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path: root/drivers/base/firmware_class.c
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2012-11-14firmware loader: document firmware cache mechanismMing Lei
This patch documents the firmware cache mechanism so that users of request_firmware() know that it can be called safely inside device's suspend and resume callback, and the device's firmware needn't be cached any more by individual driver itself to deal with firmware loss during system resume. Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14firmware loader: introduce module parameter to customize(v4) fw search pathMing Lei
This patch introduces one module parameter of 'path' in firmware_class to support customizing firmware image search path, so that people can use its own firmware path if the default built-in paths can't meet their demand[1], and the typical usage is passing the below from kernel command parameter when 'firmware_class' is built in kernel: firmware_class.path=$CUSTOMIZED_PATH [1], https://lkml.org/lkml/2012/10/11/337 Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14firmware: use noinline_for_stackCesar Eduardo Barros
The comment above fw_file_size() suggests it is noinline for stack size reasons. Use noinline_for_stack to make this more clear. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Acked-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14firmware loader: Fix the concurrent request_firmware() race for kref_get/putChuansheng Liu
There is one race that both request_firmware() with the same firmware name. The race scenerio is as below: CPU1 CPU2 request_firmware() --> _request_firmware_load() return err another request_firmware() is coming --> _request_firmware_cleanup is called --> _request_firmware_prepare --> release_firmware ---> fw_lookup_and_allocate_buf --> spin_lock(&fwc->lock) ... __fw_lookup_buf() return true fw_free_buf() will be called --> ... kref_put --> decrease the refcount to 0 kref_get(&tmp->ref) ==> it will trigger warning due to refcount == 0 __fw_free_buf() --> ... spin_unlock(&fwc->lock) spin_lock(&fwc->lock) list_del(&buf->list) spin_unlock(&fwc->lock) kfree(buf) After that, the freed buf will be used. The key race is decreasing refcount to 0 and list_del is not protected together by fwc->lock, and it is possible another thread try to get it between refcount==0 and list_del. Fix it here to protect it together. Acked-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: liu chuansheng <chuansheng.liu@intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14firmware loader: Fix the race FW_STATUS_DONE is followed by class_timeoutChuansheng Liu
There is a race as below when calling request_firmware(): CPU1 CPU2 write 0 > loading mutex_lock(&fw_lock) ... set_bit FW_STATUS_DONE class_timeout is coming set_bit FW_STATUS_ABORT complete_all &completion ... mutex_unlock(&fw_lock) In this time, the bit FW_STATUS_DONE and FW_STATUS_ABORT are set, and request_firmware() will return failure due to condition in _request_firmware_load(): if (!buf->size || test_bit(FW_STATUS_ABORT, &buf->status)) retval = -ENOENT; But from the above scenerio, it should be a successful requesting. So we need judge if the bit FW_STATUS_DONE is already set before calling fw_load_abort() in timeout function. As Ming's proposal, we need change the timer into sched_work to benefit from using &fw_lock mutex also. Signed-off-by: liu chuansheng <chuansheng.liu@intel.com> Acked-by: Ming Lei <ming.lei@canonical.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22firmware loader: sync firmware cache by async_synchronize_full_domainMing Lei
async.c has provided synchronization mechanism on async_schedule_*, so use async_synchronize_full_domain to sync caching firmware instead of reinventing the wheel. Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22firmware loader: let direct loading back on 'firmware_buf'Ming Lei
Firstly 'firmware_buf' is introduced to make all loading requests to share one firmware kernel buffer, so firmware_buf should be used in direct loading for saving memory and speedup firmware loading. Secondly, the commit below abb139e75c2cdbb955e840d6331cb5863e409d0e(firmware:teach the kernel to load firmware files directly from the filesystem) introduces direct loading for fixing udev regression, but it bypasses the firmware cache meachnism, so this patch enables caching firmware for direct loading case since it is still needed to solve drivers' dependency during system resume. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22firmware loader: fix one reqeust_firmware raceMing Lei
Several loading requests may be pending on one same firmware buf, and this patch moves fw_map_pages_buf() before complete_all(&fw_buf->completion) and let all requests see the mapped 'buf->data' once the loading is completed. Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22firmware loader: cancel uncache work before caching firmwareMing Lei
Under 'Opportunistic sleep' situation, system sleep might be triggered very frequently, so the uncahce work may not be completed before caching firmware during next suspend. This patch cancels the uncache work before caching firmware to fix the problem above. Also this patch optimizes the cacheing firmware mechanism a bit by only storing one firmware cache entry for one firmware image. So if the firmware is still cached during suspend, it doesn't need to be loaded from user space any more. Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-04firmware: use 'kernel_read()' to read firmware into kernel bufferLinus Torvalds
Fengguang correctly points out that the firmware reading should not use vfs_read(), since the buffer is in kernel space. The vfs_read() just happened to work for kernel threads, but sparse warns about the incorrect address spaces, and it's definitely incorrect and could fail for other users of the firmware loading. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-03firmware: teach the kernel to load firmware files directly from the filesystemLinus Torvalds
This is a first step in allowing people to by-pass udev for loading device firmware. Current versions of udev will deadlock (causing us to block for the 30 second timeout) under some circumstances if the firmware is loaded as part of the module initialization path, and this is causing problems for media drivers in particular. The current patch hardcodes the firmware path that udev uses by default, and will fall back to the legacy udev mode if the firmware cannot be found there. We'd like to add support for both configuring the paths and the fallback behaviour, but in the meantime this hopefully fixes the immediate problem, while also giving us a way forward. [ v2: Some VFS layer interface cleanups suggested by Al Viro ] [ v3: use the default udev paths suggested by Kay Sievers ] Suggested-by: Ivan Kalvachev <ikalvachev@gmail.com> Acked-by: Greg KH <gregkh@linuxfoundation.org> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: Kay Sievers <kay@redhat.com> Cc: Ming Lei <ming.lei@canonical.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-10firmware loader: fix compile warning when CONFIG_PM=nMing Lei
This patch replaces the previous macro of CONFIG_PM with CONFIG_PM_SLEEP becasue firmware cache is only used in system sleep situations. Also this patch fixes the below compile warning when CONFIG_PM=n: drivers/base/firmware_class.c:1147: warning: 'device_cache_fw_images' defined but not used drivers/base/firmware_class.c:1212: warning: 'device_uncache_fw_images_delay' defined but not used Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-06firmware loader: let caching firmware piggyback on loading firmwareMing Lei
After starting caching firmware, there is still some time left before devices are suspended, during the period, request_firmware or its nowait version may still be triggered by the below situations to load firmware images which can't be cached during suspend/resume cycle. - new devices added - driver bind - or device open kind of things This patch utilizes the piggyback trick to cache firmware for this kind of situation: just increase the firmware buf's reference count and add the fw name entry into cache entry list after starting caching firmware and before syscore_suspend() is called. Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-06firmware loader: fix firmware -ENOENT situationsMing Lei
If the requested firmware image doesn't exist, firmware->priv should be set for the later concurrent requests, otherwise warning and oops will be triggered inside firmware_free_data(). Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-17firmware loader: fix build failure if FW_LOADER is mMing Lei
device_cache_fw_images need to iterate devices in system, so this patch applies the introduced dpm_for_each_dev to avoid link failure if CONFIG_FW_LOADER is m. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-17firmware loader: fix compile failure if !PMMing Lei
'return 0' should be added to fw_pm_notify if !PM because return value of the funcion is defined as 'int'. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16firmware loader: cache devices firmware during suspend/resume cycleMing Lei
This patch implements caching devices' firmware automatically during system syspend/resume cycle, so any device drivers can call request_firmware or request_firmware_nowait inside resume path to get the cached firmware if they have loaded firmwares successfully at least once before entering suspend. 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>
2012-08-16firmware loader: use small timeout for cache device firmwareMing Lei
Because device_cache_fw_images only cache the firmware which has been loaded sucessfully at leat once, using a small loading timeout should be reasonable. 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>
2012-08-16firmware: introduce device_cache/uncache_fw_imagesMing Lei
This patch introduces the three helpers below: void device_cache_fw_images(void) void device_uncache_fw_images(void) void device_uncache_fw_images_delay(unsigned long) so we can use device_cache_fw_images() to cache firmware for all devices which need firmware to work, and the device driver can get the firmware easily from kernel memory when system isn't ready for completing requests of loading firmware. After system is ready for completing firmware loading, driver core will call device_uncache_fw_images() or its delay version to free the cached firmware. The above helpers will be used to cache device firmware during system suspend/resume cycle in the following patches. 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>
2012-08-16firmware loader: store firmware name into devres listMing Lei
This patch will store firmware name into devres list of the device which is requesting firmware loading, so that we can implement auto cache and uncache firmware for devices in need. 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>
2012-08-16firmware loader: fix comments on request_firmware_nowaitMing Lei
request_firmware_nowait is allowed to be called in atomic context now if @gfp is GFP_ATOMIC, so fix the obsolete comments and states which situations are suitable for using 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>
2012-08-16firmware loader: fix device lifetimeMing Lei
Callers of request_firmware* must hold the reference count of @device, otherwise it is easy to trigger oops since the firmware loader device is the child of @device. This patch adds comments about the usage. In fact, most of drivers call request_firmware* in its probe() or open(), so the constraint should be reasonable and can be satisfied. Also this patch holds the reference count of @device before schedule_work() in request_firmware_nowait() to avoid that the @device is released after request_firmware_nowait returns and before the worker function is scheduled. 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>
2012-08-16firmware loader: introduce cache_firmware and uncache_firmwareMing Lei
This patches introduce two kernel APIs of cache_firmware and uncache_firmware, both of which take the firmware file name as the only parameter. So any drivers can call cache_firmware to cache the specified firmware file into kernel memory, and can use the cached firmware in situations which can't request firmware from user space. 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>
2012-08-16firmware loader: always let firmware_buf own the pages bufferMing Lei
This patch always let firmware_buf own the pages buffer allocated inside firmware_data_write, and add all instances of firmware_buf into the firmware cache global list. Also introduce one private field in 'struct firmware', so release_firmware will see the instance of firmware_buf associated with the current firmware instance, then just 'free' the instance of firmware_buf. The firmware_buf instance represents one pages buffer for one firmware image, so lots of firmware loading requests can share the same firmware_buf instance if they request the same firmware image file. This patch will make implementation of the following cache_firmware/ uncache_firmware very easy and simple. In fact, the patch improves request_formware/release_firmware: - only request userspace to write firmware image once if several devices share one same firmware image and its drivers call request_firmware concurrently. 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>
2012-08-16firmware loader: introduce firmware_bufMing Lei
This patch introduces struct firmware_buf to describe the buffer which holds the firmware data, which will make the following cache_firmware/uncache_firmware implemented easily. 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>
2012-08-16firmware loader: fix creation failure of fw loader deviceMing Lei
If one device driver calls request_firmware_nowait() to request several different firmwares' loading, device_add() will return failure since all firmware loader device use same name of the device who is requesting firmware. This patch always use the name of firmware image as the firmware loader device name to fix the problem since the following patches for caching firmware will make sure only one loading for same firmware is alllowd at the same time. 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>
2012-08-16firmware loader: remove unnecessary wmb()Ming Lei
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>
2012-08-16firmware loader: fix races during loading firmwareMing Lei
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>
2012-08-16firmware loader: simplify pages ownership transferMing Lei
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>
2012-07-16driver-core: Use kobj_to_dev instead of re-implementing itLars-Peter Clausen
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-28firmware_class: Move request_firmware_nowait() to workqueuesStephen Boyd
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>
2012-03-28firmware_class: Reorganize fw_create_instance()Stephen Boyd
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>
2012-03-28firmware_class: Do not warn that system is not ready from async loadsRafael J. Wysocki
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
2012-03-28firmware_class: Split _request_firmware() into three functions, v2Rafael J. Wysocki
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
2012-03-28firmware_class: Rework usermodehelper checkRafael J. Wysocki
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
2012-01-23PM / Sleep: Fix read_unlock_usermodehelper() call.Tetsuo Handa
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>
2012-01-08Merge branch 'pm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm * '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
2012-01-04firmware: Fix an oops on reading fw_priv->fw in sysfs loading fileNeil Horman
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>
2011-12-09PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()Srivatsa S. Bhat
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>
2011-08-24firmware loader: allow builtin firmware load even if usermodehelper is disabledLinus Torvalds
In commit a144c6a6c924 ("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 288d5abec831: "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>
2011-05-17PM: Print a warning if firmware is requested when tasks are frozenRafael J. Wysocki
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>
2011-02-03firmware_classs: change val uevent's type to boolBob Liu
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>
2010-08-23firmware_class: fix typo in error pathJohannes Berg
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 f8a4bd3456b988fc73b2c. 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>
2010-08-05firmware loader: embed device into firmware_priv structureDmitry Torokhov
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>
2010-08-05firmware loader: use statically initialized data attributeDmitry Torokhov
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>
2010-05-21sysfs: add struct file* to bin_attr callbacksChris Wright
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>
2010-05-21firmware loader: do not allocate firmare id separatelyDmitry Torokhov
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>
2010-05-21firmware loader: split out builtin firmware handlingDmitry Torokhov
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>
2010-05-21firmware loader: rely on driver core to create class attributeDmitry Torokhov
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>
2010-05-21firmware class: export nowait to userspaceJohannes Berg
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>