Hi Mincheol, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on bluetooth-next/master] [also build test WARNING on net-next/master net/master bluetooth/master sparc-next/master v5.10-rc7 next-20201207] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Mincheol-Son/Bluetooth-smp-Fix-biased-random-passkey-generation/20201208-015207 base: https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git master config: parisc-randconfig-r035-20201207 (attached as .config) compiler: hppa-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/80c9c180f997bc9d9e1df4426fc7957839caee56 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Mincheol-Son/Bluetooth-smp-Fix-biased-random-passkey-generation/20201208-015207 git checkout 80c9c180f997bc9d9e1df4426fc7957839caee56 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=parisc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): net/bluetooth/smp.c: In function 'tk_request': >> net/bluetooth/smp.c:927:3: warning: this decimal constant is unsigned only in ISO C90 927 | } while (passkey >= (u32)4200000000); | ^ vim +927 net/bluetooth/smp.c 849 850 static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, 851 u8 local_io, u8 remote_io) 852 { 853 struct hci_conn *hcon = conn->hcon; 854 struct l2cap_chan *chan = conn->smp; 855 struct smp_chan *smp = chan->data; 856 u32 passkey = 0; 857 int ret; 858 859 /* Initialize key for JUST WORKS */ 860 memset(smp->tk, 0, sizeof(smp->tk)); 861 clear_bit(SMP_FLAG_TK_VALID, &smp->flags); 862 863 BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); 864 865 /* If neither side wants MITM, either "just" confirm an incoming 866 * request or use just-works for outgoing ones. The JUST_CFM 867 * will be converted to JUST_WORKS if necessary later in this 868 * function. If either side has MITM look up the method from the 869 * table. 870 */ 871 if (!(auth & SMP_AUTH_MITM)) 872 smp->method = JUST_CFM; 873 else 874 smp->method = get_auth_method(smp, local_io, remote_io); 875 876 /* Don't confirm locally initiated pairing attempts */ 877 if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, 878 &smp->flags)) 879 smp->method = JUST_WORKS; 880 881 /* Don't bother user space with no IO capabilities */ 882 if (smp->method == JUST_CFM && 883 hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) 884 smp->method = JUST_WORKS; 885 886 /* If Just Works, Continue with Zero TK and ask user-space for 887 * confirmation */ 888 if (smp->method == JUST_WORKS) { 889 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 890 hcon->type, 891 hcon->dst_type, 892 passkey, 1); 893 if (ret) 894 return ret; 895 set_bit(SMP_FLAG_WAIT_USER, &smp->flags); 896 return 0; 897 } 898 899 /* If this function is used for SC -> legacy fallback we 900 * can only recover the just-works case. 901 */ 902 if (test_bit(SMP_FLAG_SC, &smp->flags)) 903 return -EINVAL; 904 905 /* Not Just Works/Confirm results in MITM Authentication */ 906 if (smp->method != JUST_CFM) { 907 set_bit(SMP_FLAG_MITM_AUTH, &smp->flags); 908 if (hcon->pending_sec_level < BT_SECURITY_HIGH) 909 hcon->pending_sec_level = BT_SECURITY_HIGH; 910 } 911 912 /* If both devices have Keyoard-Display I/O, the master 913 * Confirms and the slave Enters the passkey. 914 */ 915 if (smp->method == OVERLAP) { 916 if (hcon->role == HCI_ROLE_MASTER) 917 smp->method = CFM_PASSKEY; 918 else 919 smp->method = REQ_PASSKEY; 920 } 921 922 /* Generate random passkey. */ 923 if (smp->method == CFM_PASSKEY) { 924 memset(smp->tk, 0, sizeof(smp->tk)); 925 do { 926 get_random_bytes(&passkey, sizeof(passkey)); > 927 } while (passkey >= (u32)4200000000); 928 passkey %= 1000000; 929 put_unaligned_le32(passkey, smp->tk); 930 BT_DBG("PassKey: %d", passkey); 931 set_bit(SMP_FLAG_TK_VALID, &smp->flags); 932 } 933 934 if (smp->method == REQ_PASSKEY) 935 ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, 936 hcon->type, hcon->dst_type); 937 else if (smp->method == JUST_CFM) 938 ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, 939 hcon->type, hcon->dst_type, 940 passkey, 1); 941 else 942 ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, 943 hcon->type, hcon->dst_type, 944 passkey, 0); 945 946 return ret; 947 } 948 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org