From: xiaohui.xin@intel.com
To: netdev@vger.kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, mst@redhat.com, mingo@elte.hu,
herbert@gondor.apana.org.au, jdike@linux.intel.com,
davem@davemloft.net
Cc: Xin Xiaohui <xiaohui.xin@intel.com>
Subject: Re: [PATCH v15 00/17] Provide a zero-copy method on KVM virtio-net.
Date: Wed, 10 Nov 2010 17:23:28 +0800 [thread overview]
Message-ID: <1289381008-5484-1-git-send-email-xiaohui.xin@intel.com> (raw)
In-Reply-To: <20101109.091516.112581012.davem@davemloft.net>
From: Xin Xiaohui <xiaohui.xin@intel.com>
>2) The idea to key off of skb->dev in skb_release_data() is
> fundamentally flawed since many actions can change skb->dev on you,
> which will end up causing a leak of your external data areas.
How about this one? If the destructor_arg is not a good candidate,
then I have to add an apparent field in shinfo.
Thanks
Xiaohui
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 10ba67d..ad4636e 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -199,14 +199,15 @@ struct skb_shared_info {
struct sk_buff *frag_list;
struct skb_shared_hwtstamps hwtstamps;
+ /* Intermediate layers must ensure that destructor_arg
+ * remains valid until skb destructor */
+ void * destructor_arg;
+
/*
* Warning : all fields before dataref are cleared in __alloc_skb()
*/
atomic_t dataref;
- /* Intermediate layers must ensure that destructor_arg
- * remains valid until skb destructor */
- void * destructor_arg;
/* must be last field, see pskb_expand_head() */
skb_frag_t frags[MAX_SKB_FRAGS];
};
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c83b421..eb040f4 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -343,6 +343,13 @@ static void skb_release_data(struct sk_buff *skb)
if (skb_has_frags(skb))
skb_drop_fraglist(skb);
+ if (skb_shinfo(skb)->destructor_arg) {
+ struct skb_ext_page *ext_page =
+ skb_shinfo(skb)->destructor_arg;
+ if (ext_page->dtor)
+ ext_page->dtor(ext_page);
+ }
+
kfree(skb->head);
}
}
--
1.7.3
next prev parent reply other threads:[~2010-11-10 9:23 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-09 9:03 [PATCH v15 00/17] Provide a zero-copy method on KVM virtio-net xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 01/17] Add a new structure for skb buffer from external xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 02/17]Add a new struct for device to manipulate external buffer xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 03/17]Add a ndo_mp_port_prep pointer to net_device_ops xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 04/17]Add a function make external buffer owner to query capability xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 05/17] Add a function to indicate if device use external buffer xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 06/17] Use callback to deal with skb_release_data() specially xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 07/17]Modify netdev_alloc_page() to get external buffer xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 08/17]Modify netdev_free_page() to release " xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 09/17] Don't do skb recycle, if device use " xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 10/17]If device is in zero-copy mode first, bonding will fail xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 11/17] Add a hook to intercept external buffers from NIC driver xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 12/17] Add header file for mp device xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 13/17] Add mp(mediate passthru) device xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 14/17]Add a kconfig entry and make entry for mp device xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 15/17] Provides multiple submits and asynchronous notifications xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 16/17] An example how to modifiy NIC driver to use napi_gro_frags() interface xiaohui.xin
2010-11-09 9:03 ` [PATCH v15 17/17] An example how to alloc user buffer based on " xiaohui.xin
2010-11-09 17:15 ` [PATCH v15 00/17] Provide a zero-copy method on KVM virtio-net David Miller
2010-11-10 9:23 ` xiaohui.xin [this message]
2010-11-10 17:46 ` David Miller
2010-11-11 8:28 ` Xin, Xiaohui
2010-11-17 8:09 ` Xin, Xiaohui
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