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| author | Peter Xu <peterx@redhat.com> | 2024-08-26 16:43:40 -0400 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-09-17 01:06:58 -0700 |
| commit | 10d83d7781a8a6ff02bafd172c1ab183b27f8d5a (patch) | |
| tree | a0907889049ed724bb3d08d6e47163c5fb31e58e | |
| parent | ae3c99e650da4a8f4deb3670c29059de375a88be (diff) | |
| download | linux-10d83d7781a8a6ff02bafd172c1ab183b27f8d5a.tar.gz linux-10d83d7781a8a6ff02bafd172c1ab183b27f8d5a.tar.bz2 linux-10d83d7781a8a6ff02bafd172c1ab183b27f8d5a.zip | |
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.
[peterx@redhat.com: remove some stale comments, per David]
Link: https://lkml.kernel.org/r/20240829202237.2640288-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20240826204353.2228736-7-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -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)) { |