Posted-Date: Sun, 15 Jan 2006 21:48:43 +0200 (EET)
Date: Sun, 15 Jan 2006 21:48:38 +0200
From: "Vitaly V. Bursov" <vitalyb@telenet.dn.ua>
To: linux-kernel@vger.kernel.org
Subject: linux 2.6.15.1 ppp_async panic on x86-64.
Message-Id: <20060115214838.2034a56c.vitalyb@telenet.dn.ua>
Organization: Telenet
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Hello,

PPP doesn't work for me on a x86-64 kernel. Kernel panics with a message

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3Dcut: dmesg
Jan 15 20:24:12 vb skb_over_panic: text:ffffffff886700d9 len:1 put:1
head:ffff81002b7ed000 data:ffff81012b7ed000 tail:ffff81012b7ed001
end:ffff81002b7ed600 dev:<NULL>
Jan 15 20:24:12 vb ----------- [cut here ] --------- [please bite here ] --=
-------
Jan 15 20:24:12 vb Kernel BUG at net/core/skbuff.c:94
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3Dcut
note the "tail" and "end" difference:
0xffff81012b7ed001-0xffff81002b7ed600 =3D 0xfffffa01


It looks like that problem is caused by this peace of code.
At least it works better after commenting out "skb_reserve" line.

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3Dcut: ppp_async.c
 err:
        /* frame had an error, remember that, reset SC_TOSS & SC_ESCAPE */
        ap->state =3D SC_PREV_ERROR;
        if (skb) {
                /* make skb appear as freshly allocated */
                skb_trim(skb, 0);
                skb_reserve(skb, - skb_headroom(skb));
        }
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3Dcut

skb_headroom returns 32bit "int", skb_reserve takes 32bit "unsigned int" and
adds it to a 64bit pointer, which is bad.

I'm not at the list.
--=20
Thank you,
Vitaly                                                              DON'T P=
ANIC
GPG Key ID: F95A23B9

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