Commit Graph

223 Commits

Author SHA1 Message Date
Alan Stern b10d5efdf7 Documentation update for the driver model core
This patch (as1509) documents two important points regarding the use
of device structures in the driver model:

	Structures must be initialized to all 0's before they are
	passed to device_initialize().

	Structures must not be passed to device_add() or
	device_register() more than once.

Although these restrictions have applied ever since the driver model
was first created, they have not been mentioned anywhere.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-24 10:47:41 -08:00
Linus Torvalds 972b2c7199 Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (165 commits)
  reiserfs: Properly display mount options in /proc/mounts
  vfs: prevent remount read-only if pending removes
  vfs: count unlinked inodes
  vfs: protect remounting superblock read-only
  vfs: keep list of mounts for each superblock
  vfs: switch ->show_options() to struct dentry *
  vfs: switch ->show_path() to struct dentry *
  vfs: switch ->show_devname() to struct dentry *
  vfs: switch ->show_stats to struct dentry *
  switch security_path_chmod() to struct path *
  vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb
  vfs: trim includes a bit
  switch mnt_namespace ->root to struct mount
  vfs: take /proc/*/mounts and friends to fs/proc_namespace.c
  vfs: opencode mntget() mnt_set_mountpoint()
  vfs: spread struct mount - remaining argument of next_mnt()
  vfs: move fsnotify junk to struct mount
  vfs: move mnt_devname
  vfs: move mnt_list to struct mount
  vfs: switch pnode.h macros to struct mount *
  ...
2012-01-08 12:19:57 -08:00
Greg Kroah-Hartman ff4b8a57f0 Merge branch 'driver-core-next' into Linux 3.2
This resolves the conflict in the arch/arm/mach-s3c64xx/s3c6400.c file,
and it fixes the build error in the arch/x86/kernel/microcode_core.c
file, that the merge did not catch.

The microcode_core.c patch was provided by Stephen Rothwell
<sfr@canb.auug.org.au> who was invaluable in the merge issues involved
with the large sysdev removal process in the driver-core tree.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-06 11:42:52 -08:00
Al Viro 2c9ede55ec switch device_get_devnode() and ->devnode() to umode_t *
both callers of device_get_devnode() are only interested in lower 16bits
and nobody tries to return anything wider than 16bit anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:55 -05:00
Kay Sievers ca22e56deb driver-core: implement 'sysdev' functionality for regular devices and buses
All sysdev classes and sysdev devices will converted to regular devices
and buses to properly hook userspace into the event processing.

There is no interesting difference between a 'sysdev' and 'device' which
would justify to roll an entire own subsystem with different userspace
export semantics. Userspace relies on events and generic sysfs subsystem
infrastructure from sysdev devices, which are currently not properly
available.

Every converted sysdev class will create a regular device with the class
name in /sys/devices/system and all registered devices will becom a children
of theses devices.

For compatibility reasons, the sysdev class-wide attributes are created
at this parent device. (Do not copy that logic for anything new, subsystem-
wide properties belong to the subsystem, not to some fake parent device
created in /sys/devices.)

Every sysdev driver is implemented as a simple subsystem interface now,
and no longer called a driver.

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-12-14 14:29:38 -08:00
Alan Stern fe6b91f470 PM / Driver core: leave runtime PM enabled during system shutdown
Disabling all runtime PM during system shutdown turns out not to be a
good idea, because some devices may need to be woken up from a
low-power state at that time.

The whole point of disabling runtime PM for system shutdown was to
prevent untimely runtime-suspend method calls.  This patch (as1504)
accomplishes the same result by incrementing the usage count for each
device and waiting for ongoing runtime-PM callbacks to finish.  This
is what we already do during system suspend and hibernation, which
makes sense since the shutdown method is pretty much a legacy analog
of the pm->poweroff method.

This fixes a recent regression on some OMAP systems introduced by
commit af8db1508f (PM / driver core:
disable device's runtime PM during shutdown).

Reported-and-tested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-07 22:26:56 +01:00
Peter Chen af8db1508f PM / driver core: disable device's runtime PM during shutdown
There may be an issue when the user issue "reboot/shutdown" command, then
the device has shut down its hardware, after that, this runtime-pm featured
device's driver will probably be scheduled to do its suspend routine,
and at its suspend routine, it may access hardware, but the device has
already shutdown physically, then the system hang may be occurred.

