Re: [ovs-dev] [PATCH net] net: openvswitch: silence suspicious RCU usage warning

2020-11-03 Thread Eelco Chaudron 



On 2 Nov 2020, at 20:51, Jakub Kicinski wrote:

> On Mon, 02 Nov 2020 09:52:19 +0100 Eelco Chaudron wrote:
>> On 30 Oct 2020, at 22:28, Jakub Kicinski wrote:
 @@ -1695,6 +1695,9 @@ static int ovs_dp_cmd_new(struct sk_buff *skb,
 struct genl_info *info)
if (err)
goto err_destroy_ports;

 +  /* So far only local changes have been made, now need the lock. */
 +  ovs_lock();
>>>
>>> Should we move the lock below assignments to param?
>>>
>>> Looks a little strange to protect stack variables with a global lock.
>>
>> You are right, I should have moved it down after the assignment. I will
>> send out a v2.
>>
>>> Let's update the name of the label.
>>
>> Guess now it is, unlock and destroy meters, so what label are you
>> looking for?
>>
>> err_unlock_and_destroy_meters: which looks a bit long, or just
>> err_unlock:
>
> I feel like I saw some names like err_unlock_and_destroy_meters in OvS
> code, but can't find them in this file right now.
>
> I'd personally go for kist err_unlock, or maybe err_unlock_ovs as is
> used in other functions in this file.
>
> But as long as it starts with err_unlock it's fine by me :)

Ack, sent out a v2.

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Re: [ovs-dev] [PATCH net] net: openvswitch: silence suspicious RCU usage warning

2020-11-02 Thread Jakub Kicinski 
On Mon, 02 Nov 2020 09:52:19 +0100 Eelco Chaudron wrote:
> On 30 Oct 2020, at 22:28, Jakub Kicinski wrote:
> >> @@ -1695,6 +1695,9 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, 
> >> struct genl_info *info)
> >>if (err)
> >>goto err_destroy_ports;
> >>
> >> +  /* So far only local changes have been made, now need the lock. */
> >> +  ovs_lock();  
> >
> > Should we move the lock below assignments to param?
> >
> > Looks a little strange to protect stack variables with a global lock.  
> 
> You are right, I should have moved it down after the assignment. I will 
> send out a v2.
> 
> > Let's update the name of the label.  
> 
> Guess now it is, unlock and destroy meters, so what label are you 
> looking for?
> 
> err_unlock_and_destroy_meters: which looks a bit long, or just 
> err_unlock:

I feel like I saw some names like err_unlock_and_destroy_meters in OvS
code, but can't find them in this file right now.

I'd personally go for kist err_unlock, or maybe err_unlock_ovs as is
used in other functions in this file.

But as long as it starts with err_unlock it's fine by me :)
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Re: [ovs-dev] [PATCH net] net: openvswitch: silence suspicious RCU usage warning

2020-11-02 Thread Eelco Chaudron 




On 30 Oct 2020, at 22:28, Jakub Kicinski wrote:


On Thu, 29 Oct 2020 15:53:21 +0100 Eelco Chaudron wrote:
Silence suspicious RCU usage warning in 
ovs_flow_tbl_masks_cache_resize()

by replacing rcu_dereference() with rcu_dereference_ovsl().

In addition, when creating a new datapath, make sure it's configured 
under

the ovs_lock.

Fixes: 9bf24f594c6a ("net: openvswitch: make masks cache size 
configurable")

Reported-by: syzbot+9a8f8bfcc56e85780...@syzkaller.appspotmail.com
Signed-off-by: Eelco Chaudron 
---
 net/openvswitch/datapath.c   |8 
 net/openvswitch/flow_table.c |2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 832f898edb6a..020f8539fede 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1695,6 +1695,9 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, 
struct genl_info *info)

if (err)
goto err_destroy_ports;

+   /* So far only local changes have been made, now need the lock. */
+   ovs_lock();


Should we move the lock below assignments to param?

Looks a little strange to protect stack variables with a global lock.


You are right, I should have moved it down after the assignment. I will 
send out a v2.



/* Set up our datapath device. */
parms.name = nla_data(a[OVS_DP_ATTR_NAME]);
parms.type = OVS_VPORT_TYPE_INTERNAL;
@@ -1707,9 +1710,6 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, 
struct genl_info *info)

if (err)
goto err_destroy_meters;

-   /* So far only local changes have been made, now need the lock. */
-   ovs_lock();
-
vport = new_vport();
if (IS_ERR(vport)) {
err = PTR_ERR(vport);
@@ -1725,7 +1725,6 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, 
struct genl_info *info)

ovs_dp_reset_user_features(skb, info);
}

-   ovs_unlock();
goto err_destroy_meters;
}

@@ -1742,6 +1741,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, 
struct genl_info *info)

return 0;

 err_destroy_meters:


Let's update the name of the label.


Guess now it is, unlock and destroy meters, so what label are you 
looking for?


err_unlock_and_destroy_meters: which looks a bit long, or just 
err_unlock:



+   ovs_unlock();
ovs_meters_exit(dp);
 err_destroy_ports:
kfree(dp->ports);
diff --git a/net/openvswitch/flow_table.c 
b/net/openvswitch/flow_table.c

index f3486a37361a..c89c8da99f1a 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c
@@ -390,7 +390,7 @@ static struct mask_cache 
*tbl_mask_cache_alloc(u32 size)

 }
 int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 
size)

 {
-   struct mask_cache *mc = rcu_dereference(table->mask_cache);
+   struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
struct mask_cache *new;

if (size == mc->cache_size)



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Re: [ovs-dev] [PATCH net] net: openvswitch: silence suspicious RCU usage warning

2020-10-30 Thread Jakub Kicinski 
On Thu, 29 Oct 2020 15:53:21 +0100 Eelco Chaudron wrote:
> Silence suspicious RCU usage warning in ovs_flow_tbl_masks_cache_resize()
> by replacing rcu_dereference() with rcu_dereference_ovsl().
> 
> In addition, when creating a new datapath, make sure it's configured under
> the ovs_lock.
> 
> Fixes: 9bf24f594c6a ("net: openvswitch: make masks cache size configurable")
> Reported-by: syzbot+9a8f8bfcc56e85780...@syzkaller.appspotmail.com
> Signed-off-by: Eelco Chaudron 
> ---
>  net/openvswitch/datapath.c   |8 
>  net/openvswitch/flow_table.c |2 +-
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
> index 832f898edb6a..020f8539fede 100644
> --- a/net/openvswitch/datapath.c
> +++ b/net/openvswitch/datapath.c
> @@ -1695,6 +1695,9 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct 
> genl_info *info)
>   if (err)
>   goto err_destroy_ports;
>  
> + /* So far only local changes have been made, now need the lock. */
> + ovs_lock();

Should we move the lock below assignments to param?

Looks a little strange to protect stack variables with a global lock.

>   /* Set up our datapath device. */
>   parms.name = nla_data(a[OVS_DP_ATTR_NAME]);
>   parms.type = OVS_VPORT_TYPE_INTERNAL;
> @@ -1707,9 +1710,6 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct 
> genl_info *info)
>   if (err)
>   goto err_destroy_meters;
>  
> - /* So far only local changes have been made, now need the lock. */
> - ovs_lock();
> -
>   vport = new_vport();
>   if (IS_ERR(vport)) {
>   err = PTR_ERR(vport);
> @@ -1725,7 +1725,6 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct 
> genl_info *info)
>   ovs_dp_reset_user_features(skb, info);
>   }
>  
> - ovs_unlock();
>   goto err_destroy_meters;
>   }
>  
> @@ -1742,6 +1741,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct 
> genl_info *info)
>   return 0;
>  
>  err_destroy_meters:

Let's update the name of the label.

> + ovs_unlock();
>   ovs_meters_exit(dp);
>  err_destroy_ports:
>   kfree(dp->ports);
> diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
> index f3486a37361a..c89c8da99f1a 100644
> --- a/net/openvswitch/flow_table.c
> +++ b/net/openvswitch/flow_table.c
> @@ -390,7 +390,7 @@ static struct mask_cache *tbl_mask_cache_alloc(u32 size)
>  }
>  int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size)
>  {
> - struct mask_cache *mc = rcu_dereference(table->mask_cache);
> + struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
>   struct mask_cache *new;
>  
>   if (size == mc->cache_size)
> 

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[ovs-dev] [PATCH net] net: openvswitch: silence suspicious RCU usage warning

2020-10-29 Thread Eelco Chaudron 
Silence suspicious RCU usage warning in ovs_flow_tbl_masks_cache_resize()
by replacing rcu_dereference() with rcu_dereference_ovsl().

In addition, when creating a new datapath, make sure it's configured under
the ovs_lock.

Fixes: 9bf24f594c6a ("net: openvswitch: make masks cache size configurable")
Reported-by: syzbot+9a8f8bfcc56e85780...@syzkaller.appspotmail.com
Signed-off-by: Eelco Chaudron 
---
 net/openvswitch/datapath.c   |8 
 net/openvswitch/flow_table.c |2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 832f898edb6a..020f8539fede 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1695,6 +1695,9 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct 
genl_info *info)
if (err)
goto err_destroy_ports;
 
+   /* So far only local changes have been made, now need the lock. */
+   ovs_lock();
+
/* Set up our datapath device. */
parms.name = nla_data(a[OVS_DP_ATTR_NAME]);
parms.type = OVS_VPORT_TYPE_INTERNAL;
@@ -1707,9 +1710,6 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct 
genl_info *info)
if (err)
goto err_destroy_meters;
 
-   /* So far only local changes have been made, now need the lock. */
-   ovs_lock();
-
vport = new_vport();
if (IS_ERR(vport)) {
err = PTR_ERR(vport);
@@ -1725,7 +1725,6 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct 
genl_info *info)
ovs_dp_reset_user_features(skb, info);
}
 
-   ovs_unlock();
goto err_destroy_meters;
}
 
@@ -1742,6 +1741,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct 
genl_info *info)
return 0;
 
 err_destroy_meters:
+   ovs_unlock();
ovs_meters_exit(dp);
 err_destroy_ports:
kfree(dp->ports);
diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
index f3486a37361a..c89c8da99f1a 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c
@@ -390,7 +390,7 @@ static struct mask_cache *tbl_mask_cache_alloc(u32 size)
 }
 int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size)
 {
-   struct mask_cache *mc = rcu_dereference(table->mask_cache);
+   struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
struct mask_cache *new;
 
if (size == mc->cache_size)

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