Date: Fri, 23 Jul 1999 16:31:21 -0400 (EDT) From: Alfred Perlstein <bright@rush.net> To: Maxim Sobolev <sobomax@altavista.net> Cc: stable@FreeBSD.ORG Subject: Re: Tun interface related panic Message-ID: <Pine.BSF.3.96.990723161753.27774P-100000@cygnus.rush.net> In-Reply-To: <3798AD44.EF14A396@altavista.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, 23 Jul 1999, Maxim Sobolev wrote:
> Alfred Perlstein wrote:
>
> > [Piece of debug print skipped....]
> > oops, ok, I wasn't clear, I need to know the contents of the structs
> > that those pointers point to, try this:
> >
> > print *uio
> > print *top
> > print **mp
> >
> > in, the meanwhile, try this patch:
> >
> > cvs diff: Diffing .
> > Index: if_tun.c
> > ===================================================================
> > RCS file: /home/ncvs/src/sys/net/if_tun.c,v
> > retrieving revision 1.51
> > diff -u -r1.51 if_tun.c
> > --- if_tun.c 1999/01/17 20:53:47 1.51
> > +++ if_tun.c 1999/07/23 20:42:34
> > @@ -521,7 +521,7 @@
> >
> > TUNDEBUG("%s%d: tunwrite\n", ifp->if_name, ifp->if_unit);
> >
> > - if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) {
> > + if (uio->uio_resid <= 0 || uio->uio_resid > TUNMRU) {
> > TUNDEBUG("%s%d: len=%d!\n", ifp->if_name, ifp->if_unit,
> > uio->uio_resid);
> > return EIO;
> >
> > please please tell me if it works for you so I can file a proper PR.
>
> Yeah! It works! It seems that I'm the one who have detected this problem because
> I'm using latest ppp snapshot instead of standard one. I just tested ppp from
> -stable and discovered that it doesn't make this panic (version of libalias doesn't
> matter though). However it would be great if you can commit this patch because new
> version of ppp have some really nice features on which I rely hardly. This also
> rising a question to the Brian Somers or any other who can look and find what is
> wrong with the current ppp (PPP Version 2.22 - $Date: 1999/06/23 16:48:19 $).
> Anyway, to have some belts in the kernel should not make any harm. Following is the
> ppp output which probably before your patch would kill my box (I never seen this
> message before - so to speak..):
>
> TCP/IP: IN UDP: 208.147.89.229:18422 ---> 192.168.1.1:7070
> Error: ip_Input: deflink: wrote 0, got Input/output error
I don't work on ppp, you should be sure Brian is notified of this problem.
I appreciate your help in tracking this down, the patch has been put into
-stable and -current for it.
>
> If you still want to see prints, you can see it at the end of this message.
> (kgdb) up
> #5 0xc01630f9 in tunwrite (dev=13312, uio=0xc2d15f14, flag=1)
> at ../../net/if_tun.c:559
> 559 top->m_pkthdr.len = tlen;
> (kgdb) print *uio
> $1 = {uio_iov = 0xc2d15f0c, uio_iovcnt = 1, uio_offset = 38962, uio_resid = 0,
> uio_segflg = UIO_USERSPACE, uio_rw = UIO_WRITE, uio_procp = 0xc2cc32e0}
> (kgdb) print *top
> Cannot access memory at address 0x0.
> (kgdb) print **mp
perfect, they were extremely helpful in tracking down this problem, I
assumed that uio->res_id was zero ( it was the only thing that made sense)
however I just needed to verify.
>
> In the case if my assistance in debugging ppp will be necessary please let me know.
Talk to Brian.
hrm, also can you fix your mailer to wrap at 70 chars?
-Alfred
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.3.96.990723161753.27774P-100000>