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: David S. Miller <davem@davemloft.net>
firewire-net:
- set min/max_mtu
- remove fwnet_change_mtu
nes:
- set max_mtu
- clean up nes_netdev_change_mtu
xpnet:
- set min/max_mtu
- remove xpnet_dev_change_mtu
hippi:
- set min/max_mtu
- remove hippi_change_mtu
batman-adv:
- set max_mtu
- remove batadv_interface_change_mtu
- initialization is a little async, not 100% certain that max_mtu is set
in the optimal place, don't have hardware to test with
rionet:
- set min/max_mtu
- remove rionet_change_mtu
slip:
- set min/max_mtu
- streamline sl_change_mtu
um/net_kern:
- remove pointless ndo_change_mtu
hsi/clients/ssi_protocol:
- use core MTU range checking
- remove now redundant ssip_pn_set_mtu
ipoib:
- set a default max MTU value
- Note: ipoib's actual max MTU can vary, depending on if the device is in
connected mode or not, so we'll just set the max_mtu value to the max
possible, and let the ndo_change_mtu function continue to validate any new
MTU change requests with checks for CM or not. Note that ipoib has no
min_mtu set, and thus, the network core's mtu > 0 check is the only lower
bounds here.
mptlan:
- use net core MTU range checking
- remove now redundant mpt_lan_change_mtu
fddi:
- min_mtu = 21, max_mtu = 4470
- remove now redundant fddi_change_mtu (including export)
fjes:
- min_mtu = 8192, max_mtu = 65536
- The max_mtu value is actually one over IP_MAX_MTU here, but the idea is to
get past the core net MTU range checks so fjes_change_mtu can validate a
new MTU against what it supports (see fjes_support_mtu in fjes_hw.c)
hsr:
- min_mtu = 0 (calls ether_setup, max_mtu is 1500)
f_phonet:
- min_mtu = 6, max_mtu = 65541
u_ether:
- min_mtu = 14, max_mtu = 15412
phonet/pep-gprs:
- min_mtu = 576, max_mtu = 65530
- remove redundant gprs_set_mtu
CC: netdev@vger.kernel.org
CC: linux-rdma@vger.kernel.org
CC: Stefan Richter <stefanr@s5r6.in-berlin.de>
CC: Faisal Latif <faisal.latif@intel.com>
CC: linux-rdma@vger.kernel.org
CC: Cliff Whickman <cpw@sgi.com>
CC: Robin Holt <robinmholt@gmail.com>
CC: Jes Sorensen <jes@trained-monkey.org>
CC: Marek Lindner <mareklindner@neomailbox.ch>
CC: Simon Wunderlich <sw@simonwunderlich.de>
CC: Antonio Quartulli <a@unstable.cc>
CC: Sathya Prakash <sathya.prakash@broadcom.com>
CC: Chaitra P B <chaitra.basappa@broadcom.com>
CC: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
CC: MPT-FusionLinux.pdl@broadcom.com
CC: Sebastian Reichel <sre@kernel.org>
CC: Felipe Balbi <balbi@kernel.org>
CC: Arvid Brodin <arvid.brodin@alten.se>
CC: Remi Denis-Courmont <courmisch@gmail.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use the more common dynamic_debug capable net_dbg_ratelimited
and remove the LIMIT_NETDEBUG macro.
All messages are still ratelimited.
Some KERN_<LEVEL> uses are changed to KERN_DEBUG.
This may have some negative impact on messages that were
emitted at KERN_INFO that are not not enabled at all unless
DEBUG is defined or dynamic_debug is enabled. Even so,
these messages are now _not_ emitted by default.
This also eliminates the use of the net_msg_warn sysctl
"/proc/sys/net/core/warnings". For backward compatibility,
the sysctl is not removed, but it has no function. The extern
declaration of net_msg_warn is removed from sock.h and made
static in net/core/sysctl_net_core.c
Miscellanea:
o Update the sysctl documentation
o Remove the embedded uses of pr_fmt
o Coalesce format fragments
o Realign arguments
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several spots in the kernel perform a sequence like:
skb_queue_tail(&sk->s_receive_queue, skb);
sk->sk_data_ready(sk, skb->len);
But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up. So this skb->len access is potentially
to freed up memory.
Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.
And finally, no actual implementation of this callback actually uses
the length argument. And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.
So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.
Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.
Signed-off-by: David S. Miller <davem@davemloft.net>
Newer Nokia cellular modems can use aligned payload for their GPRS pipe.
Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These are all drivers that don't touch real hardware.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is the result of an automatic spatch transformation to convert
all ndo_start_xmit() return values of 0 to NETDEV_TX_OK.
Some occurences are missed by the automatic conversion, those will be
handled in a seperate patch.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the unlikely event that gprs_writeable() and gprs_xmit() check for
writeability at the same, we could stop the device queue forever.
Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A separate xmit lock class supports GPRS over a Phonet pipe over a TUN
device (type ARPHRD_NONE).
Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/phonet/af_phonet.c:38:36: error: marked inline, but without a definition
net/phonet/pep-gprs.c:63:10: warning: incorrect type in return expression (different base types)
net/phonet/pep-gprs.c:63:10: expected int
net/phonet/pep-gprs.c:63:10: got restricted __be16 [usertype] <noident>
net/phonet/pep-gprs.c:65:10: warning: incorrect type in return expression (different base types)
net/phonet/pep-gprs.c:65:10: expected int
net/phonet/pep-gprs.c:65:10: got restricted __be16 [usertype] <noident>
net/phonet/pep-gprs.c:124:16: warning: incorrect type in assignment (different base types)
net/phonet/pep-gprs.c:124:16: expected restricted __be16 [usertype] protocol
net/phonet/pep-gprs.c:124:16: got unsigned short [unsigned] [usertype] protocol
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
