Denis V. Lunev wrote: > The patch attached should help. The idea is simple. The "init" should be > called only once without NETNS. Period. No need for any lists.
This is the kind of idea I had but I didn't think it could be that simple. :) Thanks Denis. > I'll resend it to Dave after the ACK. Tested on x86_64 with CONFIG_NET_NS=n and y. It fixes the issue we observed. Acked-by: Benjamin Thery <[EMAIL PROTECTED]> > Regards, > Den > > Benjamin Thery wrote: >> Hello Pavel, >> >> I've found a problem with one of your patch related to netns: >> >> * [NETNS] Move some code into __init section when CONFIG_NET_NS=n (v2) >> http://www.spinics.net/lists/netdev/msg43310.html >> >> This patch introduces the __net_init/__net_exit/__net_initdata >> defines to save some memory when CONFIG_NET_NS is not set. >> >> Cedric Le Goater reported he had a *non-fatal* oops when booting >> a 2.6.23-mm1-lxc1 kernel with CONFIG_NET_NS=n. (2.6.23-mm1-lxc1 >> contains the NETNS49 patchset). The oops occured when modules >> related to iptables were loaded after the boot completes. >> >> The problem is the following: >> >> - Your patch adds the __net_initdata attribute to pernet_operations >> structures. >> >> - pernet_operations are registered via register_pernet_subsys() and >> linked in the pernet_list during boot. >> >> - At the end of boot, pernet_operations are freed (because of the >> __net_initdata attribute), and the pernet_list (or first_device list) >> points to freed memory. >> >> - After boot, network modules which are netns-aware try to register >> themselves with register_pernet_subsys() and ...KABOOM... page >> fault when accessing pernet_list (or first_device list). >> (I reproduce Cedric's oops with the command: iptables --list) >> >> This is not a problem right now in 2.6.23-mm1 or net-2.6 because >> there are very few netns-aware network subsystems merged and they >> are all initialized during boot. But it will be problematic when >> we will merge netns code for subsystems which can be built as >> modules (eg. iptables, ...). I'm not sure we can use >> __net_init_data for pernet_operations then. >> Maybe we can add some checks in register_pernet_operations >> when CONFIG_NET_NS=n. >> >> I haven't found a fix yet. >> >> Regards, >> Benjamin >> > -- B e n j a m i n T h e r y - BULL/DT/Open Software R&D http://www.bull.com - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
