On Fri, Feb 27, 2026 at 09:08:41PM +0100, David Hildenbrand (Arm) wrote:
> Let's call __zap_vma_range() instead of unmap_page_range() to prepare
> for further cleanups.
>
> To keep the existing behavior, whereby we do not call uprobe_munmap()
> which could block, add a new "reaping" member to zap_details and use it.

I am always in favour of making further use of helper structs :)

>
> Likely we should handle the possible blocking in uprobe_munmap()
> differently, but for now keep it unchanged.
>
> Signed-off-by: David Hildenbrand (Arm) <[email protected]>

OK this looks like it's doing the equivalent of what was there before, so:

Reviewed-by: Lorenzo Stoakes (Oracle) <[email protected]>

> ---
>  include/linux/mm.h |  1 +
>  mm/memory.c        | 13 +++++++++----
>  2 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 21b67c203e62..4710f7c7495a 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2800,6 +2800,7 @@ struct zap_details {
>       struct folio *single_folio;     /* Locked folio to be unmapped */
>       bool skip_cows;                 /* Do not zap COWed private pages */
>       bool reclaim_pt;                /* Need reclaim page tables? */
> +     bool reaping;                   /* Reaping, do not block. */
>       zap_flags_t zap_flags;          /* Extra flags for zapping */
>  };
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 7d7c24c6917c..394b2e931974 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -2079,14 +2079,18 @@ static void __zap_vma_range(struct mmu_gather *tlb, 
> struct vm_area_struct *vma,
>               unsigned long start, unsigned long end,
>               struct zap_details *details)
>  {
> +     const bool reaping = details && details->reaping;
> +
>       VM_WARN_ON_ONCE(start >= end || !range_in_vma(vma, start, end));
>
> -     if (vma->vm_file)
> +     /* uprobe_munmap() might sleep, so skip it when reaping. */
> +     if (vma->vm_file && !reaping)
>               uprobe_munmap(vma, start, end);
>
>       if (unlikely(is_vm_hugetlb_page(vma))) {
>               zap_flags_t zap_flags = details ? details->zap_flags : 0;
>
> +             VM_WARN_ON_ONCE(reaping);
>               /*
>                * vm_file will be NULL when we fail early while instantiating
>                * a new mapping. In this case, no pages were mapped yet and
> @@ -2111,11 +2115,12 @@ static void __zap_vma_range(struct mmu_gather *tlb, 
> struct vm_area_struct *vma,
>   */
>  int zap_vma_for_reaping(struct vm_area_struct *vma)
>  {
> +     struct zap_details details = {
> +             .reaping = true,
> +     };
>       struct mmu_notifier_range range;
>       struct mmu_gather tlb;
>
> -     VM_WARN_ON_ONCE(is_vm_hugetlb_page(vma));
> -

I guess because you've moved this safety check into __zap_vma_range()?

>       mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm,
>                               vma->vm_start, vma->vm_end);
>       tlb_gather_mmu(&tlb, vma->vm_mm);
> @@ -2123,7 +2128,7 @@ int zap_vma_for_reaping(struct vm_area_struct *vma)
>               tlb_finish_mmu(&tlb);
>               return -EBUSY;
>       }
> -     unmap_page_range(&tlb, vma, range.start, range.end, NULL);
> +     __zap_vma_range(&tlb, vma, range.start, range.end, &details);
>       mmu_notifier_invalidate_range_end(&range);
>       tlb_finish_mmu(&tlb);
>       return 0;
> --
> 2.43.0
>

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