Re: [PATCH v14 2/5] fs/proc/task_mmu: Implement IOCTL to get and optionally clear info about PTEs

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

Hi Muhammad,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on next-20230417]
[cannot apply to linus/master v6.3-rc7]
[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/Muhammad-Usama-Anjum/userfaultfd-UFFD_FEATURE_WP_ASYNC/20230418-142225
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20230418062008.1434826-3-usama.anjum%40collabora.com
patch subject: [PATCH v14 2/5] fs/proc/task_mmu: Implement IOCTL to get and optionally clear info about PTEs
config: arm-defconfig (https://download.01.org/0day-ci/archive/20230419/202304190331.VR44lj9J-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/4fe2396ba406868e01de910812e7e3c719ba11be
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Muhammad-Usama-Anjum/userfaultfd-UFFD_FEATURE_WP_ASYNC/20230418-142225
        git checkout 4fe2396ba406868e01de910812e7e3c719ba11be
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash fs/proc/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304190331.VR44lj9J-lkp@intel.com/

All warnings (new ones prefixed by >>):

   fs/proc/task_mmu.c: In function 'do_pagemap_scan':
   fs/proc/task_mmu.c:2205:17: error: implicit declaration of function 'flush_tlb_mm_range'; did you mean 'flush_tlb_range'? [-Werror=implicit-function-declaration]
    2205 |                 flush_tlb_mm_range(mm, start, end, PAGE_SHIFT, false);
         |                 ^~~~~~~~~~~~~~~~~~
         |                 flush_tlb_range
   In file included from include/linux/highmem.h:14,
                    from include/linux/bvec.h:10,
                    from include/linux/blk_types.h:10,
                    from include/linux/writeback.h:13,
                    from include/linux/memcontrol.h:22,
                    from include/linux/swap.h:9,
                    from include/linux/mm_inline.h:7,
                    from fs/proc/task_mmu.c:3:
   include/linux/highmem-internal.h: In function 'pagemap_scan_pmd_entry':
>> include/linux/highmem-internal.h:271:9: warning: 'orig_pte' is used uninitialized [-Wuninitialized]
     271 |         __kunmap_atomic(__addr);                                \
         |         ^~~~~~~~~~~~~~~
   fs/proc/task_mmu.c:1934:22: note: 'orig_pte' was declared here
    1934 |         pte_t *pte, *orig_pte;
         |                      ^~~~~~~~
   cc1: some warnings being treated as errors


vim +/orig_pte +271 include/linux/highmem-internal.h

13f876ba77ebd5 Thomas Gleixner       2020-11-03  251  
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  252  /**
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  253   * kunmap_atomic - Unmap the virtual address mapped by kmap_atomic() - deprecated!
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  254   * @__addr:       Virtual address to be unmapped
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  255   *
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  256   * Unmaps an address previously mapped by kmap_atomic() and re-enables
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  257   * pagefaults. Depending on PREEMP_RT configuration, re-enables also
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  258   * migration and preemption. Users should not count on these side effects.
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  259   *
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  260   * Mappings should be unmapped in the reverse order that they were mapped.
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  261   * See kmap_local_page() for details on nesting.
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  262   *
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  263   * @__addr can be any address within the mapped page, so there is no need
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  264   * to subtract any offset that has been added. In contrast to kunmap(),
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  265   * this function takes the address returned from kmap_atomic(), not the
e7392b4eca84e8 Fabio M. De Francesco 2022-05-13  266   * page passed to it. The compiler will warn you if you pass the page.
13f876ba77ebd5 Thomas Gleixner       2020-11-03  267   */
13f876ba77ebd5 Thomas Gleixner       2020-11-03  268  #define kunmap_atomic(__addr)					\
13f876ba77ebd5 Thomas Gleixner       2020-11-03  269  do {								\
13f876ba77ebd5 Thomas Gleixner       2020-11-03  270  	BUILD_BUG_ON(__same_type((__addr), struct page *));	\
13f876ba77ebd5 Thomas Gleixner       2020-11-03 @271  	__kunmap_atomic(__addr);				\
13f876ba77ebd5 Thomas Gleixner       2020-11-03  272  } while (0)
13f876ba77ebd5 Thomas Gleixner       2020-11-03  273  

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