Messages in this thread | | | Date | Sat, 18 Feb 2012 21:05:18 +0800 | Subject | Re: linux-next: dock_link_device is oopsy | From | Hillf Danton <> |
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On Sat, Feb 18, 2012 at 7:14 PM, Holger Macht <holger@homac.de> wrote: > 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 <holger@homac.de> >> >> 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 <holger@homac.de> > --- > 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 bail out in this way, another patch looks needed to fix up mem leakage :-(
> 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/
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