There's no check to see if the device is already bound to a driver, which
could do bad things. The first thing to go wrong is that it will try to match
a driver with a device already bound to one. In some cases (it appears with
USB with drivers/usb/core/usb.c::usb_match_id()), some drivers will match a
device based on the class type, so it would be common (especially for HID
devices) to match a device that is already bound.
The fun comes when ->probe() is called, it fails, then
driver_probe_device() does this:
dev->driver = NULL;
Later on, that pointer could be be dereferenced without checking and cause
hell to break loose.
This problem could be nasty. It's very hardware dependent, since some
devices could have a different set of matching qualifiers than others.
Now, I don't quite see exactly where/how you were getting that crash.
You're dereferencing bad memory, but I'm not sure which pointer was bad
and where it came from, but it could have come from a couple of different
places.
The patch below will hopefully fix it all up for you. It's against
2.6.12-rc2-mm1, and does the following:
- Move logic to driver_probe_device() and comments uncommon returns:
1 - If device is bound
0 - If device not bound, and no error
error - If there was an error.
- Move locking to caller of that function, since we want to lock a
device for the entire time we're trying to bind it to a driver (to
prevent against a driver being loaded at the same time).
- Update __device_attach() and __driver_attach() to do that locking.
- Check if device is already bound in __driver_attach()
- Update the converse device_release_driver() so it locks the device
around all of the operations.
- Mark driver_probe_device() as static and remove export. It's an
internal function, it should stay that way, and there are no other
callers. If there is ever a need to export it, we can audit it as
necessary.
Signed-off-by: Andrew Morton <akpm@osdl.org>
- Use klist iterator in device_for_each_child(), making it safe to use for
removing devices.
- Remove unused list_to_dev() function.
- Kills all usage of devices_subsys.rwsem.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Can't wait on removing the current item in the list (the positive refcount *because*
we are using it causes it to deadlock).
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Don't add devices to bus's embedded kset, since it's not used by anyone anymore.
- Don't need to take the bus rwsem when calling {device,driver}_attach(), since
those functions use the klists and the klists' spinlocks.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Now possible, since the lists are locked using the klist lock and not the
global rwsem.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Use it in driver_for_each_device() instead of the regular list_head and stop using
the bus's rwsem for protection.
- Use driver_for_each_device() in driver_detach() so we don't deadlock on the
bus's rwsem.
- Remove ->devices.
- Move klist access and sysfs link access out from under device's semaphore, since
they're synchronized through other means.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Use it in bus_for_each_drv().
- Use the klist spinlock instead of the bus rwsem.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Use it for bus_for_each_dev().
- Use the klist spinlock instead of the bus rwsem.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now there's an iterator for accessing each device bound to a driver.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Index: linux-2.6.12-rc2/drivers/base/driver.c
===================================================================
This relocates the driver binding/unbinding code to drivers/base/dd.c. This is done
for two reasons: One, it's not code related to the bus_type itself; it uses some from
that, some from devices, and some from drivers. And Two, it will make it easier to do
some of the upcoming lock removal on that code..
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds a per-device semaphore that is taken before every call from the core to a
driver method. This prevents e.g. simultaneous calls to the ->suspend() or ->resume()
and ->probe() or ->release(), potentially saving a whole lot of headaches.
It also moves us a step closer to removing the bus rwsem, since it protects the fields
in struct device that are modified by the core.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
One step on improving the class api so that it can not be used incorrectly.
This also fixes the module owner issue with the dev files that happened when
the devt logic moved to the class core.
Based on a patch originally written by Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs: fix drivers/base so if an attribute doesn't implement
show or store method read/write will return -EIO
instead of 0.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As a result of the split of the kobject-registration and the
corresponding hotplug event, the order of events for device_add() has
changed. This restores the old order, cause it confused some userspace
applications.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The driver model has a "detach_state" mechanism that:
- Has never been used by any in-kernel drive;
- Is superfluous, since driver remove() methods can do the same thing;
- Became buggy when the suspend() parameter changed semantics and type;
- Could self-deadlock when called from certain suspend contexts;
- Is effectively wasted documentation, object code, and headspace.
This removes that "detach_state" mechanism; net code shrink, as well
as a per-device saving in the driver model and sysfs.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch includes various tweaks in the messaging that appears during
system pm state transitions:
* Warn about certain illegal calls in the device tree, like resuming
child before parent or suspending parent before child. This could
happen easily enough through sysfs, or in some cases when drivers
use device_pm_set_parent().
* Be more consistent about dev_dbg() tracing ... do it for resume() and
shutdown() too, and never if the driver doesn't have that method.
* Say which type of system sleep state is being entered.
Except for the warnings, these only affect debug messaging.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
With 2.6.11 and 2.6.12-rc2 (and perhaps a few versions before) usb
drivers for multi-interface devices, which do
usb_driver_release_interface() in their disconnect(), make rmmod hang.
It turns out to be due to a bug in drivers/base/bus.c:driver_detach(),
that iterates over the list of attached devices with
list_for_each_safe() under an assumption that device_release_driver()
only releases the current device, while it may also call
device_release_driver() for other devices on the same list.
The following patch fixes it. Please consider applying.
Signed-off-by: Roman Kagan <rkagan@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Earlier in the same function dev->bus is checked before dereferenced,
make consistent although I honestly don't know if dev->bus could
ever be NULL
Found by the Coverity tool
Signed-off-by: Alexander Nyberg <alexn@dsv.su.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some KernelDoc descriptions are updated to match the current code.
No code changes.
Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
kobject_add() and kobject_del() don't emit hotplug events anymore. Do it
ourselves if we are finished populating the device directory.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kobject_add() and kobject_del() don't emit hotplug events anymore. Do it
ourselves if we are finished populating the device directory.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
platform_add_devices can be used from within modules, so it should be
exported. This can for example happen if you have hotpluggable firmware in
an FPGA on a system on chip processor; in our case the FPGA is probed for
devices and the FPGA base code registers the devices it has found with the
kernel.
(akpm: I think this is reasonable from a licensing POV: it's unlikely that
anyone would be interested in merging such specialised modules into mainline,
and it's a GPL export).
Signed-off-by: Robert Schwebel <r.schwebel@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On Tue, 2005-03-15 at 09:25 +0100, Hannes Reinecke wrote:
> The current implementation of the firmware class breaks a fundamental
> assumption in udevd: that the physical device can be initialised fully
> prior to executing the next event for that device.
Here we add a TIMEOUT value to the hotplug environment of the firmware
requesting event. I will adapt udevd not to wait for anything else, if
it finds a TIMEOUT key.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I thought I'm done with fixing u32 vs. pm_message_t ... unfortunately
that turned out not to be the case as Russel King pointed out. Here are
fixes for Documentation and common code (mainly system devices).
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
