[PATCH net v3 00/11] net: fix nested device bugs

[PATCH net v3 00/11] net: fix nested device bugs

[Taehee Yoo]

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=$i-1
	    ip link add vlan$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 fixes unexpected IFF_BONDING bit unset.

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.

v2 -> v3 :
 - Modify nesting infrastructure code to use iterator instead of recursive.
v1 -> v2 :
 - Make the 3rd patch do not add a new priv_flag.

Taehee Yoo (11):
  net: core: limit nested device depth
  vlan: use dynamic lockdep key instead of subclass
  bonding: fix unexpected IFF_BONDING bit unset
  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               |  81 +++-
 .../net/ethernet/mellanox/mlx5/core/en_tc.c   |   2 +-
 drivers/net/macsec.c                          |  50 +-
 drivers/net/macvlan.c                         |  36 +-
 drivers/net/team/team.c                       |  61 ++-
 drivers/net/vxlan.c                           |  71 ++-
 include/linux/if_macvlan.h                    |   3 +-
 include/linux/if_team.h                       |   5 +
 include/linux/if_vlan.h                       |  13 +-
 include/linux/netdevice.h                     |  20 +-
 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                                | 456 +++++++++++++++---
 net/core/dev_addr_lists.c                     |  12 +-
 net/smc/smc_core.c                            |   2 +-
 net/smc/smc_pnet.c                            |   2 +-
 19 files changed, 667 insertions(+), 187 deletions(-)

-- 
2.17.1

[PATCH net v3 01/11] net: core: limit nested device depth

[Taehee Yoo]

Current code doesn't limit the number of nested devices.
Nested devices would be handled recursively and this needs huge stack
memory. So, unlimited nested devices could make stack overflow.

This patch adds upper_level and lower_level, they are common variables
and represent maximum lower/upper depth.
When upper/lower device is attached or dettached,
{lower/upper}_level are updated. and if maximum depth is bigger than 8,
attach routine fails and returns -EMLINK.

In addition, this patch converts recursive routine of
netdev_walk_all_{lower/upper} to iterator routine.

Test commands:
    ip link add dummy0 type dummy
    ip link add link dummy0 name vlan1 type vlan id 1
    ip link set vlan1 up

    for i in {2..200}
    do
	    let A=$i-1

	    ip link add vlan$i link vlan$A type vlan id $i
    done
    ip link del vlan1

Splat looks like:
[  132.396918] Thread overran stack, or stack corrupted
[  132.397763] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  132.398557] CPU: 1 PID: 1299 Comm: ip Not tainted 5.3.0-rc8+ #179
[  132.399241] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  132.400136] RIP: 0010:stack_depot_fetch+0x10/0x30
[  132.400683] Code: 00 75 10 48 8b 73 18 48 89 ef 5b 5d e9 79 8f 87 ff 0f 0b e8 c2 6d 9b ff eb e9 89 f8 c1 ef 110
[  132.402711] RSP: 0000:ffff8880b002eb78 EFLAGS: 00010006
[  132.404578] RAX: 00000000001fffff RBX: ffff8880b002eec0 RCX: 0000000000000000
[  132.405305] RDX: 000000000000001d RSI: ffff8880b002eb80 RDI: 0000000000003ff0
[  132.406022] RBP: ffffea0002c00a00 R08: ffffed101b53df23 R09: ffffed101b53df23
[  132.406776] R10: 0000000000000001 R11: ffffed101b53df22 R12: ffff8880d38dd900
[  132.407598] R13: ffff8880b002e600 R14: ffff8880b002eec0 R15: ffff8880b002ed20
[  132.408365] FS:  00007f5fca3c90c0(0000) GS:ffff8880da800000(0000) knlGS:0000000000000000
[  132.409213] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  132.409788] CR2: ffffffffa598b098 CR3: 00000000ccb86004 CR4: 00000000000606e0
[  132.410659] Call Trace:
[  132.410962] Modules linked in: 8021q garp stp mrp llc dummy veth openvswitch nsh nf_conncount nf_nat nf_conntrs
[  132.412410] CR2: ffffffffa598b098
[  132.412754] ---[ end trace 7f335fb982ddb2da ]---
[  132.413293] RIP: 0010:stack_depot_fetch+0x10/0x30
[  132.413851] Code: 00 75 10 48 8b 73 18 48 89 ef 5b 5d e9 79 8f 87 ff 0f 0b e8 c2 6d 9b ff eb e9 89 f8 c1 ef 110
[  132.415973] RSP: 0000:ffff8880b002eb78 EFLAGS: 00010006
[  132.416581] RAX: 00000000001fffff RBX: ffff8880b002eec0 RCX: 0000000000000000
[  132.417380] RDX: 000000000000001d RSI: ffff8880b002eb80 RDI: 0000000000003ff0
[  132.418211] RBP: ffffea0002c00a00 R08: ffffed101b53df23 R09: ffffed101b53df23
[  132.419036] R10: 0000000000000001 R11: ffffed101b53df22 R12: ffff8880d38dd900
[  132.419815] R13: ffff8880b002e600 R14: ffff8880b002eec0 R15: ffff8880b002ed20
[  132.420616] FS:  00007f5fca3c90c0(0000) GS:ffff8880da800000(0000) knlGS:0000000000000000
[  132.421489] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  132.422134] CR2: ffffffffa598b098 CR3: 00000000ccb86004 CR4: 00000000000606e0
[  132.422912] Kernel panic - not syncing: Fatal exception
[  132.423441] Kernel Offset: 0x1f000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff)
[  132.425455] Rebooting in 5 seconds..

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - Modify nesting infra code to use iterator instead of recursive
v1 -> v2 :
 - This patch is not changed

 include/linux/netdevice.h |   4 +
 net/core/dev.c            | 286 ++++++++++++++++++++++++++++++++------
 2 files changed, 245 insertions(+), 45 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 88292953aa6f..5bb5756129af 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1624,6 +1624,8 @@ enum netdev_priv_flags {
  *	@type:		Interface hardware type
  *	@hard_header_len: Maximum hardware header length.
  *	@min_header_len:  Minimum hardware header length
+ *	@upper_level:	Maximum depth level of upper devices.
+ *	@lower_level:	Maximum depth level of lower devices.
  *
  *	@needed_headroom: Extra headroom the hardware may need, but not in all
  *			  cases can this be guaranteed
@@ -1854,6 +1856,8 @@ struct net_device {
 	unsigned short		type;
 	unsigned short		hard_header_len;
 	unsigned char		min_header_len;
+	unsigned char		upper_level;
+	unsigned char		lower_level;
 
 	unsigned short		needed_headroom;
 	unsigned short		needed_tailroom;
diff --git a/net/core/dev.c b/net/core/dev.c
index 5156c0edebe8..fa847ea957ee 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -146,6 +146,7 @@
 #include "net-sysfs.h"
 
 #define MAX_GRO_SKBS 8
+#define MAX_NEST_DEV 8
 
 /* This should be increased if a protocol with a bigger head is added. */
 #define GRO_MAX_HEAD (MAX_HEADER + 128)
@@ -6602,6 +6603,21 @@ struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
 }
 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
 
+static struct net_device *netdev_next_upper_dev(struct net_device *dev,
+						struct list_head **iter)
+{
+	struct netdev_adjacent *upper;
+
+	upper = list_entry((*iter)->next, struct netdev_adjacent, list);
+
+	if (&upper->list == &dev->adj_list.upper)
+		return NULL;
+
+	*iter = &upper->list;
+
+	return upper->dev;
+}
+
 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
 						    struct list_head **iter)
 {
@@ -6619,31 +6635,103 @@ static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
 	return upper->dev;
 }
 
+int netdev_walk_all_upper_dev(struct net_device *dev,
+			      int (*fn)(struct net_device *dev,
+					void *data),
+			      void *data)
+{
+	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int ret, cur = 0;
+
+	now = dev;
+	iter = &dev->adj_list.upper;
+
+	while (1) {
+		if (now != dev) {
+			ret = fn(now, data);
+			if (ret)
+				return ret;
+		}
+
+		next = NULL;
+		while (1) {
+			udev = netdev_next_upper_dev(now, &iter);
+			if (!udev)
+				break;
+
+			if (!next) {
+				next = udev;
+				niter = &udev->adj_list.upper;
+			} else {
+				dev_stack[cur] = udev;
+				iter_stack[cur++] = &udev->adj_list.upper;
+				break;
+			}
+		}
+
+		if (!next) {
+			if (!cur)
+				return 0;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
+	}
+
+	return 0;
+}
+
 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
 				  int (*fn)(struct net_device *dev,
 					    void *data),
 				  void *data)
 {
-	struct net_device *udev;
-	struct list_head *iter;
-	int ret;
+	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int ret, cur = 0;
 
-	for (iter = &dev->adj_list.upper,
-	     udev = netdev_next_upper_dev_rcu(dev, &iter);
-	     udev;
-	     udev = netdev_next_upper_dev_rcu(dev, &iter)) {
-		/* first is the upper device itself */
-		ret = fn(udev, data);
-		if (ret)
-			return ret;
+	now = dev;
+	iter = &dev->adj_list.upper;
 
-		/* then look at all of its upper devices */
-		ret = netdev_walk_all_upper_dev_rcu(udev, fn, data);
-		if (ret)
-			return ret;
+	while (1) {
+		if (now != dev) {
+			ret = fn(now, data);
+			if (ret)
+				return ret;
+		}
+
+		next = NULL;
+		while (1) {
+			udev = netdev_next_upper_dev_rcu(now, &iter);
+			if (!udev)
+				break;
+
+			if (!next) {
+				next = udev;
+				niter = &udev->adj_list.upper;
+			} else {
+				dev_stack[cur] = udev;
+				iter_stack[cur++] = &udev->adj_list.upper;
+				break;
+			}
+		}
+
+		if (!next) {
+			if (!cur)
+				return 0;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
 	}
 
 	return 0;
+
 }
 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
 
@@ -6748,23 +6836,45 @@ int netdev_walk_all_lower_dev(struct net_device *dev,
 					void *data),
 			      void *data)
 {
-	struct net_device *ldev;
-	struct list_head *iter;
-	int ret;
+	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int ret, cur = 0;
 
-	for (iter = &dev->adj_list.lower,
-	     ldev = netdev_next_lower_dev(dev, &iter);
-	     ldev;
-	     ldev = netdev_next_lower_dev(dev, &iter)) {
-		/* first is the lower device itself */
-		ret = fn(ldev, data);
-		if (ret)
-			return ret;
+	now = dev;
+	iter = &dev->adj_list.lower;
 
-		/* then look at all of its lower devices */
-		ret = netdev_walk_all_lower_dev(ldev, fn, data);
-		if (ret)
-			return ret;
+	while (1) {
+		if (now != dev) {
+			ret = fn(now, data);
+			if (ret)
+				return ret;
+		}
+
+		next = NULL;
+		while (1) {
+			ldev = netdev_next_lower_dev(now, &iter);
+			if (!ldev)
+				break;
+
+			if (!next) {
+				next = ldev;
+				niter = &ldev->adj_list.lower;
+			} else {
+				dev_stack[cur] = ldev;
+				iter_stack[cur++] = &ldev->adj_list.lower;
+				break;
+			}
+		}
+
+		if (!next) {
+			if (!cur)
+				return 0;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
 	}
 
 	return 0;
@@ -6785,31 +6895,100 @@ static struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
 	return lower->dev;
 }
 
-int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
-				  int (*fn)(struct net_device *dev,
-					    void *data),
-				  void *data)
+static u8 __netdev_upper_depth(struct net_device *dev)
+{
+	struct net_device *udev;
+	struct list_head *iter;
+	u8 max_depth = 0;
+
+	for (iter = &dev->adj_list.upper,
+	     udev = netdev_next_upper_dev(dev, &iter);
+	     udev;
+	     udev = netdev_next_upper_dev(dev, &iter)) {
+		if (max_depth < udev->upper_level)
+			max_depth = udev->upper_level;
+	}
+
+	return max_depth;
+}
+
+static u8 __netdev_lower_depth(struct net_device *dev)
 {
 	struct net_device *ldev;
 	struct list_head *iter;
-	int ret;
+	u8 max_depth = 0;
 
 	for (iter = &dev->adj_list.lower,
-	     ldev = netdev_next_lower_dev_rcu(dev, &iter);
+	     ldev = netdev_next_lower_dev(dev, &iter);
 	     ldev;
-	     ldev = netdev_next_lower_dev_rcu(dev, &iter)) {
-		/* first is the lower device itself */
-		ret = fn(ldev, data);
-		if (ret)
-			return ret;
+	     ldev = netdev_next_lower_dev(dev, &iter)) {
+		if (max_depth < ldev->lower_level)
+			max_depth = ldev->lower_level;
+	}
 
-		/* then look at all of its lower devices */
-		ret = netdev_walk_all_lower_dev_rcu(ldev, fn, data);
-		if (ret)
-			return ret;
+	return max_depth;
+}
+
+static int __netdev_update_upper_level(struct net_device *dev, void *data)
+{
+	dev->upper_level = __netdev_upper_depth(dev) + 1;
+	return 0;
+}
+
+static int __netdev_update_lower_level(struct net_device *dev, void *data)
+{
+	dev->lower_level = __netdev_lower_depth(dev) + 1;
+	return 0;
+}
+
+int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
+				  int (*fn)(struct net_device *dev,
+					    void *data),
+				  void *data)
+{
+	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int ret, cur = 0;
+
+	now = dev;
+	iter = &dev->adj_list.lower;
+
+	while (1) {
+		if (now != dev) {
+			ret = fn(now, data);
+			if (ret)
+				return ret;
+		}
+
+		next = NULL;
+		while (1) {
+			ldev = netdev_next_lower_dev_rcu(now, &iter);
+			if (!ldev)
+				break;
+
+			if (!next) {
+				next = ldev;
+				niter = &ldev->adj_list.lower;
+			} else {
+				dev_stack[cur] = ldev;
+				iter_stack[cur++] = &ldev->adj_list.lower;
+				break;
+			}
+		}
+
+		if (!next) {
+			if (!cur)
+				return 0;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
 	}
 
 	return 0;
+
 }
 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
 
@@ -7063,6 +7242,9 @@ static int __netdev_upper_dev_link(struct net_device *dev,
 	if (netdev_has_upper_dev(upper_dev, dev))
 		return -EBUSY;
 
+	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
+		return -EMLINK;
+
 	if (!master) {
 		if (netdev_has_upper_dev(dev, upper_dev))
 			return -EEXIST;
@@ -7089,6 +7271,12 @@ static int __netdev_upper_dev_link(struct net_device *dev,
 	if (ret)
 		goto rollback;
 
+	__netdev_update_upper_level(dev, NULL);
+	netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
+
+	__netdev_update_lower_level(upper_dev, NULL);
+	netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level, NULL);
+
 	return 0;
 
 rollback:
@@ -7171,6 +7359,12 @@ void netdev_upper_dev_unlink(struct net_device *dev,
 
 	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
 				      &changeupper_info.info);
+
+	__netdev_update_upper_level(dev, NULL);
+	netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
+
+	__netdev_update_lower_level(upper_dev, NULL);
+	netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level, NULL);
 }
 EXPORT_SYMBOL(netdev_upper_dev_unlink);
 
@@ -9159,6 +9353,8 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
 
 	dev->gso_max_size = GSO_MAX_SIZE;
 	dev->gso_max_segs = GSO_MAX_SEGS;
+	dev->upper_level = 1;
+	dev->lower_level = 1;
 
 	INIT_LIST_HEAD(&dev->napi_list);
 	INIT_LIST_HEAD(&dev->unreg_list);
-- 
2.17.1

[PATCH net v3 02/11] vlan: use dynamic lockdep key instead of subclass

[Taehee Yoo]

All VLAN device has same lockdep key and subclass is initialized with
nest_level.
But actual nest_level value can be changed when a lower device is attached.
And at this moment, the subclass should be updated but it seems to be
unsafe.
So this patch makes VLAN use dynamic lockdep key instead of the subclass.

Test commands:
   ip link add dummy0 type dummy
   ip link set dummy0 up
   ip link add bond0 type bond

   ip link add vlan_dummy1 link dummy0 type vlan id 1
   ip link add vlan_bond1 link bond0 type vlan id 2
   ip link set vlan_dummy1 master bond0

   ip link set bond0 up
   ip link set vlan_dummy1 up
   ip link set vlan_bond1 up

Both vlan_dummy1 and vlan_bond1 have the same subclass and it makes
unnecessary deadlock warning message.

