x86: make page table unpinning preemptible

Enterprise / Virtualization / Xen - Jan Beulich [suse.com] - 2 May 2013 09:39 UTC

... as it may take significant amounts of time.

Since we can't re-invoke the operation in a second attempt, the continuation logic must be slightly tweaked so that we make sure do_mmuext_op() gets run one more time even when the preempted unpin operation was the last one in a batch.

This is part of CVE-2013-1918 / XSA-45.

a3e049f x86: make page table unpinning preemptible
xen/arch/x86/mm.c | 40 +++++++++++++++++++++++++++++++++++++--
xen/arch/x86/x86_64/compat/mm.c | 23 +++++++++++++++++-----
2 files changed, 56 insertions(+), 7 deletions(-)

Upstream: xenbits.xen.org

  • Share