The wmb() inside fw_load_abort is not necessary, since
complete() and wait_on_completion() has implied one pair
of memory barrier.
Also wmb() isn't a correct usage, so just remove it.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes two races in loading firmware:
1, FW_STATUS_DONE should be set before waking up the task waitting
on _request_firmware_load, otherwise FW_STATUS_ABORT may be
thought as DONE mistakenly.
2, Inside _request_firmware_load(), there is a small window between
wait_for_completion() and mutex_lock(&fw_lock), and 'echo 1 > loading'
still may happen during the period, so this patch checks FW_STATUS_DONE
to prevent pages' buffer completed from being freed in firmware_loading_store.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch doesn't transfer ownership of pages' buffer to the
instance of firmware until the firmware loading is completed,
which will simplify firmware_loading_store a lot, so help
to introduce the following cache_firmware and uncache_firmware
mechanism during system suspend-resume cycle.
In fact, this patch fixes one bug: if writing data into
firmware loader device is bypassed between writting 1 and 0 to
'loading', OOPS will be triggered without the patch.
Also handle the vmap failure case, and add some comments to make
code more readable.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Oddly enough a work_struct was already part of the firmware_work
structure but nobody was using it. Instead of creating a new
kthread for each request_firmware_nowait() call just schedule the
work on the system workqueue. This should avoid some overhead
in forking new threads when they're not strictly necessary.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Recent patches to split up the three phases of request_firmware()
lead to a casting away of const in fw_create_instance(). We can
avoid this cast by splitting up fw_create_instance() a bit.
Make _request_firmware_setup() return a struct fw_priv and use
that struct instead of passing struct firmware to
_request_firmware(). Move the uevent and device file creation
bits to the loading phase and rename the function to
_request_firmware_load() to better reflect its purpose.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
If firmware is requested asynchronously, by calling
request_firmware_nowait(), there is no reason to fail the request
(and warn the user) when the system is (presumably temporarily)
unready to handle it (because user space is not available yet or
frozen). For this reason, introduce an alternative routine for
read-locking umhelper_sem, usermodehelper_read_lock_wait(), that
will wait for usermodehelper_disabled to be unset (possibly with
a timeout) and make request_firmware_work_func() use it instead of
usermodehelper_read_trylock().
Accordingly, modify request_firmware() so that it uses
usermodehelper_read_trylock() to acquire umhelper_sem and remove
the code related to that lock from _request_firmware().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Split _request_firmware() into three functions,
_request_firmware_prepare() doing preparatory work that need not be
done under umhelper_sem, _request_firmware_cleanup() doing the
post-error cleanup and _request_firmware() carrying out the remaining
operations.
This change is requisite for moving the acquisition of umhelper_sem
from _request_firmware() to the callers, which is going to be done
subsequently.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: stable@vger.kernel.org
Instead of two functions, read_lock_usermodehelper() and
usermodehelper_is_disabled(), used in combination, introduce
usermodehelper_read_trylock() that will only return with umhelper_sem
held if usermodehelper_disabled is unset (and will return -EAGAIN
otherwise) and make _request_firmware() use it.
Rename read_unlock_usermodehelper() to
usermodehelper_read_unlock() to follow the naming convention of the
new function.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Commit b298d289
"PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()"
added read_unlock_usermodehelper() but read_unlock_usermodehelper() is called
without read_lock_usermodehelper() when kmalloc() failed.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits)
PM / Hibernate: Implement compat_ioctl for /dev/snapshot
PM / Freezer: fix return value of freezable_schedule_timeout_killable()
PM / shmobile: Allow the A4R domain to be turned off at run time
PM / input / touchscreen: Make st1232 use device PM QoS constraints
PM / QoS: Introduce dev_pm_qos_add_ancestor_request()
PM / shmobile: Remove the stay_on flag from SH7372's PM domains
PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume
PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode
PM: Drop generic_subsys_pm_ops
PM / Sleep: Remove forward-only callbacks from AMBA bus type
PM / Sleep: Remove forward-only callbacks from platform bus type
PM: Run the driver callback directly if the subsystem one is not there
PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers
PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412.
PM / Sleep: Merge internal functions in generic_ops.c
PM / Sleep: Simplify generic system suspend callbacks
PM / Hibernate: Remove deprecated hibernation snapshot ioctls
PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()
ARM: S3C64XX: Implement basic power domain support
PM / shmobile: Use common always on power domain governor
...
Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused
XBT_FORCE_SLEEP bit
This oops was reported recently:
firmware_loading_store+0xf9/0x17b
dev_attr_store+0x20/0x22
sysfs_write_file+0x101/0x134
vfs_write+0xac/0xf3
sys_write+0x4a/0x6e
system_call_fastpath+0x16/0x1b
The complete backtrace was unfortunately not captured, but details can be found
here:
https://bugzilla.redhat.com/show_bug.cgi?id=769920
The cause is fairly clear.
Its caused by the fact that firmware_loading_store has a case 0 in its
switch statement that reads and writes the fw_priv->fw poniter without the
protection of the fw_lock mutex. since there is a window between the time that
_request_firmware sets fw_priv->fw to NULL and the time the corresponding sysfs
file is unregistered, its possible for a user space application to race in, and
write a zero to the loading file, causing a NULL dereference in
firmware_loading_store. Fix it by extending the protection of the fw_lock mutex
to cover all of the firware_loading_store function.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit a144c6a (PM: Print a warning if firmware is requested when tasks
are frozen) introduced usermodehelper_is_disabled() to warn and exit
immediately if firmware is requested when usermodehelpers are disabled.
However, it is racy. Consider the following scenario, currently used in
drivers/base/firmware_class.c:
...
if (usermodehelper_is_disabled())
goto out;
/* Do actual work */
...
out:
return err;
Nothing prevents someone from disabling usermodehelpers just after the check
in the 'if' condition, which means that it is quite possible to try doing the
"actual work" with usermodehelpers disabled, leading to undesirable
consequences.
In particular, this race condition in _request_firmware() causes task freezing
failures whenever suspend/hibernation is in progress because, it wrongly waits
to get the firmware/microcode image from userspace when actually the
usermodehelpers are disabled or userspace has been frozen.
Some of the example scenarios that cause freezing failures due to this race
are those that depend on userspace via request_firmware(), such as x86
microcode module initialization and microcode image reload.
Previous discussions about this issue can be found at:
http://thread.gmane.org/gmane.linux.kernel/1198291/focus=1200591
This patch adds proper synchronization to fix this issue.
It is to be noted that this patchset fixes the freezing failures but doesn't
remove the warnings. IOW, it does not attempt to add explicit synchronization
to x86 microcode driver to avoid requesting microcode image at inopportune
moments. Because, the warnings were introduced to highlight such cases, in the
first place. And we need not silence the warnings, since we take care of the
*real* problem (freezing failure) and hence, after that, the warnings are
pretty harmless anyway.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
In commit a144c6a6c9 ("PM: Print a warning if firmware is requested
when tasks are frozen") we not only printed a warning if somebody tried
to load the firmware when tasks are frozen - we also failed the load.
But that check was done before the check for built-in firmware, and then
when we disallowed usermode helpers during bootup (commit 288d5abec8:
"Boot up with usermodehelper disabled"), that actually means that
built-in modules can no longer load their firmware even if the firmware
is built in too. Which used to work, and some people depended on it for
the R100 driver.
So move the test for usermodehelper_is_disabled() down, to after
checking the built-in firmware.
This should fix:
https://bugzilla.kernel.org/show_bug.cgi?id=40952
Reported-by: James Cloos <cloos@hjcloos.com>
Bisected-by: Elimar Riesebieter <riesebie@lxtec.de>
Cc: Michel Dänzer <michel@daenzer.net>
Cc: Rafael Wysocki <rjw@sisk.pl>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some drivers erroneously use request_firmware() from their ->resume()
(or ->thaw(), or ->restore()) callbacks, which is not going to work
unless the firmware has been built in. This causes system resume to
stall until the firmware-loading timeout expires, which makes users
think that the resume has failed and reboot their machines
unnecessarily. For this reason, make _request_firmware() print a
warning and return immediately with error code if it has been called
when tasks are frozen and it's impossible to start any new usermode
helpers.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Some place in firmware_class.c using "int uevent" define, but others use "bool
uevent".
This patch replace all int uevent define to bool.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In the error path, _request_firmware sets
firmware_p to NULL rather than *firmware_p,
which leads to passing a freed firmware
struct to drivers when the firmware file
cannot be found. Fix this.
Broken by commit f8a4bd3456.
Reported-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Both these structures have the same lifetime rules so instead of allocating
and managing them separately embed struct device into struct firmware_priv.
Also make sure to delete sysfs attributes ourselves instead of expecting
sysfs to clean up our mess.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is no reason why we are using a template for binary attribute
and copying it into per-firmware data before registering. Using the
original works as well.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fw_id has the same life time as firmware_priv so it makes sense to move
it into firmware_priv structure instead of allocating separately.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Split builtin firmware handling into separate functions to clean up the
main body of code.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Do not create 'timeout' attribute manually, let driver core do it for us.
This also ensures that attribute is cleaned up properly.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When we use request_firmware_nowait(), userspace may
not want to answer negatively right away when for
example it is answering from an initrd only, but
with request_firmware() it has to in order to not
delay the kernel boot until the request times out.
This allows userspace to differentiate between the
two in order to be able to reply negatively to async
requests only when all filesystems have been mounted
and have been checked for the requested firmware file.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The messages from _request_firmware() informing that firmware is
being requested or built-in firmware is going to be used are printed
at KERN_INFO, which produces lots of noise on systems with huge
numbers of AMD CPUs. Reduce the level of these messages to
KERN_DEBUG to get rid of that noise.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Ming Lei
Lars-Peter Clausen
Stephen Boyd
Rafael J. Wysocki
Tetsuo Handa
Linus Torvalds
Neil Horman
Srivatsa S. Bhat
Bob Liu
Johannes Berg
Dmitry Torokhov
Chris Wright