tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.19.y head: e864f43593ccf9180c61738abdf1c1dde091367d commit: b92e5db0f492026778cb31dfc479e50f33f75bca [5303/9999] powerpc/32: Avoid unsupported flags with clang config: powerpc-randconfig-r005-20210622 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project b3634d3e88b7f26534a5057bff182b7dced584fc) 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 # install powerpc cross compiling tool for clang build # apt-get install binutils-powerpc-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.gi... git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git git fetch --no-tags linux-stable-rc linux-4.19.y git checkout b92e5db0f492026778cb31dfc479e50f33f75bca # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): ~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~ In file included from drivers/net/netdevsim/netdev.c:22: include/net/netlink.h:358:18: warning: comparison of integers of different signs: 'const __u32' (aka 'const unsigned int') and 'int' [-Wsign-compare] nlh->nlmsg_len <= remaining); ~~~~~~~~~~~~~~ ^ ~~~~~~~~~ include/net/netlink.h:395:21: warning: comparison of integers of different signs: 'const __u32' (aka 'const unsigned int') and 'int' [-Wsign-compare] if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) ~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~ include/net/netlink.h:430:21: warning: comparison of integers of different signs: 'const __u32' (aka 'const unsigned int') and 'int' [-Wsign-compare] if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) ~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~ In file included from drivers/net/netdevsim/netdev.c:23: In file included from include/net/pkt_cls.h:7: In file included from include/net/sch_generic.h:16: include/net/rtnetlink.h:25:21: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare] if (nlmsg_len(nlh) >= sizeof(struct rtgenmsg)) ~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~ In file included from drivers/net/netdevsim/netdev.c:23: In file included from include/net/pkt_cls.h:7: include/net/sch_generic.h:387:33: warning: comparison of integers of different signs: 'unsigned int' and 'int' [-Wsign-compare] BUILD_BUG_ON(sizeof(qcb->data) < sz); ~~~~~~~~~~~~~~~~~ ^ ~~ include/linux/build_bug.h:69:19: note: expanded from macro 'BUILD_BUG_ON' BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) ^~~~~~~~~ include/linux/build_bug.h:45:58: note: expanded from macro 'BUILD_BUG_ON_MSG' #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) ^~~~ include/linux/compiler.h:348:22: note: expanded from macro 'compiletime_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) ^~~~~~~~~ include/linux/compiler.h:336:23: note: expanded from macro '_compiletime_assert' __compiletime_assert(condition, msg, prefix, suffix) ^~~~~~~~~ include/linux/compiler.h:328:9: note: expanded from macro '__compiletime_assert' if (!(condition)) \ ^~~~~~~~~ In file included from drivers/net/netdevsim/netdev.c:23: In file included from include/net/pkt_cls.h:7: include/net/sch_generic.h:493:13: warning: comparison of integers of different signs: 'int' and 'const unsigned int' [-Wsign-compare] return ntx < dev->real_num_tx_queues ? ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~ include/net/sch_generic.h:537:15: warning: comparison of integers of different signs: 'u32' (aka 'unsigned int') and 'int' [-Wsign-compare] return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL; ~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~ In file included from drivers/net/netdevsim/netdev.c:25: In file included from include/net/switchdev.h:17: In file included from include/net/ip_fib.h:24: In file included from include/net/inetpeer.h:16: In file included from include/net/ipv6.h:16: In file included from include/linux/ipv6.h:87: In file included from include/linux/tcp.h:23: In file included from include/net/sock.h:64: include/linux/filter.h:1011:16: warning: comparison of integers of different signs: 'const __u32' (aka 'const unsigned int') and 'int' [-Wsign-compare] if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) ~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from drivers/net/netdevsim/netdev.c:25: In file included from include/net/switchdev.h:17: In file included from include/net/ip_fib.h:24: In file included from include/net/inetpeer.h:16: In file included from include/net/ipv6.h:16: In file included from include/linux/ipv6.h:87: In file included from include/linux/tcp.h:23: include/net/sock.h:2246:43: warning: comparison of integers of different signs: 'unsigned int' and 'int' [-Wsign-compare] return refcount_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~ In file included from drivers/net/netdevsim/netdev.c:25: In file included from include/net/switchdev.h:17: In file included from include/net/ip_fib.h:24: In file included from include/net/inetpeer.h:16: In file included from include/net/ipv6.h:16: In file included from include/linux/ipv6.h:87: In file included from include/linux/tcp.h:24: include/net/inet_connection_sock.h:288:38: warning: comparison of integers of different signs: 'int' and 'const u32' (aka 'const unsigned int') [-Wsign-compare] return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~ drivers/net/netdevsim/netdev.c:342:9: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare] if (vf >= ns->num_vfs || is_multicast_ether_addr(mac)) ~~ ^ ~~~~~~~~~~~ drivers/net/netdevsim/netdev.c:354:9: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare] if (vf >= ns->num_vfs || vlan > 4095 || qos > 7) ~~ ^ ~~~~~~~~~~~ drivers/net/netdevsim/netdev.c:368:9: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare] if (vf >= ns->num_vfs) ~~ ^ ~~~~~~~~~~~ drivers/net/netdevsim/netdev.c:381:9: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare] if (vf >= ns->num_vfs) ~~ ^ ~~~~~~~~~~~ drivers/net/netdevsim/netdev.c:392:9: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare] if (vf >= ns->num_vfs) ~~ ^ ~~~~~~~~~~~ drivers/net/netdevsim/netdev.c:403:9: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare] if (vf >= ns->num_vfs) ~~ ^ ~~~~~~~~~~~ drivers/net/netdevsim/netdev.c:415:9: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare] if (vf >= ns->num_vfs) ~~ ^ ~~~~~~~~~~~ drivers/net/netdevsim/netdev.c:437:9: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare] if (vf >= ns->num_vfs) ~~ ^ ~~~~~~~~~~~ static const struct switchdev_ops nsim_switchdev_ops = { ^ 37 warnings generated. Assembler messages: Fatal error: invalid listing option `3' clang-13: error: assembler command failed with exit code 1 (use -v to see invocation) vim +/nsim_switchdev_ops +167 drivers/net/netdevsim/netdev.c 5f07655b803eca Jakub Kicinski 2018-07-17 166 5f07655b803eca Jakub Kicinski 2018-07-17 @167 static const struct switchdev_ops nsim_switchdev_ops = { 5f07655b803eca Jakub Kicinski 2018-07-17 168 .switchdev_port_attr_get = nsim_port_attr_get, 5f07655b803eca Jakub Kicinski 2018-07-17 169 }; 5f07655b803eca Jakub Kicinski 2018-07-17 170 :::::: The code at line 167 was first introduced by commit :::::: 5f07655b803eca4c215bac9aa61f4bf19f6ecd5e netdevsim: add switch_id attribute :::::: TO: Jakub Kicinski <jakub.kicinski(a)netronome.com&gt; :::::: CC: Daniel Borkmann <daniel(a)iogearbox.net&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org