[Qemu-stable] [PATCH v3 0/4] qapi: fix crash in dealloc visitor for union types

[Michael Roth]

This series introduces visit_start_union and visit_end_union as a way
of allowing visitors to trigger generated code to bail out on visiting
union fields if the visitor implementation deems doing so to be unsafe.

See patch 1 for the circumstances that cause the segfault in the
dealloc visitor.

This is a spin-off of a patch submitted by Fam Zheng earlier. See the
thread for additional background on why we're taking this approach:

  http://thread.gmane.org/gmane.comp.emulators.qemu/296090

v3:
  * fixed up commit msg in patch #2 (Eric)
  * rebased on latest master

v2:
  * added comments to clarify true/false visit_start_union vs. errp
    in dealloc visitor implementation (Eric)
  * fixed a line that was >80 characters (Eric)
  * fixed extra period in patch 2 commit msg (Eric)
  * added comments to note reasons why the interface is useable for
    dealloc visitor, but may require extra QAPI groundwork and
    interface parameters to be useful for other types of visitors
  * included Fam's qemu-iotest test case to exercise bug fix in a
    user-triggerable scenario.

 include/qapi/visitor-impl.h             |  2 ++
 include/qapi/visitor.h                  |  2 ++
 qapi/qapi-dealloc-visitor.c             | 26 +++++++++++++++++++++++
 qapi/qapi-visit-core.c                  | 15 +++++++++++++
 scripts/qapi-visit.py                   |  6 ++++++
 tests/qapi-schema/qapi-schema-test.json | 10 +++++++++
 tests/qapi-schema/qapi-schema-test.out  |  3 +++
 tests/qemu-iotests/087                  | 17 +++++++++++++++
 tests/qemu-iotests/087.out              | 13 ++++++++++++
 tests/test-qmp-input-strict.c           | 17 +++++++++++++++
 10 files changed, 111 insertions(+)