linux/net
David Howells 05d17608a6 net: Fix an RCU warning in dev_pick_tx()
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: [<ffffffff81039e65>] run_timer_softirq+0x17b/0x278
 #1:  (rcu_read_lock_bh){.+....}, at: [<ffffffff812ea3eb>] dev_queue_xmit+0x14e/0x4dc

stack backtrace:
Pid: 0, comm: swapper Not tainted 2.6.34-rc5-cachefs #4
Call Trace:
 <IRQ>  [<ffffffff810516c4>] lockdep_rcu_dereference+0xaa/0xb2
 [<ffffffff812ea4f6>] dev_queue_xmit+0x259/0x4dc
 [<ffffffff812ea3eb>] ? dev_queue_xmit+0x14e/0x4dc
 [<ffffffff81052324>] ? trace_hardirqs_on+0xd/0xf
 [<ffffffff81035362>] ? local_bh_enable_ip+0xbc/0xc1
 [<ffffffff812f0954>] neigh_resolve_output+0x24b/0x27c
 [<ffffffff8134f673>] ip6_output_finish+0x7c/0xb4
 [<ffffffff81350c34>] ip6_output2+0x256/0x261
 [<ffffffff81052324>] ? trace_hardirqs_on+0xd/0xf
 [<ffffffff813517fb>] ip6_output+0xbbc/0xbcb
 [<ffffffff8135bc5d>] ? fib6_force_start_gc+0x2b/0x2d
 [<ffffffff81368acb>] mld_sendpack+0x273/0x39d
 [<ffffffff81368858>] ? mld_sendpack+0x0/0x39d
 [<ffffffff81052099>] ? mark_held_locks+0x52/0x70
 [<ffffffff813692fc>] mld_ifc_timer_expire+0x24f/0x288
 [<ffffffff81039ed6>] run_timer_softirq+0x1ec/0x278
 [<ffffffff81039e65>] ? run_timer_softirq+0x17b/0x278
 [<ffffffff813690ad>] ? mld_ifc_timer_expire+0x0/0x288
 [<ffffffff81035531>] ? __do_softirq+0x69/0x140
 [<ffffffff8103556a>] __do_softirq+0xa2/0x140
 [<ffffffff81002e0c>] call_softirq+0x1c/0x28
 [<ffffffff81004b54>] do_softirq+0x38/0x80
 [<ffffffff81034f06>] irq_exit+0x45/0x47
 [<ffffffff810177c3>] smp_apic_timer_interrupt+0x88/0x96
 [<ffffffff810028d3>] apic_timer_interrupt+0x13/0x20
 <EOI>  [<ffffffff810488dd>] ? __atomic_notifier_call_chain+0x0/0x86
 [<ffffffff810096bf>] ? mwait_idle+0x6e/0x78
 [<ffffffff810096b6>] ? mwait_idle+0x65/0x78
 [<ffffffff810011cb>] cpu_idle+0x4d/0x83
 [<ffffffff81380b05>] rest_init+0xb9/0xc0
 [<ffffffff81380a4c>] ? rest_init+0x0/0xc0
 [<ffffffff8168dcf0>] start_kernel+0x392/0x39d
 [<ffffffff8168d2a3>] x86_64_start_reservations+0xb3/0xb7
 [<ffffffff8168d38b>] x86_64_start_kernel+0xe4/0xeb

An rcu_dereference() should be an rcu_dereference_bh().

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-21 01:09:44 -07:00
..
9p Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs 2010-04-05 13:42:54 -07:00
802 include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
8021q include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
appletalk include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
atm include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ax25 include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-04-06 08:34:06 -07:00
bridge bridge: add a missing ntohs() 2010-04-20 18:51:57 -07:00
can can: avoids a false warning 2010-04-13 03:03:14 -07:00
core net: Fix an RCU warning in dev_pick_tx() 2010-04-21 01:09:44 -07:00
dcb include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
dccp include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
decnet include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
dsa include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
econet include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ethernet include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ieee802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-04-06 08:34:06 -07:00
ipv4 ip: Fix ip_dev_loopback_xmit() 2010-04-15 14:25:22 -07:00
ipv6 ipv6: Fix tcp_v6_send_response transport header setting. 2010-04-21 00:47:15 -07:00
ipx include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
irda include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
iucv const: constify remaining dev_pm_ops 2009-12-15 08:53:25 -08:00
key include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
lapb include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
llc include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
mac80211 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2010-04-20 17:57:56 -07:00
netfilter include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
netlabel Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-04-06 08:34:06 -07:00
netlink Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-04-06 08:34:06 -07:00
netrom include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
packet packet : remove init_net restriction 2010-04-16 15:41:04 -07:00
phonet include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
rds include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
rfkill include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
rose include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
rxrpc include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sched include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sctp include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sunrpc Merge branch 'for-2.6.34' of git://linux-nfs.org/~bfields/linux 2010-04-12 18:34:56 -07:00
tipc include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
unix include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
wanrouter headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
wimax include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
wireless Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-04-06 08:34:06 -07:00
x25 Merge branch 'master' of /home/davem/src/GIT/linux-2.6/ 2010-04-11 02:44:30 -07:00
xfrm include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
compat.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
Kconfig net/compat/wext: send different messages to compat tasks 2009-07-15 08:53:39 -07:00
Makefile net: remove redundant sched/ in net/Makefile 2009-07-12 20:11:14 -07:00
nonet.c
socket.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sysctl_net.c net: spread __net_init, __net_exit 2010-01-17 19:16:02 -08:00
TUNABLE