Re: [PATCH v2 2/3] memory: export symbols for memory related functions

[kernel test robot <lkp@intel.com>]

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@intel.com/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@mediatek.com
        # 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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306141630.EQtwoD5V-lkp@intel.com/

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	

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