https://github.com/torvalds/linux
Revision 4f647e0a3c37b8d5086214128614a136064110c3 authored by Flavio Leitner on 27 March 2014, 14:05:34 UTC, committed by David S. Miller on 28 March 2014, 20:41:53 UTC
There are two problematic situations.
A deadlock can happen when is_percpu is false because it can get
interrupted while holding the spinlock. Then it executes
ovs_flow_stats_update() in softirq context which tries to get
the same lock.
The second sitation is that when is_percpu is true, the code
correctly disables BH but only for the local CPU, so the
following can happen when locking the remote CPU without
disabling BH:
CPU#0 CPU#1
ovs_flow_stats_get()
stats_read()
+->spin_lock remote CPU#1 ovs_flow_stats_get()
| <interrupted> stats_read()
| ... +--> spin_lock remote CPU#0
| | <interrupted>
| ovs_flow_stats_update() | ...
| spin_lock local CPU#0 <--+ ovs_flow_stats_update()
+---------------------------------- spin_lock local CPU#1
This patch disables BH for both cases fixing the deadlocks.
Acked-by: Jesse Gross <jesse@nicira.com>
=================================
[ INFO: inconsistent lock state ]
3.14.0-rc8-00007-g632b06a #1 Tainted: G I
---------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
swapper/0/0 [HC0[0]:SC1[5]:HE1:SE0] takes:
(&(&cpu_stats->lock)->rlock){+.?...}, at: [<ffffffffa05dd8a1>] ovs_flow_stats_update+0x51/0xd0 [openvswitch]
{SOFTIRQ-ON-W} state was registered at:
[<ffffffff810f973f>] __lock_acquire+0x68f/0x1c40
[<ffffffff810fb4e2>] lock_acquire+0xa2/0x1d0
[<ffffffff817d8d9e>] _raw_spin_lock+0x3e/0x80
[<ffffffffa05dd9e4>] ovs_flow_stats_get+0xc4/0x1e0 [openvswitch]
[<ffffffffa05da855>] ovs_flow_cmd_fill_info+0x185/0x360 [openvswitch]
[<ffffffffa05daf05>] ovs_flow_cmd_build_info.constprop.27+0x55/0x90 [openvswitch]
[<ffffffffa05db41d>] ovs_flow_cmd_new_or_set+0x4dd/0x570 [openvswitch]
[<ffffffff816c245d>] genl_family_rcv_msg+0x1cd/0x3f0
[<ffffffff816c270e>] genl_rcv_msg+0x8e/0xd0
[<ffffffff816c0239>] netlink_rcv_skb+0xa9/0xc0
[<ffffffff816c0798>] genl_rcv+0x28/0x40
[<ffffffff816bf830>] netlink_unicast+0x100/0x1e0
[<ffffffff816bfc57>] netlink_sendmsg+0x347/0x770
[<ffffffff81668e9c>] sock_sendmsg+0x9c/0xe0
[<ffffffff816692d9>] ___sys_sendmsg+0x3a9/0x3c0
[<ffffffff8166a911>] __sys_sendmsg+0x51/0x90
[<ffffffff8166a962>] SyS_sendmsg+0x12/0x20
[<ffffffff817e3ce9>] system_call_fastpath+0x16/0x1b
irq event stamp: 1740726
hardirqs last enabled at (1740726): [<ffffffff8175d5e0>] ip6_finish_output2+0x4f0/0x840
hardirqs last disabled at (1740725): [<ffffffff8175d59b>] ip6_finish_output2+0x4ab/0x840
softirqs last enabled at (1740674): [<ffffffff8109be12>] _local_bh_enable+0x22/0x50
softirqs last disabled at (1740675): [<ffffffff8109db05>] irq_exit+0xc5/0xd0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(&cpu_stats->lock)->rlock);
<Interrupt>
lock(&(&cpu_stats->lock)->rlock);
*** DEADLOCK ***
5 locks held by swapper/0/0:
#0: (((&ifa->dad_timer))){+.-...}, at: [<ffffffff810a7155>] call_timer_fn+0x5/0x320
#1: (rcu_read_lock){.+.+..}, at: [<ffffffff81788a55>] mld_sendpack+0x5/0x4a0
#2: (rcu_read_lock_bh){.+....}, at: [<ffffffff8175d149>] ip6_finish_output2+0x59/0x840
#3: (rcu_read_lock_bh){.+....}, at: [<ffffffff8168ba75>] __dev_queue_xmit+0x5/0x9b0
#4: (rcu_read_lock){.+.+..}, at: [<ffffffffa05e41b5>] internal_dev_xmit+0x5/0x110 [openvswitch]
stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G I 3.14.0-rc8-00007-g632b06a #1
Hardware name: /DX58SO, BIOS SOX5810J.86A.5599.2012.0529.2218 05/29/2012
0000000000000000 0fcf20709903df0c ffff88042d603808 ffffffff817cfe3c
ffffffff81c134c0 ffff88042d603858 ffffffff817cb6da 0000000000000005
ffffffff00000001 ffff880400000000 0000000000000006 ffffffff81c134c0
Call Trace:
<IRQ> [<ffffffff817cfe3c>] dump_stack+0x4d/0x66
[<ffffffff817cb6da>] print_usage_bug+0x1f4/0x205
[<ffffffff810f7f10>] ? check_usage_backwards+0x180/0x180
[<ffffffff810f8963>] mark_lock+0x223/0x2b0
[<ffffffff810f96d3>] __lock_acquire+0x623/0x1c40
[<ffffffff810f5707>] ? __lock_is_held+0x57/0x80
[<ffffffffa05e26c6>] ? masked_flow_lookup+0x236/0x250 [openvswitch]
[<ffffffff810fb4e2>] lock_acquire+0xa2/0x1d0
[<ffffffffa05dd8a1>] ? ovs_flow_stats_update+0x51/0xd0 [openvswitch]
[<ffffffff817d8d9e>] _raw_spin_lock+0x3e/0x80
[<ffffffffa05dd8a1>] ? ovs_flow_stats_update+0x51/0xd0 [openvswitch]
[<ffffffffa05dd8a1>] ovs_flow_stats_update+0x51/0xd0 [openvswitch]
[<ffffffffa05dcc64>] ovs_dp_process_received_packet+0x84/0x120 [openvswitch]
[<ffffffff810f93f7>] ? __lock_acquire+0x347/0x1c40
[<ffffffffa05e3bea>] ovs_vport_receive+0x2a/0x30 [openvswitch]
[<ffffffffa05e4218>] internal_dev_xmit+0x68/0x110 [openvswitch]
[<ffffffffa05e41b5>] ? internal_dev_xmit+0x5/0x110 [openvswitch]
[<ffffffff8168b4a6>] dev_hard_start_xmit+0x2e6/0x8b0
[<ffffffff8168be87>] __dev_queue_xmit+0x417/0x9b0
[<ffffffff8168ba75>] ? __dev_queue_xmit+0x5/0x9b0
[<ffffffff8175d5e0>] ? ip6_finish_output2+0x4f0/0x840
[<ffffffff8168c430>] dev_queue_xmit+0x10/0x20
[<ffffffff8175d641>] ip6_finish_output2+0x551/0x840
[<ffffffff8176128a>] ? ip6_finish_output+0x9a/0x220
[<ffffffff8176128a>] ip6_finish_output+0x9a/0x220
[<ffffffff8176145f>] ip6_output+0x4f/0x1f0
[<ffffffff81788c29>] mld_sendpack+0x1d9/0x4a0
[<ffffffff817895b8>] mld_send_initial_cr.part.32+0x88/0xa0
[<ffffffff817691b0>] ? addrconf_dad_completed+0x220/0x220
[<ffffffff8178e301>] ipv6_mc_dad_complete+0x31/0x50
[<ffffffff817690d7>] addrconf_dad_completed+0x147/0x220
[<ffffffff817691b0>] ? addrconf_dad_completed+0x220/0x220
[<ffffffff8176934f>] addrconf_dad_timer+0x19f/0x1c0
[<ffffffff810a71e9>] call_timer_fn+0x99/0x320
[<ffffffff810a7155>] ? call_timer_fn+0x5/0x320
[<ffffffff817691b0>] ? addrconf_dad_completed+0x220/0x220
[<ffffffff810a76c4>] run_timer_softirq+0x254/0x3b0
[<ffffffff8109d47d>] __do_softirq+0x12d/0x480
Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 99b192d
Tip revision: 4f647e0a3c37b8d5086214128614a136064110c3 authored by Flavio Leitner on 27 March 2014, 14:05:34 UTC
openvswitch: fix a possible deadlock and lockdep warning
openvswitch: fix a possible deadlock and lockdep warning
Tip revision: 4f647e0
| File | Mode | Size |
|---|---|---|
| fonts | ||
| lz4 | ||
| lzo | ||
| mpi | ||
| raid6 | ||
| reed_solomon | ||
| xz | ||
| zlib_deflate | ||
| zlib_inflate | ||
| .gitignore | -rw-r--r-- | 70 bytes |
| Kconfig | -rw-r--r-- | 9.8 KB |
| Kconfig.debug | -rw-r--r-- | 54.4 KB |
| Kconfig.kgdb | -rw-r--r-- | 3.1 KB |
| Kconfig.kmemcheck | -rw-r--r-- | 2.9 KB |
| Makefile | -rw-r--r-- | 5.9 KB |
| argv_split.c | -rw-r--r-- | 2.1 KB |
| asn1_decoder.c | -rw-r--r-- | 12.5 KB |
| assoc_array.c | -rw-r--r-- | 52.5 KB |
| atomic64.c | -rw-r--r-- | 4.2 KB |
| atomic64_test.c | -rw-r--r-- | 3.4 KB |
| audit.c | -rw-r--r-- | 1.2 KB |
| average.c | -rw-r--r-- | 1.9 KB |
| bcd.c | -rw-r--r-- | 261 bytes |
| bch.c | -rw-r--r-- | 35.6 KB |
| bitmap.c | -rw-r--r-- | 34.7 KB |
| bitrev.c | -rw-r--r-- | 2.1 KB |
| bsearch.c | -rw-r--r-- | 1.6 KB |
| btree.c | -rw-r--r-- | 19.2 KB |
| bug.c | -rw-r--r-- | 4.8 KB |
| build_OID_registry | -rwxr-xr-x | 4.7 KB |
| bust_spinlocks.c | -rw-r--r-- | 660 bytes |
| check_signature.c | -rw-r--r-- | 599 bytes |
| checksum.c | -rw-r--r-- | 4.9 KB |
| clz_ctz.c | -rw-r--r-- | 1009 bytes |
| clz_tab.c | -rw-r--r-- | 855 bytes |
| cmdline.c | -rw-r--r-- | 3.6 KB |
| cordic.c | -rw-r--r-- | 2.5 KB |
| cpu-notifier-error-inject.c | -rw-r--r-- | 1.2 KB |
| cpu_rmap.c | -rw-r--r-- | 7.8 KB |
| cpumask.c | -rw-r--r-- | 4.4 KB |
| crc-ccitt.c | -rw-r--r-- | 3.0 KB |
| crc-itu-t.c | -rw-r--r-- | 2.8 KB |
| crc-t10dif.c | -rw-r--r-- | 1.5 KB |
| crc16.c | -rw-r--r-- | 2.8 KB |
| crc32.c | -rw-r--r-- | 45.3 KB |
| crc32defs.h | -rw-r--r-- | 2.0 KB |
| crc7.c | -rw-r--r-- | 2.3 KB |
| crc8.c | -rw-r--r-- | 2.4 KB |
| ctype.c | -rw-r--r-- | 1.4 KB |
| debug_locks.c | -rw-r--r-- | 1.2 KB |
| debugobjects.c | -rw-r--r-- | 26.2 KB |
| dec_and_lock.c | -rw-r--r-- | 784 bytes |
| decompress.c | -rw-r--r-- | 1.5 KB |
| decompress_bunzip2.c | -rw-r--r-- | 23.4 KB |
| decompress_inflate.c | -rw-r--r-- | 3.7 KB |
| decompress_unlz4.c | -rw-r--r-- | 3.8 KB |
| decompress_unlzma.c | -rw-r--r-- | 15.8 KB |
| decompress_unlzo.c | -rw-r--r-- | 6.8 KB |
| decompress_unxz.c | -rw-r--r-- | 10.6 KB |
| devres.c | -rw-r--r-- | 10.2 KB |
| digsig.c | -rw-r--r-- | 5.5 KB |
| div64.c | -rw-r--r-- | 4.0 KB |
| dma-debug.c | -rw-r--r-- | 41.4 KB |
| dump_stack.c | -rw-r--r-- | 1.1 KB |
| dynamic_debug.c | -rw-r--r-- | 25.4 KB |
| dynamic_queue_limits.c | -rw-r--r-- | 4.3 KB |
| earlycpio.c | -rw-r--r-- | 3.9 KB |
| extable.c | -rw-r--r-- | 2.4 KB |
| fault-inject.c | -rw-r--r-- | 5.5 KB |
| fdt.c | -rw-r--r-- | 69 bytes |
| fdt_ro.c | -rw-r--r-- | 72 bytes |
| fdt_rw.c | -rw-r--r-- | 72 bytes |
| fdt_strerror.c | -rw-r--r-- | 78 bytes |
| fdt_sw.c | -rw-r--r-- | 72 bytes |
| fdt_wip.c | -rw-r--r-- | 73 bytes |
| find_last_bit.c | -rw-r--r-- | 1.1 KB |
| find_next_bit.c | -rw-r--r-- | 6.4 KB |
| flex_array.c | -rw-r--r-- | 11.0 KB |
| flex_proportions.c | -rw-r--r-- | 6.8 KB |
| gcd.c | -rw-r--r-- | 313 bytes |
| gen_crc32table.c | -rw-r--r-- | 3.2 KB |
| genalloc.c | -rw-r--r-- | 16.3 KB |
| halfmd4.c | -rw-r--r-- | 2.0 KB |
| hash.c | -rw-r--r-- | 1.0 KB |
| hexdump.c | -rw-r--r-- | 7.2 KB |
| hweight.c | -rw-r--r-- | 1.9 KB |
| idr.c | -rw-r--r-- | 28.7 KB |
| inflate.c | -rw-r--r-- | 38.6 KB |
| int_sqrt.c | -rw-r--r-- | 652 bytes |
| interval_tree.c | -rw-r--r-- | 297 bytes |
| interval_tree_test_main.c | -rw-r--r-- | 2.3 KB |
| iomap.c | -rw-r--r-- | 6.5 KB |
| iomap_copy.c | -rw-r--r-- | 2.1 KB |
| iommu-helper.c | -rw-r--r-- | 1.0 KB |
| ioremap.c | -rw-r--r-- | 2.1 KB |
| iovec.c | -rw-r--r-- | 1.0 KB |
| irq_regs.c | -rw-r--r-- | 604 bytes |
| is_single_threaded.c | -rw-r--r-- | 1.3 KB |
| jedec_ddr_data.c | -rw-r--r-- | 3.0 KB |
| kasprintf.c | -rw-r--r-- | 717 bytes |
| kfifo.c | -rw-r--r-- | 12.7 KB |
| klist.c | -rw-r--r-- | 9.3 KB |
| kobject.c | -rw-r--r-- | 25.5 KB |
| kobject_uevent.c | -rw-r--r-- | 10.5 KB |
| kstrtox.c | -rw-r--r-- | 9.4 KB |
| kstrtox.h | -rw-r--r-- | 254 bytes |
| lcm.c | -rw-r--r-- | 288 bytes |
| libcrc32c.c | -rw-r--r-- | 2.1 KB |
| list_debug.c | -rw-r--r-- | 2.6 KB |
| list_sort.c | -rw-r--r-- | 7.0 KB |
| llist.c | -rw-r--r-- | 3.1 KB |
| locking-selftest-hardirq.h | -rw-r--r-- | 207 bytes |
| locking-selftest-mutex.h | -rw-r--r-- | 120 bytes |
| locking-selftest-rlock-hardirq.h | -rw-r--r-- | 74 bytes |
| locking-selftest-rlock-softirq.h | -rw-r--r-- | 74 bytes |
| locking-selftest-rlock.h | -rw-r--r-- | 158 bytes |
| locking-selftest-rsem.h | -rw-r--r-- | 163 bytes |
| locking-selftest-softirq.h | -rw-r--r-- | 207 bytes |
| locking-selftest-spin-hardirq.h | -rw-r--r-- | 73 bytes |
| locking-selftest-spin-softirq.h | -rw-r--r-- | 73 bytes |
| locking-selftest-spin.h | -rw-r--r-- | 118 bytes |
| locking-selftest-wlock-hardirq.h | -rw-r--r-- | 74 bytes |
| locking-selftest-wlock-softirq.h | -rw-r--r-- | 74 bytes |
| locking-selftest-wlock.h | -rw-r--r-- | 158 bytes |
| locking-selftest-wsem.h | -rw-r--r-- | 163 bytes |
| locking-selftest.c | -rw-r--r-- | 40.1 KB |
| lockref.c | -rw-r--r-- | 3.7 KB |
| lru_cache.c | -rw-r--r-- | 19.2 KB |
| md5.c | -rw-r--r-- | 3.7 KB |
| memory-notifier-error-inject.c | -rw-r--r-- | 1.1 KB |
| memweight.c | -rw-r--r-- | 999 bytes |
| net_utils.c | -rw-r--r-- | 588 bytes |
| nlattr.c | -rw-r--r-- | 12.4 KB |
| notifier-error-inject.c | -rw-r--r-- | 2.7 KB |
| notifier-error-inject.h | -rw-r--r-- | 614 bytes |
| of-reconfig-notifier-error-inject.c | -rw-r--r-- | 1.3 KB |
| oid_registry.c | -rw-r--r-- | 3.8 KB |
| parser.c | -rw-r--r-- | 7.1 KB |
| pci_iomap.c | -rw-r--r-- | 1.4 KB |
| percpu-refcount.c | -rw-r--r-- | 5.8 KB |
| percpu_counter.c | -rw-r--r-- | 5.3 KB |
| percpu_ida.c | -rw-r--r-- | 9.6 KB |
| percpu_test.c | -rw-r--r-- | 3.2 KB |
| plist.c | -rw-r--r-- | 4.7 KB |
| pm-notifier-error-inject.c | -rw-r--r-- | 1.1 KB |
| prio_heap.c | -rw-r--r-- | 1.4 KB |
| proportions.c | -rw-r--r-- | 9.3 KB |
| radix-tree.c | -rw-r--r-- | 40.1 KB |
| random32.c | -rw-r--r-- | 12.7 KB |
| ratelimit.c | -rw-r--r-- | 1.5 KB |
| rational.c | -rw-r--r-- | 1.5 KB |
| rbtree.c | -rw-r--r-- | 15.0 KB |
| rbtree_test.c | -rw-r--r-- | 5.5 KB |
| reciprocal_div.c | -rw-r--r-- | 492 bytes |
| scatterlist.c | -rw-r--r-- | 17.9 KB |
| sha1.c | -rw-r--r-- | 6.1 KB |
| show_mem.c | -rw-r--r-- | 1.2 KB |
| smp_processor_id.c | -rw-r--r-- | 1.1 KB |
| sort.c | -rw-r--r-- | 2.5 KB |
| stmp_device.c | -rw-r--r-- | 2.1 KB |
| string.c | -rw-r--r-- | 16.2 KB |
| string_helpers.c | -rw-r--r-- | 3.6 KB |
| strncpy_from_user.c | -rw-r--r-- | 2.9 KB |
| strnlen_user.c | -rw-r--r-- | 3.6 KB |
| swiotlb.c | -rw-r--r-- | 27.0 KB |
| syscall.c | -rw-r--r-- | 2.4 KB |
| test-kstrtox.c | -rw-r--r-- | 17.4 KB |
| test-string_helpers.c | -rw-r--r-- | 2.5 KB |
| test_module.c | -rw-r--r-- | 753 bytes |
| test_user_copy.c | -rw-r--r-- | 3.1 KB |
| textsearch.c | -rw-r--r-- | 9.6 KB |
| timerqueue.c | -rw-r--r-- | 3.1 KB |
| ts_bm.c | -rw-r--r-- | 5.3 KB |
| ts_fsm.c | -rw-r--r-- | 10.6 KB |
| ts_kmp.c | -rw-r--r-- | 4.3 KB |
| ucs2_string.c | -rw-r--r-- | 1.2 KB |
| usercopy.c | -rw-r--r-- | 197 bytes |
| uuid.c | -rw-r--r-- | 1.3 KB |
| vsprintf.c | -rw-r--r-- | 58.7 KB |
Computing file changes ...
