On Mon, 2015-11-16 at 14:30 -0800, Eric Dumazet wrote:
> On Mon, 2015-11-16 at 23:18 +0100, Hannes Frederic Sowa wrote:
> > > need something that handles all cases properly.
> >
> > I just wanted to shut up the gcc warning which is added if a function
> > uses more than 2048 bytes of stack space. We normally don't have the
> > problem and could also divide the function into two, but I don't see a
> > general solution to the problem. Mostly they need to be custom tailored
> > to the specific usage.
> >
> > I can have a look if we can use kmalloc based storage for the stats, but
> > this also means that we add another NULL pointer check and error
> > handling for those cases. Let me have a look!
>
> Simply put the code different functions with noinline_for_stack
First step :
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 504bd17b7456..ff109fad5a7f 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1045,15 +1045,35 @@ static int rtnl_phys_switch_id_fill(struct sk_buff
*skb, struct net_device *dev)
return 0;
}
+static noinline_for_stack bool rtnl_fill_stats(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ const struct rtnl_link_stats64 *stats;
+ struct rtnl_link_stats64 temp;
+ struct nlattr *attr;
+
+ attr = nla_reserve(skb, IFLA_STATS,
+ sizeof(struct rtnl_link_stats));
+ if (!attr)
+ return true;
+ stats = dev_get_stats(dev, &temp);
+ copy_rtnl_link_stats(nla_data(attr), stats);
+
+ attr = nla_reserve(skb, IFLA_STATS64,
+ sizeof(struct rtnl_link_stats64));
+ if (!attr)
+ return true;
+ copy_rtnl_link_stats64(nla_data(attr), stats);
+ return false;
+}
+
static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
int type, u32 pid, u32 seq, u32 change,
unsigned int flags, u32 ext_filter_mask)
{
struct ifinfomsg *ifm;
struct nlmsghdr *nlh;
- struct rtnl_link_stats64 temp;
- const struct rtnl_link_stats64 *stats;
- struct nlattr *attr, *af_spec;
+ struct nlattr *af_spec;
struct rtnl_af_ops *af_ops;
struct net_device *upper_dev = netdev_master_upper_dev_get(dev);
@@ -1124,19 +1144,8 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct
net_device *dev,
if (rtnl_phys_switch_id_fill(skb, dev))
goto nla_put_failure;
- attr = nla_reserve(skb, IFLA_STATS,
- sizeof(struct rtnl_link_stats));
- if (attr == NULL)
- goto nla_put_failure;
-
- stats = dev_get_stats(dev, &temp);
- copy_rtnl_link_stats(nla_data(attr), stats);
-
- attr = nla_reserve(skb, IFLA_STATS64,
- sizeof(struct rtnl_link_stats64));
- if (attr == NULL)
+ if (rtnl_fill_stats(skb, dev))
goto nla_put_failure;
- copy_rtnl_link_stats64(nla_data(attr), stats);
if (dev->dev.parent && (ext_filter_mask & RTEXT_FILTER_VF) &&
nla_put_u32(skb, IFLA_NUM_VF, dev_num_vf(dev->dev.parent)))
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
