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* Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds2013-02-1917-229/+556
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU changes from Ingo Molnar: "SRCU changes: - These include debugging aids, updates that move towards the goal of permitting srcu_read_lock() and srcu_read_unlock() to be used from idle and offline CPUs, and a few small fixes. Changes to rcutorture and to RCU documentation: - Posted to LKML at https://lkml.org/lkml/2013/1/26/188 Enhancements to uniprocessor handling in tiny RCU: - Posted to LKML at https://lkml.org/lkml/2013/1/27/2 Tag RCU callbacks with grace-period number to simplify callback advancement: - Posted to LKML at https://lkml.org/lkml/2013/1/26/203 Miscellaneous fixes: - Posted to LKML at https://lkml.org/lkml/2013/1/26/204" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock() srcu: Update synchronize_srcu_expedited()'s comments srcu: Update synchronize_srcu()'s comments srcu: Remove checks preventing idle CPUs from calling srcu_read_lock() srcu: Remove checks preventing offline CPUs from calling srcu_read_lock() srcu: Simple cleanup for cleanup_srcu_struct() srcu: Add might_sleep() annotation to synchronize_srcu() srcu: Simplify __srcu_read_unlock() via this_cpu_dec() rcu: Allow rcutorture to be built at low optimization levels rcu: Make rcutorture's shuffler task shuffle recently added tasks rcu: Allow TREE_PREEMPT_RCU on UP systems rcu: Provide RCU CPU stall warnings for tiny RCU context_tracking: Add comments on interface and internals rcu: Remove obsolete Kconfig option from comment rcu: Remove unused code originally used for context tracking rcu: Consolidate debugging Kconfig options rcu: Correct 'optimized' to 'optimize' in header comment rcu: Trace callback acceleration rcu: Tag callback lists with corresponding grace-period number rcutorture: Don't compare ptr with 0 ...
| * Merge branch 'rcu/srcu' of ↵Ingo Molnar2013-02-132-44/+19
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull SRCU changes from Paul E. McKenney. " These include debugging aids, updates that move towards the goal of permitting srcu_read_lock() and srcu_read_unlock() to be used from idle and offline CPUs, and a few small fixes. " Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock()Lai Jiangshan2013-02-071-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The old SRCU implementation loads sp->completed within an RCU-sched section, courtesy of preempt_disable(). This was required due to the use of synchronize_sched() in the old implemenation's synchronize_srcu(). However, the new implementation does not rely on synchronize_sched(), so it in turn does not require the load of sp->completed and the ->c[] counter to be in a single preempt-disabled region of code. This commit therefore moves the sp->completed access outside of the preempt-disabled region and applies ACCESS_ONCE(). The resulting code is almost as the same as before, but it removes the now-misleading rcu_dereference_index_check() call. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * srcu: Update synchronize_srcu_expedited()'s commentsLai Jiangshan2013-02-071-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because synchronize_srcu_expedited() no longer uses synchronize_rcu_sched_expedited(), synchronize_srcu_expedited() no longer indirectly acquires any CPU-hotplug-related locks. This commit therefore updates the comments accordingly. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * srcu: Update synchronize_srcu()'s commentsLai Jiangshan2013-02-071-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | The core of SRCU is changed, but synchronize_srcu()'s comments describe the old algorithm. This commit therefore updates them to match the new algorithm. