tree: https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git work.statx head: 6bf8aea1847ea450c5bc8de1b7ef194c70e417ff commit: 8b3d898afb729019f0627a61f34622d115f54581 [1/3] getname_maybe_null() - the third variant of pathname copy-in config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20241010/202410101304.S1BUv98j-lkp@xxxxxxxxx/config) compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241010/202410101304.S1BUv98j-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202410101304.S1BUv98j-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> fs/stat.c:770:11: warning: variable 'lflags' set but not used [-Wunused-but-set-variable] 770 | unsigned lflags; | ^ 1 warning generated. vim +/lflags +770 fs/stat.c 0ef625bba6fb2b Mateusz Guzik 2024-06-25 751 a528d35e8bfcc5 David Howells 2017-01-31 752 /** a528d35e8bfcc5 David Howells 2017-01-31 753 * sys_statx - System call to get enhanced stats a528d35e8bfcc5 David Howells 2017-01-31 754 * @dfd: Base directory to pathwalk from *or* fd to stat. 0ef625bba6fb2b Mateusz Guzik 2024-06-25 755 * @filename: File to stat or either NULL or "" with AT_EMPTY_PATH a528d35e8bfcc5 David Howells 2017-01-31 756 * @flags: AT_* flags to control pathwalk. a528d35e8bfcc5 David Howells 2017-01-31 757 * @mask: Parts of statx struct actually required. a528d35e8bfcc5 David Howells 2017-01-31 758 * @buffer: Result buffer. a528d35e8bfcc5 David Howells 2017-01-31 759 * 1e2f82d1e9d122 David Howells 2017-04-26 760 * Note that fstat() can be emulated by setting dfd to the fd of interest, 0ef625bba6fb2b Mateusz Guzik 2024-06-25 761 * supplying "" (or preferably NULL) as the filename and setting AT_EMPTY_PATH 0ef625bba6fb2b Mateusz Guzik 2024-06-25 762 * in the flags. a528d35e8bfcc5 David Howells 2017-01-31 763 */ a528d35e8bfcc5 David Howells 2017-01-31 764 SYSCALL_DEFINE5(statx, a528d35e8bfcc5 David Howells 2017-01-31 765 int, dfd, const char __user *, filename, unsigned, flags, a528d35e8bfcc5 David Howells 2017-01-31 766 unsigned int, mask, a528d35e8bfcc5 David Howells 2017-01-31 767 struct statx __user *, buffer) a528d35e8bfcc5 David Howells 2017-01-31 768 { 1b6fe6e0dfecf8 Stefan Roesch 2022-02-25 769 int ret; 0ef625bba6fb2b Mateusz Guzik 2024-06-25 @770 unsigned lflags; 8b3d898afb7290 Al Viro 2024-10-07 771 struct filename *name = getname_maybe_null(filename, flags); 1b6fe6e0dfecf8 Stefan Roesch 2022-02-25 772 0ef625bba6fb2b Mateusz Guzik 2024-06-25 773 /* 0ef625bba6fb2b Mateusz Guzik 2024-06-25 774 * Short-circuit handling of NULL and "" paths. 0ef625bba6fb2b Mateusz Guzik 2024-06-25 775 * 0ef625bba6fb2b Mateusz Guzik 2024-06-25 776 * For a NULL path we require and accept only the AT_EMPTY_PATH flag 0ef625bba6fb2b Mateusz Guzik 2024-06-25 777 * (possibly |'d with AT_STATX flags). 0ef625bba6fb2b Mateusz Guzik 2024-06-25 778 * 0ef625bba6fb2b Mateusz Guzik 2024-06-25 779 * However, glibc on 32-bit architectures implements fstatat as statx 0ef625bba6fb2b Mateusz Guzik 2024-06-25 780 * with the "" pathname and AT_NO_AUTOMOUNT | AT_EMPTY_PATH flags. 0ef625bba6fb2b Mateusz Guzik 2024-06-25 781 * Supporting this results in the uglification below. 0ef625bba6fb2b Mateusz Guzik 2024-06-25 782 */ 0ef625bba6fb2b Mateusz Guzik 2024-06-25 783 lflags = flags & ~(AT_NO_AUTOMOUNT | AT_STATX_SYNC_TYPE); 8b3d898afb7290 Al Viro 2024-10-07 784 if (!name) 0ef625bba6fb2b Mateusz Guzik 2024-06-25 785 return do_statx_fd(dfd, flags & ~AT_NO_AUTOMOUNT, mask, buffer); 0ef625bba6fb2b Mateusz Guzik 2024-06-25 786 1b6fe6e0dfecf8 Stefan Roesch 2022-02-25 787 ret = do_statx(dfd, name, flags, mask, buffer); 1b6fe6e0dfecf8 Stefan Roesch 2022-02-25 788 putname(name); 1b6fe6e0dfecf8 Stefan Roesch 2022-02-25 789 1b6fe6e0dfecf8 Stefan Roesch 2022-02-25 790 return ret; a528d35e8bfcc5 David Howells 2017-01-31 791 } a528d35e8bfcc5 David Howells 2017-01-31 792 :::::: The code at line 770 was first introduced by commit :::::: 0ef625bba6fb2bc0c8ed2aab9524fdf423f67dd5 vfs: support statx(..., NULL, AT_EMPTY_PATH, ...) :::::: TO: Mateusz Guzik <mjguzik@xxxxxxxxx> :::::: CC: Christian Brauner <brauner@xxxxxxxxxx> -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
