Paul E. McKenney [Tue, 24 Jan 2017 16:51:34 +0000 (08:51 -0800)]
srcu: Reduce probability of SRCU ->unlock_count[] counter overflow
Because there are no memory barriers between the srcu_flip() ->completed
increment and the summation of the read-side ->unlock_count[] counters,
both the compiler and the CPU can reorder the summation with the
->completed increment. If the updater is preempted long enough during
this process, the read-side counters could overflow, resulting in a
too-short grace period.
This commit therefore adds a memory barrier just after the ->completed
increment, ensuring that if the summation misses an increment of
->unlock_count[] from __srcu_read_unlock(), the next __srcu_read_lock()
will see the new value of ->completed, thus bounding the number of
->unlock_count[] increments that can be missed to NR_CPUS. The actual
overflow computation is more complex due to the possibility of nesting
of __srcu_read_lock().
Reported-by: Lance Roy <ldr709@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Lance Roy [Sun, 1 Jan 2017 00:33:50 +0000 (16:33 -0800)]
rcutorture: Add CBMC-based formal verification for SRCU
This commit creates a formal/srcu-cbmc directory containing scripts that
pull SRCU in from the source code, filter it to remove things that CBMC
cannot handle, and run a series of verifications on it. This has a number
of shortcomings:
1. It does not yet hook into the upper-level self-test Makefiles.
2. It tests only a single scenario, store buffering.
3. There is no gcc-based syntax-error prefiltering.
Nevertheless, it does fully verify a piece of SRCU under a moderately
weak memory model (PSO).
Signed-off-by: Lance Roy <ldr709@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Mon, 28 Nov 2016 20:08:49 +0000 (12:08 -0800)]
srcu: Force full grace-period ordering
If a process invokes synchronize_srcu(), is delayed just the right amount
of time, and thus does not sleep when waiting for the grace period to
complete, there is no ordering between the end of the grace period and
the code following the synchronize_srcu(). Similarly, there can be a
lack of ordering between the end of the SRCU grace period and callback
invocation.
This commit adds the necessary ordering.
Reported-by: Lance Roy <ldr709@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Further smp_mb() adjustment per email with Lance Roy. ]
Lance Roy [Mon, 23 Jan 2017 21:35:18 +0000 (13:35 -0800)]
srcu: Implement more-efficient reader counts
SRCU uses two per-cpu counters: a nesting counter to count the number of
active critical sections, and a sequence counter to ensure that the nesting
counters don't change while they are being added together in
srcu_readers_active_idx_check().
This patch instead uses per-cpu lock and unlock counters. Because both
counters only increase and srcu_readers_active_idx_check() reads the unlock
counter before the lock counter, this achieves the same end without having
to increment two different counters in srcu_read_lock(). This also saves a
smp_mb() in srcu_readers_active_idx_check().
Possible bug: There is no guarantee that the lock counter won't overflow
during srcu_readers_active_idx_check(), as there are no memory barriers
around srcu_flip() (see comment in srcu_readers_active_idx_check() for
details). However, this problem was already present before this patch.
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Lance Roy <ldr709@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
rcu: Adjust FQS offline checks for exact online-CPU detection
Commit 7ec99de36f40 ("rcu: Provide exact CPU-online tracking for RCU"),
as its title suggests, got rid of RCU's remaining CPU-hotplug timing
guesswork. This commit therefore removes the one-jiffy kludge that was
used to paper over this guesswork.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Wed, 30 Nov 2016 19:21:21 +0000 (11:21 -0800)]
rcu: Check cond_resched_rcu_qs() state less often to reduce GP overhead
Commit 4a81e8328d37 ("rcu: Reduce overhead of cond_resched() checks
for RCU") moved quiescent-state generation out of cond_resched()
and commit bde6c3aa9930 ("rcu: Provide cond_resched_rcu_qs() to force
quiescent states in long loops") introduced cond_resched_rcu_qs(), and
commit 5cd37193ce85 ("rcu: Make cond_resched_rcu_qs() apply to normal RCU
flavors") introduced the per-CPU rcu_qs_ctr variable, which is frequently
polled by the RCU core state machine.
This frequent polling can increase grace-period rate, which in turn
increases grace-period overhead, which is visible in some benchmarks
(for example, the "open1" benchmark in Anton Blanchard's "will it scale"
suite). This commit therefore reduces the rate at which rcu_qs_ctr
is polled by moving that polling into the force-quiescent-state (FQS)
machinery, and by further polling it only after the grace period has
been in effect for at least jiffies_till_sched_qs jiffies.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
rcu: Abstract extended quiescent state determination
This commit is the fourth step towards full abstraction of all accesses
to the ->dynticks counter, implementing previously open-coded checks and
comparisons in new rcu_dynticks_in_eqs() and rcu_dynticks_in_eqs_since()
functions. This abstraction will ease changes to the ->dynticks counter
operation.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
rcu: Abstract dynticks extended quiescent state enter/exit operations
This commit is the third step towards full abstraction of all accesses
to the ->dynticks counter, implementing the previously open-coded atomic
add of 1 and entry checks in a new rcu_dynticks_eqs_enter() function, and
the same but with exit checks in a new rcu_dynticks_eqs_exit() function.
This abstraction will ease changes to the ->dynticks counter operation.
Note that this commit gets rid of the smp_mb__before_atomic() and the
smp_mb__after_atomic() calls that were previously present. The reason
that this is OK from a memory-ordering perspective is that the atomic
operation is now atomic_add_return(), which, as a value-returning atomic,
guarantees full ordering.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Fixed RCU_TRACE() statements added by this commit. ] Reviewed-by: Josh Triplett <josh@joshtriplett.org>
rcu: Add lockdep checks to synchronous expedited primitives
The non-expedited synchronize_*rcu() primitives have lockdep checks, but
their expedited counterparts lack these checks. This commit therefore
adds these checks to the expedited synchronize_*rcu() primitives.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Expedited grace periods no longer fall back to normal grace periods
in response to lock contention, given that expedited grace periods
now use the rcu_node tree so as to avoid contention. This commit
therfore removes the expedited_normal counter.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Joel Fernandes [Tue, 13 Dec 2016 02:01:45 +0000 (18:01 -0800)]
llist: Clarify comments about when locking is needed
llist.h comments are confusing about when locking is needed versus when it
isn't. Clarify these comments by being more descriptive about why locking is
needed for llist_del_first.
Cc: Ingo Molnar <mingo@kernel.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Huang Ying <ying.huang@intel.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
It used to be that the rcuo callback-offload kthreads were spawned
in rcu_organize_nocb_kthreads(), and the comment before the "for"
loop says as much. However, this spawning has long since moved to
the CPU-hotplug code, so this commit fixes this comment.
Reported-by: Michalis Kokologiannakis <mixaskok@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Matt Fleming [Fri, 23 Dec 2016 15:17:53 +0000 (15:17 +0000)]
rcu: Enable RCU tracepoints by default to aid in debugging
While debugging a performance issue I needed to understand why
RCU sofitrqs were firing so frequently.
Unfortunately, the RCU callback tracepoints are hidden behind
CONFIG_RCU_TRACE which defaults to off in the upstream kernel and is
likely to also be disabled in enterprise distribution configs.
Enable it by default for CONFIG_TREE_RCU. However, we must keep it
disabled for tiny RCU, because it would otherwise pull in a large
amount of code that would make tiny RCU less than tiny.
I ran some file system metadata intensive workloads (git checkout,
FS-Mark) on a variety of machines with this patch and saw no
detectable change in performance.
Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 20 Dec 2016 15:17:58 +0000 (07:17 -0800)]
rcu: Make rcu_cpu_starting() use its "cpu" argument
The rcu_cpu_starting() function uses this_cpu_ptr() to locate the
incoming CPU's rcu_data structure. This works for the boot CPU and for
all CPUs onlined after rcu_init() executes (during very early boot).
Currently, this is the full set of CPUs, so all is well. But if
anyone ever parallelizes boot before rcu_init() time, it will fail.
This commit therefore substitutes the rcu_cpu_starting() function's
this_cpu_pointer() for per_cpu_ptr(), future-proofing the code and
(arguably) improving readability.
