When we check for a poisoned page, we use the VMA to tell userspace
about the looming disaster. But we pass a pointer to this VMA
after having released the mmap_sem, which isn't a good idea.
Instead, stash the shift value that goes with this pfn while
we are holding the mmap_sem.
Reported-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
---
Based on Marc's patch:
Link: lore.kernel.org/r/20191211165651.7889-3-maz@xxxxxxxxxx
virt/kvm/arm/mmu.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 38b4c910b6c3..bb0f8d648678 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1591,16 +1591,8 @@ static void invalidate_icache_guest_page(kvm_pfn_t pfn, unsigned long size)
__invalidate_icache_guest_page(pfn, size);
}
-static void kvm_send_hwpoison_signal(unsigned long address,
- struct vm_area_struct *vma)
+static void kvm_send_hwpoison_signal(unsigned long address, short lsb)
{
- short lsb;
-
- if (is_vm_hugetlb_page(vma))
- lsb = huge_page_shift(hstate_vma(vma));
- else
- lsb = PAGE_SHIFT;
-
send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current);
}
@@ -1673,6 +1665,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct kvm *kvm = vcpu->kvm;
struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
struct vm_area_struct *vma;
+ short vma_shift;
kvm_pfn_t pfn;
pgprot_t mem_type = PAGE_S2;
bool logging_active = memslot_is_logging(memslot);
@@ -1696,7 +1689,12 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return -EFAULT;
}
- vma_pagesize = vma_kernel_pagesize(vma);
+ if (is_vm_hugetlb_page(vma))
+ vma_shift = huge_page_shift(hstate_vma(vma));
+ else
+ vma_shift = PAGE_SHIFT;
+
+ vma_pagesize = 1ULL << vma_shift;
if (logging_active ||
!fault_supports_stage2_huge_mapping(memslot, hva, vma_pagesize)) {
force_pte = true;
@@ -1735,7 +1733,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable);
if (pfn == KVM_PFN_ERR_HWPOISON) {
- kvm_send_hwpoison_signal(hva, vma);
+ kvm_send_hwpoison_signal(hva, vma_shift);
return 0;
}
if (is_error_noslot_pfn(pfn))
--
2.24.0
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