Pavel Emelyanov 0fa7fa98db packet: Protect packet sk list with mutex (v2) ... Change since v1: * Fixed inuse counters access spotted by Eric In patch eea68e2f (packet: Report socket mclist info via diag module) I've introduced a "scheduling in atomic" problem in packet diag module -- the socket list is traversed under rcu_read_lock() while performed under it sk mclist access requires rtnl lock (i.e. -- mutex) to be taken. [152363.820563] BUG: scheduling while atomic: crtools/12517/0x10000002 [152363.820573] 4 locks held by crtools/12517: [152363.820581] #0: (sock_diag_mutex){+.+.+.}, at: [<ffffffff81a2dcb5>] sock_diag_rcv+0x1f/0x3e [152363.820613] #1: (sock_diag_table_mutex){+.+.+.}, at: [<ffffffff81a2de70>] sock_diag_rcv_msg+0xdb/0x11a [152363.820644] #2: (nlk->cb_mutex){+.+.+.}, at: [<ffffffff81a67d01>] netlink_dump+0x23/0x1ab [152363.820693] #3: (rcu_read_lock){.+.+..}, at: [<ffffffff81b6a049>] packet_diag_dump+0x0/0x1af Similar thing was then re-introduced by further packet diag patches (fanount mutex and pgvec mutex for rings) :( Apart from being terribly sorry for the above, I propose to change the packet sk list protection from spinlock to mutex. This lock currently protects two modifications: * sklist * prot inuse counters The sklist modifications can be just reprotected with mutex since they already occur in a sleeping context. The inuse counters modifications are trickier -- the __this_cpu_-s are used inside, thus requiring the caller to handle the potential issues with contexts himself. Since packet sockets' counters are modified in two places only (packet_create and packet_release) we only need to protect the context from being preempted. BH disabling is not required in this case. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2012-08-22 22:58:27 -07:00
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acpi	Merge branches 'delete-gts-bfs', 'misc', 'novell-bugzilla-757888-numa' and 'osc-pcie' into base	2012-08-03 00:31:23 -04:00
asm-generic	mutex: Place lock in contended state after fastpath_lock failure	2012-08-13 18:46:54 +02:00
crypto
drm	drm/radeon/kms: implement timestamp userspace query (v2)	2012-08-13 10:50:56 -04:00
keys
linux	mdio: translation of MMD EEE registers to/from ethtool settings	2012-08-22 22:58:27 -07:00
math-emu
media	[media] v4l2: add core support for the new VIDIOC_ENUM_FREQ_BANDS ioctl	2012-07-30 20:23:05 -03:00
memory
misc
mtd
net	packet: Protect packet sk list with mutex (v2)	2012-08-22 22:58:27 -07:00
pcmcia
ras
rdma
rxrpc
scsi	Merge branch 'master' [vanilla Linus master] into libata-dev.git/upstream	2012-07-25 15:58:48 -04:00
sound	ASoC: Additional updates for 3.6	2012-08-20 21:26:04 +02:00
target
trace	Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2012-08-03 10:57:20 -07:00
video	video: da8xx-fb: configure FIFO threshold to reduce underflow errors	2012-07-29 01:11:09 +00:00
xen
Kbuild