Commit Graph

297 Commits

Author SHA1 Message Date
Yijing Wang e4a60d1390 sysfs: driver core: Fix glue dir race condition by gdp_mutex
There is a race condition when removing glue directory.
It can be reproduced in following test:

path 1: Add first child device
device_add()
    get_device_parent()
            /*find parent from glue_dirs.list*/
            list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
                    if (k->parent == parent_kobj) {
                            kobj = kobject_get(k);
                            break;
                    }
            ....
            class_dir_create_and_add()

path2: Remove last child device under glue dir
device_del()
    cleanup_device_parent()
            cleanup_glue_dir()
                    kobject_put(glue_dir);

If path2 has been called cleanup_glue_dir(), but not
call kobject_put(glue_dir), the glue dir is still
in parent's kset list. Meanwhile, path1 find the glue
dir from the glue_dirs.list. Path2 may release glue dir
before path1 call kobject_get(). So kernel will report
the warning and bug_on.

This is a "classic" problem we have of a kref in a list
that can be found while the last instance could be removed
at the same time.

This patch reuse gdp_mutex to fix this race condition.

The following calltrace is captured in kernel 3.4, but
the latest kernel still has this bug.

-----------------------------------------------------
<4>[ 3965.441471] WARNING: at ...include/linux/kref.h:41 kobject_get+0x33/0x40()
<4>[ 3965.441474] Hardware name: Romley
<4>[ 3965.441475] Modules linked in: isd_iop(O) isd_xda(O)...
...
<4>[ 3965.441605] Call Trace:
<4>[ 3965.441611]  [<ffffffff8103717a>] warn_slowpath_common+0x7a/0xb0
<4>[ 3965.441615]  [<ffffffff810371c5>] warn_slowpath_null+0x15/0x20
<4>[ 3965.441618]  [<ffffffff81215963>] kobject_get+0x33/0x40
<4>[ 3965.441624]  [<ffffffff812d1e45>] get_device_parent.isra.11+0x135/0x1f0
<4>[ 3965.441627]  [<ffffffff812d22d4>] device_add+0xd4/0x6d0
<4>[ 3965.441631]  [<ffffffff812d0dbc>] ? dev_set_name+0x3c/0x40
....
<2>[ 3965.441912] kernel BUG at ..../fs/sysfs/group.c:65!
<4>[ 3965.441915] invalid opcode: 0000 [#1] SMP
...
<4>[ 3965.686743]  [<ffffffff811a677e>] sysfs_create_group+0xe/0x10
<4>[ 3965.686748]  [<ffffffff810cfb04>] blk_trace_init_sysfs+0x14/0x20
<4>[ 3965.686753]  [<ffffffff811fcabb>] blk_register_queue+0x3b/0x120
<4>[ 3965.686756]  [<ffffffff812030bc>] add_disk+0x1cc/0x490
....
-------------------------------------------------------

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Weng Meiling <wengmeiling.weng@huawei.com>
Cc: <stable@vger.kernel.org> #3.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07 08:17:43 -08:00
Linus Torvalds 23971bdfff IOMMU Updates for Linux v3.18
This pull-request includes:
 
 	* Change in the IOMMU-API to convert the former iommu_domain_capable
 	  function to just iommu_capable
 
 	* Various fixes in handling RMRR ranges for the VT-d driver (one fix
 	  requires a device driver core change which was acked
 	  by Greg KH)
 
 	* The AMD IOMMU driver now assigns and deassigns complete alias groups
 	  to fix issues with devices using the wrong PCI request-id
 
 	* MMU-401 support for the ARM SMMU driver
 
 	* Multi-master IOMMU group support for the ARM SMMU driver
 
 	* Various other small fixes all over the place
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABAgAGBQJUPNxYAAoJECvwRC2XARrjMwMP/RLSr+oA31rGVjLXcmcCHl7Q
 Uj7xpcnG19qB0aqNR1JeJuZNkK/tw44pE353MQPbz4N9UVUiogklGIVD1iJvFV53
 0qm84bvpDJIof4aP35B3H3Umft2USTn/lmsQg/RklQcNTW8DzNj63b8BTNR7k/GL
 G7bLg7F1BUCl0shZCCsFspOIulQPAJYN2OvHlfYBav/bfDvfouQ3lrV+loGrK44r
 F2Hmp+imXlIhUCjfbiWz6wKFxvPrxZx482vm2pXBCSnXEdW4/fz6nf9VHUK/Cfsq
 JAimY1CfiDo1aqH9/yVHUOw5SD/NYOXq6E5bFPg/WENbipbbae5cK2u6PX5MMBAn
 CG4BM8l9xicfGPqgn5YFSRY/6qC6K7NlxMnt9U8l18QIkDVDqEtUgJQISJuce7wx
 FWx6eSWaxpIe5yhq19/h2ELalUUyR/fPq+UXXjYDL1kLV/vcvC/lC3mbNAQU93zU
 WK0bG2tDg88JHavc25Ewa2aOn4BVM2BpwuLbYlgQReaEmsQRnEPgtmRNyLJHqbFE
 wwpCj8pBWdufsJWRyvpnXQ+CfA7oSz4e7hz1G+0/5uiDmagfvg16Ql5JtPmmuLUm
 Kc3dVIiG0s1ewohZIIJETGCqprQbCSqs8CCQqB6p2zDBWFKpNT7F38lm/KlehkCz
 JpAiI7Y2K9Jejp0VIPrt
 =OMOt
 -----END PGP SIGNATURE-----

Merge tag 'iommu-updates-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:
 "This pull-request includes:

   - change in the IOMMU-API to convert the former iommu_domain_capable
     function to just iommu_capable

   - various fixes in handling RMRR ranges for the VT-d driver (one fix
     requires a device driver core change which was acked by Greg KH)

   - the AMD IOMMU driver now assigns and deassigns complete alias
     groups to fix issues with devices using the wrong PCI request-id

   - MMU-401 support for the ARM SMMU driver

   - multi-master IOMMU group support for the ARM SMMU driver

   - various other small fixes all over the place"

* tag 'iommu-updates-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (41 commits)
  iommu/vt-d: Work around broken RMRR firmware entries
  iommu/vt-d: Store bus information in RMRR PCI device path
  iommu/vt-d: Only remove domain when device is removed
  driver core: Add BUS_NOTIFY_REMOVED_DEVICE event
  iommu/amd: Fix devid mapping for ivrs_ioapic override
  iommu/irq_remapping: Fix the regression of hpet irq remapping
  iommu: Fix bus notifier breakage
  iommu/amd: Split init_iommu_group() from iommu_init_device()
  iommu: Rework iommu_group_get_for_pci_dev()
  iommu: Make of_device_id array const
  amd_iommu: do not dereference a NULL pointer address.
  iommu/omap: Remove omap_iommu unused owner field
  iommu: Remove iommu_domain_has_cap() API function
  IB/usnic: Convert to use new iommu_capable() API function
  vfio: Convert to use new iommu_capable() API function
  kvm: iommu: Convert to use new iommu_capable() API function
  iommu/tegra: Convert to iommu_capable() API function
  iommu/msm: Convert to iommu_capable() API function
  iommu/vt-d: Convert to iommu_capable() API function
  iommu/fsl: Convert to iommu_capable() API function
  ...
2014-10-15 07:23:49 +02:00
Joerg Roedel 599bad38cf driver core: Add BUS_NOTIFY_REMOVED_DEVICE event
This event closes an important gap in the bus notifiers.
There is already the BUS_NOTIFY_DEL_DEVICE event, but that
is sent when the device is still bound to its device driver.

This is too early for the IOMMU code to destroy any mappings
for the device, as they might still be in use by the driver.