I ran out this issue using an auto-suspend supported USB devices, like
3G modem, keyboard. The usb runtime suspend routine may be scheduled
after the usb controller has been shut down, and the usb runtime suspend
routine will try to suspend its roothub(controller), it will access
register, then the system hang occurs as the controller is shutdown.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Acked-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: stable@kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-11-15 21:52:29 +01:00
Joe Perches cbc4663552 dynamic_debug: Add __dynamic_dev_dbg
Unlike dynamic_pr_debug, dynamic uses of dev_dbg can not
currently add task_pid/KBUILD_MODNAME/__func__/__LINE__
to selected debug output.

Add a new function similar to dynamic_pr_debug to
optionally emit these prefixes.

Cc: Aloisio Almeida <aloisio.almeida@openbossa.org>
Noticed-by: Aloisio Almeida <aloisio.almeida@openbossa.org>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-22 18:23:04 -07:00
Karthigan Srinivasan 7f100d1566 drivers/base/core.c: Fixed brace coding style issue.
Fixed brace coding style issue.

Signed-off-by: Karthigan Srinivasan <karthigan.srinivasan@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-22 17:06:30 -07:00
Stephen Hemminger aed65af1cc drivers: make device_type const
The device_type structure does not contain data that changes
during usage and should be const. This allows devices to declare
the struct const.

I have patches to change all the subsystems, but need the infra
structure change first.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:45:51 -07:00
Ferenc Wagner 481e20799b driver core: Replace the dangerous to_root_device macro with an inline function
The original macro worked only when applied to variables named 'dev'.
While this could have been fixed by simply renaming the macro argument,
a more type-safe replacement by an inline function is preferred.

Signed-off-by: Ferenc Wagner <wferi@niif.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:36:40 -08:00
Timur Tabi a5462516aa driver-core: document restrictions on device_rename()
Add text, courtesy of Kay Sievers, that provides some background on
device_rename() and why it shouldn't be used.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 15:10:18 -08:00
Linus Torvalds e54be894ea Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  driver core: Document that device_rename() is only for networking
  sysfs: remove useless test from sysfs_merge_group
  driver-core: merge private parts of class and bus
  driver core: fix whitespace in class_attr_string
2011-01-10 16:10:33 -08:00
Stefan Achatz c97415a725 sysfs: Introducing binary attributes for struct class
Added dev_bin_attrs to struct class similar to existing dev_attrs.

Signed-off-by: Stefan Achatz <erazor_de@users.sourceforge.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-01-08 01:09:21 +01:00
Michael Ellerman c6c0ac664c driver core: Document that device_rename() is only for networking
Document that device_rename() is not to be used by anything
other than the network core.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-29 13:47:05 -08:00
Kay Sievers 6b6e39a6a8 driver-core: merge private parts of class and bus
As classes and busses are pretty much the same thing, and we want to
merge them together into a 'subsystem' in the future, let us share the
same private data parts to make that merge easier.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-17 14:21:08 -08:00
Linus Torvalds 229aebb873 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  Update broken web addresses in arch directory.
  Update broken web addresses in the kernel.
  Revert "drivers/usb: Remove unnecessary return's from void functions" for musb gadget
  Revert "Fix typo: configuation => configuration" partially
  ida: document IDA_BITMAP_LONGS calculation
  ext2: fix a typo on comment in ext2/inode.c
  drivers/scsi: Remove unnecessary casts of private_data
  drivers/s390: Remove unnecessary casts of private_data
  net/sunrpc/rpc_pipe.c: Remove unnecessary casts of private_data
  drivers/infiniband: Remove unnecessary casts of private_data
  drivers/gpu/drm: Remove unnecessary casts of private_data
  kernel/pm_qos_params.c: Remove unnecessary casts of private_data
  fs/ecryptfs: Remove unnecessary casts of private_data
  fs/seq_file.c: Remove unnecessary casts of private_data
  arm: uengine.c: remove C99 comments
  arm: scoop.c: remove C99 comments
  Fix typo configue => configure in comments
  Fix typo: configuation => configuration
  Fix typo interrest[ing|ed] => interest[ing|ed]
  Fix various typos of valid in comments
  ...