Splat looks like:
[   66.163164] WARNING: possible recursive locking detected
[   66.163858] 5.3.0-rc8+ #179 Not tainted
[   66.165520] --------------------------------------------
[   66.166110] ip/983 is trying to acquire lock:
[   66.166603] 000000009b85ba3e (&vlan_netdev_addr_lock_key/1){+...}, at: dev_uc_sync_multiple+0xfa/0x1a0
[   66.194006]
[   66.194006] but task is already holding lock:
[   66.194636] 00000000cc752363 (&vlan_netdev_addr_lock_key/1){+...}, at: dev_set_rx_mode+0x19/0x30
[   66.205191]
[   66.205191] other info that might help us debug this:
[   66.205903]  Possible unsafe locking scenario:
[   66.205903]
[   66.206504]        CPU0
[   66.206781]        ----
[   66.208737]   lock(&vlan_netdev_addr_lock_key/1);
[   66.257676]   lock(&vlan_netdev_addr_lock_key/1);
[   66.282069]
[   66.282069]  *** DEADLOCK ***
[   66.282069]
[   66.283708]  May be due to missing lock nesting notation
[   66.283708]
[   66.284588] 4 locks held by ip/983:
[   66.285035]  #0: 000000002989e16e (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[   66.286051]  #1: 00000000cc752363 (&vlan_netdev_addr_lock_key/1){+...}, at: dev_set_rx_mode+0x19/0x30
[   66.287217]  #2: 00000000eddac627 (&dev_addr_list_lock_key/3){+...}, at: dev_mc_sync+0xfa/0x1a0
[   66.288327]  #3: 000000001a459ff7 (rcu_read_lock){....}, at: bond_set_rx_mode+0x5/0x3c0 [bonding]
[   66.289453]
[   66.289453] stack backtrace:
[   66.290019] CPU: 1 PID: 983 Comm: ip Not tainted 5.3.0-rc8+ #179
[   66.290802] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   66.297639] Call Trace:
[   66.298009]  dump_stack+0x7c/0xbb
[   66.298447]  __lock_acquire+0x26a9/0x3de0
[   66.298965]  ? register_lock_class+0x14d0/0x14d0
[   66.299547]  ? register_lock_class+0x14d0/0x14d0
[   66.300151]  lock_acquire+0x164/0x3b0
[   66.300621]  ? dev_uc_sync_multiple+0xfa/0x1a0
[   66.301198]  _raw_spin_lock_nested+0x2e/0x60
[   66.301743]  ? dev_uc_sync_multiple+0xfa/0x1a0
[   66.302311]  dev_uc_sync_multiple+0xfa/0x1a0
[   66.307650]  bond_set_rx_mode+0x269/0x3c0 [bonding]
[   66.308175]  ? bond_init+0x6f0/0x6f0 [bonding]
[   66.308585]  dev_mc_sync+0x15a/0x1a0
[   66.308927]  vlan_dev_set_rx_mode+0x37/0x80 [8021q]
[   66.309375]  dev_set_rx_mode+0x21/0x30
[   66.309727]  __dev_open+0x202/0x310
[   66.310100]  ? dev_set_rx_mode+0x30/0x30
[   66.310513]  ? mark_held_locks+0xa5/0xe0
[   66.310934]  ? __local_bh_enable_ip+0xe9/0x1b0
[   66.311387]  __dev_change_flags+0x3c3/0x500
[   66.311839]  ? dev_set_allmulti+0x10/0x10
[   66.312248]  ? kmem_cache_alloc_trace+0x12c/0x320
[   66.312746]  dev_change_flags+0x7a/0x160
[   66.313161]  vlan_device_event+0x846/0x20d0 [8021q]
[ ... ]

Fixes: 0fe1e567d0b4 ("[VLAN]: nested VLAN: fix lockdep's recursive locking warning")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - This patch is not changed
v1 -> v2 :
 - This patch is not changed

 include/linux/if_vlan.h |  3 +++
 net/8021q/vlan_dev.c    | 28 +++++++++++++++-------------
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 244278d5c222..1aed9f613e90 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -183,6 +183,9 @@ struct vlan_dev_priv {
 	struct netpoll				*netpoll;
 #endif
 	unsigned int				nest_level;
+
+	struct lock_class_key			xmit_lock_key;
+	struct lock_class_key			addr_lock_key;
 };
 
 static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 93eadf179123..12bc80650087 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -494,24 +494,24 @@ static void vlan_dev_set_rx_mode(struct net_device *vlan_dev)
  * "super class" of normal network devices; split their locks off into a
  * separate class since they always nest.
  */
-static struct lock_class_key vlan_netdev_xmit_lock_key;
-static struct lock_class_key vlan_netdev_addr_lock_key;
-
 static void vlan_dev_set_lockdep_one(struct net_device *dev,
 				     struct netdev_queue *txq,
-				     void *_subclass)
+				     void *_unused)
 {
-	lockdep_set_class_and_subclass(&txq->_xmit_lock,
-				       &vlan_netdev_xmit_lock_key,
-				       *(int *)_subclass);
+	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
+
+	lockdep_set_class(&txq->_xmit_lock, &vlan->xmit_lock_key);
 }
 
-static void vlan_dev_set_lockdep_class(struct net_device *dev, int subclass)
+static void vlan_dev_set_lockdep_class(struct net_device *dev)
 {
-	lockdep_set_class_and_subclass(&dev->addr_list_lock,
-				       &vlan_netdev_addr_lock_key,
-				       subclass);
-	netdev_for_each_tx_queue(dev, vlan_dev_set_lockdep_one, &subclass);
+	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
+
+	lockdep_register_key(&vlan->addr_lock_key);
+	lockdep_set_class(&dev->addr_list_lock, &vlan->addr_lock_key);
+
+	lockdep_register_key(&vlan->xmit_lock_key);
+	netdev_for_each_tx_queue(dev, vlan_dev_set_lockdep_one, NULL);
 }
 
 static int vlan_dev_get_lock_subclass(struct net_device *dev)
@@ -609,7 +609,7 @@ static int vlan_dev_init(struct net_device *dev)
 
 	SET_NETDEV_DEVTYPE(dev, &vlan_type);
 
-	vlan_dev_set_lockdep_class(dev, vlan_dev_get_lock_subclass(dev));
+	vlan_dev_set_lockdep_class(dev);
 
 	vlan->vlan_pcpu_stats = netdev_alloc_pcpu_stats(struct vlan_pcpu_stats);
 	if (!vlan->vlan_pcpu_stats)
@@ -630,6 +630,8 @@ static void vlan_dev_uninit(struct net_device *dev)
 			kfree(pm);
 		}
 	}
+	lockdep_unregister_key(&vlan->addr_lock_key);
+	lockdep_unregister_key(&vlan->xmit_lock_key);
 }
 
 static netdev_features_t vlan_dev_fix_features(struct net_device *dev,
-- 
2.17.1

[PATCH net v3 03/11] bonding: fix unexpected IFF_BONDING bit unset

[Taehee Yoo]

The IFF_BONDING means bonding master or bonding slave device.
->ndo_add_slave() sets IFF_BONDING flag and ->ndo_del_slave() unsets
IFF_BONDING flag.

bond0<--bond1

Both bond0 and bond1 are bonding device and these should keep having
IFF_BONDING flag until they are removed.
But bond1 would lose IFF_BONDING at ->ndo_del_slave() because that routine
do not check whether the slave device is the bonding type or not.
This patch adds the interface type check routine before removing
IFF_BONDING flag.

Test commands:
    ip link add bond0 type bond
    ip link add bond1 type bond
    ip link set bond1 master bond0
    ip link set bond1 nomaster
    ip link del bond1 type bond
    ip link add bond1 type bond

Splat looks like:
[   58.210981] proc_dir_entry 'bonding/bond1' already registered
[   58.463875] WARNING: CPU: 0 PID: 955 at fs/proc/generic.c:361 proc_register+0x2a9/0x3e0
[   58.466423] Modules linked in: bonding veth openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nfs
[   58.483855] CPU: 0 PID: 955 Comm: ip Not tainted 5.3.0-rc8+ #179
[   58.484657] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   58.485779] RIP: 0010:proc_register+0x2a9/0x3e0
[   58.486377] Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 39 01 00 00 48 8b 04 24 48 89 ea 48 c7 c7 60 0f 14 bd 480
[   58.489003] RSP: 0018:ffff8880cc007078 EFLAGS: 00010282
[   58.553743] RAX: dffffc0000000008 RBX: ffff8880ce23c0d0 RCX: ffffffffbbd021e2
[   58.584076] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8880da5f6b8c
[   58.584901] RBP: ffff8880ce23c353 R08: ffffed101b4bff91 R09: ffffed101b4bff91
[   58.585724] R10: 0000000000000001 R11: ffffed101b4bff90 R12: ffff8880ce23c268
[   58.586508] R13: ffff8880ce23c352 R14: dffffc0000000000 R15: ffffed1019c4786a
[   58.587296] FS:  00007f52d53b60c0(0000) GS:ffff8880da400000(0000) knlGS:0000000000000000
[   58.588247] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   58.653694] CR2: 00007f31a9df9320 CR3: 00000000cd4ea006 CR4: 00000000000606f0
[   58.654591] Call Trace:
[   58.654895]  proc_create_seq_private+0xb3/0xf0
[   58.655400]  bond_create_proc_entry+0x1b3/0x3f0 [bonding]
[   58.655985]  bond_netdev_event+0x433/0x970 [bonding]
[   58.656545]  ? __module_text_address+0x13/0x140
[   58.657038]  notifier_call_chain+0x90/0x160
[   58.657541]  register_netdevice+0x9b3/0xd80
[   58.657999]  ? alloc_netdev_mqs+0x854/0xc10
[   58.658476]  ? netdev_change_features+0xa0/0xa0
[   58.663592]  ? rtnl_create_link+0x2ed/0xad0
[   58.664049]  bond_newlink+0x2a/0x60 [bonding]
[   58.664529]  __rtnl_newlink+0xb9f/0x11b0
[   58.665014]  ? rtnl_link_unregister+0x230/0x230
[ ... ]

Fixes: 0b680e753724 ("[PATCH] bonding: Add priv_flag to avoid event mishandling")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - This patch is not changed
v1 -> v2 :
 - Do not add a new priv_flag.

 drivers/net/bonding/bond_main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 931d9d935686..0db12fcfc953 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1816,7 +1816,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
 	slave_disable_netpoll(new_slave);
 
 err_close:
-	slave_dev->priv_flags &= ~IFF_BONDING;
+	if (!netif_is_bond_master(slave_dev))
+		slave_dev->priv_flags &= ~IFF_BONDING;
 	dev_close(slave_dev);
 
 err_restore_mac:
@@ -2017,7 +2018,8 @@ static int __bond_release_one(struct net_device *bond_dev,
 	else
 		dev_set_mtu(slave_dev, slave->original_mtu);
 
-	slave_dev->priv_flags &= ~IFF_BONDING;
+	if (!netif_is_bond_master(slave_dev))
+		slave_dev->priv_flags &= ~IFF_BONDING;
 
 	bond_free_slave(slave);
 
-- 
2.17.1

Re: [PATCH net v3 03/11] bonding: fix unexpected IFF_BONDING bit unset

[Jay Vosburgh]

Taehee Yoo <ap420073@gmail.com> wrote:

>The IFF_BONDING means bonding master or bonding slave device.
>->ndo_add_slave() sets IFF_BONDING flag and ->ndo_del_slave() unsets
>IFF_BONDING flag.
>
>bond0<--bond1
>
>Both bond0 and bond1 are bonding device and these should keep having
>IFF_BONDING flag until they are removed.
>But bond1 would lose IFF_BONDING at ->ndo_del_slave() because that routine
>do not check whether the slave device is the bonding type or not.
>This patch adds the interface type check routine before removing
>IFF_BONDING flag.
>
>Test commands:
>    ip link add bond0 type bond
>    ip link add bond1 type bond
>    ip link set bond1 master bond0
>    ip link set bond1 nomaster
>    ip link del bond1 type bond
>    ip link add bond1 type bond
>
>Splat looks like:
>[   58.210981] proc_dir_entry 'bonding/bond1' already registered
>[   58.463875] WARNING: CPU: 0 PID: 955 at fs/proc/generic.c:361 proc_register+0x2a9/0x3e0
>[   58.466423] Modules linked in: bonding veth openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nfs
>[   58.483855] CPU: 0 PID: 955 Comm: ip Not tainted 5.3.0-rc8+ #179
>[   58.484657] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
>[   58.485779] RIP: 0010:proc_register+0x2a9/0x3e0
>[   58.486377] Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 39 01 00 00 48 8b 04 24 48 89 ea 48 c7 c7 60 0f 14 bd 480
>[   58.489003] RSP: 0018:ffff8880cc007078 EFLAGS: 00010282
>[   58.553743] RAX: dffffc0000000008 RBX: ffff8880ce23c0d0 RCX: ffffffffbbd021e2
>[   58.584076] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8880da5f6b8c
>[   58.584901] RBP: ffff8880ce23c353 R08: ffffed101b4bff91 R09: ffffed101b4bff91
>[   58.585724] R10: 0000000000000001 R11: ffffed101b4bff90 R12: ffff8880ce23c268
>[   58.586508] R13: ffff8880ce23c352 R14: dffffc0000000000 R15: ffffed1019c4786a
>[   58.587296] FS:  00007f52d53b60c0(0000) GS:ffff8880da400000(0000) knlGS:0000000000000000
>[   58.588247] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>[   58.653694] CR2: 00007f31a9df9320 CR3: 00000000cd4ea006 CR4: 00000000000606f0
>[   58.654591] Call Trace:
>[   58.654895]  proc_create_seq_private+0xb3/0xf0
>[   58.655400]  bond_create_proc_entry+0x1b3/0x3f0 [bonding]
>[   58.655985]  bond_netdev_event+0x433/0x970 [bonding]
>[   58.656545]  ? __module_text_address+0x13/0x140
>[   58.657038]  notifier_call_chain+0x90/0x160
>[   58.657541]  register_netdevice+0x9b3/0xd80
>[   58.657999]  ? alloc_netdev_mqs+0x854/0xc10
>[   58.658476]  ? netdev_change_features+0xa0/0xa0
>[   58.663592]  ? rtnl_create_link+0x2ed/0xad0
>[   58.664049]  bond_newlink+0x2a/0x60 [bonding]
>[   58.664529]  __rtnl_newlink+0xb9f/0x11b0
>[   58.665014]  ? rtnl_link_unregister+0x230/0x230
>[ ... ]
>
>Fixes: 0b680e753724 ("[PATCH] bonding: Add priv_flag to avoid event mishandling")
>Signed-off-by: Taehee Yoo <ap420073@gmail.com>

Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>


>---
>
>v2 -> v3 :
> - This patch is not changed
>v1 -> v2 :
> - Do not add a new priv_flag.
>
> drivers/net/bonding/bond_main.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index 931d9d935686..0db12fcfc953 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -1816,7 +1816,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
> 	slave_disable_netpoll(new_slave);
> 
> err_close:
>-	slave_dev->priv_flags &= ~IFF_BONDING;
>+	if (!netif_is_bond_master(slave_dev))
>+		slave_dev->priv_flags &= ~IFF_BONDING;
> 	dev_close(slave_dev);
> 
> err_restore_mac:
>@@ -2017,7 +2018,8 @@ static int __bond_release_one(struct net_device *bond_dev,
> 	else
> 		dev_set_mtu(slave_dev, slave->original_mtu);
> 
>-	slave_dev->priv_flags &= ~IFF_BONDING;
>+	if (!netif_is_bond_master(slave_dev))
>+		slave_dev->priv_flags &= ~IFF_BONDING;
> 
> 	bond_free_slave(slave);
> 
>-- 
>2.17.1
>

Re: [PATCH net v3 03/11] bonding: fix unexpected IFF_BONDING bit unset

[Jiri Pirko]

Mon, Sep 16, 2019 at 03:47:54PM CEST, ap420073@gmail.com wrote:
>The IFF_BONDING means bonding master or bonding slave device.
>->ndo_add_slave() sets IFF_BONDING flag and ->ndo_del_slave() unsets
>IFF_BONDING flag.
>
>bond0<--bond1
>
>Both bond0 and bond1 are bonding device and these should keep having
>IFF_BONDING flag until they are removed.
>But bond1 would lose IFF_BONDING at ->ndo_del_slave() because that routine
>do not check whether the slave device is the bonding type or not.
>This patch adds the interface type check routine before removing
>IFF_BONDING flag.
>
>Test commands:
>    ip link add bond0 type bond
>    ip link add bond1 type bond
>    ip link set bond1 master bond0
>    ip link set bond1 nomaster
>    ip link del bond1 type bond
>    ip link add bond1 type bond

Interesting. I wonder why bond-in-bond is not forbidden...

