Re: kern/45827: panic: LOCKDEBUG (Reader / writer lock error: lockdebug_unlocked: no shared locks held by LWP)

["Greg A. Woods" <woods%planix.ca@localhost>]

The following reply was made to PR kern/45827; it has been noted by GNATS.

From: "Greg A. Woods" <woods%planix.ca@localhost>
To: NetBSD GNATS <gnats-bugs%NetBSD.org@localhost>
Cc: 
Subject: Re: kern/45827: panic: LOCKDEBUG (Reader / writer lock error: 
lockdebug_unlocked: no shared locks held by LWP)
Date: Sun, 22 Jan 2012 15:51:30 -0800

 Most interesting looking crash to date, this one moments after starting
 a "build.sh -j 6" run (but after the machine had been up for two days,
 but running mostly idle):
 
 Reader / writer lock error: lockdebug_unlocked: no shared locks held by LWP
 
 lock address : 0x00000000c0d52cc0 type     :     sleep/adaptive
 initialized  : 0x00000000c04e0af3
 shared holds :                  0 exclusive:                  0
 shares wanted:                  0 exclusive:                  0
 current cpu  :                  2 last held:              65535
 current lwp  : 0x00000000df8865c0 last held: 000000000000000000
 last locked  : 0x00000000c04e0191 unlocked : 0x00000000c04e0382
 owner/count  : 000000000000000000 flags    : 0x0000000000000008
 
 Turnstile chain at 0xc0d53200.
 => No active turnstile for this lock.
 
 panic: LOCKDEBUG
 fatal breakpoint trap in supervisor mode
 trap type 1 code 0 eip c05cc07c cs 8 eflags 246 cr2 bbb18000 ilevel 0
 Stopped in pid 10183.1 (systat) at      netbsd:breakpoint+0x4:  popl    %ebp
 db{2}> 
 db{2}> trace
 breakpoint(c0bfdf42,de63dac8,c3397800,c04fc76f,0,1,0,0,de63dac8,8) at 
netbsd:breakpoint+0x4
 panic(c0b90308,c0b8d22f,c093610b,c0b90368,c04e0382,18865c0,0,8,1,c0d52cc0) at 
netbsd:panic+0x1b0
 lockdebug_abort1(c0b90368,1,1,c0d5c120,0,0,c0d5c120,c3b14634,68,7fffffff) at 
netbsd:lockdebug_abort1+0xbb
 
rw_vector_exit(c0d52cc0,68,de63dc0c,c0533bd5,0,bbb94050,68,1,c053e708,df8865c0) 
at netbsd:rw_vector_exit+0xc8
 sysctl_unlock(0,bbb94050,68,1,c053e708,df8865c0,0,18,1,dc553c2c) at 
netbsd:sysctl_unlock+0x12
 sysctl_dobuf(de63dca4,4,bbb55000,de63dccc,0,0,de63dc9c,df8865c0,c336c980,0) at 
netbsd:sysctl_dobuf+0xc5
 sysctl_dispatch(de63dc9c,6,bbb55000,de63dccc,0,0,de63dc9c,df8865c0,c336c980,0) 
at netbsd:sysctl_dispatch+0xcf
 
sys___sysctl(df8865c0,de63dd00,de63dd28,de63dd40,c05b8a80,dceb3424,ca,bfbfdf2c,6,bbb55000)
 at netbsd:sys___sysctl+0xd6
 syscall(de63dd48,b3,ab,1f,1f,bfbfdf2c,bbb55000,bfbfde88,0,6) at 
netbsd:syscall+0xcf
 db{2}> machine cpu 0
 using CPU 0
 db{2}> trace
 x86_mwait(0,0,0,c04d4502,cc608c80,cc605ec0,d6f2cd2c,c04c0896,0,0) at 
netbsd:x86_mwait+0xc
 x86_cpu_idle_mwait(0,0,c04c66c9,0,0,0,c0c3dd48,cc608c80,c04c0710,cc608c80) at 
netbsd:x86_cpu_idle_mwait+0x4e
 idle_loop(cc608c80,0,c01002cd,0,c01002cd,0,0,0,0,0) at netbsd:idle_loop+0x186
 db{2}> machine cpu 1
 using CPU 1
 db{2}> trace
 copyout(df7b828c,dbb71000,bbb6b000,2000,df7b828c,0,dbb71000,14000,0,dbb71000) 
at netbsd:copyout+0x33
 uiomove(dbb71000,2000,dfbacc7c,dfbacb1c,0,101,dfbacb8c,dc440090,d743a5b4,0) at 
netbsd:uiomove+0x62
 ubc_uiomove(de97b510,dfbacc7c,4000,0,101,0,0,0,0,0) at netbsd:ubc_uiomove+0xeb
 
ffs_read(dfbacc04,0,c0937960,de97b510,1,20001,dfbacc1c,c0549d18,c0937420,de97b510)
 at netbsd:ffs_read+0x45b
 VOP_READ(de97b510,dfbacc7c,0,cc607c00,35,5e5f22,0,16,4000,bbb6b000) at 
netbsd:VOP_READ+0x6c
 
