iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

arm/arm64: KVM: Take mmap_sem in kvm_arch_prepare_memory_region

Browse Source 
commit 72f310481a08db821b614e7b5d00febcc9064b36 upstream.

We don't hold the mmap_sem while searching for VMAs (via find_vma), in
kvm_arch_prepare_memory_region, which can end up in expected failures.

Fixes: commit 8eef91239e57 ("arm/arm64: KVM: map MMIO regions at creation time")
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Eric Auger <eric.auger@rehat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
[ Handle dirty page logging failure case ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Marc Zyngier 2017-03-16 18:20:50 +00:00 committed by Greg Kroah-Hartman
parent 48f2825abc
commit a1ea318936
1 changed files with 8 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
arch/arm/kvm/mmu.c
View File

@ -1806,6 +1806,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
(KVM_PHYS_SIZE >> PAGE_SHIFT))
return -EFAULT;
down_read(&current->mm->mmap_sem);
/*
* A memory region could potentially cover multiple VMAs, and any holes
* between them, so iterate over all of them to find out if we can map
@ -1849,8 +1850,10 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
pa += vm_start - vma->vm_start;
/* IO region dirty page logging not allowed */
if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES)
return -EINVAL;
if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) {
ret = -EINVAL;
goto out;
}
ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
vm_end - vm_start,
@ -1862,7 +1865,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
} while (hva < reg_end);
if (change == KVM_MR_FLAGS_ONLY)
return ret;
goto out;
spin_lock(&kvm->mmu_lock);
if (ret)
@ -1870,6 +1873,8 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
else
stage2_flush_memslot(kvm, memslot);
spin_unlock(&kvm->mmu_lock);
out:
up_read(&current->mm->mmap_sem);
return ret;
}