On Tue, Sep 10, 2013 at 01:29:40AM +0000, Liuji (Jeremy) wrote:
-----Original Message----- From: Daniel P. Berrange [mailto:berrange@redhat.com] Sent: Monday, September 09, 2013 7:26 PM To: Liuji (Jeremy) Cc: libvir-list@redhat.com; Jinbo (Justin); Luohao (brian); Haofeng Subject: Re: [libvirt] [PATCH] virBitmapFree: Change the function to a macro
-----Original Message----- From: Daniel P. Berrange [mailto:berrange@redhat.com] Sent: Friday, September 06, 2013 6:37 PM To: Liuji (Jeremy) Cc: libvir-list@redhat.com; Jinbo (Justin); Luohao (brian); Haofeng Subject: Re: [libvirt] [PATCH] virBitmapFree: Change the function to a macro
The parameter of virBitmapFree function is just a pointer, not a pointer of
The second VIR_FREE on virBitmapFree only assign NULL to the formal
On Fri, Sep 06, 2013 at 10:30:56AM +0000, Liuji (Jeremy) wrote: pointer. parameter.
After calling the virBitmapFree function, the actual parameter are still not NULL. There are many code segment don't assign NULL to the formal parameter after calling the virBitmapFree function. This will bring potential risks.
A problem scenario: 1) The XML of VM contain the below segment: <numatune> <memory mode='preferred' placement='auto' nodeset='0'/> </numatune> 2)virsh create the VM 3)In the virDomainDefParseXML funtion: /* Ignore 'nodeset' if 'placement' is 'auto' finally */ if (placement_mode == VIR_NUMA_TUNE_MEM_PLACEMENT_MODE_AUTO) {
virBitmapFree(def->numatune.memory.nodemask);
def->numatune.memory.nodemask = NULL; } 4)Then, virsh destroy the VM. In the virDomainDefFree funtion, it also call
On Mon, Sep 09, 2013 at 01:39:42AM +0000, Liuji (Jeremy) wrote: the
virBitmapFree function to free the nodemask: virBitmapFree(def->numatune.memory.nodemask); But after this call, the value of def->numatune.memory.nodemask is still not NULL. This will generate an exception.
Have you got an actual crash happening today, or is this just a theoretical problem you're trying to address ?
Yes，it's an actual crash problem. I found the problem in the above problem scenario in my first mail.
Then can you send a patch which explicitly fixes that problem on its own, without doing this major refactoring, which obscures what is being fixed.
I had sent a patch in my first mail. You can find the mail at the following links: https://www.redhat.com/archives/libvir-list/2013-September/msg00337.html
No, I want the root cause fixed. This change to the bitmap APIs is just papering over any root cause bug. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|