[Bug 205469] [panic] lock order reversal, userret: returning with the following locks held

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=205469

Oliver Pinter <op at freebsd.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |op at freebsd.org

--- Comment #2 from Oliver Pinter <op at freebsd.org> ---
Confirmed, I can reproduce this error in bhyve: 

WARNING: WITNESS option enabled, expect reduced performance.
Trying to mount root from cd9660:/dev/iso9660/11_0__HBSD_AMD64_CD [ro]...
lock order reversal:
 1st 0xfffffe001d822e40 bufwait (bufwait) @ /usr/src/sys/vm/vm_pager.c:380
 2nd 0xfffff8000512d240 isofs (isofs) @ /usr/src/sys/kern/imgact_elf.c:883
stack backtrace:
#0 0xffffffff80a7d0a0 at witness_debugger+0x70
#1 0xffffffff80a7cfa1 at witness_checkorder+0xe71
#2 0xffffffff80a0056b at __lockmgr_args+0xd3b
#3 0xffffffff80ac320c at vop_stdlock+0x3c
#4 0xffffffff80fc0fa0 at VOP_LOCK1_APV+0x100
#5 0xffffffff80ae3baa at _vn_lock+0x9a
#6 0xffffffff809c4d81 at exec_elf64_imgact+0xa91
#7 0xffffffff809e3809 at kern_execve+0x459
#8 0xffffffff809e305c at sys_execve+0x4c
#9 0xffffffff809c788a at start_init+0x26a
#10 0xffffffff809eafe4 at fork_exit+0x84
#11 0xffffffff80e4ec6e at fork_trampoline+0xe
userret: returning with the following locks held:
exclusive lockmgr bufwait (bufwait) r = 0 (0xfffffe001d822c10) locked @
/usr/src/sys/vm/vm_pager.c:380
exclusive lockmgr bufwait (bufwait) r = 0 (0xfffffe001d822e40) locked @
/usr/src/sys/vm/vm_pager.c:380
panic: witness_warn
cpuid = 0
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe001d7906b0
vpanic() at vpanic+0x182/frame 0xfffffe001d790730
kassert_panic() at kassert_panic+0x126/frame 0xfffffe001d7907a0
witness_warn() at witness_warn+0x3c6/frame 0xfffffe001d790870
userret() at userret+0x98/frame 0xfffffe001d7908a0
trap() at trap+0x3f4/frame 0xfffffe001d790ab0
calltrap() at calltrap+0x8/frame 0xfffffe001d790ab0
--- trap 0xc, rip = 0x4001c4, rsp = 0x7231f647c380, rbp = 0x7231f647c3b0 ---
KDB: enter: panic
[ thread pid 1 tid 100002 ]
Stopped at      kdb_enter+0x3b: movq    $0,kdb_why

-- 
You are receiving this mail because:
You are the assignee for the bug.