Hi NeilBrown, kernel test robot noticed the following build errors: [auto build test ERROR on brauner-vfs/vfs.all] [also build test ERROR on trondmy-nfs/linux-next driver-core/driver-core-testing driver-core/driver-core-next driver-core/driver-core-linus cifs/for-next xfs-linux/for-next linus/master v6.14-rc2 next-20250214] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/NeilBrown/nfs-change-mkdir-inode_operation-to-return-alternate-dentry-if-needed/20250214-141741 base: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git vfs.all patch link: https://lore.kernel.org/r/20250214052204.3105610-2-neilb%40suse.de patch subject: [PATCH 1/3] Change inode_operations.mkdir to return struct dentry * config: um-randconfig-001-20250215 (https://download.01.org/0day-ci/archive/20250215/202502151519.0MA7hz8D-lkp@xxxxxxxxx/config) compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project 910be4ff90d7d07bd4518ea03b85c0974672bf9c) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250215/202502151519.0MA7hz8D-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/202502151519.0MA7hz8D-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): In file included from fs/hostfs/hostfs_kern.c:13: In file included from include/linux/pagemap.h:11: In file included from include/linux/highmem.h:12: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:14: In file included from arch/um/include/asm/io.h:24: include/asm-generic/io.h:549:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 549 | val = __raw_readb(PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:567:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 567 | val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); | ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu' 37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) | ^ In file included from fs/hostfs/hostfs_kern.c:13: In file included from include/linux/pagemap.h:11: In file included from include/linux/highmem.h:12: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:14: In file included from arch/um/include/asm/io.h:24: include/asm-generic/io.h:585:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 585 | val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); | ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu' 35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) | ^ In file included from fs/hostfs/hostfs_kern.c:13: In file included from include/linux/pagemap.h:11: In file included from include/linux/highmem.h:12: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:14: In file included from arch/um/include/asm/io.h:24: include/asm-generic/io.h:601:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 601 | __raw_writeb(value, PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:616:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 616 | __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:631:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 631 | __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:724:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 724 | readsb(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:737:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 737 | readsw(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:750:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 750 | readsl(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:764:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 764 | writesb(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:778:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 778 | writesw(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:792:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 792 | writesl(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ >> fs/hostfs/hostfs_kern.c:689:10: error: incompatible integer to pointer conversion returning 'int' from a function with result type 'struct dentry *' [-Wint-conversion] 689 | return -ENOMEM; | ^~~~~~~ 12 warnings and 1 error generated. vim +689 fs/hostfs/hostfs_kern.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 681 456289e0bd14ce NeilBrown 2025-02-14 682 static struct dentry *hostfs_mkdir(struct mnt_idmap *idmap, struct inode *ino, 549c7297717c32 Christian Brauner 2021-01-21 683 struct dentry *dentry, umode_t mode) ^1da177e4c3f41 Linus Torvalds 2005-04-16 684 { ^1da177e4c3f41 Linus Torvalds 2005-04-16 685 char *file; ^1da177e4c3f41 Linus Torvalds 2005-04-16 686 int err; ^1da177e4c3f41 Linus Torvalds 2005-04-16 687 c5322220eb91b9 Al Viro 2010-06-06 688 if ((file = dentry_name(dentry)) == NULL) f1adc05e773830 Jeff Dike 2007-05-08 @689 return -ENOMEM; ^1da177e4c3f41 Linus Torvalds 2005-04-16 690 err = do_mkdir(file, mode); e9193059b1b373 Al Viro 2010-06-06 691 __putname(file); 456289e0bd14ce NeilBrown 2025-02-14 692 if (err) 456289e0bd14ce NeilBrown 2025-02-14 693 return ERR_PTR(err); 456289e0bd14ce NeilBrown 2025-02-14 694 else 456289e0bd14ce NeilBrown 2025-02-14 695 return dentry; ^1da177e4c3f41 Linus Torvalds 2005-04-16 696 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 697 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki