on this netbsd-5 box (test NFS server with 2 fast linux clients) I got
(after fixing m_split() to handle 0 len, see previous mail):
panic: sbdrop
fatal breakpoint trap in supervisor mode
trap type 1 code 0 eip c03faa4c cs 8 eflags 246 cr2 cdb59000 ilevel 4
Stopped in pid 0.3 (system) at netbsd:breakpoint+0x4: popl %ebp
db{0}> tr
breakpoint
(c065149e,cd13bbac,c06adc00,c0361439,6,c3c14500,cd13bba0,c0388770,5043
5051,ffffffff) at netbsd:breakpoint+0x4
panic
(c0655801,c3c14500,ffffffff,c035dc93,50435851,c06adc00,0,e8,c3ba07e0,c
3c14400) at netbsd:panic+0x1b0
sbdrop(c3ba07e0,e8,c3c1446c,14,20,0,c3b40d00,14,cd13bca8,ce320030)
at netbsd:sbdrop+0x2f8
tcp_input(c3c14400,14,6,1,c01280ea,cbf87a00,0,0,14,cbf87a00) at
netbsd:tcp_input+0x24b7
ip_input(c3c14400,0,7,cbf87a00,cd137154,cd1371ec,cd13bd80,c03433ed,
0,cd130010) at netbsd:ip_input+0x61f
ipintr
(0,cd130010,cbf80030,cbf80010,c2da0010,0,f87c80,c2da3780,0,cd13bda0) a
t netbsd:ipintr+0x4d
softint_dispatch(cbf87c80,4,0,0,0,0,cd13bd90,cd13ba68,cd13bac0,18)
at netbsd:softint_dispatch+0xcd
DDB lost frame for netbsd:Xsoftintr+0x3d, trying 0xcd13bd88
Xsoftintr() at netbsd:Xsoftintr+0x3d