The new BUS_NOTIFY_REMOVED_DEVICE event introduced with this
patch closes this gap as it is sent when the device is
already unbound from its device driver and almost completly
removed from the driver core.

With this event the IOMMU code can safely destroy any
mappings and other data structures when a device is removed.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Jerry Hoemann <jerry.hoemann@hp.com>
2014-10-02 11:14:34 +02:00
Ben Hutchings 655e5b7c03 drivers/base: Fix length checks in create_syslog_header()/dev_vprintk_emit()
snprintf() returns the number of bytes that could have been written
(excluding the null), not the actual number of bytes written.  Given a
long enough subsystem or device name, these functions will advance
beyond the end of the on-stack buffer in dev_vprintk_exit(), resulting
in an information leak or stack corruption.  I don't know whether such
a long name is currently possible.

In case snprintf() returns a value >= the buffer size, do not add
structured logging information.  Also WARN if this happens, so we can
fix the driver or increase the buffer size.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 22:55:15 -07:00
Tejun Heo 33ac1257ff sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()
All device_schedule_callback_owner() users are converted to use
device_remove_file_self().  Remove now unused
{sysfs|device}_schedule_callback_owner().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-16 11:56:33 -07:00
Greg Kroah-Hartman 72099304ee Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"
This reverts commit d1ba277e79.

As reported by Stephen, this patch breaks linux-next as a ppc patch
suddenly (after 2 years) started using this old api call.  So revert it
for now, it will go away in 3.15-rc2 when we can change the PPC call to
the new api.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-25 20:54:57 -07:00
Roland Dreier aa0689b36b Revert "driver core: synchronize device shutdown"
This reverts commit 401097ea4b.  The
original changelog said:

    A patch series to make .shutdown execute asynchronously.  Some drivers's
    shutdown can take a lot of time.  The patches can help save some shutdown
    time.  The patches use Arjan's async API.

    This patch:

    synchronize all tasks submitted by .shutdown

However, I'm not able to find any evidence that any other patches from
this series were applied, nor am I able to find any async tasks that are
scheduled in a .shutdown context.

On the other hand, we see occasional hangs on shutdown that appear to be
caused by the async_synchronize_full() in device_shutdown() waiting
forever for the async probing in sd if a SCSI disk shows up at just the
wrong time — the system starts the probe, but begins shutting down and
tears down too much of the SCSI driver to finish the probe.

If we had any async shutdown tasks, I guess the right fix would be to
create a "shutdown" async domain and have device_shutdown() only wait
for that domain.  But since there apparently are no async shutdown
tasks, we can just revert the waiting.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-08 22:08:29 -08:00
Jiang Liu 5c764dfaef driver core: unexport static function create_syslog_header
Function create_syslog_header() is defined as static, so it should
not be exported.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-15 11:38:36 -08:00
Tejun Heo ce8b04aa6c sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()
All device_schedule_callback_owner() users are converted to use
device_remove_file_self().  Remove now unused
{sysfs|device}_schedule_callback_owner().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07 15:42:41 -08:00
Tejun Heo 6b0afc2a21 kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers
Sometimes it's necessary to implement a node which wants to delete
nodes including itself.  This isn't straightforward because of kernfs
active reference.  While a file operation is in progress, an active
reference is held and kernfs_remove() waits for all such references to
drain before completing.  For a self-deleting node, this is a deadlock
as kernfs_remove() ends up waiting for an active reference that itself
is sitting on top of.

This currently is worked around in the sysfs layer using
sysfs_schedule_callback() which makes such removals asynchronous.
While it works, it's rather cumbersome and inherently breaks
synchronicity of the operation - the file operation which triggered
the operation may complete before the removal is finished (or even
started) and the removal may fail asynchronously.  If a removal
operation is immmediately followed by another operation which expects
the specific name to be available (e.g. removal followed by rename
onto the same name), there's no way to make the latter operation
reliable.

The thing is there's no inherent reason for this to be asynchrnous.
All that's necessary to do this synchronous is a dedicated operation
which drops its own active ref and deactivates self.  This patch
implements kernfs_remove_self() and its wrappers in sysfs and driver
core.  kernfs_remove_self() is to be called from one of the file
operations, drops the active ref the task is holding, removes the self
node, and restores active ref to the dead node so that the ref is
balanced afterwards.  __kernfs_remove() is updated so that it takes an
early exit if the target node is already fully removed so that the
active ref restored by kernfs_remove_self() after removal doesn't
confuse the deactivation path.

This makes implementing self-deleting nodes very easy.  The normal
removal path doesn't even need to be changed to use
kernfs_remove_self() for the self-deleting node.  The method can
invoke kernfs_remove_self() on itself before proceeding the normal
removal path.  kernfs_remove() invoked on the node by the normal
deletion path will simply be ignored.

This will replace sysfs_schedule_callback().  A subtle feature of
sysfs_schedule_callback() is that it collapses multiple invocations -
even if multiple removals are triggered, the removal callback is run
only once.  An equivalent effect can be achieved by testing the return
value of kernfs_remove_self() - only the one which gets %true return
value should proceed with actual deletion.  All other instances of
kernfs_remove_self() will wait till the enclosing kernfs operation
which invoked the winning instance of kernfs_remove_self() finishes
and then return %false.  This trivially makes all users of
kernfs_remove_self() automatically show correct synchronous behavior
even when there are multiple concurrent operations - all "echo 1 >
delete" instances will finish only after the whole operation is
completed by one of the instances.

Note that manipulation of active ref is implemented in separate public
functions - kernfs_[un]break_active_protection().
kernfs_remove_self() is the only user at the moment but this will be
used to cater to more complex cases.

v2: For !CONFIG_SYSFS, dummy version kernfs_remove_self() was missing
    and sysfs_remove_file_self() had incorrect return type.  Fix it.
    Reported by kbuild test bot.

v3: kernfs_[un]break_active_protection() separated out from
    kernfs_remove_self() and exposed as public API.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07 15:42:41 -08:00
Greg Kroah-Hartman a9f138b0e5 Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers"
This reverts commit 1ae06819c7.

Tejun writes:
        I'm sorry but can you please revert the whole series?
        get_active() waiting while a node is deactivated has potential
        to lead to deadlock and that deactivate/reactivate interface is
        something fundamentally flawed and that cgroup will have to work
        with the remove_self() like everybody else.  IOW, I think the
        first posting was correct.

Cc: Tejun Heo <tj@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-13 14:05:13 -08:00
Greg Kroah-Hartman a30f82b7eb Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"
This reverts commit d1ba277e79.

Tejun writes:
        I'm sorry but can you please revert the whole series?
        get_active() waiting while a node is deactivated has potential
        to lead to deadlock and that deactivate/reactivate interface is
        something fundamentally flawed and that cgroup will have to work
        with the remove_self() like everybody else.  IOW, I think the
        first posting was correct.

Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-13 13:51:36 -08:00
Tejun Heo d1ba277e79 sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()
All device_schedule_callback_owner() users are converted to use
device_remove_file_self().  Remove now unused
{sysfs|device}_schedule_callback_owner().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10 16:03:19 -08:00
Tejun Heo 1ae06819c7 kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers
Sometimes it's necessary to implement a node which wants to delete
nodes including itself.  This isn't straightforward because of kernfs
active reference.  While a file operation is in progress, an active
reference is held and kernfs_remove() waits for all such references to
drain before completing.  For a self-deleting node, this is a deadlock
as kernfs_remove() ends up waiting for an active reference that itself
is sitting on top of.

This currently is worked around in the sysfs layer using
sysfs_schedule_callback() which makes such removals asynchronous.
While it works, it's rather cumbersome and inherently breaks
synchronicity of the operation - the file operation which triggered
the operation may complete before the removal is finished (or even
started) and the removal may fail asynchronously.  If a removal
operation is immmediately followed by another operation which expects
the specific name to be available (e.g. removal followed by rename
onto the same name), there's no way to make the latter operation
reliable.

The thing is there's no inherent reason for this to be asynchrnous.
All that's necessary to do this synchronous is a dedicated operation
which drops its own active ref and deactivates self.  This patch
implements kernfs_remove_self() and its wrappers in sysfs and driver
core.  kernfs_remove_self() is to be called from one of the file
operations, drops the active ref and deactivates using
__kernfs_deactivate_self(), removes the self node, and restores active
ref to the dead node using __kernfs_reactivate_self() so that the ref
is balanced afterwards.  __kernfs_remove() is updated so that it takes
an early exit if the target node is already fully removed so that the
active ref restored by kernfs_remove_self() after removal doesn't
confuse the deactivation path.

This makes implementing self-deleting nodes very easy.  The normal
removal path doesn't even need to be changed to use
kernfs_remove_self() for the self-deleting node.  The method can
invoke kernfs_remove_self() on itself before proceeding the normal
removal path.  kernfs_remove() invoked on the node by the normal
deletion path will simply be ignored.

This will replace sysfs_schedule_callback().  A subtle feature of
sysfs_schedule_callback() is that it collapses multiple invocations -
even if multiple removals are triggered, the removal callback is run
only once.  An equivalent effect can be achieved by testing the return
value of kernfs_remove_self() - only the one which gets %true return
value should proceed with actual deletion.  All other instances of
kernfs_remove_self() will wait till the enclosing kernfs operation
which invoked the winning instance of kernfs_remove_self() finishes
and then return %false.  This trivially makes all users of
kernfs_remove_self() automatically show correct synchronous behavior
even when there are multiple concurrent operations - all "echo 1 >
delete" instances will finish only after the whole operation is
completed by one of the instances.

v2: For !CONFIG_SYSFS, dummy version kernfs_remove_self() was missing
    and sysfs_remove_file_self() had incorrect return type.  Fix it.
    Reported by kbuild test bot.

v3: Updated to use __kernfs_{de|re}activate_self().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10 14:01:05 -08:00
Rafael J. Wysocki ecfbf6fd9c Driver core: Fix device_add_attrs() error code path
If the addition of dev_attr_online fails, device_add_attrs() should
remove device attribute groups as well as type and class attribute
groups before returning an error code.  Make that happen.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-18 15:50:16 -08:00
David Herrmann bbc780f8ba driver core: fix device_create() error path
We call put_device() in the error path, which is fine for dev==NULL.
However, in case kobject_set_name_vargs() fails, we have dev!=NULL but
device_initialized() wasn't called, yet.

Fix this by splitting device_register() into explicit calls to
device_add() and an early call to device_initialize().

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08 18:25:10 -08:00
ethan.zhao 69df75334b drivers/base/core.c: output device renaming messages with dev_dbg().
Replace pr_debug() with dev_dbg().

Signed-off-by: ethan.zhao <ethan.kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 18:33:27 -07:00
Greg Kroah-Hartman a6b01deda1 driver core: remove dev_bin_attrs from struct class
No in-kernel code is now using this, they have all be converted over to
using the bin_attrs support in attribute groups, so this field, and the
code in the driver core that was creating/remove the binary files can be
removed.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-06 00:01:47 -07:00
Greg Kroah-Hartman bcc8edb52f driver core: remove dev_attrs from struct class
Now that all in-kernel users of the dev_attrs field are converted to use
dev_groups, we can safely remove dev_attrs from struct class.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-05 23:59:34 -07:00
Greg Kroah-Hartman 88502b9c0a Merge 3.12-rc3 into driver-core-next
We want the driver core and sysfs fixes in here to make merges and
development easier.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-29 18:29:23 -07:00
Tejun Heo 4b30ee58ee sysfs: remove ktype->namespace() invocations in symlink code
There's no reason for sysfs to be calling ktype->namespace().  It is
backwards, obfuscates what's going on and unnecessarily tangles two
separate layers.

There are two places where symlink code calls ktype->namespace().

* sysfs_do_create_link_sd() calls it to find out the namespace tag of
  the target directory.  Unless symlinking races with cross-namespace
  renaming, this equals @target_sd->s_ns.

* sysfs_rename_link() uses it to find out the new namespace to rename
  to and the new namespace can be different from the existing one.
  The function is renamed to sysfs_rename_link_ns() with an explicit
  @ns argument and the ktype->namespace() invocation is shifted to the
  device layer.

While this patch replaces ktype->namespace() invocation with the
recorded result in @target_sd, this shouldn't result in any behvior
difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26 15:30:22 -07:00
Benson Leung f123db8e9d driver core : Fix use after free of dev->parent in device_shutdown
The put_device(dev) at the bottom of the loop of device_shutdown
may result in the dev being cleaned up. In device_create_release,
the dev is kfreed.

However, device_shutdown attempts to use the dev pointer again after
put_device by referring to dev->parent.

Copy the parent pointer instead to avoid this condition.

This bug was found on Chromium OS's chromeos-3.8, which is based on v3.8.11.
See bug report : https://code.google.com/p/chromium/issues/detail?id=297842
This can easily be reproduced when shutting down with
hidraw devices that report battery condition.
Two examples are the HP Bluetooth Mouse X4000b and the Apple Magic Mouse.
For example, with the magic mouse :
The dev in question is "hidraw0"
dev->parent is "magicmouse"

In the course of the shutdown for this device, the input event cleanup calls
a put on hidraw0, decrementing its reference count.
When we finally get to put_device(dev) in device_shutdown, kobject_cleanup
is called and device_create_release does kfree(dev).
dev->parent is no longer valid, and we may crash in
put_device(dev->parent).

This change should be applied on any kernel with this change :
d1c6c030fc

Cc: stable@vger.kernel.org
Signed-off-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26 14:46:11 -07:00
Linus Torvalds 40031da445 ACPI and power management updates for 3.12-rc1
1) ACPI-based PCI hotplug (ACPIPHP) subsystem rework and introduction
     of Intel Thunderbolt support on systems that use ACPI for signalling
     Thunderbolt hotplug events.  This also should make ACPIPHP work in
     some cases in which it was known to have problems.  From
     Rafael J Wysocki, Mika Westerberg and Kirill A Shutemov.
 
  2) ACPI core code cleanups and dock station support cleanups from
     Jiang Liu and Rafael J Wysocki.
 
  3) Fixes for locking problems related to ACPI device hotplug from
     Rafael J Wysocki.
 
  4) ACPICA update to version 20130725 includig fixes, cleanups, support
     for more than 256 GPEs per GPE block and a change to make the ACPI
     PM Timer optional (we've seen systems without the PM Timer in the
     field already).  One of the fixes, related to the DeRefOf operator,
     is necessary to prevent some Windows 8 oriented AML from causing
     problems to happen.  From Bob Moore, Lv Zheng, and Jung-uk Kim.
 
  5) Removal of the old and long deprecated /proc/acpi/event interface
     and related driver changes from Thomas Renninger.
 
  6) ACPI and Xen changes to make the reduced hardware sleep work with
     the latter from Ben Guthro.
 
  7) ACPI video driver cleanups and a blacklist of systems that should
     not tell the BIOS that they are compatible with Windows 8 (or ACPI
     backlight and possibly other things will not work on them).  From
     Felipe Contreras.
 
