linux-toradex.git/net/llc/llc_core.c, branch v5.3.2

llc: avoid blocking in llc_sap_close()

2018-09-13T16:04:58+00:00

llc_sap_close() is called by llc_sap_put() which
could be called in BH context in llc_rcv(). We can't
block in BH.

There is no reason to block it here, kfree_rcu() should
be sufficient.

Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

llc: use refcount_inc_not_zero() for llc_sap_find()

2018-08-07T22:54:00+00:00

llc_sap_put() decreases the refcnt before deleting sap
from the global list. Therefore, there is a chance
llc_sap_find() could find a sap with zero refcnt
in this global list.

Close this race condition by checking if refcnt is zero
or not in llc_sap_find(), if it is zero then it is being
removed so we can just treat it as gone.

Reported-by: 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

net, llc: convert llc_sap.refcnt from atomic_t to refcount_t

2017-07-04T21:35:15+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: David S. Miller

llc: make lock static

2014-01-04T01:56:48+00:00

The llc_sap_list_lock does not need to be global, only acquired
in core.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

llc: "foo* bar" should be "foo *bar"

2013-12-27T18:06:15+00:00

Signed-off-by: Weilong Chen 
Signed-off-by: David S. Miller

llc: cleanup: remove dead code from llc_init()

2010-03-24T20:34:08+00:00

We don't need "dev" any more after:
	a5a04819c5740cb1aa217af2cc8f5ef26f33d744
	[LLC]: station source mac address

Signed-off-by: Dan Carpenter 
Acked-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

llc: convert llc_sap_list to RCU

2009-12-27T04:46:28+00:00

Signed-off-by: Octavian Purdila 
Signed-off-by: David S. Miller

llc: replace the socket list with a local address based hash

2009-12-27T04:45:32+00:00

For the cases where a lot of interfaces are used in conjunction with a
lot of LLC sockets bound to the same SAP, the iteration of the socket
list becomes prohibitively expensive.

Replacing the list with a a local address based hash significantly
improves the bind and listener lookup operations as well as the
datagram delivery.

Connected sockets delivery is also improved, but this patch does not
address the case where we have lots of sockets with the same local
address connected to different remote addresses.

In order to keep the socket sanity checks alive and fast a socket
counter was added to the SAP structure.

Signed-off-by: Octavian Purdila 
Signed-off-by: David S. Miller

llc: convert the socket list to RCU locking

2009-12-27T04:41:43+00:00

For the reclamation phase we use the SLAB_DESTROY_BY_RCU mechanism,
which require some extra checks in the lookup code:

a) If the current socket was released, reallocated & inserted in
another list it will short circuit the iteration for the current list,
thus we need to restart the lookup.

b) If the current socket was released, reallocated & inserted in the
same list we just need to recheck it matches the look-up criteria and
if not we can skip to the next element.

In this case there is no need to restart the lookup, since sockets are
inserted at the start of the list and the worst that will happen is
that we will iterate throught some of the list elements more then
once.

Note that the /proc and multicast delivery was not yet converted to
RCU, it still uses spinlocks for protection.

Signed-off-by: Octavian Purdila 
Signed-off-by: David S. Miller

net: convert usage of packet_type to read_mostly

2009-03-10T12:22:43+00:00

Protocols that use packet_type can be __read_mostly section for better
locality. Elminate any unnecessary initializations of NULL.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller