4.19-stable review patch. If anyone has any objections, please let me know.
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From: Punit Agrawal punit.agrawal@arm.com
commit fd2ef358282c849c193aa36dadbf4f07f7dcd29b upstream.
PageTransCompoundMap() returns true for hugetlbfs and THP hugepages. This behaviour incorrectly leads to stage 2 faults for unsupported hugepage sizes (e.g., 64K hugepage with 4K pages) to be treated as THP faults.
Tighten the check to filter out hugetlbfs pages. This also leads to consistently mapping all unsupported hugepage sizes as PTE level entries at stage 2.
Signed-off-by: Punit Agrawal punit.agrawal@arm.com Reviewed-by: Suzuki Poulose suzuki.poulose@arm.com Cc: Christoffer Dall christoffer.dall@arm.com Cc: Marc Zyngier marc.zyngier@arm.com Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- virt/kvm/arm/mmu.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1230,8 +1230,14 @@ static bool transparent_hugepage_adjust( { kvm_pfn_t pfn = *pfnp; gfn_t gfn = *ipap >> PAGE_SHIFT; + struct page *page = pfn_to_page(pfn);
- if (PageTransCompoundMap(pfn_to_page(pfn))) { + /* + * PageTransCompoungMap() returns true for THP and + * hugetlbfs. Make sure the adjustment is done only for THP + * pages. + */ + if (!PageHuge(page) && PageTransCompoundMap(page)) { unsigned long mask; /* * The address we faulted on is backed by a transparent huge