LOR and fatal kernel trap

[Anton Shterenlikht]

on r231087M:

lock order reversal:
 1st 0xe000000011e97538 ufs (ufs) @ /usr/src/sys/kern/vfs_vnops.c:640
 2nd 0xa00000009ca60798 bufwait (bufwait) @ /usr/src/sys/kern/vfs_bio.c:1911
 3rd 0xe00000001148dad8 ufs (ufs) @ /usr/src/sys/kern/vfs_subr.c:2167
KDB: stack backtrace:
getenv with the following non-sleepable locks held:
exclusive sleep mutex vnode interlock (vnode interlock) r = 0 (0xe00000001148db08) locked @ /usr/src/sys/kern/vfs_subr.c:2165
KDB: stack backtrace:
getenv with the following non-sleepable locks held:
exclusive sleep mutex vnode interlock (vnode interlock) r = 0 (0xe00000001148db08) locked @ /usr/src/sys/kern/vfs_subr.c:2165
KDB: stack backtrace:
getenv with the following non-sleepable locks held:
exclusive sleep mutex vnode interlock (vnode interlock) r = 0 (0xe00000001148db08) locked @ /usr/src/sys/kern/vfs_subr.c:2165
KDB: stack backtrace:
getenv with the following non-sleepable locks held:
exclusive sleep mutex vnode interlock (vnode interlock) r = 0 (0xe00000001148db08) locked @ /usr/src/sys/kern/vfs_subr.c:2165
KDB: stack backtrace:
getenv with the following non-sleepable locks held:

fatal kernel trap (cpu 1):

    trap vector = 0x18 (General Exception)
    cr.iip      = 0x9ffc0000008b62d0
    cr.ipsr     = 0x1210080a6010 (mfl,ic,i,dt,dfh,rt,cpl=0,it,ri=1,bn)
    cr.isr      = 0x28000000030 (code=48,vector=0,ni,ei=1)
    cr.ifa      = 0xe000000011a5e000
    curthread   = 0xe000000011b08000
        pid = 837, comm = cp

[ thread pid 837 tid 100082 ]
Stopped at      spinlock_exit+0x71:     [M1]    srlz.d
	dhow thread
Thread 100082 at 0xe000000011b08000:
 proc (pid 837): 0xe000000011b8f630
 name: cp
 stack: 0xa0000000f876c000-0xa0000000f8773fff
 flags: 0x10004  pflags: 0x40
 state: RUNNING (CPU 1)
 priority: 152
 container lock: sched lock 1 (0x9ffc000000cb7800)
db> show proc
Process 837 (cp) at 0xe000000011b8f630:
 state: NORMAL
 uid: 1001  gids: 1001, 0, 1003, 1005
 parent: pid 787 at 0xe000000011abe470
 ABI: FreeBSD ELF64
 arguments: cp
 threads: 1
100082                   Run     CPU 1                       cp
db> bt
Tracing pid 837 tid 100082 td 0xe000000011b08000
getenv with the following non-sleepable locks held:
exclusive sleep mutex vnode interlock (vnode interlock) r = 0 (0xe00000001148db08) locked @ /usr/src/sys/kern/vfs_subr.c:2165
KDB: stack backtrace:
spinlock_exit() at spinlock_exit+0x71
uart_quicc_class(0xb00, 0xe000000011a5e430, 0x9ffc0000008885b0, 0x206, 0x9ffc000000c60968, 0x0, 0xe000000011a5e000, 0xe000000011a5e430) at 0x18
db> 
-- 
Anton Shterenlikht
Room 2.6, Queen's Building
Mech Eng Dept
Bristol University
University Walk, Bristol BS8 1TR, UK
Tel: +44 (0)117 331 5944
Fax: +44 (0)117 929 4423