Re: [PATCH] mm/migrate_device: Cleanup up PMD Checks and warnings

[Andrew Morton]

On Fri, 24 Apr 2026 22:52:08 +0530 Sunny Patel <nueralspacetech@xxxxxxxxx> wrote:

> On Sun, 19 Apr 2026 23:17:43 +0530 Sunny Patel <nueralspacetech@xxxxxxxxx> wrote:
> 
> > Remove the odd VM_WARN_ON_FOLIO(!folio, folio) usage and replace it
> > with a simpler VM_WARN_ON_ONCE(!folio) check.
> >
> > Drop the redundant VM_WARN_ON_ONCE(!pmd_none(*pmdp) &&
> > !is_huge_zero_pmd(*pmdp)).
> >
> > Refactor the PMD checks, making the control flow
> > clearer and avoiding duplicate condition checks.
> 
> AI review might have found a bug in the surrounding code:
>         https://sashiko.dev/#/patchset/20260419174747.10701-1-nueralspacetech@xxxxxxxxx
> 
> After looking into the AI comment found two potential leak.
> 
> 1. The goto should be unlock_abort instead of abort to ensure 
> the spinlock is released.
> 
> 2. The pgtable allocation at the top of the function
> is indeed not freed on the unlock_abort path. Will add a
> pte_free(vma->vm_mm, pgtable). 
> 
> Since this patch is more of Cleanup on PMD checks and
> Warnings Is it ok if I send different patch to address
> this potential leak issues or need it in this revision
> itself?

A separate patch, please.

It's best to prepare the bugfix patch against current Linus mainline,
then any cleanups come on top of the bugfix.

Thanks.