Re: [PATCH net v3 03/11] bonding: fix unexpected IFF_BONDING bit unset

[Jay Vosburgh]

Jiri Pirko <jiri@resnulli.us> wrote:

>Mon, Sep 16, 2019 at 03:47:54PM CEST, ap420073@gmail.com wrote:
>>The IFF_BONDING means bonding master or bonding slave device.
>>->ndo_add_slave() sets IFF_BONDING flag and ->ndo_del_slave() unsets
>>IFF_BONDING flag.
>>
>>bond0<--bond1
>>
>>Both bond0 and bond1 are bonding device and these should keep having
>>IFF_BONDING flag until they are removed.
>>But bond1 would lose IFF_BONDING at ->ndo_del_slave() because that routine
>>do not check whether the slave device is the bonding type or not.
>>This patch adds the interface type check routine before removing
>>IFF_BONDING flag.
>>
>>Test commands:
>>    ip link add bond0 type bond
>>    ip link add bond1 type bond
>>    ip link set bond1 master bond0
>>    ip link set bond1 nomaster
>>    ip link del bond1 type bond
>>    ip link add bond1 type bond
>
>Interesting. I wonder why bond-in-bond is not forbidden...

	I think mostly because nesting wasn't originally forbidden, and
there are apparently users of it out in the wild, judging from the
number of times I see configurations or queries about an active-backup
bond with two 802.3ad bonding slaves.  That particular configuration
doesn't have any advantage (802.3ad will internally manage that
situation), but I don't see that we can now forbid nesting bonds without
potentially breaking existing user space configurations.

	-J

---
	-Jay Vosburgh, jay.vosburgh@canonical.com

[PATCH net v3 04/11] bonding: use dynamic lockdep key instead of subclass

[Taehee Yoo]

All bonding device has same lockdep key and subclass is initialized with
nest_level.
But actual nest_level value can be changed when a lower device is attached.
And at this moment, the subclass should be updated but it seems to be
unsafe.
So this patch makes bonding use dynamic lockdep key instead of the
subclass.

Test commands:
    ip link add bond0 type bond

    for i in {1..5}
    do
	    let A=$i-1
	    ip link add bond$i type bond
	    ip link set bond$i master bond$A
    done
    ip link set bond5 master bond0

Splat looks like:
[   53.930344] WARNING: possible recursive locking detected
[   53.931041] 5.3.0-rc8+ #179 Not tainted
[   53.931554] --------------------------------------------
[   53.932285] ip/984 is trying to acquire lock:
[   53.932854] 00000000e313b280 (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0xb8/0x500 [bonding]
[   53.934144]
[   53.934144] but task is already holding lock:
[   53.934907] 00000000f5a0c2e3 (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0xb8/0x500 [bonding]
[   53.936268]
[   53.936268] other info that might help us debug this:
[   53.937135]  Possible unsafe locking scenario:
[   53.937135]
[   53.937910]        CPU0
[   53.938247]        ----
[   53.938577]   lock(&(&bond->stats_lock)->rlock#2/2);
[   53.939234]   lock(&(&bond->stats_lock)->rlock#2/2);
[   53.939903]
[   53.939903]  *** DEADLOCK ***
[   53.939903]
[   53.940745]  May be due to missing lock nesting notation
[   53.940745]
[   53.941626] 3 locks held by ip/984:
[   53.942005]  #0: 000000009e3df2a0 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[   53.942942]  #1: 00000000f5a0c2e3 (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0xb8/0x500 [bond]
[   53.944194]  #2: 000000005b301abc (rcu_read_lock){....}, at: bond_get_stats+0x9f/0x500 [bonding]
[   53.945168]
[   53.945168] stack backtrace:
[   53.945672] CPU: 0 PID: 984 Comm: ip Not tainted 5.3.0-rc8+ #179
[   53.946606] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   53.947529] Call Trace:
[   53.947795]  dump_stack+0x7c/0xbb
[   53.948213]  __lock_acquire+0x26a9/0x3de0
[   53.948666]  ? register_lock_class+0x14d0/0x14d0
[   53.949206]  lock_acquire+0x164/0x3b0
[   53.949647]  ? bond_get_stats+0xb8/0x500 [bonding]
[   53.950169]  _raw_spin_lock_nested+0x2e/0x60
[   53.950630]  ? bond_get_stats+0xb8/0x500 [bonding]
[   53.951132]  bond_get_stats+0xb8/0x500 [bonding]
[   53.951655]  ? bond_arp_rcv+0xf10/0xf10 [bonding]
[   53.952220]  ? register_lock_class+0x14d0/0x14d0
[   53.952751]  ? bond_get_stats+0xb8/0x500 [bonding]
[   53.953277]  dev_get_stats+0x1ec/0x270
[   53.984289]  bond_get_stats+0x1d1/0x500 [bonding]
[   53.984803]  ? bond_arp_rcv+0xf10/0xf10 [bonding]
[   53.985323]  ? dev_get_alias+0xe2/0x190
[   53.985748]  ? nla_put_ifalias+0x71/0x100
[   53.986213]  ? rtnl_phys_switch_id_fill+0x91/0x100
[   53.986720]  dev_get_stats+0x1ec/0x270
[   53.987100]  rtnl_fill_stats+0x44/0xbe0
[   53.987494]  ? nla_put+0xc2/0x140
[   53.987828]  rtnl_fill_ifinfo+0xec7/0x35b0
[ ... ]

Fixes: d3fff6c443fe ("net: add netdev_lockdep_set_classes() helper")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - This patch is not changed
v1 -> v2 :
 - This patch is not changed

 drivers/net/bonding/bond_main.c | 61 ++++++++++++++++++++++++++++++---
 include/net/bonding.h           |  3 ++
 2 files changed, 59 insertions(+), 5 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 0db12fcfc953..7f574e74ed78 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1857,6 +1857,32 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
 	return res;
 }
 
+static void bond_dev_set_lockdep_one(struct net_device *dev,
+				     struct netdev_queue *txq,
+				     void *_unused)
+{
+	struct bonding *bond = netdev_priv(dev);
+
+	lockdep_set_class(&txq->_xmit_lock, &bond->xmit_lock_key);
+}
+
+static void bond_update_lock_key(struct net_device *dev)
+{
+	struct bonding *bond = netdev_priv(dev);
+
+	lockdep_unregister_key(&bond->stats_lock_key);
+	lockdep_unregister_key(&bond->addr_lock_key);
+	lockdep_unregister_key(&bond->xmit_lock_key);
+
+	lockdep_register_key(&bond->stats_lock_key);
+	lockdep_register_key(&bond->addr_lock_key);
+	lockdep_register_key(&bond->xmit_lock_key);
+
+	lockdep_set_class(&bond->stats_lock, &bond->stats_lock_key);
+	lockdep_set_class(&dev->addr_list_lock, &bond->addr_lock_key);
+	netdev_for_each_tx_queue(dev, bond_dev_set_lockdep_one, NULL);
+}
+
 /* Try to release the slave device <slave> from the bond device <master>
  * It is legal to access curr_active_slave without a lock because all the function
  * is RTNL-locked. If "all" is true it means that the function is being called
@@ -2022,6 +2048,8 @@ static int __bond_release_one(struct net_device *bond_dev,
 		slave_dev->priv_flags &= ~IFF_BONDING;
 
 	bond_free_slave(slave);
+	if (netif_is_bond_master(slave_dev))
+		bond_update_lock_key(slave_dev);
 
 	return 0;
 }
@@ -3459,7 +3487,7 @@ static void bond_get_stats(struct net_device *bond_dev,
 	struct list_head *iter;
 	struct slave *slave;
 
-	spin_lock_nested(&bond->stats_lock, bond_get_nest_level(bond_dev));
+	spin_lock(&bond->stats_lock);
 	memcpy(stats, &bond->bond_stats, sizeof(*stats));
 
 	rcu_read_lock();
@@ -4297,8 +4325,6 @@ void bond_setup(struct net_device *bond_dev)
 {
 	struct bonding *bond = netdev_priv(bond_dev);
 
-	spin_lock_init(&bond->mode_lock);
-	spin_lock_init(&bond->stats_lock);
 	bond->params = bonding_defaults;
 
 	/* Initialize pointers */
@@ -4367,6 +4393,9 @@ static void bond_uninit(struct net_device *bond_dev)
 
 	list_del(&bond->bond_list);
 
+	lockdep_unregister_key(&bond->stats_lock_key);
+	lockdep_unregister_key(&bond->addr_lock_key);
+	lockdep_unregister_key(&bond->xmit_lock_key);
 	bond_debug_unregister(bond);
 }
 
@@ -4758,6 +4787,29 @@ static int bond_check_params(struct bond_params *params)
 	return 0;
 }
 
+static struct lock_class_key qdisc_tx_busylock_key;
+static struct lock_class_key qdisc_running_key;
+
+static void bond_dev_set_lockdep_class(struct net_device *dev)
+{
+	struct bonding *bond = netdev_priv(dev);
+
+	dev->qdisc_tx_busylock = &qdisc_tx_busylock_key;
+	dev->qdisc_running_key = &qdisc_running_key;
+
+	spin_lock_init(&bond->mode_lock);
+
+	spin_lock_init(&bond->stats_lock);
+	lockdep_register_key(&bond->stats_lock_key);
+	lockdep_set_class(&bond->stats_lock, &bond->stats_lock_key);
+
+	lockdep_register_key(&bond->addr_lock_key);
+	lockdep_set_class(&dev->addr_list_lock, &bond->addr_lock_key);
+
+	lockdep_register_key(&bond->xmit_lock_key);
+	netdev_for_each_tx_queue(dev, bond_dev_set_lockdep_one, NULL);
+}
+
 /* Called from registration process */
 static int bond_init(struct net_device *bond_dev)
 {
@@ -4771,8 +4823,7 @@ static int bond_init(struct net_device *bond_dev)
 		return -ENOMEM;
 
 	bond->nest_level = SINGLE_DEPTH_NESTING;
-	netdev_lockdep_set_classes(bond_dev);
-
+	bond_dev_set_lockdep_class(bond_dev);
 	list_add_tail(&bond->bond_list, &bn->dev_list);
 
 	bond_prepare_sysfs_group(bond);
diff --git a/include/net/bonding.h b/include/net/bonding.h
index f7fe45689142..c39ac7061e41 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -239,6 +239,9 @@ struct bonding {
 	struct	 dentry *debug_dir;
 #endif /* CONFIG_DEBUG_FS */
 	struct rtnl_link_stats64 bond_stats;
+	struct lock_class_key stats_lock_key;
+	struct lock_class_key xmit_lock_key;
+	struct lock_class_key addr_lock_key;
 };
 
 #define bond_slave_get_rcu(dev) \
-- 
2.17.1

[PATCH net v3 05/11] team: use dynamic lockdep key instead of static key

[Taehee Yoo]

In the current code, all team devices have same static lockdep key
and team devices could be nested so that it makes unnecessary
lockdep warning.

Test commands:
    ip link add team0 type team
    for i in {1..7}
    do
	    let A=$i-1
	    ip link add team$i type team
	    ip link set team$i master team$A
    done
    ip link del team0

Splat looks like:
[   52.518420] WARNING: possible recursive locking detected
[   52.518955] 5.3.0-rc8+ #179 Not tainted
[   52.519373] --------------------------------------------
[   52.519925] ip/1005 is trying to acquire lock:
[   52.520893] 00000000c84e69ac (&dev_addr_list_lock_key/1){+...}, at: dev_uc_sync_multiple+0xfa/0x1a0
[   52.522194]
[   52.522194] but task is already holding lock:
[   52.523038] 0000000025864f52 (&dev_addr_list_lock_key/1){+...}, at: dev_uc_unsync+0x10c/0x1b0
[   52.524609]
[   52.524609] other info that might help us debug this:
[   52.525435]  Possible unsafe locking scenario:
[   52.525435]
[   52.526154]        CPU0
[   52.526460]        ----
[   52.526766]   lock(&dev_addr_list_lock_key/1);
[   52.527311]   lock(&dev_addr_list_lock_key/1);
[   52.527854]
[   52.527854]  *** DEADLOCK ***
[   52.527854]
[   52.528573]  May be due to missing lock nesting notation
[   52.528573]
[   52.529527] 5 locks held by ip/1005:
[   52.529968]  #0: 0000000080a68bb2 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[   52.530940]  #1: 0000000035d90450 (&team->lock){+.+.}, at: team_uninit+0x3a/0x1a0 [team]
[   52.531933]  #2: 00000000c75d8f70 (&dev_addr_list_lock_key){+...}, at: dev_uc_unsync+0x98/0x1b0
[   52.532991]  #3: 0000000025864f52 (&dev_addr_list_lock_key/1){+...}, at: dev_uc_unsync+0x10c/0x1b0
[   52.534142]  #4: 00000000efa4d642 (rcu_read_lock){....}, at: team_set_rx_mode+0x5/0x1d0 [team]
[   52.535195]
[   52.535195] stack backtrace:
[   52.535727] CPU: 0 PID: 1005 Comm: ip Not tainted 5.3.0-rc8+ #179
[   52.536376] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   52.537254] Call Trace:
[   52.537549]  dump_stack+0x7c/0xbb
[   52.537917]  __lock_acquire+0x26a9/0x3de0
[   52.538340]  ? register_lock_class+0x14d0/0x14d0
[   52.538872]  ? register_lock_class+0x14d0/0x14d0
[   52.539559]  lock_acquire+0x164/0x3b0
[   52.540043]  ? dev_uc_sync_multiple+0xfa/0x1a0
[   52.540663]  _raw_spin_lock_nested+0x2e/0x60
[   52.541241]  ? dev_uc_sync_multiple+0xfa/0x1a0
[   52.541867]  dev_uc_sync_multiple+0xfa/0x1a0
[   52.542435]  team_set_rx_mode+0xa9/0x1d0 [team]
[   52.543033]  dev_uc_unsync+0x151/0x1b0
[   52.543534]  team_port_del+0x304/0x790 [team]
[   52.544110]  team_uninit+0xb0/0x1a0 [team]
[   52.544653]  rollback_registered_many+0x728/0xda0
[   52.545271]  ? generic_xdp_install+0x310/0x310
[   52.545865]  ? check_chain_key+0x236/0x5d0
[   52.546425]  ? __nla_validate_parse+0x98/0x1ad0
[   52.547023]  unregister_netdevice_many.part.124+0x13/0x1b0
[   52.547741]  rtnl_delete_link+0xbc/0x100
[   52.548262]  ? rtnl_af_register+0xc0/0xc0
[   52.548793]  rtnl_dellink+0x30e/0x8a0
[ ... ]

Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - This patch is not changed
v1 -> v2 :
 - This patch is not changed

 drivers/net/team/team.c | 61 ++++++++++++++++++++++++++++++++++++++---
 include/linux/if_team.h |  5 ++++
 2 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index e8089def5a46..bfcd6ed57493 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -1607,6 +1607,34 @@ static const struct team_option team_options[] = {
 	},
 };
 
