From: Dev Jain Date: Tue, 27 May 2025 08:26:33 +0000 (+0530) Subject: arm64: Restrict pagetable teardown to avoid false warning X-Git-Tag: v6.16-rc3~20^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=650768c512faba8070bf4cfbb28c95eb5cd203f3;p=thirdparty%2Flinux.git arm64: Restrict pagetable teardown to avoid false warning Commit 9c006972c3fe ("arm64: mmu: drop pXd_present() checks from pXd_free_pYd_table()") 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 Reported-by: Ryan Roberts Acked-by: David Hildenbrand Signed-off-by: Dev Jain Reviewed-by: Catalin Marinas Reviewed-by: Anshuman Khandual Reviewed-by: Ryan Roberts Link: https://lore.kernel.org/r/20250527082633.61073-1-dev.jain@arm.com Signed-off-by: Will Deacon --- diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 8fcf59ba39db..00ab1d648db6 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1305,7 +1305,8 @@ int pud_free_pmd_page(pud_t *pudp, unsigned long addr) next = addr; end = addr + PUD_SIZE; do { - pmd_free_pte_page(pmdp, next); + if (pmd_present(pmdp_get(pmdp))) + pmd_free_pte_page(pmdp, next); } while (pmdp++, next += PMD_SIZE, next != end); pud_clear(pudp);