vn_read(dc4e1080,dc4e1080,dfbacc7c,cc607c00,1,bbb13290,0,df7b828c,bba32000,1000)
 at netbsd:vn_read+0x93
 dofileread(35,dc4e1080,bbb6b000,4000,dc4e1080,1,dfbacd28,dfb6ea20,dfb6ea20,0) 
at netbsd:dofileread+0x75
 
sys_read(dfb6ea20,dfbacd00,dfbacd28,bba32010,bba32000,df7b828c,3,35,bbb6b000,4000)
 at netbsd:sys_read+0x6f
 syscall(dfbacd48,b3,ab,1f,1f,0,0,bfbfc338,8129f28,35) at netbsd:syscall+0xcf
 db{2}> machine cpu 2
 using CPU 2
 db{2}> trace
 breakpoint(c0bfdf42,de63dac8,c3397800,c04fc76f,0,1,0,0,de63dac8,8) at 
netbsd:breakpoint+0x4
 panic(c0b90308,c0b8d22f,c093610b,c0b90368,c04e0382,18865c0,0,8,1,c0d52cc0) at 
netbsd:panic+0x1b0
 lockdebug_abort1(c0b90368,1,1,c0d5c120,0,0,c0d5c120,c3b14634,68,7fffffff) at 
netbsd:lockdebug_abort1+0xbb
 
rw_vector_exit(c0d52cc0,68,de63dc0c,c0533bd5,0,bbb94050,68,1,c053e708,df8865c0) 
at netbsd:rw_vector_exit+0xc8
 sysctl_unlock(0,bbb94050,68,1,c053e708,df8865c0,0,18,1,dc553c2c) at 
netbsd:sysctl_unlock+0x12
 sysctl_dobuf(de63dca4,4,bbb55000,de63dccc,0,0,de63dc9c,df8865c0,c336c980,0) at 
netbsd:sysctl_dobuf+0xc5
 sysctl_dispatch(de63dc9c,6,bbb55000,de63dccc,0,0,de63dc9c,df8865c0,c336c980,0) 
at netbsd:sysctl_dispatch+0xcf
 
sys___sysctl(df8865c0,de63dd00,de63dd28,de63dd40,c05b8a80,dceb3424,ca,bfbfdf2c,6,bbb55000)
 at netbsd:sys___sysctl+0xd6
 syscall(de63dd48,b3,ab,1f,1f,bfbfdf2c,bbb55000,bfbfde88,0,6) at 
netbsd:syscall+0xcf
 db{2}> machine cpu 4   
 using CPU 4
 db{2}> trace
 x86_mwait(0,0,0,c04d4502,cc61ad20,cc605c40,d7371d20,c04c0896,0,0) at 
netbsd:x86_mwait+0xc
 x86_cpu_idle_mwait(0,0,0,0,0,0,c3398848,40,d7371da0,c0c3ed38) at 
netbsd:x86_cpu_idle_mwait+0x4e
 idle_loop(0,c04c0710,cc61ad20,c01002d0,0,c01002cd,0,c01002cd,0,0) at 
netbsd:idle_loop+0x186
 Bad frame pointer: 0xcc61ad20
 db{2}> machine cpu 5 
 using CPU 5
 db{2}> trace
 ?(0,0,0,0,0,0,0,0,0,0) at 0x80a863e
 db{2}> machine cpu 6
 using CPU 6
 db{2}> trace
 logputchar(57,dfa35cc0,dfaa2c7c,cc607c00,1,1bfdac2,1,c010cdb9,3f4c,0) at 
netbsd:logputchar+0x28
 putchar(df92e83c,1000,ffffffff,0,df85cd54,0,dfaa2d48,0,e0,df85cd54) at 
netbsd:putchar+0xda
 kprintf(c010cdb9,5,0,0,dfaa2d48,29e0,0,0,dfaa2d48,0) at netbsd:kprintf+0x217
 printf(c010cdb9,b3,ab,1f,1f,bb67d000,3f4c,bfbfc668,bbb100d0,bb67b008) at 
netbsd:printf+0x4b
 db{2}> machine cpu 7
 using CPU 7
 db{2}> trace
 x86_mwait(0,0,0,c04d4502,d7420c80,cc605ac0,d7405d20,c04c0896,0,0) at 
netbsd:x86_mwait+0xc
 x86_cpu_idle_mwait(0,0,0,0,0,0,c339a048,40,d7405da0,c0c3ed38) at 
netbsd:x86_cpu_idle_mwait+0x4e
 idle_loop(0,c04c0710,d7420c80,c01002d0,0,c01002cd,0,c01002cd,0,0) at 
netbsd:idle_loop+0x186
 _prop_array_pool(0,c339a000,cc605ac0,0,d7405da0,d7405d38,0,0,0,0) at 0xc339a000
 db{2}> 
 
 -- 
                                                Greg A. Woods
                                                Planix, Inc.
 
 <woods%planix.com@localhost>       +1 250 762-7675        
http://www.planix.com/