recursed on non-recursive lock (sleep mutex) rtentry _at_ /usr/src/sys/net/route.c:182

I got this on 5.2-RELEASE with DEBUG_LOCKS kernel when I'm starting
IPv6 routing configuration.


-----
recursed on non-recursive lock (sleep mutex) rtentry _at_ /usr/src/sys/net/route.c:182
first acquired _at_ /usr/src/sys/net/route.c:744
panic: recurse
cpuid = 0;
Debugger("panic")
Stopped at      Debugger+0x55:  xchgl   %ebx,in_Debugger.0
db> show locks
exclusive sleep mutex rtentry r = 1 (0xc6bc4164) locked _at_ /usr/src/sys/net/route.c:744
exclusive sleep mutex radix node head r = 2 (0xc6b2f57c) locked _at_ /usr/src/sys/net/route.c:133
exclusive sleep mutex Giant r = 0 (0xc07d4240) locked _at_ /usr/src/sys/kern/uipc_syscalls.c:690
db> trace
Debugger(c07582c8,0,c075b6a5,e2016694,100) at Debugger+0x55
panic(c075b6a5,c0761636,2e8,c0761636,b6) at panic+0x156
witness_lock(c6bc4164,8,c0761636,b6,c6bc4100) at witness_lock+0x3b3
_mtx_lock_flags(c6bc4164,0,c0761636,b6,c07d89e0) at _mtx_lock_flags+0xba
rtalloc1(e201677c,0,0,c6b2f54c,c6df3000) at rtalloc1+0x22d
nd6_lookup(c6df3008,0,c6952c00,0,c6bc4100) at nd6_lookup+0x55
nd6_is_addr_neighbor(c6df3000,c6952c00,c0769475,438,c6df3000) at nd6_is_addr_neighbor+0x91
nd6_rtrequest(b,c6bc4100,e2016860,c6bc4100,c0757782) at nd6_rtrequest+0x82
rtrequest1(b,e2016860,e20168bc,0,e2016a30) at rtrequest1+0x7ca
rtrequest(b,e2016a30,0,0,0) at rtrequest+0x4a
rtalloc1(e2016a30,1,0,3a8080,e2016a2c) at rtalloc1+0xe4
rtalloc_ign(e2016a2c,0,e2016a58,c0624910,e2016a2c) at rtalloc_ign+0xe6
rtalloc(e2016a2c,1c,c6c8b0f0,e20169b4,c0773b06) at rtalloc+0x19
ip6_output(c29b4700,c6df2500,e2016a2c,0,0) at ip6_output+0xa10
rip6_output(c29b4700,c6c8b0f0,e2016b48,0,1c1c) at rip6_output+0x46b
rip6_send(c6c8b0f0,0,c29b4700,c6bbc5e0,0) at rip6_send+0xcc
sosend(c6c8b0f0,c6bbc5e0,e2016c08,c29b4700,0) at sosend+0x44d
kern_sendit(c694d640,3,e2016cb8,0,0) at kern_sendit+0x17c
sendit(c694d640,3,e2016cb8,0,8050410) at sendit+0x16e
sendmsg(c694d640,e2016d14,c0778d40,3ee,3) at sendmsg+0xc3
syscall(2f,2f,2f,bfbfe630,10) at syscall+0x2c0
Xint0x80_syscall() at Xint0x80_syscall+0x1d
--- syscall (28, FreeBSD ELF32, sendmsg), eip = 0x280ede6f, esp = 0xbfbfe5fc, ebp = 0xbfbfe648 ---


-- 
Jun Kuriyama <kuriyama_at_imgsrc.co.jp> // IMG SRC, Inc.
             <kuriyama_at_FreeBSD.org> // FreeBSD Project