From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 36085DDE0E for ; Tue, 2 Sep 2008 10:13:12 +1000 (EST) Subject: Re: Trace From: Benjamin Herrenschmidt To: =?ISO-8859-1?Q?S=E9bastien_Chr=E9tien?= In-Reply-To: <48BC195F.4070505@gmail.com> References: <319b0ac50809010216jac3ae30r9260699abde6535@mail.gmail.com> <929D3CED81F34E43887A393170D66FB926B259@GBRSUN01MS002.eu.xerox.net> <319b0ac50809010525w7451ef92m5aaf6fd5f5a8958e@mail.gmail.com> <929D3CED81F34E43887A393170D66FB926B40F@GBRSUN01MS002.eu.xerox.net> <929D3CED81F34E43887A393170D66FB926B41A@GBRSUN01MS002.eu.xerox.net> <48BC195F.4070505@gmail.com> Content-Type: text/plain; charset=utf-8 Date: Tue, 02 Sep 2008 10:13:03 +1000 Message-Id: <1220314383.13010.62.camel@pasglop> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, "Jenkins, Clive" Reply-To: benh@kernel.crashing.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2008-09-01 at 18:33 +0200, Sébastien Chrétien wrote: > Thanks for your answer. > Your analyse of ttys is very well. It was not my answer. All adresses in > system.map begin with 0xc... So I think it is the case for ttys too. > > I found the mistake. It came from my board_device function in struct > console(console ->device). It didn't change the value of the parameter > int* index. > So Linux loaded a tty_structure which was in tiny_ttys[-1] > > console.h is not very well documented about this. You have a custom serial port ? Why not use the framework in drivers/serial ? Or are you using it ? Cheers, Ben. > Thanks > Sébastien Chrétien > > Jenkins, Clive a écrit : > >> Why can't tty have value 0x57555541 ? > >> > > To answer my own question, because it ends in 1 and is not word-aligned! > > > > -----Original Message----- > > From: linuxppc-dev-bounces+clive.jenkins=xerox.com@ozlabs.org [mailto:linuxppc-dev-bounces+clive.jenkins=xerox.com@ozlabs.org] On Behalf Of Jenkins, Clive > > Sent: 01 September 2008 14:54 > > To: Sébastien Chrétien > > Cc: linuxppc-dev@ozlabs.org > > Subject: RE: Trace > > > > I'm not sure that is a failure. Why can't tty have value 0x57555541 ? > > > > I think the code in tty_io.c initialises driver->ttys and you shouldn't need to do anything in your driver. > > > > If you are not already aware, a useful way to explore kernel code is to use LXR: > > http://lxr.linux.no/linux+v2.6.26/include/linux/tty_driver.h#L212 > > This may help you understand the tty code. > > > > Good luck! > > > > ________________________________ > > > > From: Sébastien Chrétien [mailto:sebastien.chretien.enseirb@gmail.com] > > Sent: 01 September 2008 13:25 > > To: Jenkins, Clive > > Cc: linuxppc-dev@ozlabs.org > > Subject: Re: Trace > > > > > > I found where is the failure with your advices > > In init_dev (tty_io.c), init_dev calls "tty = driver->ttys[idx]" > > after this call, tty value is : tty = 0x57555541 > > > > Have I to initialize driver->ttys in my driver. If yes, how have I to Initialize this ? > > > > The driver tty is used in order to have a console on my serial port. > > Thanks for your help > > > > > > > > 2008/9/1, Jenkins, Clive : > > > > The instruction that caused the fault is at this address: > > > > > NIP [c0110ddc] init_dev+0x2bc/0x584 > > > > > > The hex value of the instruction is also highlighted between <> here: > > > > > Instruction dump: > > > 7d808120 4e800020 7c832378 4bfa9ea9 7c7f1b79 418201f0 a81e0062 2f800001 > > > 409efd98 83ff00d0 2c1f0000 4182fd90 <801f00b8> 70090080 408201b0 801e0060 > > > > > > Disassemble your kernel and look at offset 0x2BC relative to the label init_dev > > > > ________________________________ > > > > From: linuxppc-dev-bounces+clive.jenkins=xerox.com@ozlabs.org [mailto:linuxppc-dev-bounces+clive.jenkins =xerox.com@ozlabs.org] On Behalf Of Sébastien Chrétien > > Sent: 01 September 2008 10:16 > > To: linuxppc-dev@ozlabs.org > > Subject: Trace > > > > > > > > Hello, > > > > I am triying to write a tty_driver under ppc. And I get a kernel panic. > > Can somebody explain me how finding the source of the error with a kernel panic trace : > > thanks > > > > Unable to handle kernel paging request for data at address 0x575555f9 > > Faulting instruction address: 0xc0110ddc > > Oops: Kernel access of bad area, sig: 11 [#1] > > Modules linked in: > > NIP: c0110ddc LR: c011118c CTR: 00000000 > > REGS: cf01bcb0 TRAP: 0300 Not tainted (2.6.26) > > MSR: 00009032 CR: 44002022 XER: 20000000 > > DAR: 575555f9, DSISR: 40000000 > > TASK = cf01c000[1] 'swapper' THREAD: cf01a000 > > GPR00: 0000000c cf01bd60 cf01c000 cf04c300 ffffffff cf01bdbc 00000000 c01d0000 > > GPR08: 00001249 fffffffc 00000000 cf000420 84002022 00000000 10000b00 007fff00 > > GPR16: 0fffa1d0 00000000 00000004 cf01bdbc 007ffec0 00000000 00000000 00800000 > > GPR24: 00000000 c01b7650 00000002 c01d0000 ffffffff ce4a6700 cf04c300 57555541 > > NIP [c0110ddc] init_dev+0x2bc/0x584 > > LR [c011118c] tty_open+0xe8/0x3e0 > > Call Trace: > > [cf01bd60] [cf01bd78] 0xcf01bd78 (unreliable) > > [cf01bdb0] [c011118c] tty_open+0xe8/0x3e0 > > [cf01bde0] [c00742c8] chrdev_open+0x114/0x1b0 > > [cf01be10] [c006fb5c] __dentry_open+0x190/0x2e8 > > [cf01be40] [c006fdac] nameidata_to_filp+0x38/0x70 > > [cf01be60] [c007bc60] do_filp_open+0x200/0x7d0 > > [cf01bf10] [c00700b4] do_sys_open+0x74/0x114 > > [cf01bf40] [c0003c94] init_post+0x34/0x258 > > [cf01bf60] [c019ca64] kernel_init+0x258/0x270 > > [cf01bff0] [c0011b3c] kernel_thread+0x44/0x60 > > Instruction dump: > > 7d808120 4e800020 7c832378 4bfa9ea9 7c7f1b79 418201f0 a81e0062 2f800001 > > 409efd98 83ff00d0 2c1f0000 4182fd90 <801f00b8> 70090080 408201b0 801e0060 > > ---[ end trace b7795a387aeb7786 ]--- > > Kernel panic - not syncing: Attempted to kill init! > > allocation failed: out of vmalloc space - use vmalloc= to increase size. > > > > > > > > > > _______________________________________________ > > Linuxppc-dev mailing list > > Linuxppc-dev@ozlabs.org > > https://ozlabs.org/mailman/listinfo/linuxppc-dev > > > > > > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-dev