Fix up trivial conflicts in:
	drivers/char/ipmi/ipmi_si_intf.c
	drivers/usb/gadget/rndis.c
	net/irda/irnet/irnet_ppp.c
2010-10-24 13:41:39 -07:00
Randy Dunlap ead454feb6 driver core: fix build for CONFIG_BLOCK not enabled
Fix build errors when CONFIG_BLOCK is not enabled:

drivers/base/core.c: In function 'get_device_parent':
drivers/base/core.c:634: error: 'block_class' undeclared (first use in this function)
drivers/base/core.c: In function 'device_add_class_symlinks':
drivers/base/core.c:723: error: 'block_class' undeclared (first use in this function)
drivers/base/core.c: In function 'device_remove_class_symlinks':
drivers/base/core.c:751: error: 'block_class' undeclared (first use in this function)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22 10:16:44 -07:00
Andi Kleen e52eec13cd SYSFS: Allow boot time switching between deprecated and modern sysfs layout
I have some systems which need legacy sysfs due to old tools that are
making assumptions that a directory can never be a symlink to another
directory, and it's a big hazzle to compile separate kernels for them.

This patch turns CONFIG_SYSFS_DEPRECATED into a run time option
that can be switched on/off the kernel command line. This way
the same binary can be used in both cases with just a option
on the command line.

The old CONFIG_SYSFS_DEPRECATED_V2 option is still there to set
the default. I kept the weird name to not break existing
config files.

Also the compat code can be still completely disabled by undefining
CONFIG_SYSFS_DEPRECATED_SWITCH -- just the optimizer takes
care of this now instead of lots of ifdefs. This makes the code
look nicer.

v2: This is an updated version on top of Kay's patch to only
handle the block devices. I tested it on my old systems
and that seems to work.

Cc: axboe@kernel.dk
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22 10:16:43 -07:00
Kay Sievers 39aba963d9 driver core: remove CONFIG_SYSFS_DEPRECATED_V2 but keep it for block devices
This patch removes the old CONFIG_SYSFS_DEPRECATED_V2 config option,
but it keeps the logic around to handle block devices in the old manner
as some people like to run new kernel versions on old (pre 2007/2008)
distros.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22 10:16:43 -07:00
Jiri Kosina fb8231a8b1 Merge branch 'master' into for-next
Conflicts:
	arch/arm/mach-omap1/board-nokia770.c
2010-08-10 13:22:08 +02:00
Stefan Weil eef35c2d41 Fix spelling fuction -> function in comments
To avoid more patches, I also fixed other spelling
and grammar bugs when they were in the same or
following line:

successfull -> successful
parse -> parses
controler -> controller
controlers -> controllers

Cc: Jiri Kosina <trivial@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-08-09 11:22:49 +02:00
Johannes Berg 6937e8f8c0 driver core: device_rename's new_name can be const
The new_name argument to device_rename() can be
const as kobject_rename's new_name argument is.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-05 13:53:35 -07:00
Linus Torvalds 6ba74014c1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1443 commits)
  phy/marvell: add 88ec048 support
  igb: Program MDICNFG register prior to PHY init
  e1000e: correct MAC-PHY interconnect register offset for 82579
  hso: Add new product ID
  can: Add driver for esd CAN-USB/2 device
  l2tp: fix export of header file for userspace
  can-raw: Fix skb_orphan_try handling
  Revert "net: remove zap_completion_queue"
  net: cleanup inclusion
  phy/marvell: add 88e1121 interface mode support
  u32: negative offset fix
  net: Fix a typo from "dev" to "ndev"
  igb: Use irq_synchronize per vector when using MSI-X
  ixgbevf: fix null pointer dereference due to filter being set for VLAN 0
  e1000e: Fix irq_synchronize in MSI-X case
  e1000e: register pm_qos request on hardware activation
  ip_fragment: fix subtracting PPPOE_SES_HLEN from mtu twice
  net: Add getsockopt support for TCP thin-streams
  cxgb4: update driver version
  cxgb4: add new PCI IDs
  ...

Manually fix up conflicts in:
 - drivers/net/e1000e/netdev.c: due to pm_qos registration
   infrastructure changes
 - drivers/net/phy/marvell.c: conflict between adding 88ec048 support
   and cleaning up the IDs
 - drivers/net/wireless/ipw2x00/ipw2100.c: trivial ipw2100_pm_qos_req
   conflict (registration change vs marking it static)
2010-08-04 11:47:58 -07:00
Eric W. Biederman 24b1442d01 Driver-core: Always create class directories for classses that support namespaces.
This fixes the regression in 2.6.35-rcX where bluetooth network devices
would fail to be deleted from sysfs, causing their destruction and
recreation to fail.  In addition this fixes the mac80211_hwsim driver
where it would leave around sysfs files when the driver was removed.

This problem is discussed at
  https://bugzilla.kernel.org/show_bug.cgi?id=16257

The reason for the regression is that the network namespace support
added to sysfs expects and requires that network devices be put in
directories that can contain only network devices.

