Am 09.10.2015 um 16:36 schrieb Markus Armbruster: > Several devices don't survive object_unref(object_new(T)): they crash > or hang during cleanup, or they leave dangling pointers behind. > > This breaks at least device-list-properties, because > qmp_device_list_properties() needs to create a device to find its > properties. Broken in commit f4eb32b "qmp: show QOM properties in > device-list-properties", v2.1. Example reproducer: > > $ qemu-system-aarch64 -nodefaults -display none -machine none -S -qmp > stdio > {"QMP": {"version": {"qemu": {"micro": 50, "minor": 4, "major": 2}, > "package": ""}, "capabilities": []}} > { "execute": "qmp_capabilities" } > {"return": {}} > { "execute": "device-list-properties", "arguments": { "typename": > "pxa2xx-pcmcia" } } > qemu-system-aarch64: /home/armbru/work/qemu/memory.c:1307: > memory_region_finalize: Assertion `((&mr->subregions)->tqh_first == ((void > *)0))' failed. > Aborted (core dumped) > [Exit 134 (SIGABRT)] > > Unfortunately, I can't fix the problems in these devices right now. > Instead, add DeviceClass member cannot_destroy_with_object_finalize_yet > to mark them: > > * Hang during cleanup (didn't debug, so I can't say why): > "realview_pci", "versatile_pci". > > * Dangling pointer in cpus: most CPUs, plus "allwinner-a10", "digic", > "fsl,imx25", "fsl,imx31", "xlnx,zynqmp", because they create such > CPUs > > * Assert kvm_enabled(): "host-x86_64-cpu", host-i386-cpu", > "host-powerpc64-cpu", "host-embedded-powerpc-cpu", > "host-powerpc-cpu" (the powerpc ones can't currently reach the > assertion, because the CPUs are only registered when KVM is enabled, > but the assertion is arguably in the wrong place all the same) > > Make qmp_device_list_properties() fail cleanly when the device is so > marked. This improves device-list-properties from "crashes, hangs or > leaves dangling pointers behind" to "fails". Not a complete fix, just > a better-than-nothing work-around. In the above reproducer, > device-list-properties now fails with "Can't list properties of device > 'pxa2xx-pcmcia'". > > This also protects -device FOO,help, which uses the same machinery > since commit ef52358 "qdev-monitor: include QOM properties in -device > FOO, help output", v2.2. Example reproducer: > > $ qemu-system-aarch64 -machine none -device pxa2xx-pcmcia,help > > Before: > > qemu-system-aarch64: .../memory.c:1307: memory_region_finalize: Assertion > `((&mr->subregions)->tqh_first == ((void *)0))' failed. > > After: > > Can't list properties of device 'pxa2xx-pcmcia' > > Cc: "Andreas Färber" <afaer...@suse.de>
In case a v4 comes up, ;) Acked-by: Andreas Färber <afaer...@suse.de> Thanks for updating, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton; HRB 21284 (AG Nürnberg)