Re: [RFC PATCH] mm/hugetlb: fix resv_map memory leak in __mmap_region error path

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

Hi Mingyu,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Mingyu-Wang/mm-hugetlb-fix-resv_map-memory-leak-in-__mmap_region-error-path/20260425-203812
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20260425070700.562229-1-25181214217%40stu.xidian.edu.cn
patch subject: [RFC PATCH] mm/hugetlb: fix resv_map memory leak in __mmap_region error path
config: hexagon-allnoconfig (https://download.01.org/0day-ci/archive/20260502/202605020645.8318Xwwx-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 5bac06718f502014fade905512f1d26d578a18f3)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260502/202605020645.8318Xwwx-lkp@intel.com/reproduce)

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/202605020645.8318Xwwx-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from mm/vma.c:7:
   In file included from mm/vma_internal.h:12:
   In file included from include/linux/backing-dev.h:13:
   In file included from include/linux/fs.h:5:
   In file included from include/linux/fs/super.h:5:
   In file included from include/linux/fs/super_types.h:7:
   In file included from include/linux/list_lru.h:14:
   In file included from include/linux/xarray.h:16:
   In file included from include/linux/gfp.h:7:
   In file included from include/linux/mmzone.h:22:
   include/linux/mm_types.h:865:28: warning: declaration of 'struct vm_area_desc' will not be visible outside of this function [-Wvisibility]
     865 |         void (*abort_hook)(struct vm_area_desc *desc);
         |                                   ^
>> mm/vma.c:2805:26: error: incompatible pointer types passing 'struct vm_area_desc *' to parameter of type 'struct vm_area_desc *' [-Wincompatible-pointer-types]
    2805 |                 desc.action.abort_hook(&desc);
         |                                        ^~~~~
   1 warning and 1 error generated.


vim +2805 mm/vma.c

  2731	
  2732	static unsigned long __mmap_region(struct file *file, unsigned long addr,
  2733			unsigned long len, vma_flags_t vma_flags,
  2734			unsigned long pgoff, struct list_head *uf)
  2735	{
  2736		struct mm_struct *mm = current->mm;
  2737		struct vm_area_struct *vma = NULL;
  2738		bool have_mmap_prepare = file && file->f_op->mmap_prepare;
  2739		VMA_ITERATOR(vmi, mm, addr);
  2740		MMAP_STATE(map, mm, &vmi, addr, len, pgoff, vma_flags, file);
  2741		struct vm_area_desc desc = {
  2742			.mm = mm,
  2743			.file = file,
  2744			.action = {
  2745				.type = MMAP_NOTHING, /* Default to no further action. */
  2746			},
  2747		};
  2748		bool allocated_new = false;
  2749		int error;
  2750	
  2751		map.check_ksm_early = can_set_ksm_flags_early(&map);
  2752	
  2753		error = __mmap_setup(&map, &desc, uf);
  2754		if (!error && have_mmap_prepare)
  2755			error = call_mmap_prepare(&map, &desc);
  2756		if (error)
  2757			goto abort_munmap;
  2758	
  2759		if (map.check_ksm_early)
  2760			update_ksm_flags(&map);
  2761	
  2762		/* Attempt to merge with adjacent VMAs... */
  2763		if (map.prev || map.next) {
  2764			VMG_MMAP_STATE(vmg, &map, /* vma = */ NULL);
  2765	
  2766			vma = vma_merge_new_range(&vmg);
  2767		}
  2768	
  2769		/* ...but if we can't, allocate a new VMA. */
  2770		if (!vma) {
  2771			error = __mmap_new_vma(&map, &vma, &desc.action);
  2772			if (error)
  2773				goto unacct_error;
  2774			allocated_new = true;
  2775		}
  2776	
  2777		if (have_mmap_prepare)
  2778			set_vma_user_defined_fields(vma, &map);
  2779	
  2780		__mmap_complete(&map, vma);
  2781	
  2782		if (have_mmap_prepare && allocated_new) {
  2783			error = mmap_action_complete(vma, &desc.action,
  2784						     /*is_compat=*/false);
  2785			if (error)
  2786				return error;
  2787		}
  2788	
  2789		return addr;
  2790	
  2791		/* Accounting was done by __mmap_setup(). */
  2792	unacct_error:
  2793		if (map.charged)
  2794			vm_unacct_memory(map.charged);
  2795	abort_munmap:
  2796		/*
  2797		 * This indicates that .mmap_prepare has set a new file, differing from
  2798		 * desc->vm_file. But since we're aborting the operation, only the
  2799		 * original file will be cleaned up. Ensure we clean up both.
  2800		 */
  2801		if (map.file_doesnt_need_get)
  2802			fput(map.file);
  2803		
  2804		if (have_mmap_prepare && desc.action.abort_hook)
> 2805			desc.action.abort_hook(&desc);
  2806		
  2807		vms_abort_munmap_vmas(&map.vms, &map.mas_detach);
  2808		return error;
  2809	}
  2810	

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