Today get_device_parent almost provides that guarantee for all class
devices, except for a specific exception when the parent of a class
devices is a class device.  It would be nice to simply remove that
arguably incorrect special case, but apparently the input devices depend
on it being there.  So I have only removed it for class devices with
network namespace support.  Which today are the network devices.

It has been suggested that a better fix would be to change the parent
device from a class device to a bus device, which in the case of the
bluetooth driver would change /sys/class/bluetooth to /sys/bus/bluetoth,
I can not see how we would avoid significant userspace breakage if we
were to make that change.

Adding an extra directory in the path to the device will also be
userspace visible but it is much less likely to break things.
Everything is still accessible from /sys/class (for example), and it
fixes two bugs.  Adding an extra directory fixes a 3 year old regression
introduced with the new sysfs layout that makes it impossible to rename
bnep0 network devices to names that conflict with hci device attributes
like hci_revsion.  Adding an additional directory removes the new
failure modes introduced by the network namespace code.

If it weren't for the regession in the renaming of network devices I
would figure out how to just make the sysfs code deal with this
configuration of devices.

In summary this patch fixes regressions by changing:
"/sys/class/bluetooth/hci0/bnep0" to "/sys/class/bluetooth/hci0/net/bnep0".

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-26 08:05:31 -07:00
Joe Perches 99bcf21718 device.h drivers/base/core.c Convert dev_<level> logging macros to functions
Reduces an x86 defconfig text and data ~55k, .6% smaller.

$ size vmlinux*
   text	   data	    bss	    dec	    hex	filename
7205273	 716016	1366288	9287577	 8db799	vmlinux
7258890	 719768	1366288	9344946	 8e97b2	vmlinux.master

Uses %pV and struct va_format
Format arguments are verified before printk

The dev_info macro is converted to _dev_info because there are
existing uses of variables named dev_info in the kernel tree
like drivers/net/pcmcia/pcnet_cs.c

A dev_info macro is created to call _dev_info

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-04 10:40:17 -07:00
Christoph Egger 1d9e882ba4 driver-core: fix Typo in drivers/base/core.c for CONFIG_MODULE
In this code section the final S of CONFIG_MODULES was missed making
the whole check useless

Signed-off-by: Christoph Egger <siccegge@cs.fau.de>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:32 -07:00
Eric W. Biederman f349cf3473 driver core: Implement ns directory support for device classes.
device_del and device_rename were modified to use
sysfs_delete_link and sysfs_rename_link respectively to ensure
when these operations happen on devices whose classes
are in namespace directories they work properly.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:31 -07:00
Eric W. Biederman bc451f2058 kobj: Add basic infrastructure for dealing with namespaces.
Move complete knowledge of namespaces into the kobject layer
so we can use that information when reporting kobjects to
userspace.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:31 -07:00
Hugh Daschbach 6245838fe4 Driver core: Protect device shutdown from hot unplug events.
While device_shutdown() walks through devices_kset to shutdown all
devices, device unplug events may race to shutdown individual devices.
Specifically, sd_shutdown(), on behalf of fc_starget_delete(), has
been observed deleting devices during device_shutdown()'s list
traversal.  So we factor out list_for_each_entry_safe_reverse(...) in
favor of while (!list_empty(...)).

Signed-off-by: Hugh Daschbach <hdasch@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:30 -07:00
Peter Zijlstra 1704f47b50 lockdep: Add novalidate class for dev->mutex conversion
The conversion of device->sem to device->mutex resulted in lockdep
warnings. Create a novalidate class for now until the driver folks
come up with separate classes. That way we have at least the basic
mutex debugging coverage.

Add a checkpatch error so the usage is reserved for device->mutex.

[ tglx: checkpatch and compile fix for LOCKDEP=n ]

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:30 -07:00
Thomas Gleixner 3142788b79 drivers/base: Convert dev->sem to mutex
The semaphore is semantically a mutex. Convert it to a real mutex and
fix up a few places where code was relying on semaphore.h to be included
by device.h, as well as the users of the trylock function, as that value
is now reversed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:30 -07:00
Alan Stern ffa156590f Driver core: don't initialize wakeup flags
This patch (as1351) removes an unnecessary and unwanted assignment
from device_initialize().  The wakeup flags are set to 0 along with
everything else when the device structure is allocated, so we don't
need to do it again.  Furthermore, the subsystem might already have
set these flags to their correct values; we don't want to override it.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:29 -07:00
Jani Nikula f0eae0ed3b driver-core: document ERR_PTR() return values
A number of functions in the driver core return ERR_PTR() values on
error. Document this in the kernel-doc of the functions.

