Hi WoZ1zh1, kernel test robot noticed the following build warnings: [auto build test WARNING on next-20231108] url: https://github.com/intel-lab-lkp/linux/commits/WoZ1zh1/proc-support-file-f_pos-checking-in-mem_lseek/20231109-103353 base: next-20231108 patch link: https://lore.kernel.org/r/20231109102658.2075547-1-wozizhi%40huawei.com patch subject: [PATCH -next V2] proc: support file->f_pos checking in mem_lseek config: um-allnoconfig (https://download.01.org/0day-ci/archive/20231110/202311101239.ihy4cKpf-lkp@xxxxxxxxx/config) compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231110/202311101239.ihy4cKpf-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/202311101239.ihy4cKpf-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from fs/proc/base.c:68: In file included from include/linux/swap.h:9: In file included from include/linux/memcontrol.h:13: In file included from include/linux/cgroup.h:26: In file included from include/linux/kernel_stat.h:9: In file included from include/linux/interrupt.h:11: 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:13: In file included from arch/um/include/asm/io.h:24: include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 547 | val = __raw_readb(PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 560 | 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/proc/base.c:68: In file included from include/linux/swap.h:9: In file included from include/linux/memcontrol.h:13: In file included from include/linux/cgroup.h:26: In file included from include/linux/kernel_stat.h:9: In file included from include/linux/interrupt.h:11: 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:13: In file included from arch/um/include/asm/io.h:24: include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 573 | 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/proc/base.c:68: In file included from include/linux/swap.h:9: In file included from include/linux/memcontrol.h:13: In file included from include/linux/cgroup.h:26: In file included from include/linux/kernel_stat.h:9: In file included from include/linux/interrupt.h:11: 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:13: In file included from arch/um/include/asm/io.h:24: include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 584 | __raw_writeb(value, PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 594 | __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 604 | __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 692 | readsb(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 700 | readsw(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 708 | readsl(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 717 | writesb(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 726 | writesw(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 735 | writesl(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ >> fs/proc/base.c:912:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough] 912 | case SEEK_SET: | ^ fs/proc/base.c:912:2: note: insert '__attribute__((fallthrough));' to silence this warning 912 | case SEEK_SET: | ^ | __attribute__((fallthrough)); fs/proc/base.c:912:2: note: insert 'break;' to avoid fall-through 912 | case SEEK_SET: | ^ | break; 13 warnings generated. vim +912 fs/proc/base.c 903 904 loff_t mem_lseek(struct file *file, loff_t offset, int orig) 905 { 906 loff_t ret = 0; 907 908 spin_lock(&file->f_lock); 909 switch (orig) { 910 case SEEK_CUR: 911 offset += file->f_pos; > 912 case SEEK_SET: 913 /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */ 914 if ((unsigned long long)offset >= -MAX_ERRNO) 915 ret = -EOVERFLOW; 916 break; 917 default: 918 ret = -EINVAL; 919 } 920 if (!ret) { 921 if (offset < 0 && !(unsigned_offsets(file))) { 922 ret = -EINVAL; 923 } else { 924 file->f_pos = offset; 925 ret = file->f_pos; 926 force_successful_syscall_return(); 927 } 928 } 929 930 spin_unlock(&file->f_lock); 931 return ret; 932 } 933 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