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * srcu: Remove checks preventing idle CPUs from calling srcu_read_lock()Lai Jiangshan2013-02-071-18/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SRCU has its own statemachine and no longer relies on normal RCU. Its read-side critical section can now be used by an offline CPU, so this commit removes the check and the comments, reverting the SRCU portion of ff195cb6 (rcu: Warn when srcu_read_lock() is used in an extended quiescent state). It also makes the codes match the comments in whatisRCU.txt: g. Do you need read-side critical sections that are respected even though they are in the middle of the idle loop, during user-mode execution, or on an offlined CPU? If so, SRCU is the only choice that will work for you. [ paulmck: There is at least one remaining issue, namely use of lockdep with tracing enabled. ] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * srcu: Remove checks preventing offline CPUs from calling srcu_read_lock()Lai Jiangshan2013-02-071-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SRCU has its own statemachine and no longer relies on normal RCU. Its read-side critical section can now be used by an offline CPU, so this commit removes the check and the comments, reverting the SRCU portion of c0d6d01b (rcu: Check for illegal use of RCU from offlined CPUs). It also makes the code match the comments in whatisRCU.txt: g. Do you need read-side critical sections that are respected even though they are in the middle of the idle loop, during user-mode execution, or on an offlined CPU? If so, SRCU is the only choice that will work for you. [ paulmck: There is at least one remaining issue, namely use of lockdep with tracing enabled. ] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * srcu: Simple cleanup for cleanup_srcu_struct()Lai Jiangshan2013-02-071-6/+2
| | | | | | | | | | | | | | | | | | | | | Pack six lines of code into two lines. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * srcu: Add might_sleep() annotation to synchronize_srcu()Lai Jiangshan2013-02-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although synchronize_srcu() can sleep, it will not sleep if the fast path succeeds, which means that illegal use of synchronize_rcu() might go unnoticed. This commit therefore adds might_sleep(), which unconditionally catches illegal use of synchronize_rcu() from atomic context. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * srcu: Simplify __srcu_read_unlock() via this_cpu_dec()Lai Jiangshan2013-02-071-3/+1
| |/ | | | | | | | | | | | | | | | | This commit replaces disabling of preemption and decrement of a per-CPU variable with this_cpu_dec(), which avoids preemption disabling on x86 and shortens the code on all platforms. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| * Merge branch 'rcu/next' of ↵Ingo Molnar2013-02-061-7/+16
| |\ | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU build fixlet from Paul E. McKenney. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * rcu: Allow rcutorture to be built at low optimization levelsSteven Rostedt2013-02-041-7/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The uses of trace_clock_local() are dead code when CONFIG_RCU_TRACE=n, but some compilers might nevertheless generate code calling this function. This commit therefore ensures that trace_clock_local() is invoked only when CONFIG_RCU_TRACE=y. Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | Merge branch 'rcu/next' of ↵Ingo Molnar2013-02-0417-189/+539
| |\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU updates from Paul E. McKenney: 1. Changes to rcutorture and to RCU documentation. Posted to LKML at https://lkml.org/lkml/2013/1/26/188. 2. Enhancements to uniprocessor handling in tiny RCU. Posted to LKML at https://lkml.org/lkml/2013/1/27/2. 3. Tag RCU callbacks with grace-period number to simplify callback advancement. Posted to LKML at https://lkml.org/lkml/2013/1/26/203. 4. Miscellaneous fixes. Posted to LKML at https://lkml.org/lkml/2013/1/26/204. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | *---. Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', ↵Paul E. McKenney2013-01-2812-163/+449
| | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD doctorture.2013.01.11a: Changes to rcutorture and to RCU documentation. fixes.2013.01.26a: Miscellaneous fixes. tagcb.2013.01.24a: Tag RCU callbacks with grace-period number to simplify callback advancement. tiny.2013.01.29b: Enhancements to uniprocessor handling in tiny RCU.