Signed-off-by: Jani Nikula <ext-jani.1.nikula@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-19 07:12:21 -07:00
Eric W. Biederman 2354dcc721 driver core: Use sysfs_rename_link in device_rename
Don't open code the renaming of symlinks in sysfs
instead use the new helper function sysfs_rename_link

Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:52 -08:00
Emese Revfy 52cf25d0ab Driver core: Constify struct sysfs_ops in struct kobj_type
Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:49 -08:00
Emese Revfy 9cd43611cc kobject: Constify struct kset_uevent_ops
Constify struct kset_uevent_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:49 -08:00
Kay Sievers 3f5468c9ae Driver-Core: require valid action string in uevent trigger
No longer fall back to "add" and warn, but always require a valid
action-string written to the "uevent" file.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:48 -08:00
Tejun Heo 77d3d7c1d5 driver-core: fix race condition in get_device_parent()
sysfs is creating several devices in cuse class concurrently and with
CONFIG_SYSFS_DEPRECATED turned off, it triggers the following oops.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
 IP: [<ffffffff81158b0a>] sysfs_addrm_start+0x4a/0xf0
 PGD 75bb067 PUD 75be067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP
 last sysfs file: /sys/devices/system/cpu/cpu7/topology/core_siblings
 CPU 1
 Modules linked in: cuse fuse
 Pid: 4737, comm: osspd Not tainted 2.6.31-work #77
 RIP: 0010:[<ffffffff81158b0a>]  [<ffffffff81158b0a>] sysfs_addrm_start+0x4a/0xf0
 RSP: 0018:ffff88000042f8f8  EFLAGS: 00010296
 RAX: ffff88000042ffd8 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff880007eef660 RDI: 0000000000000001
 RBP: ffff88000042f918 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: ffffffff81158b0a R12: ffff88000042f928
 R13: 00000000fffffff4 R14: 0000000000000000 R15: ffff88000042f9a0
 FS:  00007fe93905a950(0000) GS:ffff880008600000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000038 CR3: 00000000077c9000 CR4: 00000000000006e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process osspd (pid: 4737, threadinfo ffff88000042e000, task ffff880007eef040)
 Stack:
  ffff880005da10e8 0000000011cc8d6e ffff88000042f928 ffff880003d28a28
 <0> ffff88000042f988 ffffffff811592d7 0000000000000000 0000000000000000
 <0> 0000000000000000 0000000000000000 ffff88000042f958 0000000011cc8d6e
 Call Trace:
  [<ffffffff811592d7>] create_dir+0x67/0xe0
  [<ffffffff811593a8>] sysfs_create_dir+0x58/0xb0
  [<ffffffff8128ca7c>] ? kobject_add_internal+0xcc/0x220
  [<ffffffff812942e1>] ? vsnprintf+0x3c1/0xb90
  [<ffffffff8128cab7>] kobject_add_internal+0x107/0x220
  [<ffffffff8128cd37>] kobject_add_varg+0x47/0x80
  [<ffffffff8128ce53>] kobject_add+0x53/0x90
  [<ffffffff81357d84>] device_add+0xd4/0x690
  [<ffffffff81356c2b>] ? dev_set_name+0x4b/0x70
  [<ffffffffa001a884>] cuse_process_init_reply+0x2b4/0x420 [cuse]
  ...

The problem is that kobject_add_internal() first adds a kobject to the
kset and then try to create sysfs directory for it.  If the creation
fails, it remove the kobject from the kset.  get_device_parent()
accesses class_dirs kset while only holding class_dirs.list_lock to
see whether the cuse class dir exists.  But when it exists, it may not
have finished initialization yet or may fail and get removed soon.  In
the above case, the former happened so the second one ends up trying
to create subdirectory under NULL sysfs_dirent.

Fix it by grabbing a mutex in get_device_parent().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Colin Guthrie <cguthrie@mandriva.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:46 -08:00
Thomas Gleixner e6309e7568 Driver-core: Fix bogus 0 error return in device_add()
If device_add() is called with a device which does not have dev->p set
up, then device_private_init() is called. If that succeeds, then the
error variable is set to 0. Now if the dev_name(dev) check further
down fails, then device_add() correctly terminates, but returns 0.
That of course lets the driver progress. If later another driver uses
this half set up device as parent then device_add() of the child
device explodes and renders sysfs completely unusable.

Set the error to -EINVAL if dev_name() check fails.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: "Hans J. Koch" <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-23 11:23:44 -08:00
Phil Carmody 66ecb92be9 Driver core: bin_attribute parameters can often be const*
Many struct bin_attribute descriptors are purely read-only
structures, and there's no need to change them. Therefore
make the promise not to, which will let those descriptors
be put in a ro section.

Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-23 11:23:43 -08:00
Phil Carmody 26579ab70a Driver core: device_attribute parameters can often be const*
Most device_attributes are const, and are begging to be
put in a ro section. However, the create and remove
file interfaces were failing to propagate the const promise
which the only functions they call offer.

Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-23 11:23:43 -08:00
Alan Stern 3589972e51 Driver core: fix race in dev_driver_string
This patch (as1310) works around a race in dev_driver_string().  If
the device is unbound while the function is running, dev->driver might
become NULL after we test it and before we dereference it.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 11:24:55 -08:00
Eric W. Biederman 18ef545e47 Driver core: Don't remove kobjects in device_shutdown.
device_shutdown is defined to just shutdown the hardware and to not
clean up any kernel data structures.  Therefore don't put the kobjects
for /sys/dev and /sys/dev/block and /sys/dev/char.

This ensures we don't remove /sys/dev/block and /sys/dev/char while
we still have symlinks from there to the actual devices.

Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 11:24:52 -08:00
Kay Sievers ad72956df2 Driver Core: devtmpfs: cleanup node on device creation error
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 11:24:52 -08:00
Kay Sievers e454cea20b Driver-Core: extend devnode callbacks to provide permissions
This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 12:50:38 -07:00
Kay Sievers 2b2af54a5b Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev
Devtmpfs lets the kernel create a tmpfs instance called devtmpfs
very early at kernel initialization, before any driver-core device
is registered. Every device with a major/minor will provide a
device node in devtmpfs.

Devtmpfs can be changed and altered by userspace at any time,
and in any way needed - just like today's udev-mounted tmpfs.
Unmodified udev versions will run just fine on top of it, and will
recognize an already existing kernel-created device node and use it.
The default node permissions are root:root 0600. Proper permissions
and user/group ownership, meaningful symlinks, all other policy still
needs to be applied by userspace.

If a node is created by devtmps, devtmpfs will remove the device node
when the device goes away. If the device node was created by
userspace, or the devtmpfs created node was replaced by userspace, it
will no longer be removed by devtmpfs.

If it is requested to auto-mount it, it makes init=/bin/sh work
without any further userspace support. /dev will be fully populated
and dynamic, and always reflect the current device state of the kernel.
With the commonly used dynamic device numbers, it solves the problem
where static devices nodes may point to the wrong devices.

It is intended to make the initial bootup logic simpler and more robust,
by de-coupling the creation of the inital environment, to reliably run
userspace processes, from a complex userspace bootstrap logic to provide
a working /dev.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Tested-By: Harald Hoyer <harald@redhat.com>
Tested-By: Scott James Remnant <scott@ubuntu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15 09:50:49 -07:00
David Brownell a4dbd6740d driver model: constify attribute groups
Let attribute group vectors be declared "const".  We'd
like to let most attribute metadata live in read-only
sections... this is a start.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15 09:50:47 -07:00
Greg Kroah-Hartman b402843787 Driver core: move dev_get/set_drvdata to drivers/base/dd.c
No one should directly access the driver_data field, so remove the field
and make it private.  We dynamically create the private field now if it
is needed, to handle drivers that call get/set before they are
registered with the driver core.

Also update the copyright notices on these files while we are there.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15 09:50:47 -07:00
Alan Stern 2023c610dc Driver core: add new device to bus's list before probing
This patch (as1271) affects when new devices get linked into their
bus's list of devices.  Currently this happens after probing, and it
doesn't happen at all if probing fails.  Clearly this is wrong,
because at that point quite a few symbolic links have already been
created in sysfs.  We are committed to adding the device, so it should
be linked into the bus's list regardless.

In addition, this needs to happen before the uevent announcing the new
device gets issued.  Otherwise user programs might try to access the
device before it has been added to the bus.

To fix both these problems, the patch moves the call to
klist_add_tail() forward from bus_attach_device() to bus_add_device().
Since bus_attach_device() now does nothing but probe for drivers, it
has been renamed to bus_probe_device().  And lastly, the kerneldoc is
updated.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15 09:50:46 -07:00