+static void team_dev_set_lockdep_one(struct net_device *dev,
+				     struct netdev_queue *txq,
+				     void *_unused)
+{
+	struct team *team = netdev_priv(dev);
+
+	lockdep_set_class(&txq->_xmit_lock, &team->xmit_lock_key);
+}
+
+static struct lock_class_key qdisc_tx_busylock_key;
+static struct lock_class_key qdisc_running_key;
+
+static void team_dev_set_lockdep_class(struct net_device *dev)
+{
+	struct team *team = netdev_priv(dev);
+
+	dev->qdisc_tx_busylock = &qdisc_tx_busylock_key;
+	dev->qdisc_running_key = &qdisc_running_key;
+
+	lockdep_register_key(&team->team_lock_key);
+	__mutex_init(&team->lock, "team->team_lock_key", &team->team_lock_key);
+
+	lockdep_register_key(&team->addr_lock_key);
+	lockdep_set_class(&dev->addr_list_lock, &team->addr_lock_key);
+
+	lockdep_register_key(&team->xmit_lock_key);
+	netdev_for_each_tx_queue(dev, team_dev_set_lockdep_one, NULL);
+}
 
 static int team_init(struct net_device *dev)
 {
@@ -1615,7 +1643,6 @@ static int team_init(struct net_device *dev)
 	int err;
 
 	team->dev = dev;
-	mutex_init(&team->lock);
 	team_set_no_mode(team);
 
 	team->pcpu_stats = netdev_alloc_pcpu_stats(struct team_pcpu_stats);
@@ -1642,7 +1669,7 @@ static int team_init(struct net_device *dev)
 		goto err_options_register;
 	netif_carrier_off(dev);
 
-	netdev_lockdep_set_classes(dev);
+	team_dev_set_lockdep_class(dev);
 
 	return 0;
 
@@ -1673,6 +1700,11 @@ static void team_uninit(struct net_device *dev)
 	team_queue_override_fini(team);
 	mutex_unlock(&team->lock);
 	netdev_change_features(dev);
+
+	lockdep_unregister_key(&team->team_lock_key);
+	lockdep_unregister_key(&team->addr_lock_key);
+	lockdep_unregister_key(&team->xmit_lock_key);
+
 }
 
 static void team_destructor(struct net_device *dev)
@@ -1967,6 +1999,23 @@ static int team_add_slave(struct net_device *dev, struct net_device *port_dev,
 	return err;
 }
 
+static void team_update_lock_key(struct net_device *dev)
+{
+	struct team *team = netdev_priv(dev);
+
+	lockdep_unregister_key(&team->team_lock_key);
+	lockdep_unregister_key(&team->addr_lock_key);
+	lockdep_unregister_key(&team->xmit_lock_key);
+
+	lockdep_register_key(&team->team_lock_key);
+	lockdep_register_key(&team->addr_lock_key);
+	lockdep_register_key(&team->xmit_lock_key);
+
+	lockdep_set_class(&team->lock, &team->team_lock_key);
+	lockdep_set_class(&dev->addr_list_lock, &team->addr_lock_key);
+	netdev_for_each_tx_queue(dev, team_dev_set_lockdep_one, NULL);
+}
+
 static int team_del_slave(struct net_device *dev, struct net_device *port_dev)
 {
 	struct team *team = netdev_priv(dev);
@@ -1976,8 +2025,12 @@ static int team_del_slave(struct net_device *dev, struct net_device *port_dev)
 	err = team_port_del(team, port_dev);
 	mutex_unlock(&team->lock);
 
-	if (!err)
-		netdev_change_features(dev);
+	if (err)
+		return err;
+
+	if (netif_is_team_master(port_dev))
+		team_update_lock_key(port_dev);
+	netdev_change_features(dev);
 
 	return err;
 }
diff --git a/include/linux/if_team.h b/include/linux/if_team.h
index 06faa066496f..9c97bb19ed34 100644
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -223,6 +223,11 @@ struct team {
 		atomic_t count_pending;
 		struct delayed_work dw;
 	} mcast_rejoin;
+
+	struct lock_class_key team_lock_key;
+	struct lock_class_key xmit_lock_key;
+	struct lock_class_key addr_lock_key;
+
 	long mode_priv[TEAM_MODE_PRIV_LONGS];
 };
 
-- 
2.17.1

[PATCH net v3 06/11] macsec: use dynamic lockdep key instead of subclass

[Taehee Yoo]

All macsec device has same lockdep key and subclass is initialized with
nest_level.
But actual nest_level value can be changed when a lower device is attached.
And at this moment, the subclass should be updated but it seems to be
unsafe.
So this patch makes macsec use dynamic lockdep key instead of the subclass.

Test commands:
    ip link add bond0 type bond
    ip link add dummy0 type dummy
    ip link add macsec0 link bond0 type macsec
    ip link add macsec1 link dummy0 type macsec
    ip link set bond0 mtu 1000
    ip link set macsec1 master bond0

    ip link set bond0 up
    ip link set macsec0 up
    ip link set dummy0 up
    ip link set macsec1 up

Splat looks like:
[   57.903193] WARNING: possible recursive locking detected
[   57.913011] 5.3.0-rc8+ #179 Not tainted
[   57.915008] --------------------------------------------
[   57.916707] ip/964 is trying to acquire lock:
[   57.917102] 000000007f1963bf (&macsec_netdev_addr_lock_key/1){+...}, at: dev_uc_sync_multiple+0xfa/0x1a0
[   57.918476]
[   57.918476] but task is already holding lock:
[   57.918996] 000000006f6fbc66 (&macsec_netdev_addr_lock_key/1){+...}, at: dev_set_rx_mode+0x19/0x30
[   57.919790]
[   57.919790] other info that might help us debug this:
[   57.920367]  Possible unsafe locking scenario:
[   57.920367]
[   57.920894]        CPU0
[   57.921119]        ----
[   57.921366]   lock(&macsec_netdev_addr_lock_key/1);
[   57.921813]   lock(&macsec_netdev_addr_lock_key/1);
[   57.922250]
[   57.922250]  *** DEADLOCK ***
[   57.922250]
[   57.924742]  May be due to missing lock nesting notation
[   57.924742]
[   57.925620] 4 locks held by ip/964:
[   57.926067]  #0: 00000000bf0ca196 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[   57.927070]  #1: 000000006f6fbc66 (&macsec_netdev_addr_lock_key/1){+...}, at: dev_set_rx_mode+0x19/0x30
[   57.928241]  #2: 00000000e5b874a1 (&dev_addr_list_lock_key/3){+...}, at: dev_mc_sync+0xfa/0x1a0
[   57.929851]  #3: 000000002c43dd91 (rcu_read_lock){....}, at: bond_set_rx_mode+0x5/0x3c0 [bonding]
[   57.930983]
[   57.930983] stack backtrace:
[   57.931582] CPU: 1 PID: 964 Comm: ip Not tainted 5.3.0-rc8+ #179
[   57.932439] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   57.935333] Call Trace:
[   57.935659]  dump_stack+0x7c/0xbb
[   57.936088]  __lock_acquire+0x26a9/0x3de0
[   57.936590]  ? register_lock_class+0x14d0/0x14d0
[   57.937694]  ? register_lock_class+0x14d0/0x14d0
[   57.938269]  lock_acquire+0x164/0x3b0
[   57.938734]  ? dev_uc_sync_multiple+0xfa/0x1a0
[   57.939291]  _raw_spin_lock_nested+0x2e/0x60
[   57.940112]  ? dev_uc_sync_multiple+0xfa/0x1a0
[   57.940672]  dev_uc_sync_multiple+0xfa/0x1a0
[   57.941730]  bond_set_rx_mode+0x269/0x3c0 [bonding]
[   57.942340]  ? bond_init+0x6f0/0x6f0 [bonding]
[   57.942895]  ? do_raw_spin_trylock+0xa9/0x170
[   57.943435]  dev_mc_sync+0x15a/0x1a0
[   57.943891]  macsec_dev_set_rx_mode+0x3a/0x50 [macsec]
[   57.944560]  dev_set_rx_mode+0x21/0x30
[   57.945051]  __dev_open+0x202/0x310
[ ... ]

Fixes: e20038724552 ("macsec: fix lockdep splats when nesting devices")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - This patch is not changed
v1 -> v2 :
 - This patch is not changed

 drivers/net/macsec.c | 37 ++++++++++++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 5 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 8f46aa1ddec0..25a4fc88145d 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -267,6 +267,8 @@ struct macsec_dev {
 	struct pcpu_secy_stats __percpu *stats;
 	struct list_head secys;
 	struct gro_cells gro_cells;
+	struct lock_class_key xmit_lock_key;
+	struct lock_class_key addr_lock_key;
 	unsigned int nest_level;
 };
 
@@ -2749,7 +2751,32 @@ static netdev_tx_t macsec_start_xmit(struct sk_buff *skb,
 
 #define MACSEC_FEATURES \
 	(NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST)
-static struct lock_class_key macsec_netdev_addr_lock_key;
+
+static void macsec_dev_set_lockdep_one(struct net_device *dev,
+				       struct netdev_queue *txq,
+				       void *_unused)
+{
+	struct macsec_dev *macsec = macsec_priv(dev);
+
+	lockdep_set_class(&txq->_xmit_lock, &macsec->xmit_lock_key);
+}
+
+static struct lock_class_key qdisc_tx_busylock_key;
+static struct lock_class_key qdisc_running_key;
+
+static void macsec_dev_set_lockdep_class(struct net_device *dev)
+{
+	struct macsec_dev *macsec = macsec_priv(dev);
+
+	dev->qdisc_tx_busylock = &qdisc_tx_busylock_key;
+	dev->qdisc_running_key = &qdisc_running_key;
+
+	lockdep_register_key(&macsec->addr_lock_key);
+	lockdep_set_class(&dev->addr_list_lock, &macsec->addr_lock_key);
+
+	lockdep_register_key(&macsec->xmit_lock_key);
+	netdev_for_each_tx_queue(dev, macsec_dev_set_lockdep_one, NULL);
+}
 
 static int macsec_dev_init(struct net_device *dev)
 {
@@ -2780,6 +2807,7 @@ static int macsec_dev_init(struct net_device *dev)
 	if (is_zero_ether_addr(dev->broadcast))
 		memcpy(dev->broadcast, real_dev->broadcast, dev->addr_len);
 
+	macsec_dev_set_lockdep_class(dev);
 	return 0;
 }
 
@@ -2789,6 +2817,9 @@ static void macsec_dev_uninit(struct net_device *dev)
 
 	gro_cells_destroy(&macsec->gro_cells);
 	free_percpu(dev->tstats);
+
+	lockdep_unregister_key(&macsec->addr_lock_key);
+	lockdep_unregister_key(&macsec->xmit_lock_key);
 }
 
 static netdev_features_t macsec_fix_features(struct net_device *dev,
@@ -3263,10 +3294,6 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 	dev_hold(real_dev);
 
 	macsec->nest_level = dev_get_nest_level(real_dev) + 1;
-	netdev_lockdep_set_classes(dev);
-	lockdep_set_class_and_subclass(&dev->addr_list_lock,
-				       &macsec_netdev_addr_lock_key,
-				       macsec_get_nest_level(dev));
 
 	err = netdev_upper_dev_link(real_dev, dev, extack);
 	if (err < 0)
-- 
2.17.1

[PATCH net v3 07/11] macvlan: use dynamic lockdep key instead of subclass

[Taehee Yoo]

All macvlan device has same lockdep key and subclass is initialized with
nest_level.
But actual nest_level value can be changed when a lower device is attached.
And at this moment, the subclass should be updated but it seems to be
unsafe.
So this patch makes macvlan use dynamic lockdep key instead of the
subclass.

Test commands:
    ip link add bond0 type bond
    ip link add dummy0 type dummy
    ip link add macvlan0 link bond0 type macvlan mode bridge
    ip link add macvlan1 link dummy0 type macvlan mode bridge
    ip link set bond0 mtu 1000
    ip link set macvlan1 master bond0

    ip link set bond0 up
    ip link set macvlan0 up
    ip link set dummy0 up
    ip link set macvlan1 up

Splat looks like:
[   55.694677] WARNING: possible recursive locking detected
[   55.695420] 5.3.0-rc8+ #179 Not tainted
[   55.709918] --------------------------------------------
[   55.711814] ip/982 is trying to acquire lock:
[   55.712387] 0000000023ca93f4 (&macvlan_netdev_addr_lock_key/1){+...}, at: dev_uc_sync_multiple+0xfa/0x1a0
[   55.713621]
[   55.713621] but task is already holding lock:
[   55.714364] 0000000070c93e9d (&macvlan_netdev_addr_lock_key/1){+...}, at: dev_set_rx_mode+0x19/0x30
[   55.715548]
[   55.715548] other info that might help us debug this:
[   55.716428]  Possible unsafe locking scenario:
[   55.716428]
[   55.717231]        CPU0
[   55.717563]        ----
[   55.717907]   lock(&macvlan_netdev_addr_lock_key/1);
[   55.718574]   lock(&macvlan_netdev_addr_lock_key/1);
[   55.719149]
[   55.719149]  *** DEADLOCK ***
[   55.719149]
[   55.719865]  May be due to missing lock nesting notation
[   55.719865]
[   55.720607] 4 locks held by ip/982:
[   55.721056]  #0: 0000000096ab2afb (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[   55.722031]  #1: 0000000070c93e9d (&macvlan_netdev_addr_lock_key/1){+...}, at: dev_set_rx_mode+0x19/0x30
[   55.791914]  #2: 000000005409683b (&dev_addr_list_lock_key/3){+...}, at: dev_uc_sync+0xfa/0x1a0
[   55.792718]  #3: 0000000085f78eaf (rcu_read_lock){....}, at: bond_set_rx_mode+0x5/0x3c0 [bonding]
[   55.793533]
[   55.793533] stack backtrace:
[   55.793939] CPU: 0 PID: 982 Comm: ip Not tainted 5.3.0-rc8+ #179
[   55.794489] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   55.795227] Call Trace:
[   55.795493]  dump_stack+0x7c/0xbb
[   55.795809]  __lock_acquire+0x26a9/0x3de0
[   55.796184]  ? register_lock_class+0x14d0/0x14d0
[   55.797496]  ? register_lock_class+0x14d0/0x14d0
[   55.797971]  lock_acquire+0x164/0x3b0
[   55.838601]  ? dev_uc_sync_multiple+0xfa/0x1a0
[   55.839281]  _raw_spin_lock_nested+0x2e/0x60
[   55.840289]  ? dev_uc_sync_multiple+0xfa/0x1a0
[   55.841308]  dev_uc_sync_multiple+0xfa/0x1a0
[   55.841868]  bond_set_rx_mode+0x269/0x3c0 [bonding]
[   55.842500]  ? bond_init+0x6f0/0x6f0 [bonding]
[   55.843076]  dev_uc_sync+0x15a/0x1a0
[   55.843567]  macvlan_set_mac_lists+0x55/0x110 [macvlan]
[   55.844247]  dev_set_rx_mode+0x21/0x30
[   55.844733]  __dev_open+0x202/0x310
[   55.845186]  ? dev_set_rx_mode+0x30/0x30
[   55.845707]  ? mark_held_locks+0xa5/0xe0
[   55.846219]  ? __local_bh_enable_ip+0xe9/0x1b0
[   55.846805]  __dev_change_flags+0x3c3/0x500
[   55.847376]  ? dev_set_allmulti+0x10/0x10
[   55.847906]  ? check_chain_key+0x236/0x5d0
[   55.848881]  dev_change_flags+0x7a/0x160
[   55.850015]  do_setlink+0xa49/0x2f40
[ ... ]

Fixes: c674ac30c549 ("macvlan: Fix lockdep warnings with stacked macvlan devices")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - This patch is not changed
v1 -> v2 :
 - This patch is not changed

 drivers/net/macvlan.c      | 35 +++++++++++++++++++++++++++--------
 include/linux/if_macvlan.h |  2 ++
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 940192c057b6..dae368a2e8d1 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -852,8 +852,6 @@ static int macvlan_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
  * "super class" of normal network devices; split their locks off into a
  * separate class since they always nest.
  */
-static struct lock_class_key macvlan_netdev_addr_lock_key;
-
 #define ALWAYS_ON_OFFLOADS \
 	(NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE | \
 	 NETIF_F_GSO_ROBUST | NETIF_F_GSO_ENCAP_ALL)
@@ -874,12 +872,30 @@ static int macvlan_get_nest_level(struct net_device *dev)
 	return ((struct macvlan_dev *)netdev_priv(dev))->nest_level;
 }
 
