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pkg/report: suppress witness vnode lock order reversal on OpenBSD
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These reports are not that helpful and are rarely a problem as each
vnode has a unique lock. Reports from witness regarding lock order
reversal between two vnode locks are already suppressed by the kernel,
see RWL_IS_VNODE in the rwlock(9) manual.

While here, update `testdata/openbsd/report/10` as this report was
generated before I prefixed all output from witness.
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@mptre @dvyukov
mptre authored and dvyukov committed Oct 27, 2020
1 parent 9494229 commit 353b1a5
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Showing 3 changed files with 296 additions and 1 deletion.
1 change: 1 addition & 0 deletions pkg/report/openbsd.go
View file
Expand Up @@ -20,6 +20,7 @@ func ctorOpenbsd(cfg *config) (Reporter, []string, error) {
}
suppressions := []string{
"panic: fifo_badop called",
"witness: lock order reversal:\\n(.*\\n)*.*[0-9stnd]+ 0x[0-9a-f]+ inode",
}
return ctx, suppressions, nil
}
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3 changes: 2 additions & 1 deletion pkg/report/testdata/openbsd/report/10
View file
@@ -1,6 +1,7 @@
TITLE: witness: reversal: vmmaplk inode
SUPPRESSED: Y

lock order reversal:
witness: lock order reversal:

1st 0xfffffd806e935890 vmmaplk (&map->lock) @ /syzkaller/managers/setuid/kernel/sys/uvm/uvm_fault.c:1442
2nd 0xfffffd806e099f88 inode (&ip->i_lock) @ /syzkaller/managers/setuid/kernel/sys/ufs/ufs/ufs_vnops.c:1547
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293 changes: 293 additions & 0 deletions pkg/report/testdata/openbsd/report/33
View file
@@ -0,0 +1,293 @@
TITLE: witness: reversal: inode netlock
SUPPRESSED: Y

Warning: Permanently added '10.128.1.10' (ECDSA) to the list of known hosts.
executing program
witness: lock order reversal:
1st 0xfffffd806d95cb48 inode (&ip->i_lock)
2nd 0xffffffff8277e670 netlock (netlock)
lock order "&ip->i_lock"(rrwlock) -> "netlock"(rwlock) first seen at:
#0 witness_checkorder+0x65e
#1 rw_enter_write+0x5b
#2 uvn_get+0xeb
#3 uvm_fault+0xa41
#4 kpageflttrap+0x202
#5 kerntrap+0xef
#6 alltraps_kern_meltdown+0x7b
#7 copyin+0x53
#8 sys_connect+0x9b
#9 syscall+0x4a1
#10 Xsyscall+0x128
lock order "netlock"(rwlock) -> "&ip->i_lock"(rrwlock) first seen at:
#0 witness_checkorder+0x65e
#1 rw_enter+0xd4
#2 rrw_enter+0x88
#3 VOP_LOCK+0x4b
#4 vn_lock+0x6c
#5 vget+0x1c6
#6 ktrwriteraw+0x138
#7 ktrstruct+0x169
#8 sys_connect+0x246
#9 syscall+0x4a1
#10 Xsyscall+0x128
Stopped at db_enter+0x18: addq $0x8,%rsp
ddb{1}>
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
the kernel did not panic
ddb{1}> trace
db_enter() at db_enter+0x18
witness_checkorder(fffffd806d95cb48,9,0) at witness_checkorder+0xf5a
rw_enter(fffffd806d95cb38,1) at rw_enter+0xd4
rrw_enter(fffffd806d95cb38,1) at rrw_enter+0x88
VOP_LOCK(fffffd806d9479e0,2001) at VOP_LOCK+0x4b
vn_lock(fffffd806d9479e0,2001) at vn_lock+0x6c
vget(fffffd806d9479e0,2001) at vget+0x1c6
ktrwriteraw(ffff8000ffff62a0,fffffd806d9479e0,fffffd807f7b7a20,ffff800021256fb0,ffff800021256f90) at ktrwriteraw+0x138
ktrstruct(ffff8000ffff62a0,ffffffff823afafa,fffffd806f685020,10) at ktrstruct+0x169
sys_connect(ffff8000ffff62a0,ffff8000212570f8,ffff800021257140) at sys_connect+0x246
syscall(ffff8000212571c0) at syscall+0x4a1
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7fffff7700, count: -12
ddb{1}> show registers
rdi 0x3
rsi 0xffffffff82748230 __sancov_gen_cov_switch_values.129
rbp 0xffff800021256bc0
rbx 0x3
rdx 0x8b
rcx 0x3
rax 0x1
r8 0xffffffff81e34c43 witness_checkorder+0xf33
r9 0x5
r10 0x4c8e2b2814ec0ddb
r11 0xa2a1f000558e67b5
r12 0xffffffff8284c2f0 w_lodata+0x4f730
r13 0
r14 0xffffffff8284c240 w_lodata+0x4f680
r15 0xfffffd8002c9b500
rip 0xffffffff82243a18 db_enter+0x18
cs 0x8
rflags 0x246
rsp 0xffff800021256bb0
ss 0x10
db_enter+0x18: addq $0x8,%rsp
ddb{1}> show proc
PROC (syz-executor1584) pid=302653 stat=onproc
flags process=2<EXEC,8ORPHAN> proc=1<INKTR>
pri=17, usrpri=52, nice=20
forw=0xffffffffffffffff, list=0xffff8000ffff67c0,0xffffffff828e9418
process=0xffff8000212375b0 user=0xffff800021252000, vmspace=0xfffffd806e93f8a8
estcpu=2, cpticks=0, pctcpu=0.0
user=0, sys=0, intr=0
ddb{1}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
*51336 302653 84077 0 7 0x3 syz-executor1584
84077 52317 99949 0 3 0x10008a pause ksh
99949 122278 17718 0 3 0x92 select sshd
94583 294790 1 0 3 0x100083 ttyin getty
17718 144098 1 0 3 0x80 select sshd
3821 78474 93020 74 3 0x100092 bpf pflogd
93020 357117 1 0 3 0x80 netio pflogd
24669 81746 7856 73 3 0x100090 kqread syslogd
7856 467612 1 0 3 0x100082 netio syslogd
22732 468064 1 77 3 0x100090 poll dhclient
98556 158448 1 0 3 0x80 poll dhclient
73584 90685 0 0 3 0x14200 bored smr
50517 29306 0 0 3 0x14200 pgzero zerothread
12470 346654 0 0 3 0x14200 aiodoned aiodoned
71962 341864 0 0 3 0x14200 syncer update
76674 41497 0 0 3 0x14200 cleaner cleaner
58511 296259 0 0 3 0x14200 reaper reaper
35112 351548 0 0 3 0x14200 pgdaemon pagedaemon
47776 416066 0 0 3 0x14200 bored crynlk
5296 120071 0 0 3 0x14200 bored crypto
8780 503052 0 0 3 0x14200 bored viomb
44738 73602 0 0 3 0x40014200 acpi0 acpi0
24823 515200 0 0 3 0x40014200 idle1
79885 424571 0 0 3 0x14200 bored softnet
28507 106394 0 0 3 0x14200 bored systqmp
75046 17946 0 0 3 0x14200 bored systq
82731 522933 0 0 3 0x40014200 bored softclock
70734 56280 0 0 7 0x40014200 idle0
1 111404 0 0 3 0x82 wait init
0 0 -1 0 3 0x10200 scheduler swapper
ddb{1}> show all locks
Process 51336 (syz-executor1584) thread 0xffff8000ffff62a0 (302653)
exclusive rwlock netlock r = 0 (0xffffffff8277e670)
#0 witness_lock+0x4b0
#1 uvn_io+0x31d
#2 uvn_get+0x473
#3 uvm_fault+0xa41
#4 kpageflttrap+0x202
#5 kerntrap+0xef
#6 alltraps_kern_meltdown+0x7b
#7 copyin+0x53
#8 sys_connect+0x9b
#9 syscall+0x4a1
#10 Xsyscall+0x128
exclusive kernel_lock &kernel_lock r = 1 (0xffffffff828cea78)
#0 witness_lock+0x4b0
#1 syscall+0x3fd
#2 Xsyscall+0x128
ddb{1}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 9474 6410K 6411K 78643K 10565 0
pcb 13 8K 8K 78643K 15 0
rtable 61 2K 2K 78643K 127 0
ifaddr 29 8K 8K 78643K 30 0
counters 39 33K 33K 78643K 39 0
ioctlops 0 0K 4K 78643K 1467 0
mount 1 1K 1K 78643K 1 0
vnodes 1183 74K 75K 78643K 1188 0
UFS quota 1 32K 32K 78643K 1 0
UFS mount 5 36K 36K 78643K 5 0
shm 2 1K 1K 78643K 2 0
VM map 2 1K 1K 78643K 2 0
sem 2 0K 0K 78643K 2 0
dirhash 12 2K 2K 78643K 12 0
ACPI 1825 197K 290K 78643K 13109 0
file desc 1 0K 0K 78643K 1 0
proc 59 63K 71K 78643K 367 0
NFS srvsock 1 0K 0K 78643K 1 0
NFS daemon 1 16K 16K 78643K 1 0
in_multi 11 0K 0K 78643K 11 0
ether_multi 1 0K 0K 78643K 1 0
ISOFS mount 1 32K 32K 78643K 1 0
MSDOSFS mount 1 16K 16K 78643K 1 0
ttys 19 95K 95K 78643K 19 0
exec 0 0K 2K 78643K 302 0
pagedep 1 8K 8K 78643K 1 0
inodedep 1 32K 32K 78643K 1 0
newblk 1 0K 0K 78643K 1 0
VM swap 7 26K 26K 78643K 7 0
UVM amap 37 2K 2K 78643K 594 0
UVM aobj 3 2K 2K 78643K 3 0
memdesc 1 4K 4K 78643K 1 0
crypto data 1 1K 1K 78643K 1 0
NDP 4 0K 0K 78643K 4 0
temp 23 3949K 4013K 78643K 1690 0
kqueue 2 2K 2K 78643K 2 0
SYN cache 2 16K 16K 78643K 2 0
ddb{1}> show all pools
Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
arp 64 2 0 0 1 0 1 1 0 8 0
plcache 128 20 0 0 1 0 1 1 0 8 0
rtpcb 120 15 0 13 1 0 1 1 0 8 0
rtentry 112 23 0 1 1 0 1 1 0 8 0
unpcb 120 29 0 19 1 0 1 1 0 8 0
syncache 296 5 0 5 2 1 1 1 0 8 1
tcpcb 736 8 0 5 1 0 1 1 0 8 0
inpcb 296 30 0 23 1 0 1 1 0 8 0
pfosfp 40 1428 0 1005 5 0 5 5 0 8 0
pfosfpen 112 1428 0 714 21 0 21 21 0 8 0
pfstitem 24 8 0 0 1 0 1 1 0 8 0
pfstkey 112 8 0 0 1 0 1 1 0 8 0
pfstate 328 8 0 0 1 0 1 1 0 8 0
pfrule 1360 21 0 15 2 0 2 2 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 97 0 0 7 0 7 7 0 8 0
art_table 32 98 0 0 1 0 1 1 0 8 0
art_node 16 22 0 2 1 0 1 1 0 8 0
dirhash 1024 17 0 0 3 0 3 3 0 8 0
dino2pl 256 1399 0 16 87 0 87 87 0 8 0
ffsino 272 1399 0 16 93 0 93 93 0 8 0
nchpl 144 1573 0 33 59 1 58 58 0 8 0
uvmvnodes 72 1409 0 0 26 0 26 26 0 8 0
vnodes 208 1409 0 0 75 0 75 75 0 8 0
namei 1024 3783 0 3783 2 1 1 1 0 8 1
percpumem 16 30 0 0 1 0 1 1 0 8 0
scxspl 216 3297 0 3297 2 1 1 2 0 8 1
plimitpl 152 14 0 8 1 0 1 1 0 8 0
sigapl 424 221 0 192 4 0 4 4 0 8 0
knotepl 112 5 0 0 1 0 1 1 0 8 0
kqueuepl 152 1 0 0 1 0 1 1 0 8 0
pipepl 304 64 0 60 2 1 1 1 0 8 0
fdescpl 496 205 0 192 3 0 3 3 0 8 0
filepl 152 960 0 909 2 0 2 2 0 8 0
lockfpl 104 5 0 4 1 0 1 1 0 8 0
lockfspl 48 3 0 2 1 0 1 1 0 8 0
sessionpl 144 18 0 9 1 0 1 1 0 8 0
pgrppl 48 18 0 9 1 0 1 1 0 8 0
ucredpl 96 62 0 53 1 0 1 1 0 8 0
zombiepl 144 192 0 192 2 1 1 1 0 8 1
processpl 1056 221 0 192 3 0 3 3 0 8 0
procpl 656 221 0 192 3 0 3 3 0 8 0
sockpl 400 74 0 55 2 0 2 2 0 8 0
mcl4k 4096 2 0 0 1 0 1 1 0 8 0
mcl2k 2048 67 0 0 9 0 9 9 0 8 0
mtagpl 96 1 0 0 1 0 1 1 0 8 0
mbufpl 256 87 0 0 6 0 6 6 0 8 0
bufpl 280 1934 0 112 131 0 131 131 0 8 0
anonpl 16 19596 0 18363 8 2 6 7 0 124 1
amapchunkpl 152 527 0 490 3 1 2 3 0 158 0
amappl16 192 80 0 76 1 0 1 1 0 8 0
amappl15 184 1 0 0 1 0 1 1 0 8 0
amappl14 176 22 0 19 1 0 1 1 0 8 0
amappl13 168 14 0 13 2 1 1 1 0 8 0
amappl12 160 5 0 5 1 1 0 1 0 8 0
amappl11 152 47 0 32 1 0 1 1 0 8 0
amappl10 144 10 0 7 1 0 1 1 0 8 0
amappl9 136 197 0 197 2 1 1 1 0 8 1
amappl8 128 62 0 61 1 0 1 1 0 8 0
amappl7 120 211 0 210 1 0 1 1 0 8 0
amappl6 112 57 0 50 1 0 1 1 0 8 0
amappl5 104 357 0 340 1 0 1 1 0 8 0
amappl4 96 283 0 258 1 0 1 1 0 8 0
amappl3 88 104 0 97 1 0 1 1 0 8 0
amappl2 80 854 0 802 3 1 2 2 0 8 0
amappl1 72 14320 0 13898 15 5 10 15 0 8 0
amappl 80 403 0 383 1 0 1 1 0 84 0
dma4096 4096 1 0 1 1 1 0 1 0 8 0
dma1024 1024 1 0 0 1 0 1 1 0 8 0
dma256 256 6 0 6 1 1 0 1 0 8 0
dma128 128 253 0 253 1 1 0 1 0 8 0
dma64 64 6 0 6 1 1 0 1 0 8 0
dma32 32 7 0 7 1 1 0 1 0 8 0
dma16 16 18 0 17 1 0 1 1 0 8 0
aobjpl 64 2 0 0 1 0 1 1 0 8 0
uaddrrnd 24 205 0 192 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 205 0 192 1 0 1 1 0 8 0
vmmpekpl 168 5583 0 5565 1 0 1 1 0 8 0
vmmpepl 168 29906 0 29079 48 8 40 48 0 357 2
vmsppl 368 204 0 192 2 0 2 2 0 8 0
pdppl 4096 417 0 384 47 14 33 39 0 8 0
pvpl 32 80559 0 77564 29 1 28 28 0 265 1
pmappl 232 204 0 192 1 0 1 1 0 8 0
extentpl 40 57 0 39 1 0 1 1 0 8 0
phpool 112 266 0 17 8 0 8 8 0 8 0
ddb{1}> machine ddbcpu 0
Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp
ddb{0}> trace
x86_ipi_db(ffffffff8272eff0) at x86_ipi_db+0x1a
x86_ipi_handler() at x86_ipi_handler+0xb7
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23
__mp_lock(ffffffff828ce870) at __mp_lock+0x122
intr_handler(ffff80002117ed20,ffff80000065a300) at intr_handler+0x5e
Xintr_ioapic_edge4_untramp() at Xintr_ioapic_edge4_untramp+0x19f
__mp_lock(ffffffff828ce870) at __mp_lock+0x122
softintr_dispatch(0) at softintr_dispatch+0x4e
Xsoftclock() at Xsoftclock+0x1f
acpicpu_idle() at acpicpu_idle+0x2eb
sched_idle(ffffffff8272eff0) at sched_idle+0x417
end trace frame: 0x0, count: -11
ddb{0}> machine ddbcpu 1
Stopped at db_enter+0x18: addq $0x8,%rsp
ddb{1}> trace
db_enter() at db_enter+0x18
witness_checkorder(fffffd806d95cb48,9,0) at witness_checkorder+0xf5a
rw_enter(fffffd806d95cb38,1) at rw_enter+0xd4
rrw_enter(fffffd806d95cb38,1) at rrw_enter+0x88
VOP_LOCK(fffffd806d9479e0,2001) at VOP_LOCK+0x4b
vn_lock(fffffd806d9479e0,2001) at vn_lock+0x6c
vget(fffffd806d9479e0,2001) at vget+0x1c6
ktrwriteraw(ffff8000ffff62a0,fffffd806d9479e0,fffffd807f7b7a20,ffff800021256fb0,ffff800021256f90) at ktrwriteraw+0x138
ktrstruct(ffff8000ffff62a0,ffffffff823afafa,fffffd806f685020,10) at ktrstruct+0x169
sys_connect(ffff8000ffff62a0,ffff8000212570f8,ffff800021257140) at sys_connect+0x246
syscall(ffff8000212571c0) at syscall+0x4a1
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7fffff7700, count: -12
ddb{1}>

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