- 09 Dec, 2011 1 commit
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Srivatsa S. Bhat authored
Commit a144c6a6 (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>
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- 08 Dec, 2011 6 commits
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Srivatsa S. Bhat authored
Update the documentation to explain the perils of directly using mutex_[un]lock(&pm_mutex) and recommend the usage of the safe APIs [un]lock_system_sleep() instead. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Srivatsa S. Bhat authored
Using [un]lock_system_sleep() is safer than directly using mutex_[un]lock() on 'pm_mutex', since the latter could lead to freezing failures. Hence convert all the present users of mutex_[un]lock(&pm_mutex) to use these safe APIs instead. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Reviewed-by: Simon Horman <horms@verge.net.au> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Srivatsa S. Bhat authored
The [un]lock_system_sleep() APIs were originally introduced to mutually exclude memory hotplug and hibernation. Directly using mutex_lock(&pm_mutex) to achieve mutual exclusion with suspend or hibernation code can lead to freezing failures. However, the APIs [un]lock_system_sleep() can be safely used to achieve the same, without causing freezing failures. So, since it would be beneficial to modify all the existing users of mutex_lock(&pm_mutex) (in all parts of the kernel), so that they use these safe APIs intead, make these APIs generic by removing the restriction that they work only when CONFIG_HIBERNATE_CALLBACKS is set. Moreover, that restriction didn't buy us anything anyway. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Srivatsa S. Bhat authored
Now that freezer_count() and freezer_do_not_count() don't have the restriction that they are effective only when called by userspace processes, use them in lock_system_sleep() and unlock_system_sleep() instead of open-coding their parts. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Rafael J. Wysocki authored
* pm-freezer: PM / Freezer: Remove the "userspace only" constraint from freezer[_do_not]_count()
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Srivatsa S. Bhat authored
At present, the functions freezer_count() and freezer_do_not_count() impose the restriction that they are effective only for userspace processes. However, now, these functions have found more utility than originally intended by the commit which introduced it: ba96a0c8 (freezer: fix vfork problem). And moreover, even the vfork issue actually does not need the above restriction in these functions. So, modify these functions to make them work even for kernel threads, so that they can be used at other places in the kernel, where the userspace restriction doesn't apply. Suggested-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Tejun Heo <tj@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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- 06 Dec, 2011 8 commits
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Srivatsa S. Bhat authored
In the snapshot_ioctl() function, under SNAPSHOT_FREEZE, the code below freeze_processes() is a bit unintuitive. Improve it by replacing the second 'if' condition with an 'else' clause. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Rafael J. Wysocki authored
* pm-freezer: (26 commits) Freezer / sunrpc / NFS: don't allow TASK_KILLABLE sleeps to block the freezer Freezer: fix more fallout from the thaw_process rename freezer: fix wait_event_freezable/__thaw_task races freezer: kill unused set_freezable_with_signal() dmatest: don't use set_freezable_with_signal() usb_storage: don't use set_freezable_with_signal() freezer: remove unused @sig_only from freeze_task() freezer: use lock_task_sighand() in fake_signal_wake_up() freezer: restructure __refrigerator() freezer: fix set_freezable[_with_signal]() race freezer: remove should_send_signal() and update frozen() freezer: remove now unused TIF_FREEZE freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE cgroup_freezer: prepare for removal of TIF_FREEZE freezer: clean up freeze_processes() failure path freezer: kill PF_FREEZING freezer: test freezable conditions while holding freezer_lock freezer: make freezing indicate freeze condition in effect freezer: use dedicated lock instead of task_lock() + memory barrier freezer: don't distinguish nosig tasks on thaw ...
