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* [PATCH v2 net-next] veth: Free queues on link delete
@ 2018-08-15  1:04 dsahern
  2018-08-15  1:16 ` Toshiaki Makita
  0 siblings, 1 reply; 4+ messages in thread
From: dsahern @ 2018-08-15  1:04 UTC (permalink / raw)
  To: netdev; +Cc: davem, makita.toshiaki, David Ahern

From: David Ahern <dsahern@gmail.com>

kmemleak reported new suspected memory leaks.
$ cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff8800354d5c00 (size 1024):
  comm "ip", pid 836, jiffies 4294722952 (age 25.904s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<(____ptrval____)>] kmemleak_alloc+0x70/0x94
    [<(____ptrval____)>] slab_post_alloc_hook+0x42/0x52
    [<(____ptrval____)>] __kmalloc+0x101/0x142
    [<(____ptrval____)>] kmalloc_array.constprop.20+0x1e/0x26 [veth]
    [<(____ptrval____)>] veth_newlink+0x147/0x3ac [veth]
    ...
unreferenced object 0xffff88002e009c00 (size 1024):
  comm "ip", pid 836, jiffies 4294722958 (age 25.898s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<(____ptrval____)>] kmemleak_alloc+0x70/0x94
    [<(____ptrval____)>] slab_post_alloc_hook+0x42/0x52
    [<(____ptrval____)>] __kmalloc+0x101/0x142
    [<(____ptrval____)>] kmalloc_array.constprop.20+0x1e/0x26 [veth]
    [<(____ptrval____)>] veth_newlink+0x219/0x3ac [veth]

The allocations in question are veth_alloc_queues for the dev and its peer.

Free the queues on a delete.

Fixes: 638264dc90227 ("veth: Support per queue XDP ring")
Signed-off-by: David Ahern <dsahern@gmail.com>
---
v2
- free peer dev queues as well

 drivers/net/veth.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index e3202af72df5..2a3ce60631ef 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -1205,6 +1205,7 @@ static void veth_dellink(struct net_device *dev, struct list_head *head)
 	struct veth_priv *priv;
 	struct net_device *peer;
 
+	veth_free_queues(dev);
 	priv = netdev_priv(dev);
 	peer = rtnl_dereference(priv->peer);
 
@@ -1216,6 +1217,7 @@ static void veth_dellink(struct net_device *dev, struct list_head *head)
 	unregister_netdevice_queue(dev, head);
 
 	if (peer) {
+		veth_free_queues(peer);
 		priv = netdev_priv(peer);
 		RCU_INIT_POINTER(priv->peer, NULL);
 		unregister_netdevice_queue(peer, head);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH v2 net-next] veth: Free queues on link delete
  2018-08-15  1:04 [PATCH v2 net-next] veth: Free queues on link delete dsahern
@ 2018-08-15  1:16 ` Toshiaki Makita
  2018-08-15  1:29   ` David Ahern
  0 siblings, 1 reply; 4+ messages in thread
From: Toshiaki Makita @ 2018-08-15  1:16 UTC (permalink / raw)
  To: dsahern, netdev; +Cc: davem, David Ahern

