Re: [PATCH] mm: clean up hwpoison page cache page in fault path

[kernel test robot]

Hi Rik,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on hnaz-mm/master]

url:    https://github.com/0day-ci/linux/commits/Rik-van-Riel/mm-clean-up-hwpoison-page-cache-page-in-fault-path/20220212-060643
base:   https://github.com/hnaz/linux-mm master
config: sparc-randconfig-s031-20220211 (https://download.01.org/0day-ci/archive/20220212/202202122306.S9ByO64R-lkp@xxxxxxxxx/config)
compiler: sparc-linux-gcc (GCC) 11.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.4-dirty
        # https://github.com/0day-ci/linux/commit/abd960cdbc9487dbf0a0dc3b2395825a38f8fa44
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Rik-van-Riel/mm-clean-up-hwpoison-page-cache-page-in-fault-path/20220212-060643
        git checkout abd960cdbc9487dbf0a0dc3b2395825a38f8fa44
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=sparc SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>


sparse warnings: (new ones prefixed by >>)
>> mm/memory.c:3913:33: sparse: sparse: incorrect type in initializer (different base types) @@     expected int poisonret @@     got restricted vm_fault_t @@
   mm/memory.c:3913:33: sparse:     expected int poisonret
   mm/memory.c:3913:33: sparse:     got restricted vm_fault_t
>> mm/memory.c:3922:24: sparse: sparse: incorrect type in return expression (different base types) @@     expected restricted vm_fault_t @@     got int [assigned] poisonret @@
   mm/memory.c:3922:24: sparse:     expected restricted vm_fault_t
   mm/memory.c:3922:24: sparse:     got int [assigned] poisonret
   mm/memory.c:1024:17: sparse: sparse: context imbalance in 'copy_pte_range' - different lock contexts for basic block
   mm/memory.c:1740:16: sparse: sparse: context imbalance in '__get_locked_pte' - different lock contexts for basic block
   mm/memory.c:1788:9: sparse: sparse: context imbalance in 'insert_page' - different lock contexts for basic block
   mm/memory.c:2290:17: sparse: sparse: context imbalance in 'remap_pte_range' - different lock contexts for basic block
   mm/memory.c:2546:17: sparse: sparse: context imbalance in 'apply_to_pte_range' - unexpected unlock
   mm/memory.c:2834:17: sparse: sparse: context imbalance in 'wp_page_copy' - unexpected unlock
   mm/memory.c:3173:17: sparse: sparse: context imbalance in 'wp_pfn_shared' - unexpected unlock
   mm/memory.c:3236:19: sparse: sparse: context imbalance in 'do_wp_page' - different lock contexts for basic block
   mm/memory.c:4939:5: sparse: sparse: context imbalance in 'follow_invalidate_pte' - different lock contexts for basic block
   mm/memory.c: note: in included file (through arch/sparc/include/asm/pgtable.h, include/linux/pgtable.h, include/linux/mm.h):
   arch/sparc/include/asm/pgtable_32.h:275:29: sparse: sparse: context imbalance in 'follow_pfn' - unexpected unlock

vim +3913 mm/memory.c

  3875	
  3876	/*
  3877	 * The mmap_lock must have been held on entry, and may have been
  3878	 * released depending on flags and vma->vm_ops->fault() return value.
  3879	 * See filemap_fault() and __lock_page_retry().
  3880	 */
  3881	static vm_fault_t __do_fault(struct vm_fault *vmf)
  3882	{
  3883		struct vm_area_struct *vma = vmf->vma;
  3884		vm_fault_t ret;
  3885	
  3886		/*
  3887		 * Preallocate pte before we take page_lock because this might lead to
  3888		 * deadlocks for memcg reclaim which waits for pages under writeback:
  3889		 *				lock_page(A)
  3890		 *				SetPageWriteback(A)
  3891		 *				unlock_page(A)
  3892		 * lock_page(B)
  3893		 *				lock_page(B)
  3894		 * pte_alloc_one
  3895		 *   shrink_page_list
  3896		 *     wait_on_page_writeback(A)
  3897		 *				SetPageWriteback(B)
  3898		 *				unlock_page(B)
  3899		 *				# flush A, B to clear the writeback
  3900		 */
  3901		if (pmd_none(*vmf->pmd) && !vmf->prealloc_pte) {
  3902			vmf->prealloc_pte = pte_alloc_one(vma->vm_mm);
  3903			if (!vmf->prealloc_pte)
  3904				return VM_FAULT_OOM;
  3905		}
  3906	
  3907		ret = vma->vm_ops->fault(vmf);
  3908		if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY |
  3909				    VM_FAULT_DONE_COW)))
  3910			return ret;
  3911	
  3912		if (unlikely(PageHWPoison(vmf->page))) {
> 3913			int poisonret = VM_FAULT_HWPOISON;
  3914			if (ret & VM_FAULT_LOCKED) {
  3915				/* Retry if a clean page was removed from the cache. */
  3916				if (invalidate_inode_page(vmf->page))
  3917					poisonret = 0;
  3918				unlock_page(vmf->page);
  3919			}
  3920			put_page(vmf->page);
  3921			vmf->page = NULL;
> 3922			return poisonret;
  3923		}
  3924	
  3925		if (unlikely(!(ret & VM_FAULT_LOCKED)))
  3926			lock_page(vmf->page);
  3927		else
  3928			VM_BUG_ON_PAGE(!PageLocked(vmf->page), vmf->page);
  3929	
  3930		return ret;
  3931	}
  3932	

---
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