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Jeff Layton authored
Allow the freezer to skip wait_on_bit_killable sleeps in the sunrpc layer. This should allow suspend and hibernate events to proceed, even when there are RPC's pending on the wire. Also, wrap the TASK_KILLABLE sleeps in NFS layer in freezer_do_not_count and freezer_count calls. This allows the freezer to skip tasks that are sleeping while looping on EJUKEBOX or NFS4ERR_DELAY sorts of errors. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Rafael J. Wysocki authored
Make pm_op() and pm_noirq_op() use the same helper function for running callbacks, which will cause them to use the same format of diagnostic messages. This also reduces the complexity and size of the code quite a bit. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
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Keng-Yu Lin authored
The models do not resume correctly without acpi_sleep=nonvs. Signed-off-by: Keng-Yu Lin <kengyu@canonical.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Srivatsa S. Bhat authored
The hibernation test modes 'test' and 'testproc' are deprecated, because the 'pm_test' framework offers much more fine-grained control for debugging suspend and hibernation related problems. So, remove the deprecated 'test' and 'testproc' hibernation test modes. Suggested-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Srivatsa S. Bhat authored
Commit 2aede851 (PM / Hibernate: Freeze kernel threads after preallocating memory) moved the freezing of kernel threads to hibernation_snapshot() function. So now, if the call to hibernation_snapshot() returns early due to a successful hibernation test, the caller has to thaw processes to ensure that the system gets back to its original state. But in SNAPSHOT_CREATE_IMAGE hibernation ioctl, the caller does not thaw processes in case hibernation_snapshot() returned due to a successful freezer test. Fix this issue. But note we still send the value of 'in_suspend' (which is now 0) to userspace, because we are not in an error path per-se, and moreover, the value of in_suspend correctly depicts the situation here. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Srivatsa S. Bhat authored
In the software_resume() function defined in kernel/power/hibernate.c, if the call to create_basic_memory_bitmaps() fails, the usermodehelpers are not enabled (which had been disabled in the previous step). Fix it. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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- 24 Nov, 2011 1 commit
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Stephen Rothwell authored
Commit 944e192db53c "freezer: rename thaw_process() to __thaw_task() and simplify the implementation" did not create a !CONFIG_FREEZER version of __thaw_task(). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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- 23 Nov, 2011 20 commits
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Srivatsa S. Bhat authored
The goto statements in hibernation_snapshot() are a bit complex. Refactor the code to remove some of them, thereby simplifying the implementation. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Rafael J. Wysocki authored
Remove a few if () and return statements in device_suspend_noirq() that aren't really necessary. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
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Rafael J. Wysocki authored
The "End" label in device_prepare() in drivers/base/power/main.c is not necessary and the jumps to it have no real effect, so remove them all. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
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Srivatsa S. Bhat authored
The lock_system_sleep() function is used in the memory hotplug code at several places in order to implement mutual exclusion with hibernation. However, this function tries to acquire the 'pm_mutex' lock using mutex_lock() and hence blocks in TASK_UNINTERRUPTIBLE state if it doesn't get the lock. This would lead to task freezing failures and hence hibernation failure as a consequence, even though the hibernation call path successfully acquired the lock. But it is to be noted that, since this task tries to acquire pm_mutex, if it blocks due to this, we are *100% sure* that this task is not going to run as long as hibernation sequence is in progress, since hibernation releases 'pm_mutex' only at the very end, when everything is done. And this means, this task is going to be anyway blocked for much more longer than what the freezer intends to achieve; which means, freezing and thawing doesn't really make any difference to this task! So, to fix freezing failures, we just ask the freezer to skip freezing this task, since it is already "frozen enough". But instead of calling freezer_do_not_count() and freezer_count() as it is, we use only the relevant parts of those functions, because restrictions such as 'the task should be a userspace one' etc., might not be relevant in this scenario. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Srivatsa S. Bhat authored
Lack of proper indentation of the goto statement decreases the readability of code significantly. In fact, this made me look twice at the code to check whether it really does what it should be doing. Fix this. And in the same file, there are some extra whitespaces. Get rid of them too. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/miscRafael J. Wysocki authored
* 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc: (24 commits) freezer: fix wait_event_freezable/__thaw_task races freezer: kill unused set_freezable_with_signal() dmatest: don't use set_freezable_with_signal() usb_storage: don't use set_freezable_with_signal() freezer: remove unused @sig_only from freeze_task() freezer: use lock_task_sighand() in fake_signal_wake_up() freezer: restructure __refrigerator() freezer: fix set_freezable[_with_signal]() race freezer: remove should_send_signal() and update frozen() freezer: remove now unused TIF_FREEZE freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE cgroup_freezer: prepare for removal of TIF_FREEZE freezer: clean up freeze_processes() failure path freezer: kill PF_FREEZING freezer: test freezable conditions while holding freezer_lock freezer: make freezing indicate freeze condition in effect freezer: use dedicated lock instead of task_lock() + memory barrier freezer: don't distinguish nosig tasks on thaw freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasks freezer: rename thaw_process() to __thaw_task() and simplify the implementation ...
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Rafael J. Wysocki authored
The hibernation core code forgets to release memory preallocated for hibernation if there's an error in its early stages or if test modes causing hibernation_snapshot() to return early are used. This causes the system to be hardly usable, because the amount of preallocated memory is usually huge. Fix this problem. Reported-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktestLinus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest: ktest: Check parent options for iterated tests
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git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/stagingLinus Torvalds authored
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging: i2c: Make i2cdev_notifier_call static i2c: Delete ANY_I2C_BUS i2c: Fix device name for 10-bit slave address i2c-algo-bit: Generate correct i2c address sequence for 10-bit target
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git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulatorLinus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: regulator: TPS65910: Fix VDD1/2 voltage selector count
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git://people.freedesktop.org/~airlied/linuxLinus Torvalds authored
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (31 commits) drm: integer overflow in drm_mode_dirtyfb_ioctl() drivers/gpu/vga/vgaarb.c: add missing kfree drm/radeon/kms/atom: unify i2c gpio table handling drm/radeon/kms: fix up gpio i2c mask bits for r4xx for real ttm: Don't return the bo reserved on error path drm/radeon/kms: add a CS ioctl flag not to rewrite tiling flags in the CS drm/i915: Fix inconsistent backlight level during disabled drm, i915: Fix memory leak in i915_gem_busy_ioctl(). drm/i915: Use DPCD value for max DP lanes. drm/i915: Initiate DP link training only on the lanes we'll be using drm/i915: Remove trailing white space drm/i915: Try harder during dp pattern 1 link training drm/i915: Make DP prepare/commit consistent with DP dpms drm/i915: Let panel power sequencing hardware do its job drm/i915: Treat PCH eDP like DP in most places drm/i915: Remove link_status field from intel_dp structure drm/i915: Move common PCH_PP_CONTROL setup to ironlake_get_pp_control drm/i915: Module parameters using '-1' as default must be signed type drm/i915: Turn on another required clock gating bit on gen6. drm/i915: Turn on a required 3D clock gating bit on Sandybridge. ...
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Oleg Nesterov authored
wait_event_freezable() and friends stop the waiting if try_to_freeze() fails. This is not right, we can race with __thaw_task() and in this case - wait_event_freezable() returns the wrong ERESTARTSYS - wait_event_freezable_timeout() can return the positive value while condition == F Change the code to always check __retval/condition before return. Note: with or without this patch the timeout logic looks strange, probably we should recalc timeout if try_to_freeze() returns T. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org>
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Tejun Heo authored
There's no in-kernel user of set_freezable_with_signal() left. Mixing TIF_SIGPENDING with kernel threads can lead to nasty corner cases as kernel threads never travel signal delivery path on their own. e.g. the current implementation is buggy in the cancelation path of __thaw_task(). It calls recalc_sigpending_and_wake() in an attempt to clear TIF_SIGPENDING but the function never clears it regardless of sigpending state. This means that signallable freezable kthreads may continue executing with !freezing() && stuck TIF_SIGPENDING, which can be troublesome. This patch removes set_freezable_with_signal() along with PF_FREEZER_NOSIG and recalc_sigpending*() calls in freezer. User tasks get TIF_SIGPENDING, kernel tasks get woken up and the spurious sigpending is dealt with in the usual signal delivery path. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com>
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Tejun Heo authored
Commit 981ed70d (dmatest: make dmatest threads freezable) made dmatest kthread use set_freezable_with_signal(); however, the interface is scheduled to be removed in the next merge window. The problem is that unlike userland tasks there's no default place which handles signal pending state and it isn't clear who owns and/or is responsible for clearing TIF_SIGPENDING. For example, in the current code, try_to_freeze() clears TIF_SIGPENDING but it isn't sure whether it actually owns the TIF_SIGPENDING nor is it race-free - ie. the task may continue to run with TIF_SIGPENDING set after the freezable section. Unfortunately, we don't have wait_for_completion_freezable_timeout(). This patch open codes it and uses wait_event_freezable_timeout() instead and removes timeout reloading - wait_event_freezable_timeout() won't return across freezing events (currently racy but fix scheduled) and timer doesn't decrement while the task is in freezer. Although this does lose timer-reset-over-freezing, given that timeout is supposed to be long enough and failure to finish inside is considered irrecoverable, I don't think this is worth the complexity. While at it, move completion to outer scope and explain that we're ignoring dangling pointer problem after timeout. This should give slightly better chance at avoiding oops after timeout. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
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Afzal Mohammed authored
Count of selector voltage is required for regulator_set_voltage to work via set_voltage_sel. VDD1/2 currently have it as zero, so regulator_set_voltage won't work for VDD1/2. Update count (n_voltages) for VDD1/2. Output Voltage = (step value * 12.5 mV + 562.5 mV) * gain With above expr, number of voltages that can be selected is step value count * gain count constant for gain count will be called VDD1_2_NUM_VOLT_COARSE existing constant for step value count is VDD1_2_NUM_VOLTS, use VDD1_2_NUM_VOLT_FINE instead to make clear that step value is not the only component in deciding selectable voltage count Signed-off-by: Afzal Mohammed <afzal@ti.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
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Shubhrajyoti D authored
The function i2cdev_notifier_call is used only in i2c-dev file making it static. Also removes the following sparse warning drivers/i2c/i2c-dev.c:582:5: warning: symbol 'i2cdev_notifier_call' was not declared. Should it be static? Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
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Jean Delvare authored
Last piece of code using ANY_I2C_BUS was deleted almost 2 years ago, so ANY_I2C_BUS can go away as well. Signed-off-by: Jean Delvare <khali@linux-fr.org>
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Jean Delvare authored
10-bit addresses overlap with traditional 7-bit addresses, leading in device name collisions. Add an arbitrary offset to 10-bit addresses to prevent this collision. The offset was chosen so that the address is still easily recognizable. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
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Jeffrey (Sheng-Hui) Chu authored
The wrong bits were put on the wire, fix that. This fixes kernel bug #42562. Signed-off-by: Sheng-Hui J. Chu <jeffchu@broadcom.com> Cc: stable@kernel.org Signed-off-by: Jean Delvare <khali@linux-fr.org>
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Xi Wang authored
There is a potential integer overflow in drm_mode_dirtyfb_ioctl() if userspace passes in a large num_clips. The call to kmalloc would allocate a small buffer, and the call to fb->funcs->dirty may result in a memory corruption. Reported-by: Haogang Chen <haogangchen@gmail.com> Signed-off-by: Xi Wang <xi.wang@gmail.com> Cc: stable@kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
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- 22 Nov, 2011 4 commits
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Linus Torvalds authored
This reverts commit dc937280. As requested by Ben Herrenschmidt: "This breaks some powerpc platforms at least. The practice of having a node provide an explicit "interrupt-parent" property pointing to itself is an old trick that we've used in the past to allow a device-node to have interrupts routed to different controllers. In that case, the node also contains an interrupt-map, so the node is its own parent, the interrupt resolution hits the map, which then can route each individual interrupt to a different parent." Grant says: "Ah, nuts, yes that is broken then. Yes, please revert the commit and Rob & I will come up with a better solution. Rob, I think it can be done by explicitly checking for np == desc->interrupt_parent in of_irq_init() instead of relying on of_irq_find_parent() returning NULL." Requested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Grant Likely <grant.likely@secretlab.ca> Cc: Rob Herring <rob.herring@calxeda.com> Cc: devicetree-discuss@lists.ozlabs.org Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org> Cc: Tanmay Inamdar <tinamdar@apm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: mount_subtree() pointless use-after-free iio: fix a leak due to improper use of anon_inode_getfd() microblaze: bury asm/namei.h
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Julia Lawall authored
kbuf is a buffer that is local to this function, so all of the error paths leaving the function should release it. Signed-off-by: Julia Lawall <julia@diku.dk> Cc: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
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Alex Deucher authored
Split the quirks and i2c_rec assignment into separate functions used by both radeon_lookup_i2c_gpio() and radeon_atombios_i2c_init(). This avoids duplicating code and cases where quirks were only added to one of the functions. Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
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