  8) Assorted ACPI fixes and cleanups from Aaron Lu, Hanjun Guo,
     Kuppuswamy Sathyanarayanan, Lan Tianyu, Sachin Kamat, Tang Chen,
     Toshi Kani, and Wei Yongjun.
 
  9) cpufreq ondemand governor target frequency selection change to
     reduce oscillations between min and max frequencies (essentially,
     it causes the governor to choose target frequencies proportional
     to load) from Stratos Karafotis.
 
 10) cpufreq fixes allowing sysfs attributes file permissions to be
     preserved over suspend/resume cycles Srivatsa S Bhat.
 
 11) Removal of Device Tree parsing for CPU device nodes from multiple
     cpufreq drivers that required some changes related to
     of_get_cpu_node() to be made in a few architectures and in the
     driver core.  From Sudeep KarkadaNagesha.
 
 12) cpufreq core fixes and cleanups related to mutual exclusion and
     driver module references from Viresh Kumar, Lukasz Majewski and
     Rafael J Wysocki.
 
 13) Assorted cpufreq fixes and cleanups from Amit Daniel Kachhap,
     Bartlomiej Zolnierkiewicz, Hanjun Guo, Jingoo Han, Joseph Lo,
     Julia Lawall, Li Zhong, Mark Brown, Sascha Hauer, Stephen Boyd,
     Stratos Karafotis, and Viresh Kumar.
 
 14) Fixes to prevent race conditions in coupled cpuidle from happening
     from Colin Cross.
 
 15) cpuidle core fixes and cleanups from Daniel Lezcano and
     Tuukka Tikkanen.
 
 16) Assorted cpuidle fixes and cleanups from Daniel Lezcano,
     Geert Uytterhoeven, Jingoo Han, Julia Lawall, Linus Walleij,
     and Sahara.
 
 17) System sleep tracing changes from Todd E Brandt and Shuah Khan.
 
 18) PNP subsystem conversion to using struct dev_pm_ops for power
     management from Shuah Khan.
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.19 (GNU/Linux)
 
 iQIcBAABCAAGBQJSJcKhAAoJEKhOf7ml8uNsplIQAJSOshxhkkemvFOuHZ+0YIbh
 R9aufjXeDkMDBi8YtU+tB7ERth1j+0LUSM0NTnP51U7e+7eSGobA9s5jSZQj2l7r
 HFtnSOegLuKAfqwgfSLK91xa1rTFdfW0Kych9G2nuHtBIt6P0Oc59Cb5M0oy6QXs
 nVtaDEuU//tmO71+EF5HnMJHabRTrpvtn/7NbDUpU7LZYpWJrHJFT9xt1rXNab7H
 YRCATPm3kXGRg58Doc3EZE4G3D7DLvq74jWMaI089X/m5Pg1G6upqArypOy6oxdP
 p2FEzYVrb2bi8fakXp7BBeO1gCJTAqIgAkbSSZHLpGhFaeEMmb9/DWPXdm2TjzMV
 c1EEucvsqZWoprXgy12i5Hk814xN8d8nBBLg/UYiRJ44nc/hevXfyE9ZYj6bkseJ
 +GNHmZIa1QYC05nnGli4+W4kHns8EZf/gmvIxnPuco1RN2yMWagrud5/G6Dr9M2B
 hzJV6qauLVzgZso4oe79zv9aVxe/dPHKANLD/sg23WBiJJbJF1ocBlnj2Xlbpqze
 pmMUWGiO/gUiS0fmpW/lAJauza5jFmSCjE4E8R0Gyn0j4YXjmMhdEanaU6J3VuCi
 yVgEzYEth4sowq4AflMMLKYN+WmozDnK7taZRGmT0t+EKRFKLT6EgnNrkQgs1vKl
 oawD9LM4fZ8E0yroOEme
 =CgqW
 -----END PGP SIGNATURE-----

Merge tag 'pm+acpi-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael Wysocki:

 1) ACPI-based PCI hotplug (ACPIPHP) subsystem rework and introduction
    of Intel Thunderbolt support on systems that use ACPI for signalling
    Thunderbolt hotplug events.  This also should make ACPIPHP work in
    some cases in which it was known to have problems.  From
    Rafael J Wysocki, Mika Westerberg and Kirill A Shutemov.

 2) ACPI core code cleanups and dock station support cleanups from
    Jiang Liu and Rafael J Wysocki.

 3) Fixes for locking problems related to ACPI device hotplug from
    Rafael J Wysocki.

 4) ACPICA update to version 20130725 includig fixes, cleanups, support
    for more than 256 GPEs per GPE block and a change to make the ACPI
    PM Timer optional (we've seen systems without the PM Timer in the
    field already).  One of the fixes, related to the DeRefOf operator,
    is necessary to prevent some Windows 8 oriented AML from causing
    problems to happen.  From Bob Moore, Lv Zheng, and Jung-uk Kim.

 5) Removal of the old and long deprecated /proc/acpi/event interface
    and related driver changes from Thomas Renninger.

 6) ACPI and Xen changes to make the reduced hardware sleep work with
    the latter from Ben Guthro.

 7) ACPI video driver cleanups and a blacklist of systems that should
    not tell the BIOS that they are compatible with Windows 8 (or ACPI
    backlight and possibly other things will not work on them).  From
    Felipe Contreras.

 8) Assorted ACPI fixes and cleanups from Aaron Lu, Hanjun Guo,
    Kuppuswamy Sathyanarayanan, Lan Tianyu, Sachin Kamat, Tang Chen,
    Toshi Kani, and Wei Yongjun.

 9) cpufreq ondemand governor target frequency selection change to
    reduce oscillations between min and max frequencies (essentially,
    it causes the governor to choose target frequencies proportional
    to load) from Stratos Karafotis.

10) cpufreq fixes allowing sysfs attributes file permissions to be
    preserved over suspend/resume cycles Srivatsa S Bhat.

11) Removal of Device Tree parsing for CPU device nodes from multiple
    cpufreq drivers that required some changes related to
    of_get_cpu_node() to be made in a few architectures and in the
    driver core.  From Sudeep KarkadaNagesha.

12) cpufreq core fixes and cleanups related to mutual exclusion and
    driver module references from Viresh Kumar, Lukasz Majewski and
    Rafael J Wysocki.

13) Assorted cpufreq fixes and cleanups from Amit Daniel Kachhap,
    Bartlomiej Zolnierkiewicz, Hanjun Guo, Jingoo Han, Joseph Lo,
    Julia Lawall, Li Zhong, Mark Brown, Sascha Hauer, Stephen Boyd,
    Stratos Karafotis, and Viresh Kumar.

14) Fixes to prevent race conditions in coupled cpuidle from happening
    from Colin Cross.

15) cpuidle core fixes and cleanups from Daniel Lezcano and
    Tuukka Tikkanen.

16) Assorted cpuidle fixes and cleanups from Daniel Lezcano,
    Geert Uytterhoeven, Jingoo Han, Julia Lawall, Linus Walleij,
    and Sahara.

17) System sleep tracing changes from Todd E Brandt and Shuah Khan.

18) PNP subsystem conversion to using struct dev_pm_ops for power
    management from Shuah Khan.

* tag 'pm+acpi-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (217 commits)
  cpufreq: Don't use smp_processor_id() in preemptible context
  cpuidle: coupled: fix race condition between pokes and safe state
  cpuidle: coupled: abort idle if pokes are pending
  cpuidle: coupled: disable interrupts after entering safe state
  ACPI / hotplug: Remove containers synchronously
  driver core / ACPI: Avoid device hot remove locking issues
  cpufreq: governor: Fix typos in comments
  cpufreq: governors: Remove duplicate check of target freq in supported range
  cpufreq: Fix timer/workqueue corruption due to double queueing
  ACPI / EC: Add ASUSTEK L4R to quirk list in order to validate ECDT
  ACPI / thermal: Add check of "_TZD" availability and evaluating result
  cpufreq: imx6q: Fix clock enable balance
  ACPI: blacklist win8 OSI for buggy laptops
  cpufreq: tegra: fix the wrong clock name
  cpuidle: Change struct menu_device field types
  cpuidle: Add a comment warning about possible overflow
  cpuidle: Fix variable domains in get_typical_interval()
  cpuidle: Fix menu_device->intervals type
  cpuidle: CodingStyle: Break up multiple assignments on single line
  cpuidle: Check called function parameter in get_typical_interval()
  ...
2013-09-03 15:59:39 -07:00
Rafael J. Wysocki 5e33bc4165 driver core / ACPI: Avoid device hot remove locking issues
device_hotplug_lock is held around the acpi_bus_trim() call in
acpi_scan_hot_remove() which generally removes devices (it removes
ACPI device objects at least, but it may also remove "physical"
device objects through .detach() callbacks of ACPI scan handlers).
Thus, potentially, device sysfs attributes are removed under that
lock and to remove those attributes it is necessary to hold the
s_active references of their directory entries for writing.

On the other hand, the execution of a .show() or .store() callback
from a sysfs attribute is carried out with that attribute's s_active
reference held for reading.  Consequently, if any device sysfs
attribute that may be removed from within acpi_scan_hot_remove()
through acpi_bus_trim() has a .store() or .show() callback which
acquires device_hotplug_lock, the execution of that callback may
deadlock with the removal of the attribute.  [Unfortunately, the
"online" device attribute of CPUs and memory blocks is one of them.]

To avoid such deadlocks, make all of the sysfs attribute callbacks
that need to lock device hotplug, for example store_online(), use
a special function, lock_device_hotplug_sysfs(), to lock device
hotplug and return the result of that function immediately if it is
not zero.  This will cause the s_active reference of the directory
entry in question to be released and the syscall to be restarted
if device_hotplug_lock cannot be acquired.

[show_online() actually doesn't need to lock device hotplug, but
it is useful to serialize it with respect to device_offline() and
device_online() for the same device (in case user space attempts to
run them concurrently) which can be done with the help of
device_lock().]

Reported-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reported-and-tested-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>
2013-08-29 22:00:53 +02:00
Greg Kroah-Hartman 6396768560 driver core: add #include <linux/sysfs.h> to core files.
This is needed to fix the build on sh systems.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-27 10:24:15 -07:00
Greg Kroah-Hartman c5e064a698 driver core: core: use DEVICE_ATTR_RO
Use DEVICE_ATTR_RO() instead of a "raw" __ATTR macro, making it easier
to audit exactly what is going on with the sysfs files.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-23 17:07:26 -07:00
Greg Kroah-Hartman 3e1026b3fa sysfs.h: remove attr_name() macro
Gotta love a macro that doesn't reduce the typing you have to do.

Also, only the driver core, and one network driver uses this.  The
driver core functions will be going away soon, and I'll convert the
network driver soon to not need this as well, so delete it for now
before anyone else gets some bright ideas and wants to use it.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-22 10:25:34 -07:00
Greg Kroah-Hartman 3e9b2bae83 sysfs: add sysfs_create/remove_groups()
These functions are being open-coded in 3 different places in the driver
core, and other driver subsystems will want to start doing this as well,
so move it to the sysfs core to keep it all in one place, where we know
it is written properly.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-21 16:02:19 -07:00
Hanjun Guo 3454bf9604 drivers / base: Fix sysfs_deprecated_setup() __init attribute location
__init belongs after the return type on functions, not before it.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-19 17:10:10 -07:00
Greg Kroah-Hartman fa6fdb33b4 driver core: bus_type: add dev_groups
attribute groups are much more flexible than just a list of attributes,
due to their support for visibility of the attributes, and binary
attributes. Add dev_groups to struct bus_type which should be used
instead of dev_attrs.

dev_attrs will be removed from the structure soon.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12 15:33:31 -07:00
Jingoo Han 34da5e6770 driver core: replace strict_strto*() with kstrto*()
The usage of strict_strto*() is not preferred, because
strict_strto*() is obsolete. Thus, kstrto*() should be
used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-26 18:02:43 -07:00
David Graham White 86df268705 drivers:base:core: Moved sym export macros to respective functions
Moved 11 calls to the EXPORT_SYMBOL_GPL beneath their respective functions per
checkpatch.pl warnings.

Signed-off-by: David Graham White <dgwhite11@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-26 18:00:29 -07:00
Greg Kroah-Hartman d05a6f96c7 driver core: add default groups to struct class
We should be using groups, not attribute lists, for classes to allow
subdirectories, and soon, binary files.  Groups are just more flexible
overall, so add them.

The dev_attrs list will go away after all in-kernel users are converted
to use dev_groups.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-16 10:57:37 -07:00
Guenter Roeck 39ef311204 driver core: Introduce device_create_groups
device_create_groups lets callers create devices as well as associated
sysfs attributes with a single call. This avoids race conditions seen
if sysfs attributes on new devices are created later.

[fixed up comment block placement and add checks for printk buffer
formats - gregkh]

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-16 10:57:37 -07:00
Linus Torvalds f991fae5c6 Power management and ACPI updates for 3.11-rc1
- Hotplug changes allowing device hot-removal operations to fail
   gracefully (instead of crashing the kernel) if they cannot be
   carried out completely.  From Rafael J Wysocki and Toshi Kani.
 
 - Freezer update from Colin Cross and Mandeep Singh Baines targeted
   at making the freezing of tasks a bit less heavy weight operation.
 
 - cpufreq resume fix from Srivatsa S Bhat for a regression introduced
   during the 3.10 cycle causing some cpufreq sysfs attributes to
   return wrong values to user space after resume.
 
 - New freqdomain_cpus sysfs attribute for the acpi-cpufreq driver to
   provide information previously available via related_cpus from
   Lan Tianyu.
 
 - cpufreq fixes and cleanups from Viresh Kumar, Jacob Shin,
   Heiko Stübner, Xiaoguang Chen, Ezequiel Garcia, Arnd Bergmann, and
   Tang Yuantian.
 
 - Fix for an ACPICA regression causing suspend/resume issues to
   appear on some systems introduced during the 3.4 development cycle
   from Lv Zheng.
 
 - ACPICA fixes and cleanups from Bob Moore, Tomasz Nowicki, Lv Zheng,
   Chao Guan, and Zhang Rui.
 
 - New cupidle driver for Xilinx Zynq processors from Michal Simek.
 
 - cpuidle fixes and cleanups from Daniel Lezcano.
 
 - Changes to make suspend/resume work correctly in Xen guests from
   Konrad Rzeszutek Wilk.
 
 - ACPI device power management fixes and cleanups from Fengguang Wu
   and Rafael J Wysocki.
 
 - ACPI documentation updates from Lv Zheng, Aaron Lu and Hanjun Guo.
 
 - Fix for the IA-64 issue that was the reason for reverting commit
   9f29ab1 and updates of the ACPI scan code from Rafael J Wysocki.
 
 - Mechanism for adding CMOS RTC address space handlers from Lan Tianyu
   (to allow some EC-related breakage to be fixed on some systems).
 
 - Spec-compliant implementation of acpi_os_get_timer() from
   Mika Westerberg.
 
 - Modification of do_acpi_find_child() to execute _STA in order to
   to avoid situations in which a pointer to a disabled device object
   is returned instead of an enabled one with the same _ADR value.
   From Jeff Wu.
 
 - Intel BayTrail PCH (Platform Controller Hub) support for the ACPI
   Intel Low-Power Subsystems (LPSS) driver and modificaions of that
   driver to work around a couple of known BIOS issues from
   Mika Westerberg and Heikki Krogerus.
 
 - EC driver fix from Vasiliy Kulikov to make it use get_user() and
   put_user() instead of dereferencing user space pointers blindly.
 
 - Assorted ACPI code cleanups from Bjorn Helgaas, Nicholas Mazzuca and
   Toshi Kani.
 
 - Modification of the "runtime idle" helper routine to take the return
   values of the callbacks executed by it into account and to call
   rpm_suspend() if they return 0, which allows some code bloat
   reduction to be done, from Rafael J Wysocki and Alan Stern.
 
 - New trace points for PM QoS from Sahara <keun-o.park@windriver.com>.
 
 - PM QoS documentation update from Lan Tianyu.
 
 - Assorted core PM code cleanups and changes from Bernie Thompson,
   Bjorn Helgaas, Julius Werner, and Shuah Khan.
 
 - New devfreq driver for the Exynos5-bus device from Abhilash Kesavan.
 
 - Minor devfreq cleanups, fixes and MAINTAINERS update from
   MyungJoo Ham, Abhilash Kesavan, Paul Bolle, Rajagopal Venkat, and
   Wei Yongjun.
 
 - OMAP Adaptive Voltage Scaling (AVS) SmartReflex voltage control
   driver updates from Andrii Tseglytskyi and Nishanth Menon.
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.19 (GNU/Linux)
 
 iQIcBAABAgAGBQJR0ZNOAAoJEKhOf7ml8uNsDLYP/0EU4rmvw0TWTITfp6RS1KDE
 9GwBn96ZR4Q5bJd9gBCTPSqhHOYMqxWEUp99sn/M2wehG1pk/jw5LO56+2IhM3UZ
 g1HDcJ7te2nVT/iXsKiAGTVhU9Rk0aYwoVSknwk27qpIBGxW9w/s5tLX8pY3Q3Zq
 wL/7aTPjyL+PFFFEaxgH7qLqsl3DhbtYW5AriUBTkXout/tJ4eO1b7MNBncLDh8X
 VQ/0DNCKE95VEJfkO4rk9RKUyVp9GDn0i+HXCD/FS4IA5oYzePdVdNDmXf7g+swe
 CGlTZq8pB+oBpDiHl4lxzbNrKQjRNbGnDUkoRcWqn0nAw56xK+vmYnWJhW99gQ/I
 fKnvxeLca5po1aiqmC4VSJxZIatFZqLrZAI4dzoCLWY+bGeTnCKmj0/F8ytFnZA2
 8IuLLs7/dFOaHXV/pKmpg6FAlFa9CPxoqRFoyqb4M0GjEarADyalXUWsPtG+6xCp
 R/p0CISpwk+guKZR/qPhL7M654S7SHrPwd2DPF0KgGsvk+G2GhoB8EzvD8BVp98Z
 9siCGCdgKQfJQVI6R0k9aFmn/4gRQIAgyPhkhv9tqULUUkiaXki+/t8kPfnb8O/d
 zep+CA57E2G8MYLkDJfpFeKS7GpPD6TIdgFdGmOUC0Y6sl9iTdiw4yTx8O2JM37z
 rHBZfYGkJBrbGRu+Q1gs
 =VBBq
 -----END PGP SIGNATURE-----

Merge tag 'pm+acpi-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "This time the total number of ACPI commits is slightly greater than
  the number of cpufreq commits, but Viresh Kumar (who works on cpufreq)
  remains the most active patch submitter.

  To me, the most significant change is the addition of offline/online
  device operations to the driver core (with the Greg's blessing) and
  the related modifications of the ACPI core hotplug code.  Next are the
  freezer updates from Colin Cross that should make the freezing of
  tasks a bit less heavy weight.

  We also have a couple of regression fixes, a number of fixes for
  issues that have not been identified as regressions, two new drivers
  and a bunch of cleanups all over.

  Highlights:

   - Hotplug changes to support graceful hot-removal failures.

     It sometimes is necessary to fail device hot-removal operations
     gracefully if they cannot be carried out completely.  For example,
     if memory from a memory module being hot-removed has been allocated
     for the kernel's own use and cannot be moved elsewhere, it's
     desirable to fail the hot-removal operation in a graceful way
     rather than to crash the kernel, but currenty a success or a kernel
     crash are the only possible outcomes of an attempted memory
     hot-removal.  Needless to say, that is not a very attractive
     alternative and it had to be addressed.

     However, in order to make it work for memory, I first had to make
     it work for CPUs and for this purpose I needed to modify the ACPI
     processor driver.  It's been split into two parts, a resident one
     handling the low-level initialization/cleanup and a modular one
     playing the actual driver's role (but it binds to the CPU system
     device objects rather than to the ACPI device objects representing
     processors).  That's been sort of like a live brain surgery on a
     patient who's riding a bike.

     So this is a little scary, but since we found and fixed a couple of
     regressions it caused to happen during the early linux-next testing
     (a month ago), nobody has complained.

     As a bonus we remove some duplicated ACPI hotplug code, because the
     ACPI-based CPU hotplug is now going to use the common ACPI hotplug
     code.

   - Lighter weight freezing of tasks.

     These changes from Colin Cross and Mandeep Singh Baines are
     targeted at making the freezing of tasks a bit less heavy weight
     operation.  They reduce the number of tasks woken up every time
     during the freezing, by using the observation that the freezer
     simply doesn't need to wake up some of them and wait for them all
     to call refrigerator().  The time needed for the freezer to decide
     to report a failure is reduced too.

     Also reintroduced is the check causing a lockdep warining to
     trigger when try_to_freeze() is called with locks held (which is
     generally unsafe and shouldn't happen).

   - cpufreq updates

     First off, a commit from Srivatsa S Bhat fixes a resume regression
     introduced during the 3.10 cycle causing some cpufreq sysfs
     attributes to return wrong values to user space after resume.  The
     fix is kind of fresh, but also it's pretty obvious once Srivatsa
     has identified the root cause.

     Second, we have a new freqdomain_cpus sysfs attribute for the
     acpi-cpufreq driver to provide information previously available via
     related_cpus.  From Lan Tianyu.

     Finally, we fix a number of issues, mostly related to the
     CPUFREQ_POSTCHANGE notifier and cpufreq Kconfig options and clean
     up some code.  The majority of changes from Viresh Kumar with bits
     from Jacob Shin, Heiko Stübner, Xiaoguang Chen, Ezequiel Garcia,
     Arnd Bergmann, and Tang Yuantian.

   - ACPICA update

     A usual bunch of updates from the ACPICA upstream.

     During the 3.4 cycle we introduced support for ACPI 5 extended
     sleep registers, but they are only supposed to be used if the
     HW-reduced mode bit is set in the FADT flags and the code attempted
     to use them without checking that bit.  That caused suspend/resume
     regressions to happen on some systems.  Fix from Lv Zheng causes
     those registers to be used only if the HW-reduced mode bit is set.

     Apart from this some other ACPICA bugs are fixed and code cleanups
     are made by Bob Moore, Tomasz Nowicki, Lv Zheng, Chao Guan, and
     Zhang Rui.

   - cpuidle updates

     New driver for Xilinx Zynq processors is added by Michal Simek.

     Multidriver support simplification, addition of some missing
     kerneldoc comments and Kconfig-related fixes come from Daniel
     Lezcano.

   - ACPI power management updates

     Changes to make suspend/resume work correctly in Xen guests from
     Konrad Rzeszutek Wilk, sparse warning fix from Fengguang Wu and
     cleanups and fixes of the ACPI device power state selection
     routine.

   - ACPI documentation updates

     Some previously missing pieces of ACPI documentation are added by
     Lv Zheng and Aaron Lu (hopefully, that will help people to
     uderstand how the ACPI subsystem works) and one outdated doc is
     updated by Hanjun Guo.

   - Assorted ACPI updates

     We finally nailed down the IA-64 issue that was the reason for
     reverting commit 9f29ab11dd ("ACPI / scan: do not match drivers
     against objects having scan handlers"), so we can fix it and move
     the ACPI scan handler check added to the ACPI video driver back to
     the core.

     A mechanism for adding CMOS RTC address space handlers is
     introduced by Lan Tianyu to allow some EC-related breakage to be
     fixed on some systems.

     A spec-compliant implementation of acpi_os_get_timer() is added by
     Mika Westerberg.

     The evaluation of _STA is added to do_acpi_find_child() to avoid
     situations in which a pointer to a disabled device object is
     returned instead of an enabled one with the same _ADR value.  From
     Jeff Wu.

     Intel BayTrail PCH (Platform Controller Hub) support is added to
     the ACPI driver for Intel Low-Power Subsystems (LPSS) and that
     driver is modified to work around a couple of known BIOS issues.
     Changes from Mika Westerberg and Heikki Krogerus.

     The EC driver is fixed by Vasiliy Kulikov to use get_user() and
     put_user() instead of dereferencing user space pointers blindly.

     Code cleanups are made by Bjorn Helgaas, Nicholas Mazzuca and Toshi
     Kani.

   - Assorted power management updates

     The "runtime idle" helper routine is changed to take the return
     values of the callbacks executed by it into account and to call
     rpm_suspend() if they return 0, which allows us to reduce the
     overall code bloat a bit (by dropping some code that's not
     necessary any more after that modification).

     The runtime PM documentation is updated by Alan Stern (to reflect
     the "runtime idle" behavior change).

     New trace points for PM QoS are added by Sahara
     (<keun-o.park@windriver.com>).

     PM QoS documentation is updated by Lan Tianyu.

     Code cleanups are made and minor issues are addressed by Bernie
     Thompson, Bjorn Helgaas, Julius Werner, and Shuah Khan.

   - devfreq updates

     New driver for the Exynos5-bus device from Abhilash Kesavan.

     Minor cleanups, fixes and MAINTAINERS update from MyungJoo Ham,
     Abhilash Kesavan, Paul Bolle, Rajagopal Venkat, and Wei Yongjun.

   - OMAP power management updates

     Adaptive Voltage Scaling (AVS) SmartReflex voltage control driver
     updates from Andrii Tseglytskyi and Nishanth Menon."

* tag 'pm+acpi-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (162 commits)
  cpufreq: Fix cpufreq regression after suspend/resume
  ACPI / PM: Fix possible NULL pointer deref in acpi_pm_device_sleep_state()
  PM / Sleep: Warn about system time after resume with pm_trace
  cpufreq: don't leave stale policy pointer in cdbs->cur_policy
  acpi-cpufreq: Add new sysfs attribute freqdomain_cpus
  cpufreq: make sure frequency transitions are serialized
  ACPI: implement acpi_os_get_timer() according the spec
  ACPI / EC: Add HP Folio 13 to ec_dmi_table in order to skip DSDT scan
  ACPI: Add CMOS RTC Operation Region handler support
  ACPI / processor: Drop unused variable from processor_perflib.c
  cpufreq: tegra: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: s3c64xx: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: omap: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: imx6q: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: exynos: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: dbx500: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: davinci: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: arm-big-little: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: powernow-k8: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: pcc: call CPUFREQ_POSTCHANGE notfier in error cases
  ...
2013-07-03 14:35:40 -07:00
Rafael J. Wysocki a204dbc61b Merge branch 'acpi-hotplug'
* acpi-hotplug:
  ACPI: Do not use CONFIG_ACPI_HOTPLUG_MEMORY_MODULE
  ACPI / cpufreq: Add ACPI processor device IDs to acpi-cpufreq
  Memory hotplug: Move alternative function definitions to header
  ACPI / processor: Fix potential NULL pointer dereference in acpi_processor_add()
  Memory hotplug / ACPI: Simplify memory removal
  ACPI / scan: Add second pass of companion offlining to hot-remove code
  Driver core / MM: Drop offline_memory_block()
  ACPI / processor: Pass processor object handle to acpi_bind_one()
  ACPI: Drop removal_type field from struct acpi_device
  Driver core / memory: Simplify __memory_block_change_state()
  ACPI / processor: Initialize per_cpu(processors, pr->id) properly
  CPU: Fix sysfs cpu/online of offlined CPUs
  Driver core: Introduce offline/online callbacks for memory blocks
  ACPI / memhotplug: Bind removable memory blocks to ACPI device nodes
  ACPI / processor: Use common hotplug infrastructure
  ACPI / hotplug: Use device offline/online for graceful hot-removal
  Driver core: Use generic offline/online for CPU offline/online
  Driver core: Add offline/online device operations
2013-06-28 12:58:05 +02:00
Robert P. J. Day f8878dcb84 Documentation: Tidy up some drivers/base/core.c kerneldoc content.
Standardize the indentation, and switch the order of a couple
kerneldoc entries to match the parameter order. No functional change.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03 14:00:49 -07:00
Greg Kroah-Hartman 4993632218 Merge 3.10-rc3 into driver-core-next
We want the changes here.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-27 10:42:53 +09:00
Federico Vaga a4e2400a63 base/core.c: improve comment of the function device_find_child()
Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-21 09:29:00 -07:00
dyoung@redhat.com 97521978c5 driver core: print sysfs attribute name when warning about bogus permissions
Make it obvious to see what attribute is using bogus permissions.

Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-21 09:05:52 -07:00
Rafael J. Wysocki 4f3549d72d Driver core: Add offline/online device operations
In some cases, graceful hot-removal of devices is not possible,
although in principle the devices in question support hotplug.
For example, that may happen for the last CPU in the system or
for memory modules holding kernel memory.

In those cases it is nice to be able to check if the given device
can be gracefully hot-removed before triggering a removal procedure
that cannot be aborted or reversed.  Unfortunately, however, the
kernel currently doesn't provide any support for that.

To address that deficiency, introduce support for offline and
online operations that can be performed on devices, respectively,
before a hot-removal and in case when it is necessary (or convenient)
to put a device back online after a successful offline (that has not
been followed by removal).  The idea is that the offline will fail
whenever the given device cannot be gracefully removed from the
system and it will not be allowed to use the device after a
successful offline (until a subsequent online) in analogy with the
existing CPU offline/online mechanism.

For now, the offline and online operations are introduced at the
bus type level, as that should be sufficient for the most urgent use
cases (CPUs and memory modules).  In the future, however, the
approach may be extended to cover some more complicated device
offline/online scenarios involving device drivers etc.

The lock_device_hotplug() and unlock_device_hotplug() functions are
introduced because subsequent patches need to put larger pieces of
code under device_hotplug_lock to prevent race conditions between
device offline and removal from happening.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
2013-05-12 14:14:09 +02:00
Linus Torvalds 46d9be3e5e Merge branch 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
 "A lot of activities on workqueue side this time.  The changes achieve
  the followings.

   - WQ_UNBOUND workqueues - the workqueues which are per-cpu - are
     updated to be able to interface with multiple backend worker pools.
     This involved a lot of churning but the end result seems actually
     neater as unbound workqueues are now a lot closer to per-cpu ones.

   - The ability to interface with multiple backend worker pools are
     used to implement unbound workqueues with custom attributes.
     Currently the supported attributes are the nice level and CPU
     affinity.  It may be expanded to include cgroup association in
     future.  The attributes can be specified either by calling
     apply_workqueue_attrs() or through /sys/bus/workqueue/WQ_NAME/* if
     the workqueue in question is exported through sysfs.

     The backend worker pools are keyed by the actual attributes and
     shared by any workqueues which share the same attributes.  When
     attributes of a workqueue are changed, the workqueue binds to the
     worker pool with the specified attributes while leaving the work
     items which are already executing in its previous worker pools
     alone.

     This allows converting custom worker pool implementations which
     want worker attribute tuning to use workqueues.  The writeback pool
     is already converted in block tree and there are a couple others
     are likely to follow including btrfs io workers.

   - WQ_UNBOUND's ability to bind to multiple worker pools is also used
     to make it NUMA-aware.  Because there's no association between work
     item issuer and the specific worker assigned to execute it, before
     this change, using unbound workqueue led to unnecessary cross-node
     bouncing and it couldn't be helped by autonuma as it requires tasks
     to have implicit node affinity and workers are assigned randomly.

     After these changes, an unbound workqueue now binds to multiple
     NUMA-affine worker pools so that queued work items are executed in
     the same node.  This is turned on by default but can be disabled
     system-wide or for individual workqueues.

     Crypto was requesting NUMA affinity as encrypting data across
     different nodes can contribute noticeable overhead and doing it
     per-cpu was too limiting for certain cases and IO throughput could
     be bottlenecked by one CPU being fully occupied while others have
     idle cycles.

  While the new features required a lot of changes including
  restructuring locking, it didn't complicate the execution paths much.
  The unbound workqueue handling is now closer to per-cpu ones and the
  new features are implemented by simply associating a workqueue with
  different sets of backend worker pools without changing queue,
  execution or flush paths.

  As such, even though the amount of change is very high, I feel
  relatively safe in that it isn't likely to cause subtle issues with
  basic correctness of work item execution and handling.  If something
  is wrong, it's likely to show up as being associated with worker pools
  with the wrong attributes or OOPS while workqueue attributes are being
  changed or during CPU hotplug.

  While this creates more backend worker pools, it doesn't add too many
  more workers unless, of course, there are many workqueues with unique
  combinations of attributes.  Assuming everything else is the same,
  NUMA awareness costs an extra worker pool per NUMA node with online
  CPUs.

  There are also a couple things which are being routed outside the
  workqueue tree.

   - block tree pulled in workqueue for-3.10 so that writeback worker
     pool can be converted to unbound workqueue with sysfs control
     exposed.  This simplifies the code, makes writeback workers
     NUMA-aware and allows tuning nice level and CPU affinity via sysfs.

   - The conversion to workqueue means that there's no 1:1 association
     between a specific worker, which makes writeback folks unhappy as
     they want to be able to tell which filesystem caused a problem from
     backtrace on systems with many filesystems mounted.  This is
     resolved by allowing work items to set debug info string which is
     printed when the task is dumped.  As this change involves unifying
     implementations of dump_stack() and friends in arch codes, it's
     being routed through Andrew's -mm tree."

* 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (84 commits)
  workqueue: use kmem_cache_free() instead of kfree()
  workqueue: avoid false negative WARN_ON() in destroy_workqueue()
  workqueue: update sysfs interface to reflect NUMA awareness and a kernel param to disable NUMA affinity
  workqueue: implement NUMA affinity for unbound workqueues
  workqueue: introduce put_pwq_unlocked()
  workqueue: introduce numa_pwq_tbl_install()
  workqueue: use NUMA-aware allocation for pool_workqueues
  workqueue: break init_and_link_pwq() into two functions and introduce alloc_unbound_pwq()
  workqueue: map an unbound workqueues to multiple per-node pool_workqueues
  workqueue: move hot fields of workqueue_struct to the end
  workqueue: make workqueue->name[] fixed len
  workqueue: add workqueue->unbound_attrs
  workqueue: determine NUMA node of workers accourding to the allowed cpumask
  workqueue: drop 'H' from kworker names of unbound worker pools
  workqueue: add wq_numa_tbl_len and wq_numa_possible_cpumask[]
  workqueue: move pwq_pool_locking outside of get/put_unbound_pool()
  workqueue: fix memory leak in apply_workqueue_attrs()
  workqueue: fix unbound workqueue attrs hashing / comparison
  workqueue: fix race condition in unbound workqueue free path
  workqueue: remove pwq_lock which is no longer used
  ...
2013-04-29 19:07:40 -07:00
Greg Kroah-Hartman 4e4098a3e0 driver core: handle user namespaces properly with the uid/gid devtmpfs change
Now that devtmpfs is caring about uid/gid, we need to use the correct
internal types so users who have USER_NS enabled will have things work
properly for them.

Thanks to Eric for pointing this out, and the patch review.

Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-11 11:43:29 -07:00
Kay Sievers 3c2670e651 driver core: add uid and gid to devtmpfs
Some drivers want to tell userspace what uid and gid should be used for
their device nodes, so allow that information to percolate through the
driver core to userspace in order to make this happen.  This means that
some systems (i.e.  Android and friends) will not need to even run a
udev-like daemon for their device node manager and can just rely in
devtmpfs fully, reducing their footprint even more.

Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-08 08:21:48 -07:00
Felipe Balbi 8f46baaa7e base: core: WARN() about bogus permissions on device attributes
Whenever a struct device_attribute is registered
with mismatched permissions - read permission without
a show routine or write permission without store
routine - we will issue a big warning so we catch
those early enough.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15 09:39:15 -07:00
Tejun Heo d73ce00422 driver/base: implement subsys_virtual_register()
Kay tells me the most appropriate place to expose workqueues to
userland would be /sys/devices/virtual/workqueues/WQ_NAME which is
symlinked to /sys/bus/workqueue/devices/WQ_NAME and that we're lacking
a way to do that outside of driver core as virtual_device_parent()
isn't exported and there's no inteface to conveniently create a
virtual subsystem.

This patch implements subsys_virtual_register() by factoring out
subsys_register() from subsys_system_register() and using it with
virtual_device_parent() as the origin directory.  It's identical to
subsys_system_register() other than the origin directory but we aren't
gonna restrict the device names which should be used under it.

This will be used to expose workqueue attributes to userland.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
2013-03-12 11:36:35 -07:00
Michał Mirosław 9f3b795a62 driver-core: constify data for class_find_device()
All in-kernel users of class_find_device() don't really need mutable
data for match callback.

In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c)
this patch changes match callbacks to use const search data.

The const is propagated to rtc_class_open() and power_supply_get_by_name()
parameters.

Note that there's a dev reference leak in suspend_test.c that's not
touched in this patch.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-06 12:18:56 -08:00
Greg Kroah-Hartman 53a9c87e7e Revert "drivers: base: Convert print_symbol to %pSR"
This reverts commit e797986593 as %pSR
isn't in the tree yet.

Cc: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17 13:10:23 -08:00
Joe Perches e797986593 drivers: base: Convert print_symbol to %pSR
Use the new vsprintf extension to avoid any possible
message interleaving.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17 12:57:07 -08:00
Peter Senna Tschudin 1a5d76dbe8 drivers/base/core.c: Remove two unused variables and two useless calls to kfree
old_class_name, and new_class_name are never used. This patch remove the
declaration and calls to kfree.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r1 forall@
type T; identifier i;
@@
* T *i = NULL;
  ... when != i
* kfree(i);
// </smpl>

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17 12:57:06 -08:00