| | | | | * rcu: Allow TREE_PREEMPT_RCU on UP systemsPaul E. McKenney2013-01-281-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The TINY_PREEMPT_RCU is complex, does not provide that much memory savings, and therefore TREE_PREEMPT_RCU should be used instead. The systems where the difference between TINY_PREEMPT_RCU and TREE_PREEMPT_RCU are quite small compared to the memory footprint of CONFIG_PREEMPT. This commit therefore takes a first step towards eliminating TINY_PREEMPT_RCU by allowing TREE_PREEMPT_RCU to be configured on !SMP systems. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| | | | | * rcu: Provide RCU CPU stall warnings for tiny RCUPaul E. McKenney2013-01-288-51/+130
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tiny RCU has historically omitted RCU CPU stall warnings in order to reduce memory requirements, however, lack of these warnings caused Thomas Gleixner some debugging pain recently. Therefore, this commit adds RCU CPU stall warnings to tiny RCU if RCU_TRACE=y. This keeps the memory footprint small, while still enabling CPU stall warnings in kernels built to enable them. Updated to include Josh Triplett's suggested use of RCU_STALL_COMMON config variable to simplify #if expressions. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| | | | * | rcu: Trace callback accelerationPaul E. McKenney2013-01-082-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds event tracing for callback acceleration to allow better tracking of callbacks through the system. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | * | rcu: Tag callback lists with corresponding grace-period numberPaul E. McKenney2013-01-082-28/+169
| | | | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, callbacks are advanced each time the corresponding CPU notices a change in its leaf rcu_node structure's ->completed value (this value counts grace-period completions). This approach has worked quite well, but with the advent of RCU_FAST_NO_HZ, we cannot count on a given CPU seeing all the grace-period completions. When a CPU misses a grace-period completion that occurs while it is in dyntick-idle mode, this will delay invocation of its callbacks. In addition, acceleration of callbacks (when RCU realizes that a given callback need only wait until the end of the next grace period, rather than having to wait for a partial grace period followed by a full grace period) must be carried out extremely carefully. Insufficient acceleration will result in unnecessarily long grace-period latencies, while excessive acceleration will result in premature callback invocation. Changes that involve this tradeoff are therefore among the most nerve-wracking changes to RCU. This commit therefore explicitly tags groups of callbacks with the number of the grace period that they are waiting for. This means that callback-advancement and callback-acceleration functions are idempotent, so that excessive acceleration will merely waste a few CPU cycles. This also allows a CPU to take full advantage of any grace periods that have elapsed while it has been in dyntick-idle mode. It should also enable simulataneous simplifications to and optimizations of RCU_FAST_NO_HZ. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | context_tracking: Add comments on interface and internalsFrederic Weisbecker2013-01-261-10/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This subsystem lacks many explanations on its purpose and design. Add these missing comments. v4: Document function parameter to be more kernel-doc friendly, as per Namhyung suggestion. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | rcu: Remove obsolete Kconfig option from commentPaul E. McKenney2013-01-261-1/+1
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | rcu: Remove unused code originally used for context trackingLi Zhong2013-01-262-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As context tracking subsystem evolved, it stopped using ignore_user_qs and in_user defined in the rcu_dynticks structure. This commit therefore removes them. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
| | | * | rcu: Consolidate debugging Kconfig optionsDave Hansen2013-01-261-55/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The RCU-related debugging Kconfig options are in two different places, and consume too much screen real estate. This commit therefore consolidates them into their own menu. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | rcu: Correct 'optimized' to 'optimize' in header commentCody P Schafer2013-01-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Small grammar fix in rcutree comment regarding 'rcu_scheduler_active' var. Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| | | * | rcutorture: Don't compare ptr with 0Sasha Levin2013-01-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | rcu: Silence compiler array out-of-bounds false positivePaul E. McKenney2013-01-081-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It turns out that gcc 4.8 warns on array indexes being out of bounds unless it can prove otherwise. It gives this warning on some RCU initialization code. Because this is far from any fastpath, add an explicit check for array bounds and panic if so. This gives the compiler enough information to figure out that the array index is never out of bounds. However, if a similar false positive occurs on a fastpath, it will probably be necessary to tell the compiler to keep its array-index anxieties to itself. ;-) Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| | | * | rcu: Use new nesting value for rcu_dyntick trace in rcu_eqs_enter_commonLi Zhong2013-01-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch uses the real new value of dynticks_nesting instead of 0 in rcu_eqs_enter_common(). Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| | | * | rcu: Make rcu_is_cpu_rrupt_from_idle helper functions staticJosh Triplett2013-01-082-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both rcutiny and rcutree define a helper function named rcu_is_cpu_rrupt_from_idle(), each used exactly once, later in the same file. This commit therefore declares these helper functions static. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | rcu: Fix blimit type for trace_rcu_batch_start()Paul E. McKenney2013-01-081-3/+3
| | | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the type of global variable blimit changed from int to long, the type of the blimit argument of trace_rcu_batch_start() needed to have changed. This commit fixes this issue. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| | * | rcu: Make rcutorture's shuffler task shuffle recently added tasksPaul E. McKenney2013-01-281-4/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A number of kthreads have been added to rcutorture, but the shuffler task was not informed of them, and thus did not shuffle them. This commit therefore adds the requisite shuffling, and, while in the area fixes up some whitespace issues. However, the shuffling is intended to keep randomly selected CPUs idle, which means that the RCU priority boosting kthreads need to avoid waking up every jiffy. This commit also makes that fix. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | Documentation: Memory barrier semantics of atomic_xchg()Richard Braun2013-01-082-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add atomic_xchg() to documentation for atomic operations and memory barriers. Signed-off-by: Richard Braun <rbraun@sceen.net> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| | * | rcu: Reduce rcutorture tracingPaul E. McKenney2013-01-085-18/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, rcutorture traces every read-side access. This can be problematic because even a two-minute rcutorture run on a two-CPU system can generate 28,853,363 reads. Normally, only a failing read is of interest, so this commit traces adjusts rcutorture's tracing to only trace failing reads. The resulting event tracing records the time and the ->completed value captured at the beginning of the RCU read-side critical section, allowing correlation with other event-tracing messages. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> [ paulmck: Add fix to build problem located by Randy Dunlap based on diagnosis by Steven Rostedt. ]
| | * | tracing: Export trace_clock_local()Paul E. McKenney2013-01-081-0/+1
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | The rcutorture tests need to be able to trace the time of the beginning of an RCU read-side critical section, and thus need access to trace_clock_local(). This commit therefore adds a the needed EXPORT_SYMBOL_GPL(). Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
* | | Linux 3.8v3.8Linus Torvalds2013-02-181-1/+1
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* | | Merge branch 'for-linus' of ↵Linus Torvalds2013-02-183-6/+18
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input subsystem fixes from Dmitry Torokhov: "Two small driver fixups and a documentation update for managed input devices" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: wacom - fix wacom_set_report retry logic Input: document that unregistering managed devices is not necessary Input: lm8323 - fix checking PWM interrupt status
| * | | Input: wacom - fix wacom_set_report retry logicChris Bagwell2013-01-231-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Logic sets a value and then reads it back to make sure it worked and retries write on failures. Since read and write share a buffer, it needs to be set back up before writing though. Issue is not seen a lot because 1) it doesn't need to retry for a lot of tablets and 2) a lot of failures that need a retry are from an -ETIMEDOUT and hopefully buffer is not touched in this case. At least one user has shown logs with buffer being modified during -ETIMEDOUT case with linux 3.7 kernel. Signed-off-by: Chris Bagwell <chris@cnpbagwell.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
| * | | Input: document that unregistering managed devices is not necessaryDmitry Torokhov2013-01-091-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Apparently some users of managed input devices are confused whether input_unregister_device() is needed when working with them. Clarify this in the kernel doc for devm_input_allocate_device(): in most cases there is no need to call neither input_unregister_device() nor input_free_device() when working with managed devices. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
| * | | Input: lm8323 - fix checking PWM interrupt statusNickolai Zeldovich2013-01-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | INT_PWM1 is already a bitmask, not the bit number, so shifting by INT_PWM1 is incorrect. Signed-off-by: Nickolai Zeldovich <nickolai@csail.mit.edu> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
* | | | mm: fix pageblock bitmap allocationLinus Torvalds2013-02-181-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit c060f943d092 ("mm: use aligned zone start for pfn_to_bitidx calculation") fixed out calculation of the index into the pageblock bitmap when a !SPARSEMEM zome was not aligned to pageblock_nr_pages. However, the _allocation_ of that bitmap had never taken this alignment requirement into accout, so depending on the exact size and alignment of the zone, the use of that index could then access past the allocation, resulting in some very subtle memory corruption. This was reported (and bisected) by Ingo Molnar: one of his random config builds would hang with certain very specific kernel command line options. In the meantime, commit c060f943d092 has been marked for stable, so this fix needs to be back-ported to the stable kernels that backported the commit to use the right alignment. Bisected-and-tested-by: Ingo Molnar <mingo@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge tag 'stable/for-linus-3.8-rc7-tag-two' of ↵Linus Torvalds2013-02-155-65/+33
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen Pull xen fixes from Konrad Rzeszutek Wilk: "Two fixes: - A simple bug-fix for redundant NULL check. - CVE-2013-0228/XSA-42: x86/xen: don't assume %ds is usable in xen_iret for 32-bit PVOPS and two reverts: - Revert the PVonHVM kexec. The patch introduces a regression with older hypervisor stacks, such as Xen 4.1." * tag 'stable/for-linus-3.8-rc7-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: Revert "xen PVonHVM: use E820_Reserved area for shared_info" Revert "xen/PVonHVM: fix compile warning in init_hvm_pv_info" xen: remove redundant NULL check before unregister_and_remove_pcpu(). x86/xen: don't assume %ds is usable in xen_iret for 32-bit PVOPS.
