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[PATCH 0/2] Fix test-char reference counting bug
From: |
Eduardo Habkost |
Subject: |
[PATCH 0/2] Fix test-char reference counting bug |
Date: |
Tue, 15 Dec 2020 17:41:31 -0500 |
This series addresses a bug that seems to be the cause of the
following crash, that is reported by Patchew and other CI systems
once in a while:
Running test test-char
Unexpected error in object_property_try_add() at ../qom/object.c:1220:
attempt to add duplicate property 'serial-id' to object (type 'container')
ERROR test-char - too few tests run (expected 38, got 9)
make: *** [run-test-86] Error 1
This is what seems to be happening:
- char_file_test_internal() creates chr using qemu_chardev_new().
- qemu_chardev_new() automatically assigns ID, adds
chardev to the QOM tree.
- char_file_test_internal() does _not_ own the reference
to the created object.
- char_file_test_internal() incorrectly calls object_unref().
- object is freed but, but /containers now has a dangling
pointer.
- char_serial_test() creates a chardev with ID "serial-id", and
it ends up being allocated at the same address as the old
object.
- char_serial_test() correctly calls object_unparent().
- object_property_del_child() looks for the right child property
in the hashtable, finds the dangling pointer with the same
address, removes the wrong property, leaves a dangling
"serial-id" property.
- New object is created by char_serial_test() with ID "serial-id".
- object_property_try_add_child() will fail because of the
dangling "serial-id" property.
Eduardo Habkost (2):
test-char: Destroy chardev correctly at char_file_test_internal()
qom: Assert that objects being destroyed have no parent
qom/object.c | 1 +
tests/test-char.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)
--
2.28.0
- [PATCH 0/2] Fix test-char reference counting bug,
Eduardo Habkost <=