-static void macvlan_set_lockdep_class(struct net_device *dev)
+static void macvlan_dev_set_lockdep_one(struct net_device *dev,
+					struct netdev_queue *txq,
+					void *_unused)
+{
+	struct macvlan_dev *macvlan = netdev_priv(dev);
+
+	lockdep_set_class(&txq->_xmit_lock, &macvlan->xmit_lock_key);
+}
+
+static struct lock_class_key qdisc_tx_busylock_key;
+static struct lock_class_key qdisc_running_key;
+
+static void macvlan_dev_set_lockdep_class(struct net_device *dev)
 {
-	netdev_lockdep_set_classes(dev);
-	lockdep_set_class_and_subclass(&dev->addr_list_lock,
-				       &macvlan_netdev_addr_lock_key,
-				       macvlan_get_nest_level(dev));
+	struct macvlan_dev *macvlan = netdev_priv(dev);
+
+	dev->qdisc_tx_busylock = &qdisc_tx_busylock_key;
+	dev->qdisc_running_key = &qdisc_running_key;
+
+	lockdep_register_key(&macvlan->addr_lock_key);
+	lockdep_set_class(&dev->addr_list_lock, &macvlan->addr_lock_key);
+
+	lockdep_register_key(&macvlan->xmit_lock_key);
+	netdev_for_each_tx_queue(dev, macvlan_dev_set_lockdep_one, NULL);
 }
 
 static int macvlan_init(struct net_device *dev)
@@ -900,7 +916,7 @@ static int macvlan_init(struct net_device *dev)
 	dev->gso_max_segs	= lowerdev->gso_max_segs;
 	dev->hard_header_len	= lowerdev->hard_header_len;
 
-	macvlan_set_lockdep_class(dev);
+	macvlan_dev_set_lockdep_class(dev);
 
 	vlan->pcpu_stats = netdev_alloc_pcpu_stats(struct vlan_pcpu_stats);
 	if (!vlan->pcpu_stats)
@@ -922,6 +938,9 @@ static void macvlan_uninit(struct net_device *dev)
 	port->count -= 1;
 	if (!port->count)
 		macvlan_port_destroy(port->dev);
+
+	lockdep_unregister_key(&vlan->addr_lock_key);
+	lockdep_unregister_key(&vlan->xmit_lock_key);
 }
 
 static void macvlan_dev_get_stats64(struct net_device *dev,
diff --git a/include/linux/if_macvlan.h b/include/linux/if_macvlan.h
index 2e55e4cdbd8a..ea5b41823287 100644
--- a/include/linux/if_macvlan.h
+++ b/include/linux/if_macvlan.h
@@ -31,6 +31,8 @@ struct macvlan_dev {
 	u16			flags;
 	int			nest_level;
 	unsigned int		macaddr_count;
+	struct lock_class_key xmit_lock_key;
+	struct lock_class_key addr_lock_key;
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	struct netpoll		*netpoll;
 #endif
-- 
2.17.1

[PATCH net v3 08/11] macsec: fix refcnt leak in module exit routine

[Taehee Yoo]

When a macsec interface is created, it increases a refcnt to a lower
device(real device). when macsec interface is deleted, the refcnt is
decreased in macsec_free_netdev(), which is ->priv_destructor() of
macsec interface.

The problem scenario is this.
When nested macsec interfaces are exiting, the exit routine of the
macsec module makes refcnt leaks.

Test commands:
    ip link add dummy0 type dummy
    ip link add macsec0 link dummy0 type macsec
    ip link add macsec1 link macsec0 type macsec
    modprobe -rv macsec

[  208.629433] unregister_netdevice: waiting for macsec0 to become free. Usage count = 1

Steps of exit routine of macsec module are below.
1. Calls ->dellink() in __rtnl_link_unregister().
2. Checks refcnt and wait refcnt to be 0 if refcnt is not 0 in
netdev_run_todo().
3. Calls ->priv_destruvtor() in netdev_run_todo().

Step2 checks refcnt, but step3 decreases refcnt.
So, step2 waits forever.

This patch makes the macsec module do not hold a refcnt of the lower
device because it already holds a refcnt of the lower device with
netdev_upper_dev_link().

Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - This patch is not changed
v1 -> v2 :
 - This patch is not changed

 drivers/net/macsec.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 25a4fc88145d..41ec1ed0d545 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -3031,12 +3031,10 @@ static const struct nla_policy macsec_rtnl_policy[IFLA_MACSEC_MAX + 1] = {
 static void macsec_free_netdev(struct net_device *dev)
 {
 	struct macsec_dev *macsec = macsec_priv(dev);
-	struct net_device *real_dev = macsec->real_dev;
 
 	free_percpu(macsec->stats);
 	free_percpu(macsec->secy.tx_sc.stats);
 
-	dev_put(real_dev);
 }
 
 static void macsec_setup(struct net_device *dev)
@@ -3291,8 +3289,6 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 	if (err < 0)
 		return err;
 
-	dev_hold(real_dev);
-
 	macsec->nest_level = dev_get_nest_level(real_dev) + 1;
 
 	err = netdev_upper_dev_link(real_dev, dev, extack);
-- 
2.17.1

[PATCH net v3 09/11] net: core: add ignore flag to netdev_adjacent structure

[Taehee Yoo]

In order to link an adjacent node, netdev_upper_dev_link() is used
and in order to unlink an adjacent node, netdev_upper_dev_unlink() is used.
unlink operation does not fail, but link operation can fail.

In order to exchange adjacent nodes, we should unlink an old adjacent
node first. then, link a new adjacent node.
If link operation is failed, we should link an old adjacent node again.
But this link operation can fail too.
It eventually breaks the adjacent link relationship.

This patch adds an ignore flag into the netdev_adjacent structure.
If this flag is set, netdev_upper_dev_link() ignores an old adjacent
node for a moment.
So we can skip unlink operation before link operation.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - Modify nesting infra code to use iterator instead of recursive
v1 -> v2 :
 - This patch is not changed

 include/linux/netdevice.h |   4 +
 net/core/dev.c            | 180 ++++++++++++++++++++++++++++++++++----
 2 files changed, 166 insertions(+), 18 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 5bb5756129af..4506810c301b 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4319,6 +4319,10 @@ int netdev_master_upper_dev_link(struct net_device *dev,
 				 struct netlink_ext_ack *extack);
 void netdev_upper_dev_unlink(struct net_device *dev,
 			     struct net_device *upper_dev);
+void netdev_adjacent_dev_disable(struct net_device *upper_dev,
+				 struct net_device *lower_dev);
+void netdev_adjacent_dev_enable(struct net_device *upper_dev,
+				struct net_device *lower_dev);
 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname);
 void *netdev_lower_dev_get_private(struct net_device *dev,
 				   struct net_device *lower_dev);
diff --git a/net/core/dev.c b/net/core/dev.c
index fa847ea957ee..12d76b983064 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6448,6 +6448,9 @@ struct netdev_adjacent {
 	/* upper master flag, there can only be one master device per list */
 	bool master;
 
+	/* lookup ignore flag */
+	bool ignore;
+
 	/* counter for the number of times this device was added to us */
 	u16 ref_nr;
 
@@ -6553,6 +6556,22 @@ struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
 }
 EXPORT_SYMBOL(netdev_master_upper_dev_get);
 
+struct net_device *netdev_master_upper_dev_get_ignore(struct net_device *dev)
+{
+	struct netdev_adjacent *upper;
+
+	ASSERT_RTNL();
+
+	if (list_empty(&dev->adj_list.upper))
+		return NULL;
+
+	upper = list_first_entry(&dev->adj_list.upper,
+				 struct netdev_adjacent, list);
+	if (likely(upper->master) && !upper->ignore)
+		return upper->dev;
+	return NULL;
+}
+
 /**
  * netdev_has_any_lower_dev - Check if device is linked to some device
  * @dev: device
@@ -6603,8 +6622,9 @@ struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
 }
 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
 
-static struct net_device *netdev_next_upper_dev(struct net_device *dev,
-						struct list_head **iter)
+static struct net_device *netdev_next_upper_dev_ignore(struct net_device *dev,
+						       struct list_head **iter,
+						       bool *ignore)
 {
 	struct netdev_adjacent *upper;
 
@@ -6614,6 +6634,7 @@ static struct net_device *netdev_next_upper_dev(struct net_device *dev,
 		return NULL;
 
 	*iter = &upper->list;
+	*ignore = upper->ignore;
 
 	return upper->dev;
 }
@@ -6635,14 +6656,15 @@ static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
 	return upper->dev;
 }
 
-int netdev_walk_all_upper_dev(struct net_device *dev,
-			      int (*fn)(struct net_device *dev,
-					void *data),
-			      void *data)
+int netdev_walk_all_upper_dev_ignore(struct net_device *dev,
+				     int (*fn)(struct net_device *dev,
+					       void *data),
+				     void *data)
 {
 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
 	int ret, cur = 0;
+	bool ignore;
 
 	now = dev;
 	iter = &dev->adj_list.upper;
@@ -6656,9 +6678,12 @@ int netdev_walk_all_upper_dev(struct net_device *dev,
 
 		next = NULL;
 		while (1) {
-			udev = netdev_next_upper_dev(now, &iter);
+			udev = netdev_next_upper_dev_ignore(now, &iter,
+							    &ignore);
 			if (!udev)
 				break;
+			if (ignore)
+				continue;
 
 			if (!next) {
 				next = udev;
@@ -6735,6 +6760,15 @@ int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
 }
 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
 
+bool netdev_has_upper_dev_ignore(struct net_device *dev,
+				 struct net_device *upper_dev)
+{
+	ASSERT_RTNL();
+
+	return netdev_walk_all_upper_dev_ignore(dev, __netdev_has_upper_dev,
+						upper_dev);
+}
+
 /**
  * netdev_lower_get_next_private - Get the next ->private from the
  *				   lower neighbour list
@@ -6831,6 +6865,23 @@ static struct net_device *netdev_next_lower_dev(struct net_device *dev,
 	return lower->dev;
 }
 
+static struct net_device *netdev_next_lower_dev_ignore(struct net_device *dev,
+						       struct list_head **iter,
+						       bool *ignore)
+{
+	struct netdev_adjacent *lower;
+
+	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
+
+	if (&lower->list == &dev->adj_list.lower)
+		return NULL;
+
+	*iter = &lower->list;
+	*ignore = lower->ignore;
+
+	return lower->dev;
+}
+
 int netdev_walk_all_lower_dev(struct net_device *dev,
 			      int (*fn)(struct net_device *dev,
 					void *data),
@@ -6881,6 +6932,59 @@ int netdev_walk_all_lower_dev(struct net_device *dev,
 }
 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
 
+int netdev_walk_all_lower_dev_ignore(struct net_device *dev,
+				     int (*fn)(struct net_device *dev,
+					       void *data),
+				     void *data)
+{
+	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int ret, cur = 0;
+	bool ignore;
+
+	now = dev;
+	iter = &dev->adj_list.lower;
+
+	while (1) {
+		if (now != dev) {
+			ret = fn(now, data);
+			if (ret)
+				return ret;
+		}
+
+		next = NULL;
+		while (1) {
+			ldev = netdev_next_lower_dev_ignore(now, &iter,
+							    &ignore);
+			if (!ldev)
+				break;
+			if (ignore)
+				continue;
+
+			if (!next) {
+				next = ldev;
+				niter = &ldev->adj_list.lower;
+			} else {
+				dev_stack[cur] = ldev;
+				iter_stack[cur++] = &ldev->adj_list.lower;
+				break;
+			}
+		}
+
+		if (!next) {
+			if (!cur)
+				return 0;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
+	}
+
+	return 0;
+}
+
 static struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
 						    struct list_head **iter)
 {
@@ -6900,11 +7004,14 @@ static u8 __netdev_upper_depth(struct net_device *dev)
 	struct net_device *udev;
 	struct list_head *iter;
 	u8 max_depth = 0;
+	bool ignore;
 
 	for (iter = &dev->adj_list.upper,
-	     udev = netdev_next_upper_dev(dev, &iter);
+	     udev = netdev_next_upper_dev_ignore(dev, &iter, &ignore);
 	     udev;
-	     udev = netdev_next_upper_dev(dev, &iter)) {
+	     udev = netdev_next_upper_dev_ignore(dev, &iter, &ignore)) {
+		if (ignore)
+			continue;
 		if (max_depth < udev->upper_level)
 			max_depth = udev->upper_level;
 	}
@@ -6917,11 +7024,14 @@ static u8 __netdev_lower_depth(struct net_device *dev)
 	struct net_device *ldev;
 	struct list_head *iter;
 	u8 max_depth = 0;
+	bool ignore;
 
 	for (iter = &dev->adj_list.lower,
-	     ldev = netdev_next_lower_dev(dev, &iter);
+	     ldev = netdev_next_lower_dev_ignore(dev, &iter, &ignore);
 	     ldev;
-	     ldev = netdev_next_lower_dev(dev, &iter)) {
+	     ldev = netdev_next_lower_dev_ignore(dev, &iter, &ignore)) {
+		if (ignore)
+			continue;
 		if (max_depth < ldev->lower_level)
 			max_depth = ldev->lower_level;
 	}
@@ -7089,6 +7199,7 @@ static int __netdev_adjacent_dev_insert(struct net_device *dev,
 	adj->master = master;
 	adj->ref_nr = 1;
 	adj->private = private;
+	adj->ignore = false;
 	dev_hold(adj_dev);
 
 	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
@@ -7239,17 +7350,17 @@ static int __netdev_upper_dev_link(struct net_device *dev,
 		return -EBUSY;
 
 	/* To prevent loops, check if dev is not upper device to upper_dev. */
-	if (netdev_has_upper_dev(upper_dev, dev))
+	if (netdev_has_upper_dev_ignore(upper_dev, dev))
 		return -EBUSY;
 
 	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
 		return -EMLINK;
 
 	if (!master) {
-		if (netdev_has_upper_dev(dev, upper_dev))
+		if (netdev_has_upper_dev_ignore(dev, upper_dev))
 			return -EEXIST;
 	} else {
-		master_dev = netdev_master_upper_dev_get(dev);
+		master_dev = netdev_master_upper_dev_get_ignore(dev);
 		if (master_dev)
 			return master_dev == upper_dev ? -EEXIST : -EBUSY;
 	}
@@ -7272,10 +7383,12 @@ static int __netdev_upper_dev_link(struct net_device *dev,
 		goto rollback;
 
 	__netdev_update_upper_level(dev, NULL);
-	netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
+	netdev_walk_all_lower_dev_ignore(dev,
+					 __netdev_update_upper_level, NULL);
 
 	__netdev_update_lower_level(upper_dev, NULL);
-	netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level, NULL);
+	netdev_walk_all_upper_dev_ignore(upper_dev,
+					 __netdev_update_lower_level, NULL);
 
 	return 0;
 
@@ -7361,13 +7474,44 @@ void netdev_upper_dev_unlink(struct net_device *dev,
 				      &changeupper_info.info);
 
 	__netdev_update_upper_level(dev, NULL);
-	netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
+	netdev_walk_all_lower_dev_ignore(dev,
+					 __netdev_update_upper_level, NULL);
 
 	__netdev_update_lower_level(upper_dev, NULL);
-	netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level, NULL);
+	netdev_walk_all_upper_dev_ignore(upper_dev,
+					 __netdev_update_lower_level, NULL);
 }
 EXPORT_SYMBOL(netdev_upper_dev_unlink);
 
+void __netdev_adjacent_dev_set(struct net_device *upper_dev,
+			       struct net_device *lower_dev,
+			       bool val)
+{
+	struct netdev_adjacent *adj;
+
+	adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
+	if (adj)
+		adj->ignore = val;
+
+	adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
+	if (adj)
+		adj->ignore = val;
+}
+
+void netdev_adjacent_dev_disable(struct net_device *upper_dev,
+				 struct net_device *lower_dev)
+{
+	__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
+}
+EXPORT_SYMBOL(netdev_adjacent_dev_disable);
+
+void netdev_adjacent_dev_enable(struct net_device *upper_dev,
+				struct net_device *lower_dev)
+{
+	__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
+}
+EXPORT_SYMBOL(netdev_adjacent_dev_enable);
+
 /**
  * netdev_bonding_info_change - Dispatch event about slave change
  * @dev: device
-- 
2.17.1

Re: [PATCH net v3 09/11] net: core: add ignore flag to netdev_adjacent structure

[Jakub Kicinski]

On Mon, 16 Sep 2019 22:48:00 +0900, Taehee Yoo wrote:
> In order to link an adjacent node, netdev_upper_dev_link() is used
> and in order to unlink an adjacent node, netdev_upper_dev_unlink() is used.
> unlink operation does not fail, but link operation can fail.
> 
> In order to exchange adjacent nodes, we should unlink an old adjacent
> node first. then, link a new adjacent node.
> If link operation is failed, we should link an old adjacent node again.
> But this link operation can fail too.
> It eventually breaks the adjacent link relationship.
> 
> This patch adds an ignore flag into the netdev_adjacent structure.
> If this flag is set, netdev_upper_dev_link() ignores an old adjacent
> node for a moment.
> So we can skip unlink operation before link operation.
> 
> Signed-off-by: Taehee Yoo <ap420073@gmail.com>

I think there's a number of local functions here which are missing the
static keyword, we'll get a flurry of fixes as soon as we apply this.

Could you please take a look at fixing that, I think W=1 should help,
-Wmissing-prototypes in particular, if I'm remembering right.

Re: [PATCH net v3 09/11] net: core: add ignore flag to netdev_adjacent structure

[Jakub Kicinski]

On Mon, 16 Sep 2019 22:48:00 +0900, Taehee Yoo wrote:
> In order to link an adjacent node, netdev_upper_dev_link() is used
> and in order to unlink an adjacent node, netdev_upper_dev_unlink() is used.
> unlink operation does not fail, but link operation can fail.
> 
> In order to exchange adjacent nodes, we should unlink an old adjacent
> node first. then, link a new adjacent node.
> If link operation is failed, we should link an old adjacent node again.
> But this link operation can fail too.
> It eventually breaks the adjacent link relationship.
> 
> This patch adds an ignore flag into the netdev_adjacent structure.
> If this flag is set, netdev_upper_dev_link() ignores an old adjacent
> node for a moment.
> So we can skip unlink operation before link operation.
> 
> Signed-off-by: Taehee Yoo <ap420073@gmail.com>

Could this perhaps be achieved by creating prepare, commit, and abort
helpers? That would make the API look slightly more canonical.

netdev_adjacent_change_prepare(old, new, dev)
netdev_adjacent_change_commit(old, new, dev)
netdev_adjacent_change_abort(old, new, dev)

The current naming makes the operation a little harder to follow if one
is just reading the vxlan code.

Please let me know if I didn't read the code closely enough to
understand why that's not fitting here.

> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 5bb5756129af..4506810c301b 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -4319,6 +4319,10 @@ int netdev_master_upper_dev_link(struct net_device *dev,
>  				 struct netlink_ext_ack *extack);
>  void netdev_upper_dev_unlink(struct net_device *dev,
>  			     struct net_device *upper_dev);
> +void netdev_adjacent_dev_disable(struct net_device *upper_dev,
> +				 struct net_device *lower_dev);
> +void netdev_adjacent_dev_enable(struct net_device *upper_dev,
> +				struct net_device *lower_dev);
>  void netdev_adjacent_rename_links(struct net_device *dev, char *oldname);
>  void *netdev_lower_dev_get_private(struct net_device *dev,
>  				   struct net_device *lower_dev);

Re: [PATCH net v3 09/11] net: core: add ignore flag to netdev_adjacent structure

[Taehee Yoo]

On Sat, 21 Sep 2019 at 08:55, Jakub Kicinski
<jakub.kicinski@netronome.com> wrote:
>
> On Mon, 16 Sep 2019 22:48:00 +0900, Taehee Yoo wrote:
> > In order to link an adjacent node, netdev_upper_dev_link() is used
> > and in order to unlink an adjacent node, netdev_upper_dev_unlink() is used.
> > unlink operation does not fail, but link operation can fail.
> >
> > In order to exchange adjacent nodes, we should unlink an old adjacent
> > node first. then, link a new adjacent node.
> > If link operation is failed, we should link an old adjacent node again.
> > But this link operation can fail too.
> > It eventually breaks the adjacent link relationship.
> >
> > This patch adds an ignore flag into the netdev_adjacent structure.
> > If this flag is set, netdev_upper_dev_link() ignores an old adjacent
> > node for a moment.
> > So we can skip unlink operation before link operation.
> >
> > Signed-off-by: Taehee Yoo <ap420073@gmail.com>
>
> Could this perhaps be achieved by creating prepare, commit, and abort
> helpers? That would make the API look slightly more canonical.
>
> netdev_adjacent_change_prepare(old, new, dev)
> netdev_adjacent_change_commit(old, new, dev)
> netdev_adjacent_change_abort(old, new, dev)
>
> The current naming makes the operation a little harder to follow if one
> is just reading the vxlan code.
>

I fully agree with your opinion.
I will provide these three functions that you mentioned.
   netdev_adjacent_change_prepare
   netdev_adjacent_change_commit
   netdev_adjacent_change_abort

> Please let me know if I didn't read the code closely enough to
> understand why that's not fitting here.
>
> > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> > index 5bb5756129af..4506810c301b 100644
> > --- a/include/linux/netdevice.h
> > +++ b/include/linux/netdevice.h
> > @@ -4319,6 +4319,10 @@ int netdev_master_upper_dev_link(struct net_device *dev,
> >                                struct netlink_ext_ack *extack);
> >  void netdev_upper_dev_unlink(struct net_device *dev,
> >                            struct net_device *upper_dev);
> > +void netdev_adjacent_dev_disable(struct net_device *upper_dev,
> > +                              struct net_device *lower_dev);
> > +void netdev_adjacent_dev_enable(struct net_device *upper_dev,
> > +                             struct net_device *lower_dev);
> >  void netdev_adjacent_rename_links(struct net_device *dev, char *oldname);
> >  void *netdev_lower_dev_get_private(struct net_device *dev,
> >                                  struct net_device *lower_dev);

I found that I missed static keyword.
So I will fix this too.

Thank you!

[PATCH net v3 10/11] vxlan: add adjacent link to limit depth level

[Taehee Yoo]

Current vxlan code doesn't limit the number of nested devices.
Nested devices would be handled recursively and this routine needs
huge stack memory. So, unlimited nested devices could make
stack overflow.

In order to fix this issue, this patch adds adjacent links.
The adjacent link APIs internally check the depth level.

Test commands:
    ip link add dummy0 type dummy
    ip link add vxlan0 type vxlan id 0 group 239.1.1.1 dev dummy0 \
	    dstport 4789
    for i in {1..100}
    do
            let A=$i-1
            ip link add vxlan$i type vxlan id $i group 239.1.1.1 \
		    dev vxlan$A dstport 4789
    done
    ip link del dummy0

The top upper link is vxlan100 and the lowest link is vxlan0.
When vxlan0 is deleting, the upper devices will be deleted recursively.
It needs huge stack memory so it makes stack overflow.

Splat looks like:
[  229.628477] =============================================================================
[  229.629785] BUG page->ptl (Not tainted): Padding overwritten. 0x0000000026abf214-0x0000000091f6abb2
[  229.629785] -----------------------------------------------------------------------------
[  229.629785]
[  229.655439] ==================================================================
[  229.629785] INFO: Slab 0x00000000ff7cfda8 objects=19 used=19 fp=0x00000000fe33776c flags=0x200000000010200
[  229.655688] BUG: KASAN: stack-out-of-bounds in unmap_single_vma+0x25a/0x2e0
[  229.655688] Read of size 8 at addr ffff888113076928 by task vlan-network-in/2334
[  229.655688]
[  229.629785] Padding 0000000026abf214: 00 80 14 0d 81 88 ff ff 68 91 81 14 81 88 ff ff  ........h.......
[  229.629785] Padding 0000000001e24790: 38 91 81 14 81 88 ff ff 68 91 81 14 81 88 ff ff  8.......h.......
[  229.629785] Padding 00000000b39397c8: 33 30 62 a7 ff ff ff ff ff eb 60 22 10 f1 ff 1f  30b.......`"....
[  229.629785] Padding 00000000bc98f53a: 80 60 07 13 81 88 ff ff 00 80 14 0d 81 88 ff ff  .`..............
[  229.629785] Padding 000000002aa8123d: 68 91 81 14 81 88 ff ff f7 21 17 a7 ff ff ff ff  h........!......
[  229.629785] Padding 000000001c8c2369: 08 81 14 0d 81 88 ff ff 03 02 00 00 00 00 00 00  ................
[  229.629785] Padding 000000004e290c5d: 21 90 a2 21 10 ed ff ff 00 00 00 00 00 fc ff df  !..!............
[  229.629785] Padding 000000000e25d731: 18 60 07 13 81 88 ff ff c0 8b 13 05 81 88 ff ff  .`..............
[  229.629785] Padding 000000007adc7ab3: b3 8a b5 41 00 00 00 00                          ...A....
[  229.629785] FIX page->ptl: Restoring 0x0000000026abf214-0x0000000091f6abb2=0x5a
[  ... ]

Fixes: acaf4e70997f ("net: vxlan: when lower dev unregisters remove vxlan dev as well")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - This patch is not changed
v1 -> v2 :
 - This patch is not changed

 drivers/net/vxlan.c | 71 ++++++++++++++++++++++++++++++++++++++-------
 include/net/vxlan.h |  1 +
 2 files changed, 62 insertions(+), 10 deletions(-)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 3d9bcc957f7d..0d5c8d22d8a4 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -3567,6 +3567,8 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
 	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct vxlan_fdb *f = NULL;
+	struct net_device *remote_dev = NULL;
+	struct vxlan_rdst *dst = &vxlan->default_dst;
 	bool unregister = false;
 	int err;
 
@@ -3577,14 +3579,14 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
 	dev->ethtool_ops = &vxlan_ethtool_ops;
 
 	/* create an fdb entry for a valid default destination */
-	if (!vxlan_addr_any(&vxlan->default_dst.remote_ip)) {
+	if (!vxlan_addr_any(&dst->remote_ip)) {
 		err = vxlan_fdb_create(vxlan, all_zeros_mac,
-				       &vxlan->default_dst.remote_ip,
+				       &dst->remote_ip,
 				       NUD_REACHABLE | NUD_PERMANENT,
 				       vxlan->cfg.dst_port,
-				       vxlan->default_dst.remote_vni,
-				       vxlan->default_dst.remote_vni,
-				       vxlan->default_dst.remote_ifindex,
+				       dst->remote_vni,
+				       dst->remote_vni,
+				       dst->remote_ifindex,
 				       NTF_SELF, &f);
 		if (err)
 			return err;
@@ -3595,26 +3597,43 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
 		goto errout;
 	unregister = true;
 
+	if (dst->remote_ifindex) {
+		remote_dev = __dev_get_by_index(net, dst->remote_ifindex);
+		if (!remote_dev)
+			goto errout;
+
+		err = netdev_upper_dev_link(remote_dev, dev, extack);
+		if (err)
+			goto errout;
+	}
+
 	err = rtnl_configure_link(dev, NULL);
 	if (err)
-		goto errout;
+		goto unlink;
 
 	if (f) {
-		vxlan_fdb_insert(vxlan, all_zeros_mac,
-				 vxlan->default_dst.remote_vni, f);
+		vxlan_fdb_insert(vxlan, all_zeros_mac, dst->remote_vni, f);
 
 		/* notify default fdb entry */
 		err = vxlan_fdb_notify(vxlan, f, first_remote_rtnl(f),
 				       RTM_NEWNEIGH, true, extack);
 		if (err) {
 			vxlan_fdb_destroy(vxlan, f, false, false);
+			if (remote_dev)
+				netdev_upper_dev_unlink(remote_dev, dev);
 			goto unregister;
 		}
 	}
 
 	list_add(&vxlan->next, &vn->vxlan_list);
+	if (remote_dev) {
+		dst->remote_dev = remote_dev;
+		dev_hold(remote_dev);
+	}
 	return 0;
-
+unlink:
+	if (remote_dev)
+		netdev_upper_dev_unlink(remote_dev, dev);
 errout:
 	/* unregister_netdevice() destroys the default FDB entry with deletion
 	 * notification. But the addition notification was not sent yet, so
@@ -3936,6 +3955,8 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 	struct net_device *lowerdev;
 	struct vxlan_config conf;
 	int err;
+	bool linked = false;
+	bool disabled = false;
 
 	err = vxlan_nl2conf(tb, data, dev, &conf, true, extack);
 	if (err)
@@ -3946,6 +3967,16 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 	if (err)
 		return err;
 
+	if (lowerdev) {
+		if (dst->remote_dev && lowerdev != dst->remote_dev) {
+			netdev_adjacent_dev_disable(dst->remote_dev, dev);
+			disabled = true;
+		}
+		err = netdev_upper_dev_link(lowerdev, dev, extack);
+		if (err)
+			goto err;
+		linked = true;
+	}
 	/* handle default dst entry */
 	if (!vxlan_addr_equal(&conf.remote_ip, &dst->remote_ip)) {
 		u32 hash_index = fdb_head_index(vxlan, all_zeros_mac, conf.vni);
@@ -3962,7 +3993,7 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 					       NTF_SELF, true, extack);
 			if (err) {
 				spin_unlock_bh(&vxlan->hash_lock[hash_index]);
-				return err;
+				goto err;
 			}
 		}
 		if (!vxlan_addr_any(&dst->remote_ip))
@@ -3979,8 +4010,24 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 	if (conf.age_interval != vxlan->cfg.age_interval)
 		mod_timer(&vxlan->age_timer, jiffies);
 
+	if (disabled) {
+		netdev_adjacent_dev_enable(dst->remote_dev, dev);
+		netdev_upper_dev_unlink(dst->remote_dev, dev);
+		dev_put(dst->remote_dev);
+	}
+	if (linked) {
+		dst->remote_dev = lowerdev;
+		dev_hold(dst->remote_dev);
+	}
+
 	vxlan_config_apply(dev, &conf, lowerdev, vxlan->net, true);
 	return 0;
+err:
+	if (linked)
+		netdev_upper_dev_unlink(lowerdev, dev);
+	if (disabled)
+		netdev_adjacent_dev_enable(dst->remote_dev, dev);
+	return err;
 }
 
 static void vxlan_dellink(struct net_device *dev, struct list_head *head)
@@ -3991,6 +4038,10 @@ static void vxlan_dellink(struct net_device *dev, struct list_head *head)
 
 	list_del(&vxlan->next);
 	unregister_netdevice_queue(dev, head);
+	if (vxlan->default_dst.remote_dev) {
+		netdev_upper_dev_unlink(vxlan->default_dst.remote_dev, dev);
+		dev_put(vxlan->default_dst.remote_dev);
+	}
 }
 
 static size_t vxlan_get_size(const struct net_device *dev)
diff --git a/include/net/vxlan.h b/include/net/vxlan.h
index dc1583a1fb8a..08e237d7aa73 100644
--- a/include/net/vxlan.h
+++ b/include/net/vxlan.h
@@ -197,6 +197,7 @@ struct vxlan_rdst {
 	u8			 offloaded:1;
 	__be32			 remote_vni;
 	u32			 remote_ifindex;
+	struct net_device	 *remote_dev;
 	struct list_head	 list;
 	struct rcu_head		 rcu;
 	struct dst_cache	 dst_cache;
-- 
2.17.1

Re: [PATCH net v3 10/11] vxlan: add adjacent link to limit depth level

[Jakub Kicinski]

On Mon, 16 Sep 2019 22:48:01 +0900, Taehee Yoo wrote:
> Current vxlan code doesn't limit the number of nested devices.
> Nested devices would be handled recursively and this routine needs
> huge stack memory. So, unlimited nested devices could make
> stack overflow.
> 
> In order to fix this issue, this patch adds adjacent links.
> The adjacent link APIs internally check the depth level.

> Fixes: acaf4e70997f ("net: vxlan: when lower dev unregisters remove vxlan dev as well")
> Signed-off-by: Taehee Yoo <ap420073@gmail.com>

Minor nit picks here, I hope you don't mind.

> diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
> index 3d9bcc957f7d..0d5c8d22d8a4 100644
> --- a/drivers/net/vxlan.c
> +++ b/drivers/net/vxlan.c
> @@ -3567,6 +3567,8 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
>  	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
>  	struct vxlan_dev *vxlan = netdev_priv(dev);
>  	struct vxlan_fdb *f = NULL;
> +	struct net_device *remote_dev = NULL;
> +	struct vxlan_rdst *dst = &vxlan->default_dst;

Especially in places where reverse christmas tree variable ordering is
adhered to, could you please preserve it? That'd mean:

	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
	struct vxlan_dev *vxlan = netdev_priv(dev);
	struct net_device *remote_dev = NULL;
	struct vxlan_fdb *f = NULL;
	bool unregister = false;
	struct vxlan_rdst *dst;
	int err;

	dst = &vxlan->default_dst;

here.

