Subject: Re: [PATCH] arm64: mm: call pagetable dtor when freeing hot-removed page tables

From: Catalin Marinas <[email-masked]>
Date: Fri, 22 May 2026 08:32:32 +0100

On Fri, May 22, 2026 at 08:15:09AM +0100, Catalin Marinas wrote:
> On Thu, May 21, 2026 at 03:31:30PM -0700, Andrew Morton wrote:
> > On Thu, 21 May 2026 13:27:30 +1000 Alistair Popple <[email-masked]> wrote:
> > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> > > index 8e1d80a7033e..0c24fe650e95 100644
> > > --- a/arch/arm64/mm/mmu.c
> > > +++ b/arch/arm64/mm/mmu.c
> > > @@ -1422,6 +1422,7 @@ static void free_hotplug_page_range(struct page *page, size_t size,
> > >  
> > >  static void free_hotplug_pgtable_page(struct page *page)
> > >  {
> > > +	pagetable_dtor(page_ptdesc(page));
> > >  	free_hotplug_page_range(page, PAGE_SIZE, NULL);
> > >  }
> > 
> > I'd of course prefer that arm maintainers handle this.  But
> > 5e8eb9aeeda3 came via myself so convention kinda-dictates that I get to
> > fix it.
> 
> That's fine but Sashiko has some points:
> 
> https://sashiko.dev/#/patchset/[email-masked]

The other Sashiko find looks like a false positive. vmemmap_*_populate()
do not allocate the page table from altmap, only the page pointed at by
the vmemmap pte.

-- 
Catalin