diff options
| author | Peter Xu <[email protected]> | 2024-08-26 16:43:40 -0400 |
|---|---|---|
| committer | Andrew Morton <[email protected]> | 2024-09-17 01:06:58 -0700 |
| commit | 10d83d7781a8a6ff02bafd172c1ab183b27f8d5a (patch) | |
| tree | a0907889049ed724bb3d08d6e47163c5fb31e58e | |
| parent | ae3c99e650da4a8f4deb3670c29059de375a88be (diff) | |
mm/pagewalk: check pfnmap for folio_walk_start()
Teach folio_walk_start() to recognize special pmd/pud mappings, and fail
them properly as it means there's no folio backing them.
[[email protected]: remove some stale comments, per David]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Peter Xu <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Alex Williamson <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Gavin Shan <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Niklas Schnelle <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
| -rw-r--r-- | mm/memory.c | 9 | ||||
| -rw-r--r-- | mm/pagewalk.c | 2 |
2 files changed, 5 insertions, 6 deletions
diff --git a/mm/memory.c b/mm/memory.c index 93c0c25433d0..9a540e231625 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -672,11 +672,10 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr, { unsigned long pfn = pmd_pfn(pmd); - /* - * There is no pmd_special() but there may be special pmds, e.g. - * in a direct-access (dax) mapping, so let's just replicate the - * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here. - */ + /* Currently it's only used for huge pfnmaps */ + if (unlikely(pmd_special(pmd))) + return NULL; + if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) { if (vma->vm_flags & VM_MIXEDMAP) { if (!pfn_valid(pfn)) diff --git a/mm/pagewalk.c b/mm/pagewalk.c index cd79fb3b89e5..461ea3bbd8d9 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -753,7 +753,7 @@ struct folio *folio_walk_start(struct folio_walk *fw, fw->pudp = pudp; fw->pud = pud; - if (!pud_present(pud) || pud_devmap(pud)) { + if (!pud_present(pud) || pud_devmap(pud) || pud_special(pud)) { spin_unlock(ptl); goto not_found; } else if (!pud_leaf(pud)) { |