Hi Christophe, I love your patch! Yet something to improve: [auto build test ERROR on linux/master] [also build test ERROR on linus/master v5.17-rc3] [cannot apply to hnaz-mm/master next-20220211] [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/Christophe-Leroy/mm-Uninline-cop... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 2c271fe77d52a0555161926c232cd5bc07178b39 config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20220213/202202130121.dZLDqfpe-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/cf4474ac62f0332bd9d39f9dd74dbb5af... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Christophe-Leroy/mm-Uninline-copy_overflow/20220212-155040 git checkout cf4474ac62f0332bd9d39f9dd74dbb5afce9a7a4 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from arch/x86/include/asm/preempt.h:7, from include/linux/preempt.h:78, from include/linux/percpu.h:6, from include/linux/context_tracking_state.h:5, from include/linux/hardirq.h:5, from drivers/net/ethernet/mellanox/mlx4/cq.c:37: In function 'check_copy_size', inlined from 'copy_to_user' at include/linux/uaccess.h:199:6, inlined from 'mlx4_init_user_cqes' at drivers/net/ethernet/mellanox/mlx4/cq.c:317:9, inlined from 'mlx4_cq_alloc' at drivers/net/ethernet/mellanox/mlx4/cq.c:394:10: 228 | __bad_copy_from(); | ^~~~~~~~~~~~~~~~~ vim +/__bad_copy_from +228 include/linux/thread_info.h b0377fedb65280 Al Viro 2017-06-29 219 9dd819a15162f8 Kees Cook 2019-09-25 220 static __always_inline __must_check bool b0377fedb65280 Al Viro 2017-06-29 221 check_copy_size(const void *addr, size_t bytes, bool is_source) b0377fedb65280 Al Viro 2017-06-29 222 { c80d92fbb67b2c Kees Cook 2021-06-17 223 int sz = __builtin_object_size(addr, 0); b0377fedb65280 Al Viro 2017-06-29 224 if (unlikely(sz >= 0 && sz < bytes)) { b0377fedb65280 Al Viro 2017-06-29 225 if (!__builtin_constant_p(bytes)) b0377fedb65280 Al Viro 2017-06-29 226 copy_overflow(sz, bytes); b0377fedb65280 Al Viro 2017-06-29 227 else if (is_source) b0377fedb65280 Al Viro 2017-06-29 @228 __bad_copy_from(); b0377fedb65280 Al Viro 2017-06-29 229 else b0377fedb65280 Al Viro 2017-06-29 230 __bad_copy_to(); b0377fedb65280 Al Viro 2017-06-29 231 return false; b0377fedb65280 Al Viro 2017-06-29 232 } 6d13de1489b6bf Kees Cook 2019-12-04 233 if (WARN_ON_ONCE(bytes > INT_MAX)) 6d13de1489b6bf Kees Cook 2019-12-04 234 return false; b0377fedb65280 Al Viro 2017-06-29 235 check_object_size(addr, bytes, is_source); b0377fedb65280 Al Viro 2017-06-29 236 return true; b0377fedb65280 Al Viro 2017-06-29 237 } b0377fedb65280 Al Viro 2017-06-29 238 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org