driver core: create bus_is_registered()

A local function to the driver core to determine if a bus really is
registered with the kernel or not. To be used only by the driver core
code, as part of the driver registration path as it's not really "safe"
because the bus could be unregistered instantly after being called.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-17-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: move driver_find() to bus.c

This function really is a bus function, not a driver one, so move it
from driver.c to bus.c so that we can clean up some internal bus logic
easier.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-15-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: fix driver_set_override() issue with empty strings

Python likes to send an empty string for some sysfs files, including the
driver_override field. When commit 23d99baf9d72 ("PCI: Use
driver_set_override() instead of open-coding") moved the PCI core to use
the driver core function instead of hand-rolling their own handler, this
showed up as a regression from some userspace tools, like DPDK.

Fix this up by actually looking at the length of the string first
instead of trusting that userspace got it correct.

Fixes: 23d99baf9d72 ("PCI: Use driver_set_override() instead of open-coding")
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: stable <stable@kernel.org>
Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Tested-by: Huisong Li <lihuisong@huawei.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220901163734.3583106-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Extend deferred probe timeout on driver registration

The deferred probe timer that's used for this currently starts at
late_initcall and runs for driver_deferred_probe_timeout seconds. The
assumption being that all available drivers would be loaded and
registered before the timer expires. This means, the
driver_deferred_probe_timeout has to be pretty large for it to cover the
worst case. But if we set the default value for it to cover the worst
case, it would significantly slow down the average case. For this
reason, the default value is set to 0.

Also, with CONFIG_MODULES=y and the current default values of
driver_deferred_probe_timeout=0 and fw_devlink=on, devices with missing
drivers will cause their consumer devices to always defer their probes.
This is because device links created by fw_devlink defer the probe even
before the consumer driver's probe() is called.

Instead of a fixed timeout, if we extend an unexpired deferred probe
timer on every successful driver registration, with the expectation more
modules would be loaded in the near future, then the default value of
driver_deferred_probe_timeout only needs to be as long as the worst case
time difference between two consecutive module loads.

So let's implement that and set the default value to 10 seconds when
CONFIG_MODULES=y.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Rob Herring <robh@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: iommu@lists.linux-foundation.org
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220429220933.1350374-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver: platform: Add helper for safer setting of driver_override

Several core drivers and buses expect that driver_override is a
dynamically allocated memory thus later they can kfree() it.

However such assumption is not documented, there were in the past and
there are already users setting it to a string literal. This leads to
kfree() of static memory during device release (e.g. in error paths or
during unbind):

kernel BUG at ../mm/slub.c:3960!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
...
(kfree) from [<c058da50>] (platform_device_release+0x88/0xb4)
(platform_device_release) from [<c0585be0>] (device_release+0x2c/0x90)
(device_release) from [<c0a69050>] (kobject_put+0xec/0x20c)
(kobject_put) from [<c0f2f120>] (exynos5_clk_probe+0x154/0x18c)
(exynos5_clk_probe) from [<c058de70>] (platform_drv_probe+0x6c/0xa4)
(platform_drv_probe) from [<c058b7ac>] (really_probe+0x280/0x414)
(really_probe) from [<c058baf4>] (driver_probe_device+0x78/0x1c4)
(driver_probe_device) from [<c0589854>] (bus_for_each_drv+0x74/0xb8)
(bus_for_each_drv) from [<c058b48c>] (__device_attach+0xd4/0x16c)
(__device_attach) from [<c058a638>] (bus_probe_device+0x88/0x90)
(bus_probe_device) from [<c05871fc>] (device_add+0x3dc/0x62c)
(device_add) from [<c075ff10>] (of_platform_device_create_pdata+0x94/0xbc)
(of_platform_device_create_pdata) from [<c07600ec>] (of_platform_bus_create+0x1a8/0x4fc)
(of_platform_bus_create) from [<c0760150>] (of_platform_bus_create+0x20c/0x4fc)
(of_platform_bus_create) from [<c07605f0>] (of_platform_populate+0x84/0x118)
(of_platform_populate) from [<c0f3c964>] (of_platform_default_populate_init+0xa0/0xb8)
(of_platform_default_populate_init) from [<c01031f8>] (do_one_initcall+0x8c/0x404)

Provide a helper which clearly documents the usage of driver_override.
This will allow later to reuse the helper and reduce the amount of
duplicated code.

Convert the platform driver to use a new helper and make the
driver_override field const char (it is not modified by the core).

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220419113435.246203-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers: base: Convert to printk alias functions

The file mixes printk calls together with calls to pr_*().
Covert to printk alias functions to unify the code.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Link: https://lore.kernel.org/r/20200608095217.21162-2-matthias.bgg@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

device.h: move 'struct driver' stuff out to device/driver.h

device.h has everything and the kitchen sink when it comes to struct
device things, so split out the struct driver things things to a
separate .h file to make things easier to maintain and manage over time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20191209193303.1694546-7-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver_find_device: Unify the match function with class_find_device()

The driver_find_device() accepts a match function pointer to
filter the devices for lookup, similar to bus/class_find_device().
However, there is a minor difference in the prototype for the
match parameter for driver_find_device() with the now unified
version accepted by {bus/class}_find_device(), where it doesn't
accept a "const" qualifier for the data argument. This prevents
us from reusing the generic match functions for driver_find_device().

For this reason, change the prototype of the driver_find_device() to
make the "match" parameter in line with {bus/class}_find_device()
and adjust its callers to use the const qualifier. Also, we could
now promote the "data" parameter to const as we pass it down
as a const parameter to the match functions.

Cc: Corey Minyard <minyard@acm.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Sebastian Ott <sebott@linux.ibm.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Nehal Shah <nehal-bakulchandra.shah@amd.com>
Cc: Shyam Sundar S K <shyam-sundar.s-k@amd.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver-core: return EINVAL error instead of BUG_ON()

I triggerd the BUG_ON() in driver_register() when booting a domU Xen
domain. Since there was no contextual information logged, I needed to
attach kgdb to determine the culprit (the wmi-bmof driver in my
case). The BUG_ON() was added in commit f48f3febb2cb ("driver-core: do
not register a driver with bus_type not registered").

Instead of running into a BUG_ON() we print an error message
identifying the, likely faulty, driver but continue booting.

Signed-off-by: Florian Schmaus <flo@geekplace.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers: base: omit redundant interations

When error happens, these interators return the error, no interation should
be continued, so make the change for getting out of while immediately.

Signed-off-by: Gimcuan Hui <gimcuan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Remove redundant license text

Now that the SPDX tag is in all driver core files, that identifies the
license in a specific and legally-defined manner. So the extra GPL text
wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: add SPDX identifiers to all driver core files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the driver core files files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: add missing blank line after declaration

Found using checkpatch.pl
Signed-off-by: Lavinia Tache <lavinia.tachee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "core: platform: add warning if driver has no owner"

This is too noisy at the moment, triggered by codepaths not accessed on
our test-systems. Needs more investigation.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

core: platform: add warning if driver has no owner

Commit 9447057eaff8 ("platform_device: use a macro instead of
platform_driver_register") introduced a codepath which could result into
drivers having no owner. This went unnoticed for months, so add a
warning in case this happens again somewhere else somewhen.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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>

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>

driver core: bus_type: add drv_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 drv_groups to struct bus_type which should be used
instead of drv_attrs.

drv_attrs will be removed from the structure soon.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: don't trigger uevent after failure

Do not send the uevent if driver_add_groups failed.

Reported-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: move uevent call to driver_register

Device driver attribute groups are created after userspace is notified
via an add event. Fix this by moving the kobject_uevent call to
driver_register after the attribute groups are added.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Driver Core: don't oops with unregistered driver in driver_find_device()

driver_find_device() can be called with an unregistered driver. Need
to check driver_private to see if it's populated or not, especially
under deferrable probe.

In the case that there are 2 drivers, one depends on the other. With
-EPROBE_DEFER, two drivers can use deferred probe to ensure that their
relative probe order doesn't matter. If dependee driver is probed
first, then the dependant's driver_find_device('dependee')
succeeds. If the dependant is probed first, then the dependant's
driver_find_device('dependee') should return NULL, and the dependant
should get -EPROBE_DEFER. driver_find_device() needs to return NULL if
it's not populated.

In [PATCHv5 2/3] ARM: tegra: Add SMMU enabler in AHB:
http://article.gmane.org/gmane.linux.ports.tegra/4658

"tegra_ahb_driver" may not be populated when it's called.

For more SMMU/AHB specific discussion, refer to the following thread:
https://lkml.org/lkml/2012/5/10/21

Signed-off-by: Hiroshi DOYU <hdoyu@nvidia.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "driver core: check start node in klist_iter_init_node"

This reverts commit a15d49fd3094cff90e5410ca454a870e0a722fe1 as that
patch broke the build.

Cc: Hannes Reinecke <hare@suse.de>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: check start node in klist_iter_init_node

klist_iter_init_node() takes a node as a start argument.
However, this node might not be valid anymore.
This patch updates the klist_iter_init_node() and
dependent functions to return an error if so.
All calling functions have been audited to check
for a return code here.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Greg Kroah-Hartmann <gregkh@linuxfoundation.org>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Stable Kernel <stable@kernel.org>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver-core: remove legacy iSeries hack

The PowerPC legacy iSeries plateform is being removed along with the
"one looney iseries driver", so this code can now be removed as well.

cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Eliminate get_driver() and put_driver()

Now that there are no users of get_driver() or put_driver(), this
patch (as1513) removes those routines completely.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: driver_find() drops reference before returning

As part of the removal of get_driver()/put_driver(), this patch
(as1510) changes driver_find(); it now drops the reference it acquires
before returning. The patch also adjusts all the callers of
driver_find() to remove the now unnecessary calls to put_driver().

In addition, the patch adds a warning to driver_find(): Callers must
make sure the driver they are searching for does not get unloaded
while they are using it. This has always been the case; driver_find()
has never prevented a driver from being unregistered or unloaded.
Hence the patch will not introduce any new bugs. The existing callers
all seem to be okay in this respect, however I don't understand the
video drivers well enough to be certain about them.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
CC: Kyungmin Park <kyungmin.park@samsung.com>
CC: Andy Walls <awalls@md.metrocast.net>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

Driver core: driver_attribute parameters can often be const*

Many struct driver_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>

Driver core: fix driver_register() return value

In this patch:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=16dc42e018c2868211b4928f20a957c0c216126c
the check was added for another driver to already claim the same device
on the same bus. But the returned error code was wrong: to modprobe, the
-EEXIST means that _this_ driver is already installed. It therefore
doesn't produce the needed error message when _another_ driver is trying
to register for the same device. Returning -EBUSY fixes the problem.

Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

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>

Driver Core: do not oops when driver_unregister() is called for unregistered drivers

We also fix a problem with cleaning up properly when initializing
drivers and devices, so checks like this will work successfully.

Portions of the patch by Linus and Greg and Ingo.

Reported-by: Ozan Çağlayan <ozan@pardus.org.tr>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: move knode_driver into private structure

Nothing outside of the driver core should ever touch knode_driver, so
move it out of the public eye.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver-core: do not register a driver with bus_type not registered

If the bus_type is not registerd, driver_register to that bus will cause oops.

I found this bug when test built-in usb serial drivers (ie. aircable driver)
with 'nousb' cmdline params.

In this patch:
1. set the bus->p=NULL when bus_register failed and unregisterd.
2. if bus->p is NULL, driver_register BUG_ON will be triggered.

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Revert "driver core: move knode_driver into private structure"

This reverts commit 93e746db183b3bdbbda67900f79b5835f9cb388f.

Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.

Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: move knode_driver into private structure

Nothing outside of the driver core should ever touch knode_driver, so
move it out of the public eye.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/base/driver.c: remove unused to_dev() macro

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: warn about duplicate driver names on the same bus

Currently an attempt to register multiple
drivers with the same name causes the
stack trace with some cryptic error message.
The attached patch adds the necessary check
and the clear error message.

Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: fix small mem leak in driver_add_kobj()

The Coverity checker spotted that we leak the storage allocated to 'name' in
int driver_add_kobj(). The leak looks legit to me - this is the code :

int driver_add_kobj(struct device_driver *drv, struct kobject *kobj,
const char *fmt, ...)
{
va_list args;
char *name;
int ret;

va_start(args, fmt);
name = kvasprintf(GFP_KERNEL, fmt, args);
^^^^^^^^ This dynamically allocates space...

va_end(args);

if (!name)
return -ENOMEM;

return kobject_add(kobj, &drv->p->kobj, "%s", name);
^^^^^^^^ This neglects to free the space allocated
}

Inside kobject_add() a copy of 'name' will be made and used. As far as I can
see, Coverity is correct in flagging this as a leak, but I'd like some
configmation before the patch is applied.

This should fix it.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

driver-core: fix kernel-doc function parameters

Fix drivers/base/ missing kernel-doc parameters:
Warning(linux-2.6.24-git12//drivers/base/driver.c:133): No description found for parameter 'drv'
Warning(linux-2.6.24-git12//drivers/base/driver.c:133): No description found for parameter 'kobj'
Warning(linux-2.6.24-git12//drivers/base/driver.c:133): No description found for parameter 'fmt'
Warning(linux-2.6.24-git12//drivers/base/power/main.c:530): No description found for parameter 'state'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: Remove unneeded get_{device,driver}() calls.

Driver core: Remove unneeded get_{device,driver}() calls.

Code trying to add/remove attributes must hold a reference to
the device resp. driver anyway, so let's remove those reference
count games.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: coding style fixes

Fix up a number of coding style issues in the drivers/base/ directory
that have annoyed me over the years. checkpatch.pl is now very happy.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Kobject: rename kobject_add_ng() to kobject_add()

Now that the old kobject_add() function is gone, rename kobject_add_ng()
to kobject_add() to clean up the namespace.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: move the static kobject out of struct driver

This patch removes the kobject, and a few other driver-core-only fields
out of struct driver and into the driver core only. Now drivers can be
safely create on the stack or statically (like they currently are.)

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver: add driver_add_kobj for looney iseries_veth driver

The iseries driver wants to hang kobjects off of its driver, so, to
preserve backwards compatibility, we need to add a call to the driver
core to allow future changes to work properly.

Hopefully no one uses this function in the future and the iseries_veth
driver authors come to their senses so I can remove this hack...

Cc: Dave Larson <larson1@us.ibm.com>
Cc: Santiago Leon <santil@us.ibm.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: Introduce default attribute groups.

This is lot like default attributes for devices (and indeed,
a lot of the code is lifted from there).

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: remove fields from struct bus_type

struct bus_type is static everywhere in the kernel. This moves the
kobject in the structure out of it, and a bunch of other private only to
the driver core fields are now moved to a private structure. This lets
us dynamically create the backing kobject properly and gives us the
chance to be able to document to users exactly how to use the struct
bus_type as there are no fields they can improperly access.

Thanks to Kay for the build fixes on this patch.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

kset: convert struct bus_device->drivers to use kset_create

Dynamically create the kset instead of declaring it statically.

Having 3 static kobjects in one structure is not only foolish, but ripe
for nasty race conditions if handled improperly. We also rename the
field to catch any potential users of it (not that there should be
outside of the driver core...)

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: remove unneeded completion from driver release path

The completion in the driver release path is due to ancient history in
the _very_ early 2.5 days when we were not tracking the module reference
count of attributes. It is not needed at all and can be removed.

Note, we now have an empty release function for the driver structure.
This is due to the fact that drivers are statically allocated in the
system at this point in time, something which I want to change in the
future. But remember, drivers are really code, which is reference
counted by the module, unlike devices, which are data and _must_ be
reference counted properly in order to work correctly.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: do not wait unnecessarily in driver_unregister()

Ingo reported that built-in drivers suffered bootup hangs with certain
driver unregistry sequences, due to sysfs breakage.

Do the minimal fix for v2.6.21: only wait if the driver is a module.

Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Driver core: Remove unneeded routines from driver core

This patch (as783) simplifies the driver core slightly by removing four
unnecessary _get and _put methods.

It is vital that when a driver is removed from its bus's klist of
registered drivers, or when a device is removed from a driver's klist
of bound devices, that the klist updates complete synchronously.
Otherwise the kernel might try binding an unregistered driver to a
newly-registered device, or adding a device to the klist for a new
driver before it has been removed from the old driver's klist.

Since the removals must be synchronous, they don't need to update any
reference counts. Hence the _get and _put methods can be dispensed
with.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[PATCH] Add bus_type probe, remove, shutdown methods.

Add bus_type probe, remove and shutdown methods to replace the
corresponding methods in struct device_driver. This matches
the way we handle the suspend/resume methods.

Since the bus methods override the device_driver methods, warn
if a device driver is registered whose methods will not be
called.

The long-term idea is to remove the device_driver methods entirely.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] kernel-doc: drivers/base fixes

driver/base: add missing function parameters; eliminate all warnings.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] fix klist semantics for lists which have elements removed on traversal

The problem is that klists claim to provide semantics for safe traversal of
lists which are being modified. The failure case is when traversal of a
list causes element removal (a fairly common case). The issue is that
although the list node is refcounted, if it is embedded in an object (which
is universally the case), then the object will be freed regardless of the
klist refcount leading to slab corruption because the klist iterator refers
to the prior element to get the next.

The solution is to make the klist take and release references to the
embedding object meaning that the embedding object won't be released until
the list relinquishes the reference to it.

(akpm: fast-track this because it's needed for the 2.6.13 scsi merge)

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] driver core: add bus_find_device & driver_find_device functions

Add bus_find_device() and driver_find_device() which allow searching for a
device in the bus's resp. the driver's klist and obtain a reference on it.

Signed-off-by: Cornelia Huck <cohuck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] driver core: change export symbol for driver_for_each_device()

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Index: linux-2.6.12-rc2/drivers/base/driver.c
===================================================================

[PATCH] Fix up bogus comment.

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff -Nru a/drivers/base/driver.c b/drivers/base/driver.c

[PATCH] Add a klist to struct device_driver for the devices bound to it.

- Use it in driver_for_each_device() instead of the regular list_head and stop using
the bus's rwsem for protection.
- Use driver_for_each_device() in driver_detach() so we don't deadlock on the
bus's rwsem.
- Remove ->devices.
- Move klist access and sysfs link access out from under device's semaphore, since
they're synchronized through other means.

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] Add driver_for_each_device().

Now there's an iterator for accessing each device bound to a driver.

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Index: linux-2.6.12-rc2/drivers/base/driver.c
===================================================================

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!