This commit inadvertently fixes a latent bug: If there ever had been
more than just the boot CPU online at rcu_init() time, the old code
would not initialize the non-boot CPUs, but rather would repeatedly
initialize the boot CPU.
Reported-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Sun, 18 Dec 2016 21:31:02 +0000 (13:31 -0800)]
rcu: Add comment headers to expedited-grace-period counter functions
These functions (rcu_exp_gp_seq_start(), rcu_exp_gp_seq_end(),
rcu_exp_gp_seq_snap(), and rcu_exp_gp_seq_done() seemed too obvious
to comment when written, but not so much when being documented.
This commit therefore adds header comments to each of them.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Thu, 15 Dec 2016 23:37:47 +0000 (15:37 -0800)]
rcu: Don't wake rcuc/X kthreads on NOCB CPUs
Chris Friesen notice that rcuc/X kthreads were consuming CPU even on
NOCB CPUs. This makes no sense because the only purpose or these
kthreads is to invoke normal (non-offloaded) callbacks, of which there
will never be any on NOCB CPUs. This problem was due to a bug in
cpu_has_callbacks_ready_to_invoke(), which should have been checking
->nxttail[RCU_NEXT_TAIL] for NULL, but which was instead (incorrectly)
checking ->nxttail[RCU_DONE_TAIL]. Because ->nxttail[RCU_DONE_TAIL] is
never NULL, the only effect is to cause the rcuc/X kthread to execute
when it should not do so.
This commit therefore checks ->nxttail[RCU_NEXT_TAIL], which is NULL
for NOCB CPUs.
Reported-by: Chris Friesen <chris.friesen@windriver.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Wed, 14 Dec 2016 22:03:14 +0000 (14:03 -0800)]
rcu: Re-enable TASKS_RCU for User Mode Linux
Now that User Mode Linux supports arch_irqs_disabled_flags(), this
commit re-enables TASKS_RCU for User Mode Linux.
Reported-by: Richard Weinberger <richard@nod.at> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 29 Nov 2016 13:49:06 +0000 (05:49 -0800)]
rcu: Once again use NMI-based stack traces in stall warnings
This commit is for all intents and purposes a revert of bc1dce514e9b
("rcu: Don't use NMIs to dump other CPUs' stacks"). The reason to suppose
that this can now safely be reverted is the presence of 42a0bb3f7138
("printk/nmi: generic solution for safe printk in NMI"), which is said
to have made NMI-based stack dumps safe.
However, this reversion keeps one nice property of bc1dce514e9b
("rcu: Don't use NMIs to dump other CPUs' stacks"), namely that
only those CPUs blocking the grace period are dumped. The new
trigger_single_cpu_backtrace() is used to make this happen, as
suggested by Josh Poimboeuf.
Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Fri, 25 Nov 2016 08:07:23 +0000 (00:07 -0800)]
rcu: Remove short-term CPU kicking
Commit 4914950aaa12d ("rcu: Stop treating in-kernel CPU-bound workloads
as errors") added a (relatively) short-timeout call to resched_cpu().
This was inspired by as issue that was fixed by b7e7ade34e61 ("sched/core:
Fix remote wakeups"). But given that this issue was fixed, it is time
for the current commit to remove this call to resched_cpu().
Reported-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit prepares for the removal of short-term CPU kicking (in a
subsequent commit). It does so by starting to invoke resched_cpu()
for each holdout at each force-quiescent-state interval that is more
than halfway through the stall-warning interval.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tobias Klauser [Mon, 17 Oct 2016 09:13:07 +0000 (11:13 +0200)]
rcu: Remove unused but set variable
Since commit 7ec99de36f40 ("rcu: Provide exact CPU-online tracking for
RCU"), the variable mask in rcu_init_percpu_data is set but no longer
used. Remove it to fix the following warning when building with 'W=1':
kernel/rcu/tree.c: In function ‘rcu_init_percpu_data’:
kernel/rcu/tree.c:3765:16: warning: variable ‘mask’ set but not used [-Wunused-but-set-variable]
Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The declarations of __rcu_process_callbacks() and rcu_process_callbacks()
are not needed, as the definition of both of these functions appear before
any uses. This commit therefore removes both declarations.
