{pktgen, xfrm} Correct xfrm state lock usage when transforming
authorFan Du <fan.du@windriver.com>
Fri, 3 Jan 2014 03:18:27 +0000 (11:18 +0800)
committerSteffen Klassert <steffen.klassert@secunet.com>
Fri, 3 Jan 2014 06:29:10 +0000 (07:29 +0100)
commit0af0a4136b456d3b337948c76a3d709a38d80d2c
tree3c6f86ceebedfd557907d3f84da2b9c8bc177bb5
parent2f3ea9a95c58fd0e4bed18a9c9dfe53739fee3b2
{pktgen, xfrm} Correct xfrm state lock usage when transforming

xfrm_state lock protects its state, i.e., VALID/DEAD and statistics,
not the transforming procedure, as both mode/type output functions
are reentrant.

Another issue is state lock can be used in BH context when state timer
alarmed, after transformation in pktgen, update state statistics acquiring
state lock should disabled BH context for a moment. Otherwise LOCKDEP
critisize this:

[   62.354339] pktgen: Packet Generator for packet performance testing. Version: 2.74
[   62.655444]
[   62.655448] =================================
[   62.655451] [ INFO: inconsistent lock state ]
[   62.655455] 3.13.0-rc2+ #70 Not tainted
[   62.655457] ---------------------------------
[   62.655459] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[   62.655463] kpktgend_0/2764 [HC0[0]:SC0[0]:HE1:SE1] takes:
[   62.655466]  (&(&x->lock)->rlock){+.?...}, at: [<ffffffffa00886f6>] pktgen_thread_worker+0x1796/0x1860 [pktgen]
[   62.655479] {IN-SOFTIRQ-W} state was registered at:
[   62.655484]   [<ffffffff8109a61d>] __lock_acquire+0x62d/0x1d70
[   62.655492]   [<ffffffff8109c3c7>] lock_acquire+0x97/0x130
[   62.655498]   [<ffffffff81774af6>] _raw_spin_lock+0x36/0x70
[   62.655505]   [<ffffffff816dc3a3>] xfrm_timer_handler+0x43/0x290
[   62.655511]   [<ffffffff81059437>] __tasklet_hrtimer_trampoline+0x17/0x40
[   62.655519]   [<ffffffff8105a1b7>] tasklet_hi_action+0xd7/0xf0
[   62.655523]   [<ffffffff81059ac6>] __do_softirq+0xe6/0x2d0
[   62.655526]   [<ffffffff8105a026>] irq_exit+0x96/0xc0
[   62.655530]   [<ffffffff8177fd0a>] smp_apic_timer_interrupt+0x4a/0x60
[   62.655537]   [<ffffffff8177e96f>] apic_timer_interrupt+0x6f/0x80
[   62.655541]   [<ffffffff8100b7c6>] arch_cpu_idle+0x26/0x30
[   62.655547]   [<ffffffff810ace28>] cpu_startup_entry+0x88/0x2b0
[   62.655552]   [<ffffffff81761c3c>] rest_init+0xbc/0xd0
[   62.655557]   [<ffffffff81ea5e5e>] start_kernel+0x3c4/0x3d1
[   62.655583]   [<ffffffff81ea55a8>] x86_64_start_reservations+0x2a/0x2c
[   62.655588]   [<ffffffff81ea569f>] x86_64_start_kernel+0xf5/0xfc
[   62.655592] irq event stamp: 77
[   62.655594] hardirqs last  enabled at (77): [<ffffffff810ab7f2>] vprintk_emit+0x1b2/0x520
[   62.655597] hardirqs last disabled at (76): [<ffffffff810ab684>] vprintk_emit+0x44/0x520
[   62.655601] softirqs last  enabled at (22): [<ffffffff81059b57>] __do_softirq+0x177/0x2d0
[   62.655605] softirqs last disabled at (15): [<ffffffff8105a026>] irq_exit+0x96/0xc0
[   62.655609]
[   62.655609] other info that might help us debug this:
[   62.655613]  Possible unsafe locking scenario:
[   62.655613]
[   62.655616]        CPU0
[   62.655617]        ----
[   62.655618]   lock(&(&x->lock)->rlock);
[   62.655622]   <Interrupt>
[   62.655623]     lock(&(&x->lock)->rlock);
[   62.655626]
[   62.655626]  *** DEADLOCK ***
[   62.655626]
[   62.655629] no locks held by kpktgend_0/2764.
[   62.655631]
[   62.655631] stack backtrace:
[   62.655636] CPU: 0 PID: 2764 Comm: kpktgend_0 Not tainted 3.13.0-rc2+ #70
[   62.655638] Hardware name: innotek GmbH VirtualBox, BIOS VirtualBox 12/01/2006
[   62.655642]  ffffffff8216b7b0 ffff88001be43ab8 ffffffff8176af37 0000000000000007
[   62.655652]  ffff88001c8d4fc0 ffff88001be43b18 ffffffff81766d78 0000000000000000
[   62.655663]  ffff880000000001 ffff880000000001 ffffffff8101025f ffff88001be43b18
[   62.655671] Call Trace:
[   62.655680]  [<ffffffff8176af37>] dump_stack+0x46/0x58
[   62.655685]  [<ffffffff81766d78>] print_usage_bug+0x1f1/0x202
[   62.655691]  [<ffffffff8101025f>] ? save_stack_trace+0x2f/0x50
[   62.655696]  [<ffffffff81099f8c>] mark_lock+0x28c/0x2f0
[   62.655700]  [<ffffffff810994b0>] ? check_usage_forwards+0x150/0x150
[   62.655704]  [<ffffffff8109a67a>] __lock_acquire+0x68a/0x1d70
[   62.655712]  [<ffffffff81115b09>] ? irq_work_queue+0x69/0xb0
[   62.655717]  [<ffffffff810ab7f2>] ? vprintk_emit+0x1b2/0x520
[   62.655722]  [<ffffffff8109cec5>] ? trace_hardirqs_on_caller+0x105/0x1d0
[   62.655730]  [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen]
[   62.655734]  [<ffffffff8109c3c7>] lock_acquire+0x97/0x130
[   62.655741]  [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen]
[   62.655745]  [<ffffffff81774af6>] _raw_spin_lock+0x36/0x70
[   62.655752]  [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen]
[   62.655758]  [<ffffffffa00886f6>] pktgen_thread_worker+0x1796/0x1860 [pktgen]
[   62.655766]  [<ffffffffa0087a79>] ? pktgen_thread_worker+0xb19/0x1860 [pktgen]
[   62.655771]  [<ffffffff8109cf9d>] ? trace_hardirqs_on+0xd/0x10
[   62.655777]  [<ffffffff81775410>] ? _raw_spin_unlock_irq+0x30/0x40
[   62.655785]  [<ffffffff8151faa0>] ? e1000_clean+0x9d0/0x9d0
[   62.655791]  [<ffffffff81094310>] ? __init_waitqueue_head+0x60/0x60
[   62.655795]  [<ffffffff81094310>] ? __init_waitqueue_head+0x60/0x60
[   62.655800]  [<ffffffffa0086f60>] ? mod_cur_headers+0x7f0/0x7f0 [pktgen]
[   62.655806]  [<ffffffff81078f84>] kthread+0xe4/0x100
[   62.655813]  [<ffffffff81078ea0>] ? flush_kthread_worker+0x170/0x170
[   62.655819]  [<ffffffff8177dc6c>] ret_from_fork+0x7c/0xb0
[   62.655824]  [<ffffffff81078ea0>] ? flush_kthread_worker+0x170/0x170

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
net/core/pktgen.c