On Thu, 5 Sep 2019 03:38:28 +0900
Taehee Yoo <ap420...@gmail.com> wrote:
> This patchset fixes several bugs that are related to nesting
> device infrastructure.
> Current nesting infrastructure code doesn't limit the depth level of
> devices. nested devices could be handled recursively. at that moment,
> it needs huge memory and stack overflow could occur.
> Below devices type have same bug.
> VLAN, BONDING, TEAM, MACSEC, MACVLAN and VXLAN.
>
> Test commands:
> ip link add dummy0 type dummy
> ip link add vlan1 link dummy0 type vlan id 1
>
> for i in {2..100}
> do
> let A=$i-1
> ip link add name vlan$i link vlan$A type vlan id $i
> done
> ip link del dummy0
>
> 1st patch actually fixes the root cause.
> It adds new common variables {upper/lower}_level that represent
> depth level. upper_level variable is depth of upper devices.
> lower_level variable is depth of lower devices.
>
> [U][L] [U][L]
> vlan1 1 5 vlan4 1 4
> vlan2 2 4 vlan5 2 3
> vlan3 3 3 |
> | |
> +------------+
> |
> vlan6 4 2
> dummy0 5 1
>
> After this patch, the nesting infrastructure code uses this variable to
> check the depth level.
>
> 2, 4, 5, 6, 7 patches fix lockdep related problem.
> Before this patch, devices use static lockdep map.
> So, if devices that are same type is nested, lockdep will warn about
> recursive situation.
> These patches make these devices use dynamic lockdep key instead of
> static lock or subclass.
>
> 3rd patch splits IFF_BONDING flag into IFF_BONDING and IFF_BONDING_SLAVE.
> Before this patch, there is only IFF_BONDING flags, which means
> a bonding master or a bonding slave device.
> But this single flag could be problem when bonding devices are set to
> nested.
>
> 8th patch fixes a refcnt leak in the macsec module.
>
> 9th patch adds ignore flag to an adjacent structure.
> In order to exchange an adjacent node safely, ignore flag is needed.
>
> 10th patch makes vxlan add an adjacent link to limit depth level.
>
> 11th patch removes unnecessary variables and callback.
>
> Taehee Yoo (11):
> net: core: limit nested device depth
> vlan: use dynamic lockdep key instead of subclass
> bonding: split IFF_BONDING into IFF_BONDING and IFF_BONDING_SLAVE
> bonding: use dynamic lockdep key instead of subclass
> team: use dynamic lockdep key instead of static key
> macsec: use dynamic lockdep key instead of subclass
> macvlan: use dynamic lockdep key instead of subclass
> macsec: fix refcnt leak in module exit routine
> net: core: add ignore flag to netdev_adjacent structure
> vxlan: add adjacent link to limit depth level
> net: remove unnecessary variables and callback
>
> drivers/net/bonding/bond_alb.c | 2 +-
> drivers/net/bonding/bond_main.c | 87 ++++--
> .../net/ethernet/mellanox/mlx5/core/en_tc.c | 2 +-
> .../ethernet/qlogic/netxen/netxen_nic_main.c | 2 +-
> drivers/net/hyperv/netvsc_drv.c | 3 +-
> drivers/net/macsec.c | 50 ++--
> drivers/net/macvlan.c | 36 ++-
> drivers/net/team/team.c | 61 ++++-
> drivers/net/vxlan.c | 71 ++++-
> drivers/scsi/fcoe/fcoe.c | 2 +-
> drivers/target/iscsi/cxgbit/cxgbit_cm.c | 2 +-
> include/linux/if_macvlan.h | 3 +-
> include/linux/if_team.h | 5 +
> include/linux/if_vlan.h | 13 +-
> include/linux/netdevice.h | 29 +-
> include/net/bonding.h | 4 +-
> include/net/vxlan.h | 1 +
> net/8021q/vlan.c | 1 -
> net/8021q/vlan_dev.c | 32 +--
> net/core/dev.c | 252 ++++++++++++++++--
> net/core/dev_addr_lists.c | 12 +-
> net/smc/smc_core.c | 2 +-
> net/smc/smc_pnet.c | 2 +-
> 23 files changed, 519 insertions(+), 155 deletions(-)
>
The network receive path already avoids excessive stack
depth. Maybe the real problem is in the lockdep code.
