On Thu, 5 Sep 2019 at 03:58, Stephen Hemminger
<step...@networkplumber.org> wrote:
>
> 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(-)
> >
>
Hi Stephen,
Thank you so much for the review!
> The network receive path already avoids excessive stack
> depth. Maybe the real problem is in the lockdep code.
Sorry, I don't understand the point that you mentioned.
I appreciate if you tell me more in details about your review.
