From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Re: ahci_host_activate NULL pointer (was Re: Linux 3.11-rc1) Date: Mon, 15 Jul 2013 20:29:16 -0600 Message-ID: <1373941756.8441.324.camel@ul30vt.home> References: <1373906960.8441.258.camel@ul30vt.home> <1373909907.8441.259.camel@ul30vt.home> <1373916197.8441.260.camel@ul30vt.home> <1373917448.8441.264.camel@ul30vt.home> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:26741 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752676Ab3GPC3V (ORCPT ); Mon, 15 Jul 2013 22:29:21 -0400 In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Xiaotian Feng Cc: linux-kernel , tj , linux-ide@vger.kernel.org, Alexander Gordeev On Mon, 2013-07-15 at 21:02 -0400, Xiaotian Feng wrote: > On Mon, Jul 15, 2013 at 3:44 PM, Alex Williamson > wrote: > > On Mon, 2013-07-15 at 13:23 -0600, Alex Williamson wrote: > >> On Mon, 2013-07-15 at 14:46 -0400, Xiaotian Feng wrote: > >> > On Tue, Jul 16, 2013 at 1:38 AM, Alex Williamson >> > > wrote: > >> > > >> > > On Mon, 2013-07-15 at 10:49 -0600, Alex Williamson wrote: > >> > > > On Sun, 2013-07-14 at 16:57 -0700, Linus Torvalds wrote: > >> > > > > It's been two weeks, and the merge window has closed. If I missed > >> > > > > anything, holler, but I don't have anything pending that I am aware > >> > > > > of. > >> > > > > > >> > > > > This merge window was smaller in terms of number of commits than the > >> > > > > 3.10 merge window, but we actually have more new lines. Most of that > >> > > > > seems to be in staging - a full third of all changes by line-count is > >> > > > > staging, and merging in Lustre is the bulk of that. Let's see how that > >> > > > > all turns out, I have to say that we don't have a great track record > >> > > > > on merging filesystems through staging. > >> > > > > > >> > > > > Ignoring the lustre merge, I think this really was a somewhat calmer > >> > > > > merge window. We had a few trees with problems, and we have an > >> > > > > on-going debate about stable patches that was triggered largely thanks > >> > > > > to this merge window, so now we'll have something to discuss for the > >> > > > > kernel summit. But on the whole, I suspect we might be starting to see > >> > > > > the traditional summer slump (Australia notwithstanding). > >> > > > > > >> > > > > Despite being a bit smaller than the last merge window, it's not like > >> > > > > this was a _tiny_ one, and so as usual I'm only summarizing with the > >> > > > > normal -rc1 mergelog: and as usual the people credited here are *not* > >> > > > > the people who actually wrote the code (although in some cases that is > >> > > > > true), they are the people who I merged the code from. > >> > > > > > >> > > > > Hey, let's all start testing, > >> > > > > >> > > > Anyone else seeing this: > >> > > > > >> > > > [ 2.212548] ahci 0000:00:1f.2: AHCI 0001.0200 32 slots 6 ports 3 Gbps > >> > > 0x29 impl SATA mode > >> > > > [ 2.220732] ahci 0000:00:1f.2: flags: 64bit ncq sntf led clo pmp pio > >> > > slum part ccc sxs > >> > > > [ 2.228997] BUG: unable to handle kernel NULL pointer dereference at > >> > > 0000000000000508 > >> > > > [ 2.236850] IP: [] ahci_host_activate+0x87/0x140 > >> > > > [ 2.243047] PGD 0 > >> > > > [ 2.245077] Oops: 0000 [#1] SMP > >> > > > [ 2.248335] Modules linked in: > >> > > > [ 2.251405] CPU: 7 PID: 1 Comm: swapper/0 Not tainted 3.11.0-rc1+ #574 > >> > > > [ 2.257929] Hardware name: LENOVO 4157CTO/LENOVO, BIOS 60KT41AUS > >> > > 01/04/2011 > >> > > > [ 2.264880] task: ffff880371508000 ti: ffff880371510000 task.ti: > >> > > ffff880371510000 > >> > > > [ 2.272353] RIP: 0010:[] [] > >> > > ahci_host_activate+0x87/0x140 > >> > > > [ 2.280969] RSP: 0018:ffff880371511b38 EFLAGS: 00010293 > >> > > > [ 2.286273] RAX: ffff88036e724000 RBX: ffff88036e71c028 RCX: > >> > > ffffffff8140bce0 > >> > > > [ 2.293397] RDX: 0000000000000000 RSI: 000000000000002f RDI: > >> > > ffff88037122f098 > >> > > > [ 2.300521] RBP: ffff880371511b68 R08: 0000000000000080 R09: > >> > > 0000000000000001 > >> > > > [ 2.307645] R10: 0000000000000000 R11: 0000000000000000 R12: > >> > > 0000000000000001 > >> > > > [ 2.314772] R13: 000000000000002e R14: 0000000000000000 R15: > >> > > ffff88037122f000 > >> > > > [ 2.321896] FS: 0000000000000000(0000) GS:ffff88037fdc0000(0000) > >> > > knlGS:0000000000000000 > >> > > > [ 2.329973] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > >> > > > [ 2.335711] CR2: 0000000000000508 CR3: 0000000001c0b000 CR4: > >> > > 00000000000007e0 > >> > > > [ 2.342835] Stack: > >> > > > [ 2.344848] ffff88036e720000 ffff88037122f000 0000000000000005 > >> > > ffff88037122f098 > >> > > > [ 2.352301] ffff88036e734000 ffff88036e71c028 ffff880371511c38 > >> > > ffffffff81408eae > >> > > > [ 2.359756] ffff880300000000 ffff88037122f098 ffff8803710be7a8 > >> > > ffff880300000010 > >> > > > [ 2.367210] Call Trace: > >> > > > [ 2.369655] [] ahci_init_one+0x8fe/0xaa0 > >> > > > [ 2.375221] [] ? > >> > > _raw_spin_unlock_irqrestore+0x3f/0x70 > >> > > > [ 2.382006] [] local_pci_probe+0x4b/0x80 > >> > > > [ 2.387571] [] pci_device_probe+0x111/0x120 > >> > > > [ 2.393405] [] driver_probe_device+0x8b/0x390 > >> > > > [ 2.399411] [] __driver_attach+0xab/0xb0 > >> > > > [ 2.404984] [] ? driver_probe_device+0x390/0x390 > >> > > > [ 2.411241] [] bus_for_each_dev+0x5d/0xa0 > >> > > > [ 2.416893] [] driver_attach+0x1e/0x20 > >> > > > [ 2.422284] [] bus_add_driver+0x117/0x290 > >> > > > [ 2.427937] [] ? libata_transport_init+0x5e/0x5e > >> > > > [ 2.434201] [] driver_register+0x7a/0x170 > >> > > > [ 2.439853] [] ? libata_transport_init+0x5e/0x5e > >> > > > [ 2.446110] [] __pci_register_driver+0x64/0x70 > >> > > > [ 2.452196] [] ahci_pci_driver_init+0x19/0x1b > >> > > > [ 2.458196] [] do_one_initcall+0xfa/0x1b0 > >> > > > [ 2.463853] [] ? parse_args+0x1f0/0x450 > >> > > > [ 2.469332] [] kernel_init_freeable+0x154/0x1e3 > >> > > > [ 2.475510] [] ? do_early_param+0x8c/0x8c > >> > > > [ 2.481163] [] ? rest_init+0xe0/0xe0 > >> > > > [ 2.486390] [] kernel_init+0xe/0xf0 > >> > > > [ 2.491530] [] ret_from_fork+0x7c/0xb0 > >> > > > [ 2.496928] [] ? rest_init+0xe0/0xe0 > >> > > > [ 2.502144] Code: 88 00 00 00 49 63 c4 48 8b 7b 38 43 8d 34 2c 48 8b > >> > > 84 c3 00 01 00 00 41 b8 80 00 00 00 48 c7 c1 e0 bc 40 81 48 8b 90 78 37 00 > >> > > 00 <4c> 8b 8a 08 05 00 00 48 89 04 24 48 c7 c2 90 be 40 81 e8 f2 b7 > >> > > > [ 2.522097] RIP [] ahci_host_activate+0x87/0x140 > >> > > > [ 2.528372] RSP > >> > > > [ 2.531858] CR2: 0000000000000508 > >> > > > [ 2.535184] ---[ end trace 66267c9b7b73f56b ]--- > >> > > > [ 2.539808] Kernel panic - not syncing: Attempted to kill init! > >> > > exitcode=0x00000009 > >> > > > > >> > > > >> > > Bisected to: > >> > > > >> > > commit b29900e62598cecd519c9ab2b8e4d03f8ebf702d > >> > > Author: Alexander Gordeev > >> > > Date: Wed May 22 08:53:48 2013 +0900 > >> > > > >> > > AHCI: Make distinct names for ports in /proc/interrupts > >> > > > >> > > Currently all interrupts assigned to AHCI ports show up in > >> > > '/proc/interrupts' as 'ahci'. This fix adds port numbers as > >> > > suffixes and hence makes the descriptions distinct. > >> > > > >> > > Reported-by: Jan Beulich > >> > > Signed-off-by: Alexander Gordeev > >> > > Signed-off-by: Tejun Heo > >> > > > >> > > > >> > Could you please try this patch? > >> > > >> > diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c > >> > index acfd0f7..e4b7176 100644 > >> > --- a/drivers/ata/libahci.c > >> > +++ b/drivers/ata/libahci.c > >> > @@ -2234,7 +2234,7 @@ static int ahci_port_start(struct ata_port *ap) > >> > if (!pp) > >> > return -ENOMEM; > >> > > >> > - if (ap->host->n_ports > 1) { > >> > + if (ap->host->n_ports > 0) { > >> > pp->irq_desc = devm_kzalloc(dev, 8, GFP_KERNEL); > >> > if (!pp->irq_desc) { > >> > devm_kfree(dev, pp); > >> > > >> > >> It does not help. Thanks, > > > > Some further debugging, nr_ports is 6. ahci_port_start gets called for > > ap->port_no 0, 3 and 5. The loop in ahci_host_activate dies on i = 1 > > because ->private_data is null. Thanks, > > > > I think following patch can fix this panic. For ahci ports, when the > port is dummy port, its private_data will be NULL, as dummy_port_ops > doesn't support ->port_start. Could you please try this? > > drivers/ata/ahci.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c > index 5064f3e..26e07ba 100644 > --- a/drivers/ata/ahci.c > +++ b/drivers/ata/ahci.c > @@ -1147,10 +1147,16 @@ int ahci_host_activate(struct ata_host *host, > int irq, unsigned int n_msis) > > for (i = 0; i < host->n_ports; i++) { > struct ahci_port_priv *pp = host->ports[i]->private_data; > + const char *desc; > + > + if (ata_port_is_dummy(host->ports[i])) > + desc = dev_driver_string(host->dev); > + else > + desc = pp->irq_desc; > > rc = devm_request_threaded_irq(host->dev, > irq + i, ahci_hw_interrupt, ahci_thread_fn, IRQF_SHARED, > - pp->irq_desc, host->ports[i]); > + desc, host->ports[i]); > if (rc) > goto out_free_irqs; > } This works, so the ports must be using ata_dummy_port_ops. Thanks, Alex