Re: [libvirt] [PATCH] qemu: fix use a nonexist address in qemuDomainAttachDeviceConfig

On 12/16/2014 08:00 PM, Peter Krempa wrote: > On 12/15/14 10:10, Luyao Huang wrote: >> We free them before, then use it. This make we always do > We clear the pointer, not free. > >> virDomainDefAddImplicitControllers when attach a disk. >> >> Signed-off-by: Luyao Huang <lhuang(a)redhat.com&gt; >> --- >> src/qemu/qemu_driver.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c >> index df3ba6d..a9afa5d 100644 >> --- a/src/qemu/qemu_driver.c >> +++ b/src/qemu/qemu_driver.c >> @@ -7223,10 +7223,10 @@ qemuDomainAttachDeviceConfig(virQEMUCapsPtr >> qemuCaps, >> if (virDomainDiskInsert(vmdef, disk)) >> return -1; >> /* vmdef has the pointer. Generic codes for vmdef will do >> all jobs */ >> - dev->data.disk = NULL; > The comment even explains why the line is there. From that point on, the > pointer is owned by 'vmdef' and thus the original needs to be cleared so > that it isn't freed (and doulbe freed) later on. Oh, i see. Thanks for your review and i found seems i don't check if gdb is real go to virDomainDefAddImplicitControllers, just check the pointer's value is optimized out. (gdb) 7204 dev->data.disk = NULL; (gdb) 7205 if (disk->bus != VIR_DOMAIN_DISK_BUS_VIRTIO) (gdb) p disk $3 = <optimized out>