Reported-by: "Ahmed, Iftekhar" <ahmedi@oregonstate.edu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Byungchul Park [Wed, 9 Nov 2016 08:57:13 +0000 (17:57 +0900)]
rcu: Only dump stalled-tasks stacks if there was a real stall
The print_other_cpu_stall() function currently unconditionally invokes
rcu_print_detail_task_stall(). This is OK because if there was a stall
sufficient to cause print_other_cpu_stall() to be invoked, that stall
is very likely to persist through the entire print_other_cpu_stall()
execution. However, if the stall did not persist, the variable ndetected
will be zero, and that variable is already tested in an "if" statement.
Therefore, this commit moves the call to rcu_print_detail_task_stall()
under that pre-existing "if" to improve readability, with a very rare
reduction in overhead.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
[ paulmck: Reworked commit log. ] Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Fix: Disable sys_membarrier when nohz_full is enabled
Userspace applications should be allowed to expect the membarrier system
call with MEMBARRIER_CMD_SHARED command to issue memory barriers on
nohz_full CPUs, but synchronize_sched() does not take those into
account.
Given that we do not want unrelated processes to be able to affect
real-time sensitive nohz_full CPUs, simply return ENOSYS when membarrier
is invoked on a kernel with enabled nohz_full CPUs.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> CC: Josh Triplett <josh@joshtriplett.org> CC: Steven Rostedt <rostedt@goodmis.org> CC: <stable@vger.kernel.org> [3.10+] Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: Lai Jiangshan <jiangshanlai@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
lockdep: Make RCU suspicious-access splats use pr_err
This commit switches RCU suspicious-access splats use pr_err()
instead of the current INFO printk()s. This change makes it easier
to automatically classify splats.
Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
rcu: update: Make RCU_EXPEDITE_BOOT be the default
RCU_EXPEDITE_BOOT should speed up the boot process by enforcing
synchronize_rcu_expedited() instead of synchronize_rcu() during the boot
process. There should be no reason why one does not want this and there
is no need worry about real time latency at this point.
Therefore make it default.
Note that users wishing to avoid expediting entirely, for example when
bringing up new hardware possibly having flaky IPIs, can use the
rcu_normal boot parameter to override boot-time expediting.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ paulmck: Reworded commit log. ] Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit is the second step towards full abstraction of all accesses to
the ->dynticks counter, implementing the previously open-coded atomic
add of zero in a new rcu_dynticks_snap() function. This abstraction will
ease changes o the ->dynticks counter operation.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
rcu: Abstract the dynticks momentary-idle operation
This commit is the first step towards full abstraction of all accesses to
the ->dynticks counter, implementing the previously open-coded atomic add
of two in a new rcu_dynticks_momentary_idle() function. This abstraction
will ease changes to the ->dynticks counter operation.
Note that this commit gets rid of the smp_mb__before_atomic() and the
smp_mb__after_atomic() calls that were previously present. The reason
that this is OK from a memory-ordering perspective is that the atomic
operation is now atomic_add_return(), which, as a value-returning atomic,
guarantees full ordering.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Thu, 17 Nov 2016 20:54:39 +0000 (12:54 -0800)]
torture: Enable DEBUG_OBJECTS_RCU_HEAD for Tiny RCU
The RCU torture tests currently do not run any Tiny RCU scenarios for
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. This is a hole in the test, given
that someone might need this in real life and given that Tiny RCU uses
different callback-handling code than does Tree RCU. This commit
therefore enables this Kconfig option for scenario TINY02.
Reported-by: "Ahmed, Iftekhar" <ahmedi@oregonstate.edu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
It is because cxt.lwsa and cxt.lrsa don't get freed in module_exit, so free
them in lock_torture_cleanup() and free writer_tasks if reader_tasks is
failed at memory allocation.
