Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752628Ab2BRLOZ (ORCPT ); Sat, 18 Feb 2012 06:14:25 -0500 Received: from cantor2.suse.de ([195.135.220.15]:53696 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752317Ab2BRLOY (ORCPT ); Sat, 18 Feb 2012 06:14:24 -0500 Date: Sat, 18 Feb 2012 12:14:19 +0100 From: Holger Macht To: Hugh Dickins Cc: Matthew Garrett , Jeff Garzik , Stephen Rothwell , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: linux-next: dock_link_device is oopsy Message-ID: <20120218111419.GA2488@homac.suse.de> References: <20120217222922.GA2741@homac.suse.de> <20120217230107.GA12929@homac.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4250 Lines: 122 On Fr 17. Feb - 15:49:02, Hugh Dickins wrote: > On Sat, 18 Feb 2012, Holger Macht wrote: > > On Fr 17. Feb - 14:42:31, Hugh Dickins wrote: > > > On Fri, 17 Feb 2012, Holger Macht wrote: > > > > On Fr 17. Feb - 13:46:04, Hugh Dickins wrote: > > > > > Matthew, > > > > > > > > > > A linux-next oops at bootup in dock_link_device() tells me that you > > > > > were not feeling well when you wrote that and dock_unlink_device(): > > > > > I hope you're feeling better now and can rewrite them soon. > > > > > > > > Andrew Morton experienced a similar problem. What system are you using? > > > > I didn't encounter this problem with the systems I tested with. > > > > > > The two systems I got that on were both 4-year-old Core2 Duo systems, > > > one an HP quad desktop, one a Fujitsu-Siemens laptop. > > > > Thanks for the information I think this is really independent from the > > fact if a laptop, or more precicely if a system with dock station/bay is > > used. > > > > > > > > > > > > > Do you actually have a /sys/devices/platform/dock.?/ directory with a > > > > file 'type' that contains 'dock_station'? > > > > > > I'll have to report back on that this evening, I'm away from them now. > > > > I actually guess that those systems don't have a > > /sys/devices/platform/dock.? directory at all, which is fine. > > > > I also think this will fix it, would be great if you could confirm this: > > > > acpi: Bail out when linking devices and there are no dock stations > > > > If dock_station_count is zero, we allocate zero memory and don't check > > this at future references. So bail out if there are actually no dock > > stations. > > > > Signed-off-by: Holger Macht > > Certainly won't fix it as is (well, it shifts the crash over into kfree). > This function is expected to return a pointer, not an error or success > code. Oh well, too late for me yesterday... > > I've little doubt that returning NULL rather than -ENODEV there would fix > the boot crash; and if you're in a hurry to fix up booting (understandable) > then I suppose that would do for the moment. I really think this will basically do the trick. dock_(un)link_device() is called by ata_acpi_(un)bind_dock(), which in turn is called by ata_scsi_scan_host() unconditionally, thus not depending on the presence of a dock device. And dock_(un)link_device() simply misses the check if there is a dock/bay device. So how about that? acpi: Bail out when linking devices and there are no dock stations If dock_station_count is zero, we allocate zero memory and don't check this at future references. So bail out if there are actually no dock stations. Signed-off-by: Holger Macht --- drivers/acpi/dock.c | 19 ++++++++++++++----- 1 files changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c index b5e4142..0b3072c 100644 --- a/drivers/acpi/dock.c +++ b/drivers/acpi/dock.c @@ -281,11 +281,15 @@ EXPORT_SYMBOL_GPL(is_dock_device); */ struct device **dock_link_device(acpi_handle handle) { - struct device *dev = acpi_get_physical_device(handle); + struct device *dev; struct dock_station *dock_station; int ret, dock = 0; struct device **devices; + if (!dock_station_count) + return NULL; + + dev = acpi_get_physical_device(handle); devices = kmalloc(dock_station_count * sizeof(struct device *), GFP_KERNEL); @@ -320,12 +324,17 @@ EXPORT_SYMBOL_GPL(dock_link_device); */ struct device **dock_unlink_device(acpi_handle handle) { - struct device *dev = acpi_get_physical_device(handle); + struct device *dev; struct dock_station *dock_station; int dock = 0; - struct device **devices = - kmalloc(dock_station_count * sizeof(struct device *), - GFP_KERNEL); + struct device **devices; + + if (!dock_station_count) + return NULL; + + dev = acpi_get_physical_device(handle); + devices = kmalloc(dock_station_count * sizeof(struct device *), + GFP_KERNEL); if (!dev) return NULL; -- 1.7.7 -- 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/