tree:   https://github.com/ammarfaizi2/linux-block akpm/mm/mm-unstable
head:   4661cf99c1e4946297434595994227e47f33c014
commit: b7edf4b1cdb10106ea63ff2a416b5680d8392dcb [71/161] mm: hwpoison: support recovery from ksm_might_need_to_copy()
config: i386-randconfig-a001
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/ammarfaizi2/linux-block/commit/b7edf4b1cdb10106ea63ff2a416b5680d8392dcb
        git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
        git fetch --no-tags ammarfaizi2-block akpm/mm/mm-unstable
        git checkout b7edf4b1cdb10106ea63ff2a416b5680d8392dcb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

Note: the ammarfaizi2-block/akpm/mm/mm-unstable HEAD 4661cf99c1e4946297434595994227e47f33c014 builds fine.
      It only hurts bisectability.

All errors (new ones prefixed by >>):

   mm/ksm.c: In function 'ksm_might_need_to_copy':
>> mm/ksm.c:2605:21: error: implicit declaration of function 'copy_mc_user_highpage'; did you mean 'copy_user_highpage'? [-Werror=implicit-function-declaration]
    2605 |                 if (copy_mc_user_highpage(new_page, page, address, vma)) {
         |                     ^~~~~~~~~~~~~~~~~~~~~
         |                     copy_user_highpage
   cc1: some warnings being treated as errors


vim +2605 mm/ksm.c

  2577	
  2578	struct page *ksm_might_need_to_copy(struct page *page,
  2579				struct vm_area_struct *vma, unsigned long address)
  2580	{
  2581		struct folio *folio = page_folio(page);
  2582		struct anon_vma *anon_vma = folio_anon_vma(folio);
  2583		struct page *new_page;
  2584	
  2585		if (PageKsm(page)) {
  2586			if (page_stable_node(page) &&
  2587			    !(ksm_run & KSM_RUN_UNMERGE))
  2588				return page;	/* no need to copy it */
  2589		} else if (!anon_vma) {
  2590			return page;		/* no need to copy it */
  2591		} else if (page->index == linear_page_index(vma, address) &&
  2592				anon_vma->root == vma->anon_vma->root) {
  2593			return page;		/* still no need to copy it */
  2594		}
  2595		if (!PageUptodate(page))
  2596			return page;		/* let do_swap_page report the error */
  2597	
  2598		new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
  2599		if (new_page &&
  2600		    mem_cgroup_charge(page_folio(new_page), vma->vm_mm, GFP_KERNEL)) {
  2601			put_page(new_page);
  2602			new_page = NULL;
  2603		}
  2604		if (new_page) {
> 2605			if (copy_mc_user_highpage(new_page, page, address, vma)) {
  2606				put_page(new_page);
  2607				new_page = ERR_PTR(-EHWPOISON);
  2608				memory_failure_queue(page_to_pfn(page), 0);
  2609				return new_page;
  2610			}
  2611			SetPageDirty(new_page);
  2612			__SetPageUptodate(new_page);
  2613			__SetPageLocked(new_page);
  2614	#ifdef CONFIG_SWAP
  2615			count_vm_event(KSM_SWPIN_COPY);
  2616	#endif
  2617		}
  2618	
  2619		return new_page;
  2620	}
  2621	

-- 
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