| * | | | Revert "xen PVonHVM: use E820_Reserved area for shared_info"Konrad Rzeszutek Wilk2013-02-143-55/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 9d02b43dee0d7fb18dfb13a00915550b1a3daa9f. We are doing this b/c on 32-bit PVonHVM with older hypervisors (Xen 4.1) it ends up bothing up the start_info. This is bad b/c we use it for the time keeping, and the timekeeping code loops forever - as the version field never changes. Olaf says to revert it, so lets do that. Acked-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | | | Revert "xen/PVonHVM: fix compile warning in init_hvm_pv_info"Konrad Rzeszutek Wilk2013-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit a7be94ac8d69c037d08f0fd94b45a593f1d45176. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | | | xen: remove redundant NULL check before unregister_and_remove_pcpu().Cyril Roelandt2013-02-131-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | unregister_and_remove_pcpu on a NULL pointer is a no-op, so the NULL check in sync_pcpu can be removed. Signed-off-by: Cyril Roelandt <tipecaml@gmail.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | | | x86/xen: don't assume %ds is usable in xen_iret for 32-bit PVOPS.Jan Beulich2013-02-131-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes CVE-2013-0228 / XSA-42 Drew Jones while working on CVE-2013-0190 found that that unprivileged guest user in 32bit PV guest can use to crash the > guest with the panic like this: ------------- general protection fault: 0000 [#1] SMP last sysfs file: /sys/devices/vbd-51712/block/xvda/dev Modules linked in: sunrpc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 xen_netfront ext4 mbcache jbd2 xen_blkfront dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan] Pid: 1250, comm: r Not tainted 2.6.32-356.el6.i686 #1 EIP: 0061:[<c0407462>] EFLAGS: 00010086 CPU: 0 EIP is at xen_iret+0x12/0x2b EAX: eb8d0000 EBX: 00000001 ECX: 08049860 EDX: 00000010 ESI: 00000000 EDI: 003d0f00 EBP: b77f8388 ESP: eb8d1fe0 DS: 0000 ES: 007b FS: 0000 GS: 00e0 SS: 0069 Process r (pid: 1250, ti=eb8d0000 task=c2953550 task.ti=eb8d0000) Stack: 00000000 0027f416 00000073 00000206 b77f8364 0000007b 00000000 00000000 Call Trace: Code: c3 8b 44 24 18 81 4c 24 38 00 02 00 00 8d 64 24 30 e9 03 00 00 00 8d 76 00 f7 44 24 08 00 00 02 80 75 33 50 b8 00 e0 ff ff 21 e0 <8b> 40 10 8b 04 85 a0 f6 ab c0 8b 80 0c b0 b3 c0 f6 44 24 0d 02 EIP: [<c0407462>] xen_iret+0x12/0x2b SS:ESP 0069:eb8d1fe0 general protection fault: 0000 [#2] ---[ end trace ab0d29a492dcd330 ]--- Kernel panic - not syncing: Fatal exception Pid: 1250, comm: r Tainted: G D --------------- 2.6.32-356.el6.i686 #1 Call Trace: [<c08476df>] ? panic+0x6e/0x122 [<c084b63c>] ? oops_end+0xbc/0xd0 [<c084b260>] ? do_general_protection+0x0/0x210 [<c084a9b7>] ? error_code+0x73/ ------------- Petr says: " I've analysed the bug and I think that xen_iret() cannot cope with mangled DS, in this case zeroed out (null selector/descriptor) by either xen_failsafe_callback() or RESTORE_REGS because the corresponding LDT entry was invalidated by the reproducer. " Jan took a look at the preliminary patch and came up a fix that solves this problem: "This code gets called after all registers other than those handled by IRET got already restored, hence a null selector in %ds or a non-null one that got loaded from a code or read-only data descriptor would cause a kernel mode fault (with the potential of crashing the kernel as a whole, if panic_on_oops is set)." The way to fix this is to realize that the we can only relay on the registers that IRET restores. The two that are guaranteed are the %cs and %ss as they are always fixed GDT selectors. Also they are inaccessible from user mode - so they cannot be altered. This is the approach taken in this patch. Another alternative option suggested by Jan would be to relay on the subtle realization that using the %ebp or %esp relative references uses the %ss segment. In which case we could switch from using %eax to %ebp and would not need the %ss over-rides. That would also require one extra instruction to compensate for the one place where the register is used as scaled index. However Andrew pointed out that is too subtle and if further work was to be done in this code-path it could escape folks attention and lead to accidents. Reviewed-by: Petr Matousek <pmatouse@redhat.com> Reported-by: Petr Matousek <pmatouse@redhat.