Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
1 年多 前同步成功

通知 161
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 16 6月, 2017 2 次提交
    • J
      networking: introduce and use skb_put_data() · 59ae1d12
      由 Johannes Berg 提交于 
      A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)
Reviewed-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      59ae1d12
    • J
      networking: convert many more places to skb_put_zero() · b080db58
      由 Johannes Berg 提交于 
      There were many places that my previous spatch didn't find,
as pointed out by yuan linyu in various patches.

The following spatch found many more and also removes the
now unnecessary casts:

    @@
    identifier p, p2;
    expression len;
    expression skb;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_zero(skb, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_zero(skb, len);
    )
    ... when != p
    (
    p2 = (t2)p;
    -memset(p2, 0, len);
    |
    -memset(p, 0, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_zero(skb, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_zero(skb, sizeof(t));
    )
    ... when != p
    (
    p2 = (t2)p;
    -memset(p2, 0, sizeof(*p));
    |
    -memset(p, 0, sizeof(*p));
    )

    @@
    expression skb, len;
    @@
    -memset(skb_put(skb, len), 0, len);
    +skb_put_zero(skb, len);

Apply it to the tree (with one manual fixup to keep the
comment in vxlan.c, which spatch removed.)
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b080db58
  3. 14 6月, 2017 1 次提交
  5. 08 6月, 2017 1 次提交
    • D
      net: Fix inconsistent teardown and release of private netdev state. · cf124db5
      由 David S. Miller 提交于 
      Network devices can allocate reasources and private memory using
netdev_ops->ndo_init().  However, the release of these resources
can occur in one of two different places.

Either netdev_ops->ndo_uninit() or netdev->destructor().

The decision of which operation frees the resources depends upon
whether it is necessary for all netdev refs to be released before it
is safe to perform the freeing.

netdev_ops->ndo_uninit() presumably can occur right after the
NETDEV_UNREGISTER notifier completes and the unicast and multicast
address lists are flushed.

netdev->destructor(), on the other hand, does not run until the
netdev references all go away.

Further complicating the situation is that netdev->destructor()
almost universally does also a free_netdev().

This creates a problem for the logic in register_netdevice().
Because all callers of register_netdevice() manage the freeing
of the netdev, and invoke free_netdev(dev) if register_netdevice()
fails.

If netdev_ops->ndo_init() succeeds, but something else fails inside
of register_netdevice(), it does call ndo_ops->ndo_uninit().  But
it is not able to invoke netdev->destructor().

This is because netdev->destructor() will do a free_netdev() and
then the caller of register_netdevice() will do the same.

However, this means that the resources that would normally be released
by netdev->destructor() will not be.

Over the years drivers have added local hacks to deal with this, by
invoking their destructor parts by hand when register_netdevice()
fails.

Many drivers do not try to deal with this, and instead we have leaks.

Let's close this hole by formalizing the distinction between what
private things need to be freed up by netdev->destructor() and whether
the driver needs unregister_netdevice() to perform the free_netdev().

netdev->priv_destructor() performs all actions to free up the private
resources that used to be freed by netdev->destructor(), except for
free_netdev().

netdev->needs_free_netdev is a boolean that indicates whether
free_netdev() should be done at the end of unregister_netdevice().

Now, register_netdevice() can sanely release all resources after
ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit()
and netdev->priv_destructor().

And at the end of unregister_netdevice(), we invoke
netdev->priv_destructor() and optionally call free_netdev().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      cf124db5
  7. 06 6月, 2017 10 次提交
  9. 01 6月, 2017 5 次提交
  11. 31 5月, 2017 5 次提交
  13. 24 5月, 2017 16 次提交