[Qemu-devel] [PATCH v3 for-2.11 0/4] Fix segfault in blockjob race condition

[Jeff Cody <jcody@redhat.com>]

Changes from v2 -> v3:
-----------------------

Patch 1: Updated commit message to include why immediate cancel is
         ok to remove (Thanks Paolo)

         Dropped useless hunk (Thanks Stefan)


Patch 2: Use correct atomic primitives, and document implicit
         assumptions (Thanks Stefan, Paolo)

        Fix spelling in commit message (Thanks Eric)

Patch 3/4: Unchanged.


Changes from v1 -> v2:
-----------------------

Patch 1: Updated docs in blockjob_int.h (Thanks Stefan)

Patch 2/3: Squashed, and used const char * to hold the __func__ name of
           the original scheduler (Thanks Paolo)

Patch 4: Unchanged.

Patch 5: Dropped qcow format for the test, it was so slow the test times
         out, and it doesn't add any new dimension to the test.


# git-backport-diff -r qemu/master.. -u github/bz1508708

001/4:[0003] [FC] 'blockjob: do not allow coroutine double entry or entry-after-completion'
002/4:[down] 'coroutine: abort if we try to schedule or enter a pending coroutine'
003/4:[----] [--] 'qemu-iotests: add option in common.qemu for mismatch only'
004/4:[0002] [FC] 'qemu-iotest: add test for blockjob coroutine race condition'


This series fixes a race condition segfault when using iothreads with
blockjobs.

The qemu iotest in this series is a reproducer, as is the reproducer
script attached in this bug report:

https://bugzilla.redhat.com/show_bug.cgi?id=1508708

There are two additional patches to try and catch this sort of scenario
with an abort, before a segfault or memory corruption occurs.


Jeff Cody (4):
  blockjob: do not allow coroutine double entry or
    entry-after-completion
  coroutine: abort if we try to schedule or enter a pending coroutine
  qemu-iotests: add option in common.qemu for mismatch only
  qemu-iotest: add test for blockjob coroutine race condition

 blockjob.c                     |  7 ++-
 include/block/blockjob_int.h   |  3 +-
 include/qemu/coroutine_int.h   |  6 +++
 tests/qemu-iotests/200         | 99 ++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/200.out     | 14 ++++++
 tests/qemu-iotests/common.qemu |  8 +++-
 tests/qemu-iotests/group       |  1 +
 util/async.c                   | 13 ++++++
 util/qemu-coroutine-sleep.c    | 12 +++++
 util/qemu-coroutine.c          | 13 ++++++
 10 files changed, 172 insertions(+), 4 deletions(-)
 create mode 100755 tests/qemu-iotests/200
 create mode 100644 tests/qemu-iotests/200.out

-- 
2.9.5