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | | | | Revert "[media] dvb_frontend: return -ENOTTY for unimplement IOCTL"Mauro Carvalho Chehab2013-02-151-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As reported by Klaus Schmidinger: "In VDR I use an ioctl() call with FE_READ_UNCORRECTED_BLOCKS on a device (using stb0899). After this call I check 'errno' for EOPNOTSUPP to determine whether this device supports this call. This used to work just fine, until a few months ago I noticed that my devices using stb0899 didn't display their signal quality in VDR's OSD any more. After further investigation I found that ioctl(FE_READ_UNCORRECTED_BLOCKS) no longer returns EOPNOTSUPP, but rather ENOTTY. And since I stop getting the signal quality in case any unknown errno value appears, this broke my signal quality query function." While the changes reflect what is there at: http://comments.gmane.org/gmane.linux.kernel/1235728 it does cause regression on userspace. So, revert it to stop the damage. This reverts commit 177ffe506cf8 ("[media] dvb_frontend: return -ENOTTY for unimplement IOCTL"). Reported-by: Klaus Schmidinger <Klaus.Schmidinger@tvdr.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparcLinus Torvalds2013-02-155-14/+68
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull sparc fixes from David Miller: "A couple small fixes for sparc including some THP brown-paper-bag material: 1) During the merging of all the THP support for various architectures, sparc missed adding a HAVE_ARCH_TRANSPARENT_HUGEPAGE to it's Kconfig, oops. 2) Sparc needs to be mindful of hugepages in get_user_pages_fast(). 3) Fix memory leak in SBUS probe, from Cong Ding. 4) The sunvdc virtual disk client driver has a test of the bitmask of vdisk server supported operations which was off by one bit" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc: sunvdc: Fix off-by-one in generic_request(). sparc64: Fix get_user_pages_fast() wrt. THP. sparc64: Add missing HAVE_ARCH_TRANSPARENT_HUGEPAGE. sparc: kernel/sbus.c: fix memory leakage
| * | | | | sunvdc: Fix off-by-one in generic_request().David S. Miller2013-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'operations' bitmap corresponds one-for-one with the operation codes, no adjustment is necessary. Reported-by: Mark Kettenis <mark.kettenis@xs4all.nl> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | sparc64: Fix get_user_pages_fast() wrt. THP.David S. Miller2013-02-132-10/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mostly mirrors the s390 logic, as unlike x86 we don't need the SetPageReferenced() bits. On sparc64 we also lack a user/privileged bit in the huge PMDs. In order to make this work for THP and non-THP builds, some header file adjustments were necessary. Namely, provide the PMD_HUGE_* bit defines and the pmd_large() inline unconditionally rather than protected by TRANSPARENT_HUGEPAGE. Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | sparc64: Add missing HAVE_ARCH_TRANSPARENT_HUGEPAGE.David S. Miller2013-02-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This got missed in the cleanups done for the S390 THP support. CC: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | sparc: kernel/sbus.c: fix memory leakageCong Ding2013-01-211-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The variable iommu and strbuf are not freed properly if it goes to error. Signed-off-by: Cong Ding <dinggnu@gmail.com> Reviewed-by: Richard Mortimer <richm@oldelvet.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | | | | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2013-02-151-1/+1
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull one more x86 fix from Peter Anvin: "Sigh. One more patch in the "please don't brick my Samsung" series" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by "noefi" boot parameter
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-28 19:04:02 +0000