linux-toradex.git/net/core/dev.c, branch v2.6.34

veth: Dont kfree_skb() after dev_forward_skb()

2010-05-06T07:53:53+00:00

In case of congestion, netif_rx() frees the skb, so we must assume
dev_forward_skb() also consume skb.

Bug introduced by commit 445409602c092
(veth: move loopback logic to common location)

We must change dev_forward_skb() to always consume skb, and veth to not
double free it.

Bug report : http://marc.info/?l=linux-netdev&m=127310770900442&w=3

Reported-by: Martín Ferrari 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: Fix an RCU warning in dev_pick_tx()

2010-04-21T08:09:44+00:00

Fix the following RCU warning in dev_pick_tx():

===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
net/core/dev.c:1993 invoked rcu_dereference_check() without protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
2 locks held by swapper/0:
 #0:  (&idev->mc_ifc_timer){+.-...}, at: [] run_timer_softirq+0x17b/0x278
 #1:  (rcu_read_lock_bh){.+....}, at: [] dev_queue_xmit+0x14e/0x4dc

stack backtrace:
Pid: 0, comm: swapper Not tainted 2.6.34-rc5-cachefs #4
Call Trace:
   [] lockdep_rcu_dereference+0xaa/0xb2
 [] dev_queue_xmit+0x259/0x4dc
 [] ? dev_queue_xmit+0x14e/0x4dc
 [] ? trace_hardirqs_on+0xd/0xf
 [] ? local_bh_enable_ip+0xbc/0xc1
 [] neigh_resolve_output+0x24b/0x27c
 [] ip6_output_finish+0x7c/0xb4
 [] ip6_output2+0x256/0x261
 [] ? trace_hardirqs_on+0xd/0xf
 [] ip6_output+0xbbc/0xbcb
 [] ? fib6_force_start_gc+0x2b/0x2d
 [] mld_sendpack+0x273/0x39d
 [] ? mld_sendpack+0x0/0x39d
 [] ? mark_held_locks+0x52/0x70
 [] mld_ifc_timer_expire+0x24f/0x288
 [] run_timer_softirq+0x1ec/0x278
 [] ? run_timer_softirq+0x17b/0x278
 [] ? mld_ifc_timer_expire+0x0/0x288
 [] ? __do_softirq+0x69/0x140
 [] __do_softirq+0xa2/0x140
 [] call_softirq+0x1c/0x28
 [] do_softirq+0x38/0x80
 [] irq_exit+0x45/0x47
 [] smp_apic_timer_interrupt+0x88/0x96
 [] apic_timer_interrupt+0x13/0x20
   [] ? __atomic_notifier_call_chain+0x0/0x86
 [] ? mwait_idle+0x6e/0x78
 [] ? mwait_idle+0x65/0x78
 [] cpu_idle+0x4d/0x83
 [] rest_init+0xb9/0xc0
 [] ? rest_init+0x0/0xc0
 [] start_kernel+0x392/0x39d
 [] x86_64_start_reservations+0xb3/0xb7
 [] x86_64_start_kernel+0xe4/0xeb

An rcu_dereference() should be an rcu_dereference_bh().

Signed-off-by: David Howells 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: dev_pick_tx() fix

2010-04-15T08:27:11+00:00

When dev_pick_tx() caches tx queue_index on a socket, we must check
socket dst_entry matches skb one, or risk a crash later, as reported by
Denys Fedorysychenko, if old packets are in flight during a route
change, involving devices with different number of queues.

Bug introduced by commit a4ee3ce3
(net: Use sk_tx_queue_mapping for connected sockets)

Reported-by: Denys Fedorysychenko 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

net: Potential null skb->dev dereference

2010-03-19T04:16:45+00:00

When doing "ifenslave -d bond0 eth0", there is chance to get NULL
dereference in netif_receive_skb(), because dev->master suddenly becomes
NULL after we tested it.

We should use ACCESS_ONCE() to avoid this (or rcu_dereference())

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

Merge branch 'master' of /home/davem/src/GIT/linux-2.6/

2010-03-01T03:23:06+00:00

Conflicts:
	drivers/firmware/iscsi_ibft.c

dev: support deferring device flag change notifications

2010-02-27T10:43:40+00:00

Split dev_change_flags() into two functions: __dev_change_flags() to
perform the actual changes and __dev_notify_flags() to invoke netdevice
notifiers. This will be used by rtnl_link to defer netlink notifications
until the device has been fully configured.

This changes ordering of some operations, in particular:

- netlink notifications are sent after all changes have been performed.
  As a side effect this surpresses one unnecessary netlink message when
  the IFF_UP and other flags are changed simultaneously.

- The NETDEV_UP/NETDEV_DOWN and NETDEV_CHANGE notifiers are invoked
  after all changes have been performed. Their relative is unchanged.

- net_dmaengine_put() is invoked before the NETDEV_DOWN notifier instead
  of afterwards. This should not make any difference since both RX and TX
  are already shut down at this point.

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

rtnetlink: handle rtnl_link netlink notifications manually

2010-02-27T10:43:39+00:00

In order to support specifying device flags during device creation,
we must be able to roll back device registration in case setting the
flags fails without sending any notifications related to the device
to userspace.

This patch changes rollback_registered_many() and register_netdevice()
to manually send netlink notifications for devices not handled by
rtnl_link and allows to defer notifications for devices handled by
rtnl_link until setup is complete.

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

netdev: use list_first_entry macro

2010-02-26T12:18:35+00:00

Use list_first_entry macro; no longer any need to use
'next' directly in list to find first entry.

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

net: Add checking to rcu_dereference() primitives

2010-02-25T08:41:03+00:00

Update rcu_dereference() primitives to use new lockdep-based
checking. The rcu_dereference() in __in6_dev_get() may be
protected either by rcu_read_lock() or RTNL, per Eric Dumazet.
The rcu_dereference() in __sk_free() is protected by the fact
that it is never reached if an update could change it.  Check
for this by using rcu_dereference_check() to verify that the
struct sock's ->sk_wmem_alloc counter is zero.

Acked-by: Eric Dumazet 
Acked-by: David S. Miller 
Signed-off-by: Paul E. McKenney 
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-5-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar