Jason, I have sent you the patch for testing. Could you please help testing this patch? Will submit it here once it is tested by you. Regards, Suresh -----Original Message----- From: Suresh Thiagarajan [mailto:sureshkalki@xxxxxxxxx] Sent: Wednesday, November 27, 2013 11:11 AM To: Jason Seba Cc: linux-scsi@xxxxxxxxxxxxxxx; Suresh Thiagarajan Subject: Re: Possible locking bug in pm8xxx/pm8001 Hi Jason On Sat, Oct 12, 2013 at 2:02 AM, Jason Seba <jason.seba42@xxxxxxxxx> wrote: > The pm8xxx driver uses a per-adapter spinlock (pm8001_ha->lock) which > is usually acquired and released with the irqsave routines. However, > some functions which are called with the lock held > (mpi_sata_completion, mpi_sata_event, pm8001_chip_sata_req) will > temporary release the lock to complete a task. However, when releasing > and reacquiring the lock in this case, the irqsave routine are not > used; instead spin_unlock_irq/spin_lock_irq are used. As far as I can > tell, this is wrong and dangerous, and appears to result in the hard > lockup shown below. > > It isn't obvious to me what the best way to fix this is. Suggestions? This can be fixed by using flag variable from pm8001_hba_info structure instead of taking it as local variable in all the functions. Will send out a patch soon to fix this. Regards, Suresh > > > > [ 2048.017802] ------------[ cut here ]------------ [ 2048.022621] > WARNING: CPU: 0 PID: 1606 at kernel/watchdog.c:245 > watchdog_overflow_callback+0xac/0xd0() > [ 2048.031827] Watchdog detected hard LOCKUP on cpu 0 [ 2048.036439] > Modules linked in: ses enclosure xt_CHECKSUM iptable_mangle > ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat bridge sunrpc fcoe 8021q > mrp garp libfcoe libfc scsi_transport_fc stp llc scsi_tgt xt_physdev > nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT > nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter > ip6_tables binfmt_misc uinput iTCO_wdt iTCO_vendor_support mgag200 ttm > drm_kms_helper drm i2c_algo_bit sysimgblt sysfillrect syscopyarea > pm80xx libsas scsi_transport_sas joydev dcdbas pcspkr i2c_i801 > i2c_core lpc_ich mfd_core tg3 ptp pps_core [last unloaded: > speedstep_lib] > [ 2048.090159] CPU: 0 PID: 1606 Comm: libvirtd Not tainted 3.11.0-rc5+ > #2 [ 2048.096682] Hardware name: Dell Inc. PowerEdge T110 II/015TH9, > BIOS > 2.0.5 03/13/2012 > [ 2048.104410] 000000f5 f3401828 c1580fe3 c1710301 f3401858 c10418e4 > c17061bc f3401884 [ 2048.112277] 00000646 c1710301 000000f5 c10c415c > c10c415c f5822800 > c10c40b0 00000000 > [ 2048.120153] f3401870 c10419a3 00000009 f3401868 c17061bc f3401884 > f3401888 c10c415c > [ 2048.128022] Call Trace: > [ 2048.130476] [<c1580fe3>] dump_stack+0x41/0x56 [ 2048.134921] > [<c10418e4>] warn_slowpath_common+0x84/0xa0 [ 2048.140231] > [<c10c415c>] ? watchdog_overflow_callback+0xac/0xd0 > [ 2048.146236] [<c10c415c>] ? watchdog_overflow_callback+0xac/0xd0 > [ 2048.152239] [<c10c40b0>] ? watchdog_cleanup+0x10/0x10 [ > 2048.157369] [<c10419a3>] warn_slowpath_fmt+0x33/0x40 [ 2048.162420] > [<c10c415c>] watchdog_overflow_callback+0xac/0xd0 > [ 2048.168243] [<c10fbbef>] __perf_event_overflow+0xaf/0x280 [ > 2048.173729] [<c101322a>] ? x86_perf_event_set_period+0x12a/0x1e0 > [ 2048.179819] [<c10fc685>] perf_event_overflow+0x15/0x20 [ > 2048.185043] [<c1019d9b>] intel_pmu_handle_irq+0x1bb/0x390 [ > 2048.190519] [<c107019d>] ? sched_clock_cpu+0x11d/0x1a0 [ 2048.195744] > [<c1586871>] perf_event_nmi_handler+0x31/0x50 [ 2048.201229] > [<c1585f52>] nmi_handle+0x52/0x190 [ 2048.205762] [<c1342b60>] ? > serial8250_modem_status+0xb0/0xb0 [ 2048.211504] [<c1586172>] > do_nmi+0xe2/0x3d0 [ 2048.215681] [<c15856bb>] > nmi_stack_correct+0x2f/0x34 [ 2048.220732] [<c15800d8>] ? > __pci_bus_size_bridges+0x868/0x890 > [ 2048.226563] [<c1584c12>] ? _raw_spin_lock_irqsave+0x22/0x30 [ > 2048.232215] [<f80f018e>] process_oq+0x6ae/0x1820 [pm80xx] [ > 2048.237698] [<f80f1323>] pm8001_chip_isr+0x23/0x40 [pm80xx] [ > 2048.243356] [<f80e501f>] pm8001_tasklet+0x1f/0x30 [pm80xx] [ > 2048.248925] [<c10458de>] tasklet_action+0x8e/0xa0 [ 2048.253709] > [<c104616f>] __do_softirq+0xaf/0x200 [ 2048.258406] [<c10463a5>] > irq_exit+0xa5/0xb0 [ 2048.262676] [<c158c45b>] do_IRQ+0x4b/0xc0 [ > 2048.266768] [<c105f67b>] ? add_wait_queue+0x3b/0x50 [ 2048.271730] > [<c158c333>] common_interrupt+0x33/0x38 [ 2048.276687] [<c14800d8>] ? > qi_flush_dev_iotlb+0x98/0xf0 [ 2048.282001] [<c1167fb1>] ? > poll_schedule_timeout+0x1/0xb0 [ 2048.287483] [<c1168eed>] ? > do_sys_poll+0x4ad/0x530 [ 2048.292352] [<c11681e0>] ? > __pollwait+0xe0/0xe0 [ 2048.296962] [<c11681e0>] ? > __pollwait+0xe0/0xe0 [ 2048.301581] [<c11681e0>] ? > __pollwait+0xe0/0xe0 [ 2048.306197] [<c11681e0>] ? > __pollwait+0xe0/0xe0 [ 2048.310808] [<c11681e0>] ? > __pollwait+0xe0/0xe0 [ 2048.315416] [<c11681e0>] ? > __pollwait+0xe0/0xe0 [ 2048.320026] [<c14c4ef4>] ? > netlink_recvmsg+0x294/0x340 [ 2048.325244] [<c123827d>] ? > selinux_socket_recvmsg+0x1d/0x20 [ 2048.330901] [<c148d5b0>] ? > sock_recvmsg+0xc0/0xf0 [ 2048.335692] [<c10733c7>] ? > update_curr+0x1e7/0x290 [ 2048.340572] [<c148b56d>] ? > move_addr_to_user+0x7d/0xb0 [ 2048.345796] [<c148db52>] ? > ___sys_recvmsg+0x142/0x1e0 [ 2048.350933] [<c148d4f0>] ? > kernel_sendmsg+0x50/0x50 [ 2048.355898] [<c148de0f>] ? > __sys_recvmsg+0x5f/0x70 [ 2048.360775] [<c148de36>] ? > SyS_recvmsg+0x16/0x20 [ 2048.365473] [<c148e617>] ? > SyS_socketcall+0x107/0x2e0 [ 2048.370609] [<c1168fca>] > SyS_poll+0x5a/0xd0 [ 2048.374873] [<c158be81>] > sysenter_do_call+0x12/0x22 [ 2048.379828] ---[ end trace > 723e25b4ff5b3a4f ]--- > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" > in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo > info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
