mm/page_vma_mapped: use huge_ptep_get() for hugetlb

check_pte() is the final validation step in page_vma_mapped_walk().  It
reads pvmw->pte with ptep_get() to decide whether the entry maps the PFN
range being walked.  For hugetlb VMAs, that pointer refers to a hugetlb
entry.

On arches which provide their own huge_ptep_get() to dereference a huge
pte pointer, accessing via ptep_get() would cause pte_pfn(), pte_present()
etc to misbehave.

It is not clear whether this has a trivially visible effect to userspace.

Use huge_ptep_get() to dereference a huge pte pointer.

Link: https://lore.kernel.org/20260703114202.365553-6-dev.jain@arm.com
Fixes: ace71a19ce ("mm: introduce page_vma_mapped_walk()")
Signed-off-by: Dev Jain <dev.jain@arm.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jann Horn <jannh@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Jun'ichi "Nick" Nomura <j-nomura@ce.jp.nec.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Dev Jain
2026-07-03 11:41:58 +00:00
committed by Andrew Morton
parent ac1ec50d71
commit e87df0d5d6

View File

@@ -107,7 +107,13 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw, pmd_t *pmdvalp,
static bool check_pte(struct page_vma_mapped_walk *pvmw, unsigned long pte_nr)
{
unsigned long pfn;
pte_t ptent = ptep_get(pvmw->pte);
pte_t ptent;
if (is_vm_hugetlb_page(pvmw->vma))
ptent = huge_ptep_get(pvmw->vma->vm_mm, pvmw->address,
pvmw->pte);
else
ptent = ptep_get(pvmw->pte);
if (pvmw->flags & PVMW_MIGRATION) {
const softleaf_t entry = softleaf_from_pte(ptent);