow_data(skb, 0, &trailer); 889 if (unlikely(ret < 0)) { 890 kfree_skb(skb); 891 return ERR_PTR(ret); 892 } 893 req = macsec_alloc_req(rx_sa->key.tfm, &iv, &sg, ret); 894 if (!req) { 895 kfree_skb(skb); 896 return ERR_PTR(-ENOMEM); 897 } 898 899 hdr = (struct macsec_eth_header *)skb->data; 900 hdr_pn = ntohl(hdr->packet_number); 901 902 if (secy->xpn) { 903 pn_t recovered_pn = rx_sa->next_pn_halves; 904 906 if (hdr_pn < rx_sa->next_pn_halves.lower && 907 !pn_same_half(hdr_pn, rx_sa->next_pn_halves.lower)) 909 910 macsec_fill_iv_xpn(iv, rx_sa->ssci, recovered_pn.full64, 911 rx_sa->key.salt); 912 } else { 913 macsec_fill_iv(iv, sci, hdr_pn); 914 } 915 916 sg_init_table(sg, ret); 917 ret = skb_to_sgvec(skb, sg, 0, skb->len); 918 if (unlikely(ret < 0)) { 919 aead_request_free(req); 920 kfree_skb(skb); 921 return ERR_PTR(ret); 922 } 923 924 if (hdr->tci_an & MACSEC_TCI_E) { 925 /* confidentiality: ethernet + macsec header 926 * authenticated, encrypted payload 927 */ 928 int len = skb->len - macsec_hdr_len(macsec_skb_cb(skb)->has_sci); 929 930 aead_request_set_crypt(req, sg, sg, len, iv); 931 aead_request_set_ad(req, macsec_hdr_len(macsec_skb_cb(skb)->has_sci)); 932 skb = skb_unshare(skb, GFP_ATOMIC); 933 if (!skb) { 934 aead_request_free(req); 935 return ERR_PTR(-ENOMEM); 936 } 937 } else { 938 /* integrity only: all headers + data authenticated */ 939 aead_request_set_crypt(req, sg, sg, icv_len, iv); 940 aead_request_set_ad(req, skb->len - icv_len); 941 } 942 943 macsec_skb_cb(skb)->req = req; 944 skb->dev = dev; 945 aead_request_set_callback(req, 0, macsec_decrypt_done, skb); 946 947 dev_hold(dev); 948 ret = crypto_aead_decrypt(req); 949 if (ret == -EINPROGRESS) { 950 return ERR_PTR(ret); 951 } else if (ret != 0) { 952 /* decryption/authentication failed 953 * 10.6 if validateFrames is disabled, deliver anyway 954 */ 955 if (ret != -EBADMSG) { 956 kfree_skb(skb); 957 skb = ERR_PTR(ret); 958 } 959 } else { 960 macsec_skb_cb(skb)->valid = true; 961 } 962 dev_put(dev); 963 964 aead_request_free(req); 965 966 return skb; 967 } 968 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org