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| author |   Sean Christopherson <sean.j.christopherson@intel.com> | 2020-01-08 12:24:36 -0800 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2020-01-27 20:00:01 +0100 |
| commit | 005ba37cb89bcc0cf63c2029a41f8db165aeb615 (patch) | |
| tree | 0d0b3d133dfd012cfe53f548397308a7089da89c /include/linux/huge_mm.h | |
| parent | KVM: x86/mmu: Enforce max_level on HugeTLB mappings (diff) | |
| download | wireguard-linux-005ba37cb89bcc0cf63c2029a41f8db165aeb615.tar.xz wireguard-linux-005ba37cb89bcc0cf63c2029a41f8db165aeb615.zip | |
mm: thp: KVM: Explicitly check for THP when populating secondary MMU
Add a helper, is_transparent_hugepage(), to explicitly check whether a
compound page is a THP and use it when populating KVM's secondary MMU.
The explicit check fixes a bug where a remapped compound page, e.g. for
an XDP Rx socket, is mapped into a KVM guest and is mistaken for a THP,
which results in KVM incorrectly creating a huge page in its secondary
MMU.
Fixes: 936a5fe6e6148 ("thp: kvm mmu transparent hugepage support")
Reported-by: syzbot+c9d1fb51ac9d0d10c39d@syzkaller.appspotmail.com
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/linux/huge_mm.h')
| -rw-r--r-- | include/linux/huge_mm.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 0b84e13e88e2..5aca3d1bdb32 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -160,6 +160,7 @@ extern unsigned long thp_get_unmapped_area(struct file *filp, extern void prep_transhuge_page(struct page *page); extern void free_transhuge_page(struct page *page); +bool is_transparent_hugepage(struct page *page); bool can_split_huge_page(struct page *page, int *pextra_pins); int split_huge_page_to_list(struct page *page, struct list_head *list); @@ -308,6 +309,11 @@ static inline bool transhuge_vma_suitable(struct vm_area_struct *vma, static inline void prep_transhuge_page(struct page *page) {} +static inline bool is_transparent_hugepage(struct page *page) +{ + return false; +} + #define transparent_hugepage_flags 0UL #define thp_get_unmapped_area NULL |