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author | Lai Jiangshan <laijs@linux.alibaba.com> | 2020-12-17 18:41:18 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-12 22:16:22 +0300 |
commit | a5c7a456680f00b1c0dc405e758d19c184ba57db (patch) | |
tree | ffd93b931dcdb99c5f6c05eec6c4231f996e43f0 /samples/kfifo | |
parent | 10dcb79ec79eed3a8becfef892d7719f4cd52e11 (diff) | |
download | linux-a5c7a456680f00b1c0dc405e758d19c184ba57db.tar.xz |
kvm: check tlbs_dirty directly
commit 88bf56d04bc3564542049ec4ec168a8b60d0b48c upstream.
In kvm_mmu_notifier_invalidate_range_start(), tlbs_dirty is used as:
need_tlb_flush |= kvm->tlbs_dirty;
with need_tlb_flush's type being int and tlbs_dirty's type being long.
It means that tlbs_dirty is always used as int and the higher 32 bits
is useless. We need to check tlbs_dirty in a correct way and this
change checks it directly without propagating it to need_tlb_flush.
Note: it's _extremely_ unlikely this neglecting of higher 32 bits can
cause problems in practice. It would require encountering tlbs_dirty
on a 4 billion count boundary, and KVM would need to be using shadow
paging or be running a nested guest.
Cc: stable@vger.kernel.org
Fixes: a4ee1ca4a36e ("KVM: MMU: delay flush all tlbs on sync_page path")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20201217154118.16497-1-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'samples/kfifo')
0 files changed, 0 insertions, 0 deletions