From: James Morse <james.morse@xxxxxxx> 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> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxx> Link: https://lore.kernel.org/r/20191211165651.7889-3-maz@xxxxxxxxxx Link: https://lore.kernel.org/r/20191217123809.197392-1-james.morse@xxxxxxx --- 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 0b32a904a1bb..e3ad95013192 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1596,16 +1596,8 @@ 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); } @@ -1678,6 +1670,7 @@ 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); @@ -1701,7 +1694,12 @@ 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 || (vma->vm_flags & VM_PFNMAP) || !fault_supports_stage2_huge_mapping(memslot, hva, vma_pagesize)) { @@ -1741,7 +1739,7 @@ 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)) -- 2.20.1 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
