Hi Wei, kernel test robot noticed the following build warnings: [auto build test WARNING on char-misc/char-misc-testing] [also build test WARNING on char-misc/char-misc-next char-misc/char-misc-linus linus/master v6.4-rc6 next-20230613] [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/Wei-Chin-Tsai/kernel-process-fork-exit-export-symbol-for-fork-exit-tracing-functions/20230614-112218 base: char-misc/char-misc-testing patch link: https://lore.kernel.org/r/20230614032038.11699-3-Wei-chin.Tsai%40mediatek.com patch subject: [PATCH v2 2/3] memory: export symbols for memory related functions config: hexagon-randconfig-r041-20230612 (https://download.01.org/0day-ci/archive/20230614/202306141630.EQtwoD5V-lkp@xxxxxxxxx/config) compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a) reproduce (this is a W=1 build): mkdir -p ~/bin wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git remote add char-misc https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git git fetch char-misc char-misc-testing git checkout char-misc/char-misc-testing b4 shazam https://lore.kernel.org/r/20230614032038.11699-3-Wei-chin.Tsai@xxxxxxxxxxxx # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=hexagon olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash fs/proc/ 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/202306141630.EQtwoD5V-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from fs/proc/task_mmu.c:3: In file included from include/linux/mm_inline.h:7: 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/hexagon/include/generated/asm/hardirq.h:1: 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/hexagon/include/asm/io.h:334: 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/task_mmu.c:3: In file included from include/linux/mm_inline.h:7: 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/hexagon/include/generated/asm/hardirq.h:1: 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/hexagon/include/asm/io.h:334: 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/task_mmu.c:3: In file included from include/linux/mm_inline.h:7: 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/hexagon/include/generated/asm/hardirq.h:1: 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/hexagon/include/asm/io.h:334: 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); | ~~~~~~~~~~ ^ >> fs/proc/task_mmu.c:776:6: warning: no previous prototype for function 'smap_gather_stats' [-Wmissing-prototypes] 776 | void smap_gather_stats(struct vm_area_struct *vma, | ^ fs/proc/task_mmu.c:776:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 776 | void smap_gather_stats(struct vm_area_struct *vma, | ^ | static 7 warnings generated. vim +/smap_gather_stats +776 fs/proc/task_mmu.c 769 770 /* 771 * Gather mem stats from @vma with the indicated beginning 772 * address @start, and keep them in @mss. 773 * 774 * Use vm_start of @vma as the beginning address if @start is 0. 775 */ > 776 void smap_gather_stats(struct vm_area_struct *vma, 777 struct mem_size_stats *mss, unsigned long start) 778 { 779 const struct mm_walk_ops *ops = &smaps_walk_ops; 780 781 /* Invalid start */ 782 if (start >= vma->vm_end) 783 return; 784 785 if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) { 786 /* 787 * For shared or readonly shmem mappings we know that all 788 * swapped out pages belong to the shmem object, and we can 789 * obtain the swap value much more efficiently. For private 790 * writable mappings, we might have COW pages that are 791 * not affected by the parent swapped out pages of the shmem 792 * object, so we have to distinguish them during the page walk. 793 * Unless we know that the shmem object (or the part mapped by 794 * our VMA) has no swapped out pages at all. 795 */ 796 unsigned long shmem_swapped = shmem_swap_usage(vma); 797 798 if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) || 799 !(vma->vm_flags & VM_WRITE))) { 800 mss->swap += shmem_swapped; 801 } else { 802 ops = &smaps_shmem_walk_ops; 803 } 804 } 805 806 /* mmap_lock is held in m_start */ 807 if (!start) 808 walk_page_vma(vma, ops, mss); 809 else 810 walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss); 811 } 812 EXPORT_SYMBOL_GPL(smap_gather_stats); 813 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki