lkml.org 
[lkml]   [2012]   [Feb]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: linux-next: dock_link_device is oopsy
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.

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.

But it won't address the rest of the breakage and leakage in here,
which I suspect will reveal more once Matthew has time to look.

Hugh

> ---
> drivers/acpi/dock.c | 13 ++++++++++---
> 1 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
> index b5e4142..8641912 100644
> --- a/drivers/acpi/dock.c
> +++ b/drivers/acpi/dock.c
> @@ -286,6 +286,9 @@ struct device **dock_link_device(acpi_handle handle)
> int ret, dock = 0;
> struct device **devices;
>
> + if (!dock_station_count)
> + return -ENODEV;
> +
> devices = kmalloc(dock_station_count * sizeof(struct device *),
> GFP_KERNEL);
>
> @@ -323,9 +326,13 @@ struct device **dock_unlink_device(acpi_handle handle)
> struct device *dev = acpi_get_physical_device(handle);
> 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 -ENODEV;
> +
> + devices = kmalloc(dock_station_count * sizeof(struct device *),
> + GFP_KERNEL);
>
> if (!dev)
> return NULL;
> --
> 1.7.7


\
 
 \ /
  Last update: 2012-02-18 00:53    [W:0.060 / U:6.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site