>  	bool unregister = false;
>  	int err;
>  
> @@ -3577,14 +3579,14 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
>  	dev->ethtool_ops = &vxlan_ethtool_ops;
>  
>  	/* create an fdb entry for a valid default destination */
> -	if (!vxlan_addr_any(&vxlan->default_dst.remote_ip)) {
> +	if (!vxlan_addr_any(&dst->remote_ip)) {
>  		err = vxlan_fdb_create(vxlan, all_zeros_mac,
> -				       &vxlan->default_dst.remote_ip,
> +				       &dst->remote_ip,
>  				       NUD_REACHABLE | NUD_PERMANENT,
>  				       vxlan->cfg.dst_port,
> -				       vxlan->default_dst.remote_vni,
> -				       vxlan->default_dst.remote_vni,
> -				       vxlan->default_dst.remote_ifindex,
> +				       dst->remote_vni,
> +				       dst->remote_vni,
> +				       dst->remote_ifindex,
>  				       NTF_SELF, &f);
>  		if (err)
>  			return err;
> @@ -3595,26 +3597,43 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
>  		goto errout;
>  	unregister = true;
>  
> +	if (dst->remote_ifindex) {
> +		remote_dev = __dev_get_by_index(net, dst->remote_ifindex);
> +		if (!remote_dev)
> +			goto errout;
> +
> +		err = netdev_upper_dev_link(remote_dev, dev, extack);
> +		if (err)
> +			goto errout;
> +	}
> +
>  	err = rtnl_configure_link(dev, NULL);
>  	if (err)
> -		goto errout;
> +		goto unlink;
>  
>  	if (f) {
> -		vxlan_fdb_insert(vxlan, all_zeros_mac,
> -				 vxlan->default_dst.remote_vni, f);
> +		vxlan_fdb_insert(vxlan, all_zeros_mac, dst->remote_vni, f);
>  
>  		/* notify default fdb entry */
>  		err = vxlan_fdb_notify(vxlan, f, first_remote_rtnl(f),
>  				       RTM_NEWNEIGH, true, extack);
>  		if (err) {
>  			vxlan_fdb_destroy(vxlan, f, false, false);
> +			if (remote_dev)
> +				netdev_upper_dev_unlink(remote_dev, dev);
>  			goto unregister;
>  		}
>  	}
>  
>  	list_add(&vxlan->next, &vn->vxlan_list);
> +	if (remote_dev) {
> +		dst->remote_dev = remote_dev;
> +		dev_hold(remote_dev);
> +	}
>  	return 0;
> -
> +unlink:
> +	if (remote_dev)
> +		netdev_upper_dev_unlink(remote_dev, dev);
>  errout:
>  	/* unregister_netdevice() destroys the default FDB entry with deletion
>  	 * notification. But the addition notification was not sent yet, so
> @@ -3936,6 +3955,8 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
>  	struct net_device *lowerdev;
>  	struct vxlan_config conf;
>  	int err;
> +	bool linked = false;
> +	bool disabled = false;

Same here.

>  	err = vxlan_nl2conf(tb, data, dev, &conf, true, extack);
>  	if (err)
> @@ -3946,6 +3967,16 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
>  	if (err)
>  		return err;
>  
> +	if (lowerdev) {
> +		if (dst->remote_dev && lowerdev != dst->remote_dev) {
> +			netdev_adjacent_dev_disable(dst->remote_dev, dev);
> +			disabled = true;
> +		}
> +		err = netdev_upper_dev_link(lowerdev, dev, extack);
> +		if (err)
> +			goto err;

would you mind naming the label errout? there is an err variable, and
other places in this file use errout

> +		linked = true;
> +	}
>  	/* handle default dst entry */
>  	if (!vxlan_addr_equal(&conf.remote_ip, &dst->remote_ip)) {
>  		u32 hash_index = fdb_head_index(vxlan, all_zeros_mac, conf.vni);
> @@ -3962,7 +3993,7 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
>  					       NTF_SELF, true, extack);
>  			if (err) {
>  				spin_unlock_bh(&vxlan->hash_lock[hash_index]);
> -				return err;
> +				goto err;
>  			}
>  		}
>  		if (!vxlan_addr_any(&dst->remote_ip))
> @@ -3979,8 +4010,24 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
>  	if (conf.age_interval != vxlan->cfg.age_interval)
>  		mod_timer(&vxlan->age_timer, jiffies);
>  
> +	if (disabled) {
> +		netdev_adjacent_dev_enable(dst->remote_dev, dev);
> +		netdev_upper_dev_unlink(dst->remote_dev, dev);
> +		dev_put(dst->remote_dev);
> +	}
> +	if (linked) {
> +		dst->remote_dev = lowerdev;
> +		dev_hold(dst->remote_dev);
> +	}
> +
>  	vxlan_config_apply(dev, &conf, lowerdev, vxlan->net, true);
>  	return 0;
> +err:
> +	if (linked)
> +		netdev_upper_dev_unlink(lowerdev, dev);
> +	if (disabled)
> +		netdev_adjacent_dev_enable(dst->remote_dev, dev);
> +	return err;
>  }
>  
>  static void vxlan_dellink(struct net_device *dev, struct list_head *head)
> @@ -3991,6 +4038,10 @@ static void vxlan_dellink(struct net_device *dev, struct list_head *head)
>  
>  	list_del(&vxlan->next);
>  	unregister_netdevice_queue(dev, head);
> +	if (vxlan->default_dst.remote_dev) {
> +		netdev_upper_dev_unlink(vxlan->default_dst.remote_dev, dev);
> +		dev_put(vxlan->default_dst.remote_dev);
> +	}
>  }
>  
>  static size_t vxlan_get_size(const struct net_device *dev)
> diff --git a/include/net/vxlan.h b/include/net/vxlan.h
> index dc1583a1fb8a..08e237d7aa73 100644
> --- a/include/net/vxlan.h
> +++ b/include/net/vxlan.h
> @@ -197,6 +197,7 @@ struct vxlan_rdst {
>  	u8			 offloaded:1;
>  	__be32			 remote_vni;
>  	u32			 remote_ifindex;
> +	struct net_device	 *remote_dev;
>  	struct list_head	 list;
>  	struct rcu_head		 rcu;
>  	struct dst_cache	 dst_cache;

Re: [PATCH net v3 10/11] vxlan: add adjacent link to limit depth level

[Taehee Yoo]

On Sat, 21 Sep 2019 at 08:48, Jakub Kicinski
<jakub.kicinski@netronome.com> wrote:
>

Hi Jakub,
Thank you so much for your detailed review!

> On Mon, 16 Sep 2019 22:48:01 +0900, Taehee Yoo wrote:
> > Current vxlan code doesn't limit the number of nested devices.
> > Nested devices would be handled recursively and this routine needs
> > huge stack memory. So, unlimited nested devices could make
> > stack overflow.
> >
> > In order to fix this issue, this patch adds adjacent links.
> > The adjacent link APIs internally check the depth level.
>
> > Fixes: acaf4e70997f ("net: vxlan: when lower dev unregisters remove vxlan dev as well")
> > Signed-off-by: Taehee Yoo <ap420073@gmail.com>
>
> Minor nit picks here, I hope you don't mind.
>
> > diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
> > index 3d9bcc957f7d..0d5c8d22d8a4 100644
> > --- a/drivers/net/vxlan.c
> > +++ b/drivers/net/vxlan.c
> > @@ -3567,6 +3567,8 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
> >       struct vxlan_net *vn = net_generic(net, vxlan_net_id);
> >       struct vxlan_dev *vxlan = netdev_priv(dev);
> >       struct vxlan_fdb *f = NULL;
> > +     struct net_device *remote_dev = NULL;
> > +     struct vxlan_rdst *dst = &vxlan->default_dst;
>
> Especially in places where reverse christmas tree variable ordering is
> adhered to, could you please preserve it? That'd mean:
>
>         struct vxlan_net *vn = net_generic(net, vxlan_net_id);
>         struct vxlan_dev *vxlan = netdev_priv(dev);
>         struct net_device *remote_dev = NULL;
>         struct vxlan_fdb *f = NULL;
>         bool unregister = false;
>         struct vxlan_rdst *dst;
>         int err;
>
>         dst = &vxlan->default_dst;
>
> here.
>
> >       bool unregister = false;
> >       int err;
> >
> > @@ -3577,14 +3579,14 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
> >       dev->ethtool_ops = &vxlan_ethtool_ops;
> >
> >       /* create an fdb entry for a valid default destination */
> > -     if (!vxlan_addr_any(&vxlan->default_dst.remote_ip)) {
> > +     if (!vxlan_addr_any(&dst->remote_ip)) {
> >               err = vxlan_fdb_create(vxlan, all_zeros_mac,
> > -                                    &vxlan->default_dst.remote_ip,
> > +                                    &dst->remote_ip,
> >                                      NUD_REACHABLE | NUD_PERMANENT,
> >                                      vxlan->cfg.dst_port,
> > -                                    vxlan->default_dst.remote_vni,
> > -                                    vxlan->default_dst.remote_vni,
> > -                                    vxlan->default_dst.remote_ifindex,
> > +                                    dst->remote_vni,
> > +                                    dst->remote_vni,
> > +                                    dst->remote_ifindex,
> >                                      NTF_SELF, &f);
> >               if (err)
> >                       return err;
> > @@ -3595,26 +3597,43 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
> >               goto errout;
> >       unregister = true;
> >
> > +     if (dst->remote_ifindex) {
> > +             remote_dev = __dev_get_by_index(net, dst->remote_ifindex);
> > +             if (!remote_dev)
> > +                     goto errout;
> > +
> > +             err = netdev_upper_dev_link(remote_dev, dev, extack);
> > +             if (err)
> > +                     goto errout;
> > +     }
> > +
> >       err = rtnl_configure_link(dev, NULL);
> >       if (err)
> > -             goto errout;
> > +             goto unlink;
> >
> >       if (f) {
> > -             vxlan_fdb_insert(vxlan, all_zeros_mac,
> > -                              vxlan->default_dst.remote_vni, f);
> > +             vxlan_fdb_insert(vxlan, all_zeros_mac, dst->remote_vni, f);
> >
> >               /* notify default fdb entry */
> >               err = vxlan_fdb_notify(vxlan, f, first_remote_rtnl(f),
> >                                      RTM_NEWNEIGH, true, extack);
> >               if (err) {
> >                       vxlan_fdb_destroy(vxlan, f, false, false);
> > +                     if (remote_dev)
> > +                             netdev_upper_dev_unlink(remote_dev, dev);
> >                       goto unregister;
> >               }
> >       }
> >
> >       list_add(&vxlan->next, &vn->vxlan_list);
> > +     if (remote_dev) {
> > +             dst->remote_dev = remote_dev;
> > +             dev_hold(remote_dev);
> > +     }
> >       return 0;
> > -
> > +unlink:
> > +     if (remote_dev)
> > +             netdev_upper_dev_unlink(remote_dev, dev);
> >  errout:
> >       /* unregister_netdevice() destroys the default FDB entry with deletion
> >        * notification. But the addition notification was not sent yet, so
> > @@ -3936,6 +3955,8 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
> >       struct net_device *lowerdev;
> >       struct vxlan_config conf;
> >       int err;
> > +     bool linked = false;
> > +     bool disabled = false;
>
> Same here.
>
> >       err = vxlan_nl2conf(tb, data, dev, &conf, true, extack);
> >       if (err)
> > @@ -3946,6 +3967,16 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
> >       if (err)
> >               return err;
> >
> > +     if (lowerdev) {
> > +             if (dst->remote_dev && lowerdev != dst->remote_dev) {
> > +                     netdev_adjacent_dev_disable(dst->remote_dev, dev);
> > +                     disabled = true;
> > +             }
> > +             err = netdev_upper_dev_link(lowerdev, dev, extack);
> > +             if (err)
> > +                     goto err;
>
> would you mind naming the label errout? there is an err variable, and
> other places in this file use errout
>
> > +             linked = true;
> > +     }
> >       /* handle default dst entry */
> >       if (!vxlan_addr_equal(&conf.remote_ip, &dst->remote_ip)) {
> >               u32 hash_index = fdb_head_index(vxlan, all_zeros_mac, conf.vni);
> > @@ -3962,7 +3993,7 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
> >                                              NTF_SELF, true, extack);
> >                       if (err) {
> >                               spin_unlock_bh(&vxlan->hash_lock[hash_index]);
> > -                             return err;
> > +                             goto err;
> >                       }
> >               }
> >               if (!vxlan_addr_any(&dst->remote_ip))
> > @@ -3979,8 +4010,24 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
> >       if (conf.age_interval != vxlan->cfg.age_interval)
> >               mod_timer(&vxlan->age_timer, jiffies);
> >
> > +     if (disabled) {
> > +             netdev_adjacent_dev_enable(dst->remote_dev, dev);
> > +             netdev_upper_dev_unlink(dst->remote_dev, dev);
> > +             dev_put(dst->remote_dev);
> > +     }
> > +     if (linked) {
> > +             dst->remote_dev = lowerdev;
> > +             dev_hold(dst->remote_dev);
> > +     }
> > +
> >       vxlan_config_apply(dev, &conf, lowerdev, vxlan->net, true);
> >       return 0;
> > +err:
> > +     if (linked)
> > +             netdev_upper_dev_unlink(lowerdev, dev);
> > +     if (disabled)
> > +             netdev_adjacent_dev_enable(dst->remote_dev, dev);
> > +     return err;
> >  }
> >
> >  static void vxlan_dellink(struct net_device *dev, struct list_head *head)
> > @@ -3991,6 +4038,10 @@ static void vxlan_dellink(struct net_device *dev, struct list_head *head)
> >
> >       list_del(&vxlan->next);
> >       unregister_netdevice_queue(dev, head);
> > +     if (vxlan->default_dst.remote_dev) {
> > +             netdev_upper_dev_unlink(vxlan->default_dst.remote_dev, dev);
> > +             dev_put(vxlan->default_dst.remote_dev);
> > +     }
> >  }
> >
> >  static size_t vxlan_get_size(const struct net_device *dev)
> > diff --git a/include/net/vxlan.h b/include/net/vxlan.h
> > index dc1583a1fb8a..08e237d7aa73 100644
> > --- a/include/net/vxlan.h
> > +++ b/include/net/vxlan.h
> > @@ -197,6 +197,7 @@ struct vxlan_rdst {
> >       u8                       offloaded:1;
> >       __be32                   remote_vni;
> >       u32                      remote_ifindex;
> > +     struct net_device        *remote_dev;
> >       struct list_head         list;
> >       struct rcu_head          rcu;
> >       struct dst_cache         dst_cache;
>

Thank you for letting me know about "reverse christmas tree variable ordering".
I will send a v4 patch that will include things that you mentioned.

Thank you!

[PATCH net v3 11/11] net: remove unnecessary variables and callback

[Taehee Yoo]

This patch removes variables and callback these are related to the nested
device structure.
devices that can be nested have their own nest_level variable that
represents the depth of nested devices.
In the previous patch, new {lower/upper}_level variables are added and
they replace old private nest_level variable.
So, this patch removes all 'nest_level' variables.

