Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751909AbZGXHSr (ORCPT ); Fri, 24 Jul 2009 03:18:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751293AbZGXHSq (ORCPT ); Fri, 24 Jul 2009 03:18:46 -0400 Received: from chilli.pcug.org.au ([203.10.76.44]:57106 "EHLO smtps.tip.net.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751214AbZGXHSp (ORCPT ); Fri, 24 Jul 2009 03:18:45 -0400 Date: Fri, 24 Jul 2009 17:18:41 +1000 From: Stephen Rothwell To: Alan Cox Cc: linux-next@vger.kernel.org, LKML Subject: linux-next: boot panic in serial init Message-Id: <20090724171841.b128f8be.sfr@canb.auug.org.au> X-Mailer: Sylpheed 2.6.0 (GTK+ 2.16.4; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg="PGP-SHA1"; boundary="Signature=_Fri__24_Jul_2009_17_18_41_+1000_olGmIiZ7e3MchuU0" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2494 Lines: 72 --Signature=_Fri__24_Jul_2009_17_18_41_+1000_olGmIiZ7e3MchuU0 Content-Type: text/plain; charset=US-ASCII Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Alan, Today's linux-next on a pSeries PowerPC machine panics during boot like this: calling .serial8250_init+0x0/0x230 @ 1 Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled ------------[ cut here ]------------ kernel BUG at arch/powerpc/lib/locks.c:36! cpu 0x0: Vector: 700 (Program Check) at [c0000000be683740] pc: c000000000039460: .__spin_yield+0x40/0x90 lr: c000000000570284: ._spin_lock+0x84/0x90 sp: c0000000be6839c0 msr: 8000000000029032 current =3D 0xc0000000be67e000 paca =3D 0xc000000000947200 pid =3D 1, comm =3D swapper kernel BUG at arch/powerpc/lib/locks.c:36! enter ? for help [c0000000be683a30] c000000000570284 ._spin_lock+0x84/0x90 [c0000000be683ab0] c00000000056e75c .__mutex_lock_slowpath+0xec/0x2d0 [c0000000be683b90] c00000000056e274 .mutex_lock+0x54/0x60 [c0000000be683c10] c00000000032f6f8 .uart_add_one_port+0xd8/0x3f0 [c0000000be683d30] c0000000007a48c4 .serial8250_init+0x1a4/0x230 [c0000000be683de0] c00000000000947c .do_one_initcall+0x6c/0x1e0 [c0000000be683ee0] c000000000779d6c .kernel_init+0x23c/0x2c0 [c0000000be683f90] c00000000002a8e4 .kernel_thread+0x54/0x70 arch/powerpc/lib/locks.c line 36 is: lock_value =3D lock->slock; if (lock_value =3D=3D 0) return; holder_cpu =3D lock_value & 0xffff; BUG_ON(holder_cpu >=3D NR_CPUS); this last line. Which would imply that the lock has probably not been initialised. Indeed, uart_add_one_port does: struct tty_port *port; mutex_lock(&port->mutex); without assigning to port. See "serial-move-mutex" from the ttydev tree. --=20 Cheers, Stephen Rothwell sfr@canb.auug.org.au http://www.canb.auug.org.au/~sfr/ --Signature=_Fri__24_Jul_2009_17_18_41_+1000_olGmIiZ7e3MchuU0 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkppYFEACgkQjjKRsyhoI8zFAgCggYX9ZSlUhQwwRhu5egWUcrpk gfMAnjtKLiVIfs52W7iPTDKRxLMkDmHq =jdui -----END PGP SIGNATURE----- --Signature=_Fri__24_Jul_2009_17_18_41_+1000_olGmIiZ7e3MchuU0-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/