tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: c9e9cdd8bdcc3e1ea330d49ea587ec71884dd0f5 commit: 39356d3c334e86be701f857a5f22db2346c59f50 [1756/4000] btrfs: turn on -Wmaybe-uninitialized config: s390-randconfig-r034-20230111 compiler: s390-linux-gcc (GCC) 12.1.0 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://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=39356d3c334e86be701f857a5f22db2346c59f50 git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout 39356d3c334e86be701f857a5f22db2346c59f50 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot Note: it may well be a FALSE warning. FWIW you are at least aware of it now. http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings All warnings (new ones prefixed by >>): In file included from include/asm-generic/rwonce.h:27, from ./arch/s390/include/generated/asm/rwonce.h:1, from include/linux/compiler.h:247, from include/linux/kernel.h:20, from fs/btrfs/ioctl.c:6: include/linux/kcsan-checks.h: In function 'btrfs_ioctl_wait_sync': include/linux/kcsan-checks.h:220:28: warning: 'transid' may be used uninitialized [-Wmaybe-uninitialized] 220 | #define kcsan_check_access __kcsan_check_access | ^~~~~~~~~~~~~~~~~~~~ include/linux/kcsan-checks.h:37:6: note: by argument 1 of type 'const volatile void *' to '__kcsan_check_access' declared here 37 | void __kcsan_check_access(const volatile void *ptr, size_t size, int type); | ^~~~~~~~~~~~~~~~~~~~ fs/btrfs/ioctl.c:3134:13: note: 'transid' declared here 3134 | u64 transid; | ^~~~~~~ include/linux/kcsan-checks.h: In function '_btrfs_ioctl_send': >> include/linux/kcsan-checks.h:220:28: warning: 'args32' may be used uninitialized [-Wmaybe-uninitialized] 220 | #define kcsan_check_access __kcsan_check_access | ^~~~~~~~~~~~~~~~~~~~ include/linux/kcsan-checks.h:37:6: note: by argument 1 of type 'const volatile void *' to '__kcsan_check_access' declared here 37 | void __kcsan_check_access(const volatile void *ptr, size_t size, int type); | ^~~~~~~~~~~~~~~~~~~~ fs/btrfs/ioctl.c:4320:49: note: 'args32' declared here 4320 | struct btrfs_ioctl_send_args_32 args32; | ^~~~~~ include/linux/kcsan-checks.h: In function 'btrfs_ioctl_space_info': include/linux/kcsan-checks.h:220:28: warning: 'space_args' may be used uninitialized [-Wmaybe-uninitialized] 220 | #define kcsan_check_access __kcsan_check_access | ^~~~~~~~~~~~~~~~~~~~ include/linux/kcsan-checks.h:37:6: note: by argument 1 of type 'const volatile void *' to '__kcsan_check_access' declared here 37 | void __kcsan_check_access(const volatile void *ptr, size_t size, int type); | ^~~~~~~~~~~~~~~~~~~~ fs/btrfs/ioctl.c:2973:39: note: 'space_args' declared here 2973 | struct btrfs_ioctl_space_args space_args; | ^~~~~~~~~~ vim +/args32 +220 include/linux/kcsan-checks.h dfd402a4c4baae Marco Elver 2019-11-14 214 19acd03d95dad1 Marco Elver 2020-04-24 215 #ifdef __SANITIZE_THREAD__ dfd402a4c4baae Marco Elver 2019-11-14 216 /* 19acd03d95dad1 Marco Elver 2020-04-24 217 * Only calls into the runtime when the particular compilation unit has KCSAN 19acd03d95dad1 Marco Elver 2020-04-24 218 * instrumentation enabled. May be used in header files. dfd402a4c4baae Marco Elver 2019-11-14 219 */ dfd402a4c4baae Marco Elver 2019-11-14 @220 #define kcsan_check_access __kcsan_check_access 19acd03d95dad1 Marco Elver 2020-04-24 221 :::::: The code at line 220 was first introduced by commit :::::: dfd402a4c4baae42398ce9180ff424d589b8bffc kcsan: Add Kernel Concurrency Sanitizer infrastructure :::::: TO: Marco Elver :::::: CC: Paul E. McKenney -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests