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 |
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...