Re: [PATCH v3] arm64: Restrict pagetable teardown to avoid false warning

On Tue, May 27, 2025 at 01:56:33PM +0530, Dev Jain wrote:

Commit 9c006972c3fe removes the pxd_present() checks because the caller checks pxd_present(). But, in case of vmap_try_huge_pud(), the caller only checks pud_present(); pud_free_pmd_page() recurses on each pmd through pmd_free_pte_page(), wherein the pmd may be none. Thus it is possible to hit a warning in the latter, since pmd_none => !pmd_table(). Thus, add a pmd_present() check in pud_free_pmd_page().

This problem was found by code inspection.

Fixes: 9c006972c3fe (arm64: mmu: drop pXd_present() checks from pXd_free_pYd_table()) Cc: stable@vger.kernel.org

Reviewed-by: Catalin Marinas catalin.marinas@arm.com