From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 1E8DBB7B96 for ; Wed, 5 Aug 2009 00:15:51 +1000 (EST) Received: from bilbo.ozlabs.org (bilbo.ozlabs.org [203.10.76.25]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "bilbo.ozlabs.org", Issuer "CAcert Class 3 Root" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 0DCB4DDD04 for ; Wed, 5 Aug 2009 00:15:51 +1000 (EST) Subject: Re: 2.6.31-rc5-git2 crash [net/core/flow.c:flow_cache_new_hashrnd] From: Michael Ellerman To: Sachin Sant In-Reply-To: <4A783B1F.7000602@in.ibm.com> References: <4A78292A.5000607@in.ibm.com> <4A783B1F.7000602@in.ibm.com> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-c/6DjyA9naNp3wCGmgoS" Date: Wed, 05 Aug 2009 00:15:50 +1000 Message-Id: <1249395350.8016.5.camel@concordia> Mime-Version: 1.0 Cc: netdev , David Miller , linuxppc-dev@ozlabs.org Reply-To: michael@ellerman.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-c/6DjyA9naNp3wCGmgoS Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, 2009-08-04 at 19:13 +0530, Sachin Sant wrote: > Forgot to copy netdev in my original message. Forwarding .. >=20 > I have a power6 blade [IBM,7998-61X] running 2.6.31-rc5-git2 > kernel (a33a052f19a21d727847391c8c1aff3fb221c472). After some > period of inactivity the machine drops into xmon with following > traces. >=20 > cpu 0x0: Vector: 700 (Program Check) at [c00000000ffffa90] > pc: c000000000600000: .flow_cache_new_hashrnd+0x3c/0xcc > lr: c0000000000c6038: .run_timer_softirq+0x20c/0x2f4 > sp: c00000000ffffd10 > msr: 8000000000089032 > current =3D 0xc000000000f58b70 > paca =3D 0xc0000000010b2400 > pid =3D 0, comm =3D swapper > enter ? for help > [c00000000ffffda0] c0000000000c6038 .run_timer_softirq+0x20c/0x2f4 > [c00000000ffffea0] c0000000000be8a0 .__do_softirq+0x174/0x2c8 > [c00000000fffff90] c0000000000307b0 .call_do_softirq+0x14/0x24 > [c000000001013870] c00000000000ecf8 .do_softirq+0xa0/0x104 > [c000000001013910] c0000000000be1d0 .irq_exit+0x74/0xd4 > [c000000001013990] c00000000002ce20 .timer_interrupt+0x1cc/0x200 > [c000000001013a30] c000000000003728 decrementer_common+0x128/0x180 > --- Exception: 901 (Decrementer) at c00000000000ec3c .raw_local_irq_resto= re+0xc0/0xdc > [c000000001013dc0] c000000000015824 .cpu_idle+0x13c/0x1e0 > [c000000001013e60] c000000000009fe8 .rest_init+0x94/0xcc > [c000000001013ee0] c000000000990cf4 .start_kernel+0x484/0x4a8 > [c000000001013f90] c000000000008408 .start_here_common+0x2c/0xa4 > 0:mon> di $.flow_cache_new_hashrnd > c0000000005fffc4 7c0802a6 mflr r0 > c0000000005fffc8 f8010010 std r0,16(r1) > c0000000005fffcc fb81ffe0 std r28,-32(r1) > c0000000005fffd0 fba1ffe8 std r29,-24(r1) > c0000000005fffd4 fbc1fff0 std r30,-16(r1) > c0000000005fffd8 fbe1fff8 std r31,-8(r1) > c0000000005fffdc f821ff71 stdu r1,-144(r1) > c0000000005fffe0 7c3f0b78 mr r31,r1 > c0000000005fffe4 ebc2dc90 ld r30,-9072(r2) > c0000000005fffe8 3b800001 li r28,1 > c0000000005fffec 60000000 nop > ... > c0000000005ffff4 e93e8048 ld r9,-32696(r30) > c0000000005ffff8 38a0ffff li r5,-1 > c0000000005ffffc eba90000 ld r29,0(r9) > c000000000600000 00001010 .long 0x1010 > 0:mon> > c000000000600004 00000008 .long 0x8 > c000000000600008 00001013 .long 0x1013 > c00000000060000c 0000000f .long 0xf > c000000000600010 7961626f rldimi. r1,r11,44,41 > c000000000600014 6f740000 xoris r20,r27,0 > c000000000600018 00101600 .long 0x101600 > c00000000060001c 00000c00 .long 0xc00 > c000000000600020 00000400 .long 0x400 > c000000000600024 00101100 .long 0x101100 > c000000000600028 000008e9 .long 0x8e9 What's going on here? How does the above disassembly compare with an objdump -d of your vmlinux? It looks like either: * gcc is generating some weird code sequences * xmon doesn't know how to disassemble those instructions * someone crapped on your kernel text cheers --=-c/6DjyA9naNp3wCGmgoS Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAkp4QpIACgkQdSjSd0sB4dKbJQCgxLmN1soiVk76X3gG07D06zC0 2g8AmgPkbKRWvfwRjItJns6GQqXUpLb8 =3aqg -----END PGP SIGNATURE----- --=-c/6DjyA9naNp3wCGmgoS--