Signed-off-by: Yang Shi <yang.shi@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
torture: Add tests without slow grace period setup/cleanup
This commit moves CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP,
CONFIG_RCU_TORTURE_TEST_SLOW_INIT, and CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT
from CFcommon to all of the TREE scenarios other than TREE08 and TREE09
in order to do at least some testing without these Kconfig options set.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Sun, 18 Dec 2016 21:46:45 +0000 (13:46 -0800)]
doc: Quick-Quiz answers are now inline
Now that quick-quiz answers are inline, there is no separate section
containing those answers. This commit therefore removes the dangling
reference from the RCU data-structures design documentation.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Wed, 29 Jun 2016 02:52:01 +0000 (19:52 -0700)]
rcu: Design documentation for expedited grace periods
This commit adds design documentation for expedited grace periods.
This documentation is in HTML rather than the new documentation
format because (1) I have prototype documentation already in HTML,
and (2) Attempting to learn the new documentation format while
creating the design documentation seems likely to result in neither
happening in a timely fashion.
Once the design documentation is complete, we can start a conversion effort.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 10 Jan 2017 10:28:26 +0000 (02:28 -0800)]
rcu: Narrow early boot window of illegal synchronous grace periods
The current preemptible RCU implementation goes through three phases
during bootup. In the first phase, there is only one CPU that is running
with preemption disabled, so that a no-op is a synchronous grace period.
In the second mid-boot phase, the scheduler is running, but RCU has
not yet gotten its kthreads spawned (and, for expedited grace periods,
workqueues are not yet running. During this time, any attempt to do
a synchronous grace period will hang the system (or complain bitterly,
depending). In the third and final phase, RCU is fully operational and
everything works normally.
This has been OK for some time, but there has recently been some
synchronous grace periods showing up during the second mid-boot phase.
This code worked "by accident" for awhile, but started failing as soon
as expedited RCU grace periods switched over to workqueues in commit 8b355e3bc140 ("rcu: Drive expedited grace periods from workqueue").
Note that the code was buggy even before this commit, as it was subject
to failure on real-time systems that forced all expedited grace periods
to run as normal grace periods (for example, using the rcu_normal ksysfs
parameter). The callchain from the failure case is as follows:
The kernel showing this callchain was built with CONFIG_PREEMPT_RCU=y,
which caused the code to try using workqueues before they were
initialized, which did not go well.
This commit therefore reworks RCU to permit synchronous grace periods
to proceed during this mid-boot phase. This commit is therefore a
fix to a regression introduced in v4.9, and is therefore being put
forward post-merge-window in v4.10.
This commit sets a flag from the existing rcu_scheduler_starting()
function which causes all synchronous grace periods to take the expedited
path. The expedited path now checks this flag, using the requesting task
to drive the expedited grace period forward during the mid-boot phase.
Finally, this flag is updated by a core_initcall() function named
rcu_exp_runtime_mode(), which causes the runtime codepaths to be used.
Note that this arrangement assumes that tasks are not sent POSIX signals
(or anything similar) from the time that the first task is spawned
through core_initcall() time.
Fixes: 8b355e3bc140 ("rcu: Drive expedited grace periods from workqueue") Reported-by: "Zheng, Lv" <lv.zheng@intel.com> Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Stan Kain <stan.kain@gmail.com> Tested-by: Ivan <waffolz@hotmail.com> Tested-by: Emanuel Castelo <emanuel.castelo@gmail.com> Tested-by: Bruno Pesavento <bpesavento@infinito.it> Tested-by: Borislav Petkov <bp@suse.de> Tested-by: Frederic Bezies <fredbezies@gmail.com> Cc: <stable@vger.kernel.org> # 4.9.0-
Paul E. McKenney [Tue, 10 Jan 2017 07:23:15 +0000 (23:23 -0800)]
rcu: Remove cond_resched() from Tiny synchronize_sched()
It is now legal to invoke synchronize_sched() at early boot, which causes
Tiny RCU's synchronize_sched() to emit spurious splats. This commit
therefore removes the cond_resched() from Tiny RCU's synchronize_sched().
Fixes: 8b355e3bc140 ("rcu: Drive expedited grace periods from workqueue") Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> # 4.9.0-
Linus Torvalds [Sun, 8 Jan 2017 19:42:04 +0000 (11:42 -0800)]
Merge tag 'usb-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are a bunch of USB fixes for 4.10-rc3. Yeah, it's a lot, an
artifact of the holiday break I think.
Lots of gadget and the usual XHCI fixups for reported issues (one day
that driver will calm down...) Also included are a bunch of usb-serial
driver fixes, and for good measure, a number of much-reported MUSB
driver issues have finally been resolved.
All of these have been in linux-next with no reported issues"
* tag 'usb-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (72 commits)
USB: fix problems with duplicate endpoint addresses
usb: ohci-at91: use descriptor-based gpio APIs correctly
usb: storage: unusual_uas: Add JMicron JMS56x to unusual device
usb: hub: Move hub_port_disable() to fix warning if PM is disabled
usb: musb: blackfin: add bfin_fifo_offset in bfin_ops
usb: musb: fix compilation warning on unused function
usb: musb: Fix trying to free already-free IRQ 4
usb: musb: dsps: implement clear_ep_rxintr() callback
usb: musb: core: add clear_ep_rxintr() to musb_platform_ops
USB: serial: ti_usb_3410_5052: fix NULL-deref at open
USB: serial: spcp8x5: fix NULL-deref at open
USB: serial: quatech2: fix sleep-while-atomic in close
USB: serial: pl2303: fix NULL-deref at open
USB: serial: oti6858: fix NULL-deref at open
USB: serial: omninet: fix NULL-derefs at open and disconnect
USB: serial: mos7840: fix misleading interrupt-URB comment
USB: serial: mos7840: remove unused write URB
USB: serial: mos7840: fix NULL-deref at open
USB: serial: mos7720: remove obsolete port initialisation
USB: serial: mos7720: fix parallel probe
...
Linus Torvalds [Sun, 8 Jan 2017 19:37:44 +0000 (11:37 -0800)]
Merge tag 'char-misc-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc fixes from Greg KH:
"Here are a few small char/misc driver fixes for 4.10-rc3.
Two MEI driver fixes, and three NVMEM patches for reported issues, and
a new Hyper-V driver MAINTAINER update. Nothing major at all, all have
been in linux-next with no reported issues"
* tag 'char-misc-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
hyper-v: Add myself as additional MAINTAINER
nvmem: fix nvmem_cell_read() return type doc
nvmem: imx-ocotp: Fix wrong register size
nvmem: qfprom: Allow single byte accesses for read/write
mei: move write cb to completion on credentials failures
mei: bus: fix mei_cldev_enable KDoc
Linus Torvalds [Sun, 8 Jan 2017 19:22:00 +0000 (11:22 -0800)]
Merge tag 'staging-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging/IIO fixes from Greg KH:
"Here are some staging and IIO driver fixes for 4.10-rc3.
Most of these are minor IIO fixes of reported issues, along with one
network driver fix to resolve an issue. And a MAINTAINERS update with
a new mailing list. All of these, except the MAINTAINERS file update,
have been in linux-next with no reported issues (the MAINTAINERS patch
happened on Friday...)"
* tag 'staging-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
MAINTAINERS: add greybus subsystem mailing list
staging: octeon: Call SET_NETDEV_DEV()
iio: accel: st_accel: fix LIS3LV02 reading and scaling
iio: common: st_sensors: fix channel data parsing
iio: max44000: correct value in illuminance_integration_time_available
iio: adc: TI_AM335X_ADC should depend on HAS_DMA
iio: bmi160: Fix time needed to sleep after command execution
iio: 104-quad-8: Fix active level mismatch for the preset enable option
iio: 104-quad-8: Fix off-by-one errors when addressing IOR
iio: 104-quad-8: Fix index control configuration
Johannes Weiner [Sat, 7 Jan 2017 00:21:43 +0000 (19:21 -0500)]
mm: workingset: fix use-after-free in shadow node shrinker
Several people report seeing warnings about inconsistent radix tree
nodes followed by crashes in the workingset code, which all looked like
use-after-free access from the shadow node shrinker.
Dave Jones managed to reproduce the issue with a debug patch applied,
which confirmed that the radix tree shrinking indeed frees shadow nodes
while they are still linked to the shadow LRU:
This is the WARN_ON_ONCE(!list_empty(&node->private_list)) placed in the
inlined radix_tree_shrink().
