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1144182a87
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Paul E. McKenney 1144182a87 net: suppress RCU lockdep false positive in sock_update_classid 
> ===================================================
> [ INFO: suspicious rcu_dereference_check() usage. ]
> ---------------------------------------------------
> include/linux/cgroup.h:542 invoked rcu_dereference_check() without protection!
>
> other info that might help us debug this:
>
>
> rcu_scheduler_active = 1, debug_locks = 0
> 1 lock held by swapper/1:
>  #0:  (net_mutex){+.+.+.}, at: [<ffffffff813e9010>]
> register_pernet_subsys+0x1f/0x47
>
> stack backtrace:
> Pid: 1, comm: swapper Not tainted 2.6.35.4-28.fc14.x86_64 #1
> Call Trace:
>  [<ffffffff8107bd3a>] lockdep_rcu_dereference+0xaa/0xb3
>  [<ffffffff813e04b9>] sock_update_classid+0x7c/0xa2
>  [<ffffffff813e054a>] sk_alloc+0x6b/0x77
>  [<ffffffff8140b281>] __netlink_create+0x37/0xab
>  [<ffffffff813f941c>] ? rtnetlink_rcv+0x0/0x2d
>  [<ffffffff8140cee1>] netlink_kernel_create+0x74/0x19d
>  [<ffffffff8149c3ca>] ? __mutex_lock_common+0x339/0x35b
>  [<ffffffff813f7e9c>] rtnetlink_net_init+0x2e/0x48
>  [<ffffffff813e8d7a>] ops_init+0xe9/0xff
>  [<ffffffff813e8f0d>] register_pernet_operations+0xab/0x130
>  [<ffffffff813e901f>] register_pernet_subsys+0x2e/0x47
>  [<ffffffff81db7bca>] rtnetlink_init+0x53/0x102
>  [<ffffffff81db835c>] netlink_proto_init+0x126/0x143
>  [<ffffffff81db8236>] ? netlink_proto_init+0x0/0x143
>  [<ffffffff810021b8>] do_one_initcall+0x72/0x186
>  [<ffffffff81d78ebc>] kernel_init+0x23b/0x2c9
>  [<ffffffff8100aae4>] kernel_thread_helper+0x4/0x10
>  [<ffffffff8149e2d0>] ? restore_args+0x0/0x30
>  [<ffffffff81d78c81>] ? kernel_init+0x0/0x2c9
>  [<ffffffff8100aae0>] ? kernel_thread_helper+0x0/0x10

The sock_update_classid() function calls task_cls_classid(current),
but the calling task cannot go away, so there is no danger of
the associated structures disappearing.  Insert an RCU read-side
critical section to suppress the false positive.

Reported-by: Subrata Modak <subrata@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-10-07 10:02:28 -07:00
..
9p Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-28 12:01:26 -07:00
802
8021q vlan: dont drop packets from unknown vlans in promiscuous mode 2010-09-30 18:04:21 -07:00
appletalk
atm br2684: fix scheduling while atomic 2010-09-26 18:29:18 -07:00
ax25 ax25: missplaced sock_put(sk) 2010-08-26 15:18:27 -07:00
bluetooth
bridge bridge: Clear INET control block of SKBs passed into ip_fragment(). 2010-09-01 19:17:34 -07:00
caif net/caif/cfrfml.c: use asm/unaligned.h 2010-08-26 16:11:08 -07:00
can can: add limit for nframes and clean up signed/unsigned variables 2010-08-11 16:12:35 -07:00
core net: suppress RCU lockdep false positive in sock_update_classid 2010-10-07 10:02:28 -07:00
dcb
dccp
decnet
dns_resolver DNS: If the DNS server returns an error, allow that to be cached [ver #2] 2010-08-11 17:11:28 +00:00
dsa phylib: available for any speed ethernet 2010-08-11 23:03:50 -07:00
econet
ethernet
ieee802154
ipv4 Merge commit 'v2.6.36-rc7' into core/rcu 2010-10-07 09:43:45 +02:00
ipv6 ipv6: add IPv6 to neighbour table overflow warning 2010-09-27 15:02:18 -07:00
ipx
irda irda: off by one 2010-09-07 13:57:22 -07:00
iucv
key
l2tp l2tp: test for ethernet header in l2tp_eth_dev_recv() 2010-08-26 13:29:38 -07:00
lapb
llc net/llc: storing negative error codes in unsigned short 2010-09-16 22:38:23 -07:00
mac80211 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2010-09-30 12:02:22 -07:00
netfilter Merge commit 'v2.6.36-rc7' into core/rcu 2010-10-07 09:43:45 +02:00
netlabel
netlink netlink: Make NETLINK_USERSOCK work again. 2010-08-31 09:51:37 -07:00
netrom
packet
phonet Phonet: Correct header retrieval after pskb_may_pull 2010-09-29 19:41:04 -07:00
rds net: fix a lockdep splat 2010-09-24 22:26:10 -07:00
rfkill
rose rose: Fix signedness issues wrt. digi count. 2010-09-20 15:40:35 -07:00
rxrpc Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
sched sch_atm: Fix potential NULL deref. 2010-09-12 11:56:44 -07:00
sctp sctp: Do not reset the packet during sctp_packet_config(). 2010-09-17 16:47:56 -07:00
sunrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-28 12:01:26 -07:00
tipc
unix UNIX: Do not loop forever at unix_autobind(). 2010-09-07 13:57:23 -07:00
wanrouter
wimax
wireless wext: fix potential private ioctl memory content leak 2010-09-20 13:41:40 -04:00
x25
xfrm xfrm: Allow different selector family in temporary state 2010-09-20 11:11:38 -07:00
compat.c
Kconfig net: RPS needs to depend upon USE_GENERIC_SMP_HELPERS 2010-09-14 21:42:22 -07:00
Makefile
nonet.c
socket.c
sysctl_net.c
TUNABLE