In order to avoid lockdep warning, ->ndo_get_lock_subclass() was added
to get lockdep subclass value, which is actually lower nested depth value.
But now, they use the dynamic lockdep key to avoid lockdep warning instead
of the subclass.
So, this patch removes ->ndo_get_lock_subclass() callback.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2 -> v3 :
 - This patch is not changed
v1 -> v2 :
 - This patch is not changed

 drivers/net/bonding/bond_alb.c                |  2 +-
 drivers/net/bonding/bond_main.c               | 14 -------------
 .../net/ethernet/mellanox/mlx5/core/en_tc.c   |  2 +-
 drivers/net/macsec.c                          |  9 ---------
 drivers/net/macvlan.c                         |  7 -------
 include/linux/if_macvlan.h                    |  1 -
 include/linux/if_vlan.h                       | 12 -----------
 include/linux/netdevice.h                     | 12 -----------
 include/net/bonding.h                         |  1 -
 net/8021q/vlan.c                              |  1 -
 net/8021q/vlan_dev.c                          |  6 ------
 net/core/dev.c                                | 20 -------------------
 net/core/dev_addr_lists.c                     | 12 +++++------
 net/smc/smc_core.c                            |  2 +-
 net/smc/smc_pnet.c                            |  2 +-
 15 files changed, 10 insertions(+), 93 deletions(-)

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 8c79bad2a9a5..4f2e6910c623 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -952,7 +952,7 @@ static int alb_upper_dev_walk(struct net_device *upper, void *_data)
 	struct bond_vlan_tag *tags;
 
 	if (is_vlan_dev(upper) &&
-	    bond->nest_level == vlan_get_encap_level(upper) - 1) {
+	    bond->dev->lower_level == upper->lower_level - 1) {
 		if (upper->addr_assign_type == NET_ADDR_STOLEN) {
 			alb_send_lp_vid(slave, mac_addr,
 					vlan_dev_vlan_proto(upper),
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 7f574e74ed78..69eb61466fbe 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1733,8 +1733,6 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
 		goto err_upper_unlink;
 	}
 
-	bond->nest_level = dev_get_nest_level(bond_dev) + 1;
-
 	/* If the mode uses primary, then the following is handled by
 	 * bond_change_active_slave().
 	 */
@@ -1983,9 +1981,6 @@ static int __bond_release_one(struct net_device *bond_dev,
 	if (!bond_has_slaves(bond)) {
 		bond_set_carrier(bond);
 		eth_hw_addr_random(bond_dev);
-		bond->nest_level = SINGLE_DEPTH_NESTING;
-	} else {
-		bond->nest_level = dev_get_nest_level(bond_dev) + 1;
 	}
 
 	unblock_netpoll_tx();
@@ -3472,13 +3467,6 @@ static void bond_fold_stats(struct rtnl_link_stats64 *_res,
 	}
 }
 
-static int bond_get_nest_level(struct net_device *bond_dev)
-{
-	struct bonding *bond = netdev_priv(bond_dev);
-
-	return bond->nest_level;
-}
-
 static void bond_get_stats(struct net_device *bond_dev,
 			   struct rtnl_link_stats64 *stats)
 {
@@ -4298,7 +4286,6 @@ static const struct net_device_ops bond_netdev_ops = {
 	.ndo_neigh_setup	= bond_neigh_setup,
 	.ndo_vlan_rx_add_vid	= bond_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid	= bond_vlan_rx_kill_vid,
-	.ndo_get_lock_subclass  = bond_get_nest_level,
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_netpoll_setup	= bond_netpoll_setup,
 	.ndo_netpoll_cleanup	= bond_netpoll_cleanup,
@@ -4822,7 +4809,6 @@ static int bond_init(struct net_device *bond_dev)
 	if (!bond->wq)
 		return -ENOMEM;
 
-	bond->nest_level = SINGLE_DEPTH_NESTING;
 	bond_dev_set_lockdep_class(bond_dev);
 	list_add_tail(&bond->bond_list, &bn->dev_list);
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 00b2d4a86159..e056f9aad8df 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -2797,7 +2797,7 @@ static int add_vlan_pop_action(struct mlx5e_priv *priv,
 			       struct mlx5_esw_flow_attr *attr,
 			       u32 *action)
 {
-	int nest_level = vlan_get_encap_level(attr->parse_attr->filter_dev);
+	int nest_level = attr->parse_attr->filter_dev->lower_level;
 	struct flow_action_entry vlan_act = {
 		.id = FLOW_ACTION_VLAN_POP,
 	};
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 41ec1ed0d545..c0cb595f2bba 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -269,7 +269,6 @@ struct macsec_dev {
 	struct gro_cells gro_cells;
 	struct lock_class_key xmit_lock_key;
 	struct lock_class_key addr_lock_key;
-	unsigned int nest_level;
 };
 
 /**
@@ -2988,11 +2987,6 @@ static int macsec_get_iflink(const struct net_device *dev)
 	return macsec_priv(dev)->real_dev->ifindex;
 }
 
-static int macsec_get_nest_level(struct net_device *dev)
-{
-	return macsec_priv(dev)->nest_level;
-}
-
 static const struct net_device_ops macsec_netdev_ops = {
 	.ndo_init		= macsec_dev_init,
 	.ndo_uninit		= macsec_dev_uninit,
@@ -3006,7 +3000,6 @@ static const struct net_device_ops macsec_netdev_ops = {
 	.ndo_start_xmit		= macsec_start_xmit,
 	.ndo_get_stats64	= macsec_get_stats64,
 	.ndo_get_iflink		= macsec_get_iflink,
-	.ndo_get_lock_subclass  = macsec_get_nest_level,
 };
 
 static const struct device_type macsec_type = {
@@ -3289,8 +3282,6 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 	if (err < 0)
 		return err;
 
-	macsec->nest_level = dev_get_nest_level(real_dev) + 1;
-
 	err = netdev_upper_dev_link(real_dev, dev, extack);
 	if (err < 0)
 		goto unregister;
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index dae368a2e8d1..2c14bc606514 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -867,11 +867,6 @@ static int macvlan_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 #define MACVLAN_STATE_MASK \
 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
 
-static int macvlan_get_nest_level(struct net_device *dev)
-{
-	return ((struct macvlan_dev *)netdev_priv(dev))->nest_level;
-}
-
 static void macvlan_dev_set_lockdep_one(struct net_device *dev,
 					struct netdev_queue *txq,
 					void *_unused)
@@ -1180,7 +1175,6 @@ static const struct net_device_ops macvlan_netdev_ops = {
 	.ndo_fdb_add		= macvlan_fdb_add,
 	.ndo_fdb_del		= macvlan_fdb_del,
 	.ndo_fdb_dump		= ndo_dflt_fdb_dump,
-	.ndo_get_lock_subclass  = macvlan_get_nest_level,
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_poll_controller	= macvlan_dev_poll_controller,
 	.ndo_netpoll_setup	= macvlan_dev_netpoll_setup,
@@ -1464,7 +1458,6 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
 	vlan->dev      = dev;
 	vlan->port     = port;
 	vlan->set_features = MACVLAN_FEATURES;
-	vlan->nest_level = dev_get_nest_level(lowerdev) + 1;
 
 	vlan->mode     = MACVLAN_MODE_VEPA;
 	if (data && data[IFLA_MACVLAN_MODE])
diff --git a/include/linux/if_macvlan.h b/include/linux/if_macvlan.h
index ea5b41823287..e9202edcf101 100644
--- a/include/linux/if_macvlan.h
+++ b/include/linux/if_macvlan.h
@@ -29,7 +29,6 @@ struct macvlan_dev {
 	netdev_features_t	set_features;
 	enum macvlan_mode	mode;
 	u16			flags;
-	int			nest_level;
 	unsigned int		macaddr_count;
 	struct lock_class_key xmit_lock_key;
 	struct lock_class_key addr_lock_key;
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 1aed9f613e90..6f30284a58e5 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -182,8 +182,6 @@ struct vlan_dev_priv {
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	struct netpoll				*netpoll;
 #endif
-	unsigned int				nest_level;
-
 	struct lock_class_key			xmit_lock_key;
 	struct lock_class_key			addr_lock_key;
 };
@@ -224,11 +222,6 @@ extern void vlan_vids_del_by_dev(struct net_device *dev,
 
 extern bool vlan_uses_dev(const struct net_device *dev);
 
-static inline int vlan_get_encap_level(struct net_device *dev)
-{
-	BUG_ON(!is_vlan_dev(dev));
-	return vlan_dev_priv(dev)->nest_level;
-}
 #else
 static inline struct net_device *
 __vlan_find_dev_deep_rcu(struct net_device *real_dev,
@@ -298,11 +291,6 @@ static inline bool vlan_uses_dev(const struct net_device *dev)
 {
 	return false;
 }
-static inline int vlan_get_encap_level(struct net_device *dev)
-{
-	BUG();
-	return 0;
-}
 #endif
 
 /**
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 4506810c301b..31283b86a1e2 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1408,7 +1408,6 @@ struct net_device_ops {
 	void			(*ndo_dfwd_del_station)(struct net_device *pdev,
 							void *priv);
 
-	int			(*ndo_get_lock_subclass)(struct net_device *dev);
 	int			(*ndo_set_tx_maxrate)(struct net_device *dev,
 						      int queue_index,
 						      u32 maxrate);
@@ -4047,16 +4046,6 @@ static inline void netif_addr_lock(struct net_device *dev)
 	spin_lock(&dev->addr_list_lock);
 }
 
-static inline void netif_addr_lock_nested(struct net_device *dev)
-{
-	int subclass = SINGLE_DEPTH_NESTING;
-
-	if (dev->netdev_ops->ndo_get_lock_subclass)
-		subclass = dev->netdev_ops->ndo_get_lock_subclass(dev);
-
-	spin_lock_nested(&dev->addr_list_lock, subclass);
-}
-
 static inline void netif_addr_lock_bh(struct net_device *dev)
 {
 	spin_lock_bh(&dev->addr_list_lock);
@@ -4334,7 +4323,6 @@ void netdev_lower_state_changed(struct net_device *lower_dev,
 extern u8 netdev_rss_key[NETDEV_RSS_KEY_LEN] __read_mostly;
 void netdev_rss_key_fill(void *buffer, size_t len);
 
-int dev_get_nest_level(struct net_device *dev);
 int skb_checksum_help(struct sk_buff *skb);
 int skb_crc32c_csum_help(struct sk_buff *skb);
 int skb_csum_hwoffload_help(struct sk_buff *skb,
diff --git a/include/net/bonding.h b/include/net/bonding.h
index c39ac7061e41..74f41dd73866 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -203,7 +203,6 @@ struct bonding {
 	struct   slave __rcu *primary_slave;
 	struct   bond_up_slave __rcu *slave_arr; /* Array of usable slaves */
 	bool     force_primary;
-	u32      nest_level;
 	s32      slave_cnt; /* never change this value outside the attach/detach wrappers */
 	int     (*recv_probe)(const struct sk_buff *, struct bonding *,
 			      struct slave *);
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 54728d2eda18..d4bcfd8f95bf 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -172,7 +172,6 @@ int register_vlan_dev(struct net_device *dev, struct netlink_ext_ack *extack)
 	if (err < 0)
 		goto out_uninit_mvrp;
 
-	vlan->nest_level = dev_get_nest_level(real_dev) + 1;
 	err = register_netdevice(dev);
 	if (err < 0)
 		goto out_uninit_mvrp;
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 12bc80650087..e8707827540c 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -514,11 +514,6 @@ static void vlan_dev_set_lockdep_class(struct net_device *dev)
 	netdev_for_each_tx_queue(dev, vlan_dev_set_lockdep_one, NULL);
 }
 
-static int vlan_dev_get_lock_subclass(struct net_device *dev)
-{
-	return vlan_dev_priv(dev)->nest_level;
-}
-
 static const struct header_ops vlan_header_ops = {
 	.create	 = vlan_dev_hard_header,
 	.parse	 = eth_header_parse,
@@ -814,7 +809,6 @@ static const struct net_device_ops vlan_netdev_ops = {
 	.ndo_netpoll_cleanup	= vlan_dev_netpoll_cleanup,
 #endif
 	.ndo_fix_features	= vlan_dev_fix_features,
-	.ndo_get_lock_subclass  = vlan_dev_get_lock_subclass,
 	.ndo_get_iflink		= vlan_dev_get_iflink,
 };
 
diff --git a/net/core/dev.c b/net/core/dev.c
index 12d76b983064..5b14a70bea49 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7624,26 +7624,6 @@ void *netdev_lower_dev_get_private(struct net_device *dev,
 }
 EXPORT_SYMBOL(netdev_lower_dev_get_private);
 
-
-int dev_get_nest_level(struct net_device *dev)
-{
-	struct net_device *lower = NULL;
-	struct list_head *iter;
-	int max_nest = -1;
-	int nest;
-
-	ASSERT_RTNL();
-
-	netdev_for_each_lower_dev(dev, lower, iter) {
-		nest = dev_get_nest_level(lower);
-		if (max_nest < nest)
-			max_nest = nest;
-	}
-
-	return max_nest + 1;
-}
-EXPORT_SYMBOL(dev_get_nest_level);
-
 /**
  * netdev_lower_change - Dispatch event about lower device state change
  * @lower_dev: device
diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c
index 6393ba930097..2f949b5a1eb9 100644
--- a/net/core/dev_addr_lists.c
+++ b/net/core/dev_addr_lists.c
@@ -637,7 +637,7 @@ int dev_uc_sync(struct net_device *to, struct net_device *from)
 	if (to->addr_len != from->addr_len)
 		return -EINVAL;
 
-	netif_addr_lock_nested(to);
+	netif_addr_lock(to);
 	err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
 	if (!err)
 		__dev_set_rx_mode(to);
@@ -667,7 +667,7 @@ int dev_uc_sync_multiple(struct net_device *to, struct net_device *from)
 	if (to->addr_len != from->addr_len)
 		return -EINVAL;
 
-	netif_addr_lock_nested(to);
+	netif_addr_lock(to);
 	err = __hw_addr_sync_multiple(&to->uc, &from->uc, to->addr_len);
 	if (!err)
 		__dev_set_rx_mode(to);
@@ -691,7 +691,7 @@ void dev_uc_unsync(struct net_device *to, struct net_device *from)
 		return;
 
 	netif_addr_lock_bh(from);
-	netif_addr_lock_nested(to);
+	netif_addr_lock(to);
 	__hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
 	__dev_set_rx_mode(to);
 	netif_addr_unlock(to);
@@ -858,7 +858,7 @@ int dev_mc_sync(struct net_device *to, struct net_device *from)
 	if (to->addr_len != from->addr_len)
 		return -EINVAL;
 
-	netif_addr_lock_nested(to);
+	netif_addr_lock(to);
 	err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
 	if (!err)
 		__dev_set_rx_mode(to);
@@ -888,7 +888,7 @@ int dev_mc_sync_multiple(struct net_device *to, struct net_device *from)
 	if (to->addr_len != from->addr_len)
 		return -EINVAL;
 
-	netif_addr_lock_nested(to);
+	netif_addr_lock(to);
 	err = __hw_addr_sync_multiple(&to->mc, &from->mc, to->addr_len);
 	if (!err)
 		__dev_set_rx_mode(to);
@@ -912,7 +912,7 @@ void dev_mc_unsync(struct net_device *to, struct net_device *from)
 		return;
 
 	netif_addr_lock_bh(from);
-	netif_addr_lock_nested(to);
+	netif_addr_lock(to);
 	__hw_addr_unsync(&to->mc, &from->mc, to->addr_len);
 	__dev_set_rx_mode(to);
 	netif_addr_unlock(to);
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 4ca50ddf8d16..a2e91b8d04b3 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -558,7 +558,7 @@ int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
 	}
 
 	rtnl_lock();
-	nest_lvl = dev_get_nest_level(ndev);
+	nest_lvl = ndev->lower_level;
 	for (i = 0; i < nest_lvl; i++) {
 		struct list_head *lower = &ndev->adj_list.lower;
 
diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
index bab2da8cf17a..2920b006f65c 100644
--- a/net/smc/smc_pnet.c
+++ b/net/smc/smc_pnet.c
@@ -718,7 +718,7 @@ static struct net_device *pnet_find_base_ndev(struct net_device *ndev)
 	int i, nest_lvl;
 
 	rtnl_lock();
-	nest_lvl = dev_get_nest_level(ndev);
+	nest_lvl = ndev->lower_level;
 	for (i = 0; i < nest_lvl; i++) {
 		struct list_head *lower = &ndev->adj_list.lower;
 
-- 
2.17.1

Re: [PATCH net v3 00/11] net: fix nested device bugs

[Jakub Kicinski]

On Mon, 16 Sep 2019 22:47:51 +0900, Taehee Yoo 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.

Is this list exhaustive? Looks like qmi_wwan.c perhaps could also have
similar problem? Or virt_wifi? Perhaps worth CCing the authors of those
drivers and mentioning that?

Thank you for working on this!

Re: [PATCH net v3 00/11] net: fix nested device bugs

[Taehee Yoo]

On Sat, 21 Sep 2019 at 08:59, Jakub Kicinski
<jakub.kicinski@netronome.com> wrote:
>
> On Mon, 16 Sep 2019 22:47:51 +0900, Taehee Yoo 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.
>
> Is this list exhaustive? Looks like qmi_wwan.c perhaps could also have
> similar problem? Or virt_wifi? Perhaps worth CCing the authors of those
> drivers and mentioning that?
>
> Thank you for working on this!

I couldn't test all interface types.
So there could be more interface types that have a similar problem.
I will send a v4 patch and add more authors to the CC list.

Thank you so much for your review again!