kern/85864: Lock order reversal in 6.0-BETA3

[Anon]

>Number:         85864
>Category:       kern
>Synopsis:       Lock order reversal in 6.0-BETA3
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Sep 08 11:20:12 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Anon
>Release:        6.0-BETA3
>Organization:
>Environment:
FreeBSD XXX 6.0-BETA3 FreeBSD 6.0-BETA3 #0: Mon Aug 22 22:59:46 UTC 2005     root at harlow.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386
>Description:
lock order reversal
 1st 0xc097ca00 UMA lock (UMA lock) @ /usr/src/sys/vm/uma_core.c:1494
 2nd 0xc1060144 system map (system map) @ /usr/src/sys/vm/vm_map.c:2317
KDB: stack backtrace:
kdb_backtrace(0,ffffffff,c0931ab8,c0931bf8,c08bc1c4) at kdb_backtrace+0x29
witness_checkorder(c1060144,9,c087273f,90d) at witness_checkorder+0x564
_mtx_lock_flags(c1060144,0,c087273f,90d) at _mtx_lock_flags+0x5b
_vm_map_lock(c10600c0,c087273f,90d) at _vm_map_lock+0x26
vm_map_remove(c10600c0,c19f2000,c19f3000,c8393c0c,c077fba9) at vm_map_remove+0x1f
kmem_free(c10600c0,c19f2000,1000,c8393c3c,c077f556) at kmem_free+0x25
page_free(c19f2000,1000,2) at page_free+0x29
zone_drain(c103fd20) at zone_drain+0x26a
zone_foreach(c077f2ec,c8393cec,c07914d7,c8393c74,246) at zone_foreach+0x37
uma_reclaim(c8393c74,246,0,c8393c80,c062a4f5) at uma_reclaim+0x12
vm_pageout_scan(0,c097ce60,0,c0873c2c,604) at vm_pageout_scan+0x103
vm_pageout(0,c8393d38,0,c079232c,0) at vm_pageout+0x2c3
fork_exit(c079232c,0,c8393d38) at fork_exit+0xa0
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = 0xc8393d6c, ebp = 0 ---
pid 5094 (xterm-static), uid 0: exited on signal 6

>How-To-Repeat:
The last line may or may not be related
>Fix:
I don't know enough about kernel hacking to debug this alone, sorry.
However if more information is required I'd be happy to provide it
>Release-Note:
>Audit-Trail:
>Unformatted: