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>
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>
Subsystems such as ALSA, DRM and others require a single card-level
device structure to represent a subsystem. However, firmware tends to
describe the individual devices and the connections between them.
Therefore, we need a way to gather up the individual component devices
together, and indicate when we have all the component devices.
We do this in DT by providing a "superdevice" node which specifies
the components, eg:
imx-drm {
compatible = "fsl,drm";
crtcs = <&ipu1>;
connectors = <&hdmi>;
};
The superdevice is declared into the component support, along with the
subcomponents. The superdevice receives callbacks to locate the
subcomponents, and identify when all components are present. At this
point, we bind the superdevice, which causes the appropriate subsystem
to be initialised in the conventional way.
When any of the components or superdevice are removed from the system,
we unbind the superdevice, thereby taking the subsystem down.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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>
We expect to read firmware blobs with a single call to kernel_read(),
which returns int. Therefore the size must be within the range of
int, not long.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Avoid that bus_unregister() triggers a use-after-free with
CONFIG_DEBUG_KOBJECT_RELEASE=y. This patch avoids that the
following sequence triggers a kernel crash with memory poisoning
enabled:
* bus_register()
* driver_register()
* driver_unregister()
* bus_unregister()
The above sequence causes the bus private data to be freed from
inside the bus_unregister() call although it is not guaranteed in
that function that the reference count on the bus private data has
dropped to zero. As an example, with CONFIG_DEBUG_KOBJECT_RELEASE=y
the ${bus}/drivers kobject is still holding a reference on
bus->p->subsys.kobj via its parent pointer at the time the bus
private data is freed. Fix this by deferring freeing the bus private
data until the last kobject_put() call on bus->p->subsys.kobj.
The kernel oops triggered by the above sequence and with memory
poisoning enabled and that is fixed by this patch is as follows:
general protection fault: 0000 [#1] PREEMPT SMP
CPU: 3 PID: 2711 Comm: kworker/3:32 Tainted: G W O 3.13.0-rc4-debug+ #1
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Workqueue: events kobject_delayed_cleanup
task: ffff880037f866d0 ti: ffff88003b638000 task.ti: ffff88003b638000
Call Trace:
[<ffffffff81263105>] ? kobject_get_path+0x25/0x100
[<ffffffff81264354>] kobject_uevent_env+0x134/0x600
[<ffffffff8126482b>] kobject_uevent+0xb/0x10
[<ffffffff81262fa2>] kobject_delayed_cleanup+0xc2/0x1b0
[<ffffffff8106c047>] process_one_work+0x217/0x700
[<ffffffff8106bfdb>] ? process_one_work+0x1ab/0x700
[<ffffffff8106c64b>] worker_thread+0x11b/0x3a0
[<ffffffff8106c530>] ? process_one_work+0x700/0x700
[<ffffffff81074b70>] kthread+0xf0/0x110
[<ffffffff81074a80>] ? insert_kthread_work+0x80/0x80
[<ffffffff815673bc>] ret_from_fork+0x7c/0xb0
[<ffffffff81074a80>] ? insert_kthread_work+0x80/0x80
Code: 89 f8 48 89 e5 f6 82 c0 27 63 81 20 74 15 0f 1f 44 00 00 48 83 c0 01 0f b6 10 f6 82 c0 27 63 81 20 75 f0 5d c3 66 0f 1f 44 00 00 <80> 3f 00 55 48 89 e5 74 15 48 89 f8 0f 1f 40 00 48 83 c0 01 80
RIP [<ffffffff81267ed0>] strlen+0x0/0x30
RSP <ffff88003b639c70>
---[ end trace 210f883ef80376aa ]---
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Avoid that sparse reports the following warning on __fw_free_buf():
drivers/base/firmware_class.c:230:9: warning: context imbalance in '__fw_free_buf' - unexpected unlock
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The deleted variable is always 1 in current code.
Initialize deleted variable to be 0, so delete_path() will be called only when
necessary.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
a8b1474442 ("sysfs: give different locking key to regular and bin
files") in driver-core-linus modifies sysfs_open_file() so that it
gives out different locking classes to sysfs_open_files depending on
whether the file is bin or not. Due to the massive kernfs
reorganization in driver-core-next, this naturally causes merge
conflict in fs/sysfs/file.c.
Due to the way things are split between kernfs and sysfs in
driver-core-next, the same fix can't easily be applied to
driver-core-next. This merge simply ignores the offending commit. A
following patch will implement a separate fix for the issue.
Signed-off-by: Tejun Heo <tj@kernel.org>
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>
The commit [3e358ac2bb: firmware: Be a bit more verbose about direct
firmware loading failure] introduced a new warning message about
falling back to user helper, but this isn't true when
CONFIG_FW_LOADER_USER_HELPER isn't set.
In this patch, clear the FW_OPT_FALLBACK flag in the case without
userhelper, so that the corresponding code will be disabled.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
More than two boolean arguments to a function are rather confusing and
error-prone for callers. Let's make the behavior bit flags instead of
triple combos.
A nice suggestion by Borislav Petkov.
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When CONFIG_FW_LOADER_USER_HELPER is set, request_firmware() falls
back to the usermode helper for loading via udev when the direct
loading fails. But the recent udev takes way too long timeout (60
seconds) for non-existing firmware. This is unacceptable for the
drivers like microcode loader where they load firmwares optionally,
i.e. it's no error even if no requested file exists.
This patch provides a new helper function, request_firmware_direct().
It behaves as same as request_firmware() except for that it doesn't
fall back to usermode helper but returns an error immediately if the
f/w can't be loaded directly in kernel.
Without CONFIG_FW_LOADER_USER_HELPER=y, request_firmware_direct() is
just an alias of request_firmware(), due to obvious reason.
Tested-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pm-cpuidle:
cpuidle: Check for dev before deregistering it.
intel_idle: Fixed C6 state on Avoton/Rangeley processors
* pm-cpufreq:
cpufreq: fix garbage kobjects on errors during suspend/resume
cpufreq: suspend governors on system suspend/hibernate
This patch adds cpufreq suspend/resume calls to dpm_{suspend|resume}_noirq()
for handling suspend/resume of cpufreq governors.
Lan Tianyu (Intel) & Jinhyuk Choi (Broadcom) found anr issue where
tunables configuration for clusters/sockets with non-boot CPUs was
getting lost after suspend/resume, as we were notifying governors
with CPUFREQ_GOV_POLICY_EXIT on removal of the last cpu for that
policy and so deallocating memory for tunables. This is fixed by
this patch as we don't allow any operation on governors after
device suspend and before device resume now.
Reported-and-tested-by: Lan Tianyu <tianyu.lan@intel.com>
Reported-by: Jinhyuk Choi <jinchoi@broadcom.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[rjw: Changelog, minor cleanups]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
clk_get() returns an error pointer, or a valid token to pass back to the
clock API. Hence, the result must be checked with IS_ERR(), not by
comparison against NULL.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Pull more ACPI and power management updates from Rafael Wysocki:
- ACPI-based device hotplug fixes for issues introduced recently and a
fix for an older error code path bug in the ACPI PCI host bridge
driver
- Fix for recently broken OMAP cpufreq build from Viresh Kumar
- Fix for a recent hibernation regression related to s2disk
- Fix for a locking-related regression in the ACPI EC driver from
Puneet Kumar
- System suspend error code path fix related to runtime PM and runtime
PM documentation update from Ulf Hansson
- cpufreq's conservative governor fix from Xiaoguang Chen
- New processor IDs for intel_idle and turbostat and removal of an
obsolete Kconfig option from Len Brown
- New device IDs for the ACPI LPSS (Low-Power Subsystem) driver and
ACPI-based PCI hotplug (ACPIPHP) cleanup from Mika Westerberg
- Removal of several ACPI video DMI blacklist entries that are not
necessary any more from Aaron Lu
- Rework of the ACPI companion representation in struct device and code
cleanup related to that change from Rafael J Wysocki, Lan Tianyu and
Jarkko Nikula
- Fixes for assigning names to ACPI-enumerated I2C and SPI devices from
Jarkko Nikula
* tag 'pm+acpi-2-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (24 commits)
PCI / hotplug / ACPI: Drop unused acpiphp_debug declaration
ACPI / scan: Set flags.match_driver in acpi_bus_scan_fixed()
ACPI / PCI root: Clear driver_data before failing enumeration
ACPI / hotplug: Fix PCI host bridge hot removal
ACPI / hotplug: Fix acpi_bus_get_device() return value check
cpufreq: governor: Remove fossil comment in the cpufreq_governor_dbs()
ACPI / video: clean up DMI table for initial black screen problem
ACPI / EC: Ensure lock is acquired before accessing ec struct members
PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps()
ACPI / AC: Remove struct acpi_device pointer from struct acpi_ac
spi: Use stable dev_name for ACPI enumerated SPI slaves
i2c: Use stable dev_name for ACPI enumerated I2C slaves
ACPI: Provide acpi_dev_name accessor for struct acpi_device device name
ACPI / bind: Use (put|get)_device() on ACPI device objects too
ACPI: Eliminate the DEVICE_ACPI_HANDLE() macro
ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node
cpufreq: OMAP: Fix compilation error 'r & ret undeclared'
PM / Runtime: Fix error path for prepare
PM / Runtime: Update documentation around probe|remove|suspend
cpufreq: conservative: set requested_freq to policy max when it is over policy max
...
Pull trivial tree updates from Jiri Kosina:
"Usual earth-shaking, news-breaking, rocket science pile from
trivial.git"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits)
doc: usb: Fix typo in Documentation/usb/gadget_configs.txt
doc: add missing files to timers/00-INDEX
timekeeping: Fix some trivial typos in comments
mm: Fix some trivial typos in comments
irq: Fix some trivial typos in comments
NUMA: fix typos in Kconfig help text
mm: update 00-INDEX
doc: Documentation/DMA-attributes.txt fix typo
DRM: comment: `halve' -> `half'
Docs: Kconfig: `devlopers' -> `developers'
doc: typo on word accounting in kprobes.c in mutliple architectures
treewide: fix "usefull" typo
treewide: fix "distingush" typo
mm/Kconfig: Grammar s/an/a/
kexec: Typo s/the/then/
Documentation/kvm: Update cpuid documentation for steal time and pv eoi
treewide: Fix common typo in "identify"
__page_to_pfn: Fix typo in comment
Correct some typos for word frequency
clk: fixed-factor: Fix a trivial typo
...
