kern/81324: panic: "Duplicate free of item %p from zone %p(%s)\n"

[Gleb Smirnoff]

  Giorgos,

On Sat, May 21, 2005 at 05:53:19AM +0300, Giorgos Keramidas wrote:
G> > #22 0xc0532dbb in panic (
G> >     fmt=0xc06e28f8 "Duplicate free of item %p from zone %p(%s)\n")
G> >     at /usr/src/sys/kern/kern_shutdown.c:550
G> > #23 0xc0657260 in uma_dbg_free (zone=0xc0c6aae0, slab=0xc1355fa8,
G> >     item=0xc1355e00) at /usr/src/sys/vm/uma_dbg.c:301
G> > #24 0xc065602f in uma_zfree_arg (zone=0xc0c6aae0, item=0xc1355e00, udata=0x0)
G> >     at /usr/src/sys/vm/uma_core.c:2273
G> > #25 0xc0564b82 in m_freem (mb=0x0) at uma.h:304
G> > #26 0xc044f864 in fr_check (ip=0xc1355e50, hlen=25, ifp=0xc1120000, out=0,
G> >     mp=0xca869c88) at /usr/src/sys/contrib/ipfilter/netinet/fil.c:1387
G> > #27 0xc0451302 in fr_check_wrapper (arg=0x0, mp=0x0, ifp=0xc1120000, dir=1,
G> >     inp=0x0) at /usr/src/sys/contrib/ipfilter/netinet/ip_fil.c:345
G> > #28 0xc059cfad in pfil_run_hooks (ph=0xc0760c20, mp=0xca869cd4,
G> >     ifp=0xc1120000, dir=1, inp=0x0) at /usr/src/sys/net/pfil.c:137
G> > #29 0xc05b2dd5 in ip_input (m=0xc1355e00)
G> >     at /usr/src/sys/netinet/ip_input.c:457
G> 
G> That's odd...
G> 
G> The pfil_run_hooks() function passes the address of a local struct mbuf,
G> which should be on the stack.  How can this ever appear as a null pointer
G> (mp=0x0) in frame #27 ?!

A known bug of gdb, I'd say.

-- 
Totus tuus, Glebius.
GLEBIUS-RIPN GLEB-RIPE