Re: [PATCH] net: cgroup: fix access the unallocated memory in netprio cgroup

于 2012年07月10日 17:15, Eric Dumazet 写道:

On Tue, 2012-07-10 at 16:53 +0800, Gao feng wrote:

quoted

quoted

Hi Gao

Is it still needed to call update_netdev_tables() from write_priomap() ?

Yes, I think it's needed,because read_priomap will show all of the net devices,

But we may add the netdev after create a netprio cgroup, so the new added netdev's
priomap will not be allocated. if we don't call update_netdev_tables in write_priomap,
we may access this unallocated memory.

I realize my question was not clear.

If we write in write_priomap() a field of a single netdevice,
why should we allocate memory for all netdevices on the machine ?

So the question was : Do we really need to call
update_netdev_tables(alldevs), instead of extend_netdev_table(dev)

I get it.

You are right,Indeed we only need to call extend_netdev_table
for the netdev witch we want to change.

and I read the commit f5c38208d32412d72b97a4f0d44af0eb39feb20b,
found why we need delay allocation.

I will send a v2 patch.

Thanks!