On 2018/08/15 10:04, dsahern@kernel.org wrote:
> From: David Ahern <dsahern@gmail.com>
> 
> kmemleak reported new suspected memory leaks.
> $ cat /sys/kernel/debug/kmemleak
> unreferenced object 0xffff8800354d5c00 (size 1024):
>   comm "ip", pid 836, jiffies 4294722952 (age 25.904s)
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace:
>     [<(____ptrval____)>] kmemleak_alloc+0x70/0x94
>     [<(____ptrval____)>] slab_post_alloc_hook+0x42/0x52
>     [<(____ptrval____)>] __kmalloc+0x101/0x142
>     [<(____ptrval____)>] kmalloc_array.constprop.20+0x1e/0x26 [veth]
>     [<(____ptrval____)>] veth_newlink+0x147/0x3ac [veth]
>     ...
> unreferenced object 0xffff88002e009c00 (size 1024):
>   comm "ip", pid 836, jiffies 4294722958 (age 25.898s)
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace:
>     [<(____ptrval____)>] kmemleak_alloc+0x70/0x94
>     [<(____ptrval____)>] slab_post_alloc_hook+0x42/0x52
>     [<(____ptrval____)>] __kmalloc+0x101/0x142
>     [<(____ptrval____)>] kmalloc_array.constprop.20+0x1e/0x26 [veth]
>     [<(____ptrval____)>] veth_newlink+0x219/0x3ac [veth]
> 
> The allocations in question are veth_alloc_queues for the dev and its peer.
> 
> Free the queues on a delete.
> 
> Fixes: 638264dc90227 ("veth: Support per queue XDP ring")
> Signed-off-by: David Ahern <dsahern@gmail.com>
> ---
> v2
> - free peer dev queues as well
> 
>  drivers/net/veth.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/veth.c b/drivers/net/veth.c
> index e3202af72df5..2a3ce60631ef 100644
> --- a/drivers/net/veth.c
> +++ b/drivers/net/veth.c
> @@ -1205,6 +1205,7 @@ static void veth_dellink(struct net_device *dev, struct list_head *head)
>  	struct veth_priv *priv;
>  	struct net_device *peer;
>  
> +	veth_free_queues(dev);
>  	priv = netdev_priv(dev);
>  	peer = rtnl_dereference(priv->peer);
>  
> @@ -1216,6 +1217,7 @@ static void veth_dellink(struct net_device *dev, struct list_head *head)
>  	unregister_netdevice_queue(dev, head);
>  
>  	if (peer) {
> +		veth_free_queues(peer);
>  		priv = netdev_priv(peer);
>  		RCU_INIT_POINTER(priv->peer, NULL);
>  		unregister_netdevice_queue(peer, head);

Hmm, on second thought this queues need to be freed after veth_close()
to make sure no packet will reference them. That means we need to free
them in .ndo_uninit() or destructor.
(rtnl_delete_link() calls dellink() before unregister_netdevice_many()
which calls dev_close_many() through rollback_registered_many())

Currently veth has destructor veth_dev_free() for vstats, so we can free
queues in the function.
To be in line with vstats, allocation also should be moved to
veth_dev_init().

-- 
Toshiaki Makita

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2 net-next] veth: Free queues on link delete
  2018-08-15  1:16 ` Toshiaki Makita
@ 2018-08-15  1:29   ` David Ahern
  2018-08-15  1:32     ` Toshiaki Makita
  0 siblings, 1 reply; 4+ messages in thread
From: David Ahern @ 2018-08-15  1:29 UTC (permalink / raw)
  To: Toshiaki Makita, dsahern, netdev; +Cc: davem

On 8/14/18 7:16 PM, Toshiaki Makita wrote:
> Hmm, on second thought this queues need to be freed after veth_close()
> to make sure no packet will reference them. That means we need to free
> them in .ndo_uninit() or destructor.
> (rtnl_delete_link() calls dellink() before unregister_netdevice_many()
> which calls dev_close_many() through rollback_registered_many())
> 
> Currently veth has destructor veth_dev_free() for vstats, so we can free
> queues in the function.
> To be in line with vstats, allocation also should be moved to
> veth_dev_init().

given that, can you take care of the free in the proper location?

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2 net-next] veth: Free queues on link delete
  2018-08-15  1:29   ` David Ahern
@ 2018-08-15  1:32     ` Toshiaki Makita
  0 siblings, 0 replies; 4+ messages in thread
From: Toshiaki Makita @ 2018-08-15  1:32 UTC (permalink / raw)
  To: David Ahern, dsahern, netdev; +Cc: davem

On 2018/08/15 10:29, David Ahern wrote:
> On 8/14/18 7:16 PM, Toshiaki Makita wrote:
>> Hmm, on second thought this queues need to be freed after veth_close()
>> to make sure no packet will reference them. That means we need to free
>> them in .ndo_uninit() or destructor.
>> (rtnl_delete_link() calls dellink() before unregister_netdevice_many()
>> which calls dev_close_many() through rollback_registered_many())
>>
>> Currently veth has destructor veth_dev_free() for vstats, so we can free
>> queues in the function.
>> To be in line with vstats, allocation also should be moved to
>> veth_dev_init().
> 
> given that, can you take care of the free in the proper location?

Sure, will cook a patch.
Thanks!

-- 
Toshiaki Makita

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2018-08-15  4:23 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2018-08-15  1:04 [PATCH v2 net-next] veth: Free queues on link delete dsahern
2018-08-15  1:16 ` Toshiaki Makita
2018-08-15  1:29   ` David Ahern
2018-08-15  1:32     ` Toshiaki Makita

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