The problem is with 14b468791fa9 ("mm: workingset: move shadow entry
tracking to radix tree exceptional tracking"), which passes an update
callback into the radix tree to link and unlink shadow leaf nodes when
tree entries change, but forgot to pass the callback when reclaiming a
shadow node.
While the reclaimed shadow node itself is unlinked by the shrinker, its
deletion from the tree can cause the left-most leaf node in the tree to
be shrunk. If that happens to be a shadow node as well, we don't unlink
it from the LRU as we should.
Consider this tree, where the s are shadow entries:
root->rnode
|
[0 n]
| |
[s ] [sssss]
Now the shadow node shrinker reclaims the rightmost leaf node through
the shadow node LRU:
root->rnode
|
[0 ]
|
[s ]
Because the parent of the deleted node is the first level below the
root and has only one child in the left-most slot, the intermediate
level is shrunk and the node containing the single shadow is put in
its place:
root->rnode
|
[s ]
The shrinker again sees a single left-most slot in a first level node
and thus decides to store the shadow in root->rnode directly and free
the node - which is a leaf node on the shadow node LRU.
root->rnode
|
s
Without the update callback, the freed node remains on the shadow LRU,
where it causes later shrinker runs to crash.
Pass the node updater callback into __radix_tree_delete_node() in case
the deletion causes the left-most branch in the tree to collapse too.
Also add warnings when linked nodes are freed right away, rather than
wait for the use-after-free when the list is scanned much later.
Fixes: 14b468791fa9 ("mm: workingset: move shadow entry tracking to radix tree exceptional tracking") Reported-by: Dave Chinner <david@fromorbit.com> Reported-by: Hugh Dickins <hughd@google.com> Reported-by: Andrea Arcangeli <aarcange@redhat.com> Reported-and-tested-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Chris Leech <cleech@redhat.com> Cc: Lee Duncan <lduncan@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Sat, 7 Jan 2017 23:37:31 +0000 (15:37 -0800)]
mm: stop leaking PageTables
4.10-rc loadtest (even on x86, and even without THPCache) fails with
"fork: Cannot allocate memory" or some such; and /proc/meminfo shows
PageTables growing.
Commit 953c66c2b22a ("mm: THP page cache support for ppc64") that got
merged in rc1 removed the freeing of an unused preallocated pagetable
after do_fault_around() has called map_pages().
This is usually a good optimization, so that the followup doesn't have
to reallocate one; but it's not sufficient to shift the freeing into
alloc_set_pte(), since there are failure cases (most commonly
VM_FAULT_RETRY) which never reach finish_fault().
Check and free it at the outer level in do_fault(), then we don't need
to worry in alloc_set_pte(), and can restore that to how it was (I
cannot find any reason to pte_free() under lock as it was doing).
And fix a separate pagetable leak, or crash, introduced by the same
change, that could only show up on some ppc64: why does do_set_pmd()'s
failure case attempt to withdraw a pagetable when it never deposited
one, at the same time overwriting (so leaking) the vmf->prealloc_pte?
Residue of an earlier implementation, perhaps? Delete it.
Fixes: 953c66c2b22a ("mm: THP page cache support for ppc64") Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sat, 7 Jan 2017 17:47:43 +0000 (09:47 -0800)]
Merge branch 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild fix from Michal Marek:
"The asm-prototypes.h file added in the last merge window results in
invalid code with CONFIG_KMEMCHECK=y. The net result is that genksyms
segfaults.
This pull request fixes the header, the genksyms fix is in my kbuild
branch for 4.11"
* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
asm-prototypes: Clear any CPP defines before declaring the functions
Linus Torvalds [Fri, 6 Jan 2017 23:38:39 +0000 (15:38 -0800)]
Merge tag 'sound-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"Nothing particular stands out, only a few small fixes for USB-audio,
HD-audio and Firewire. The USB-audio fix is the respin of the previous
race fix after a revert due to the regression"
* tag 'sound-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
Revert "ALSA: firewire-lib: change structure member with proper type"
ALSA: usb-audio: test EP_FLAG_RUNNING at urb completion
ALSA: usb-audio: Fix irq/process data synchronization
ALSA: hda - Apply asus-mode8 fixup to ASUS X71SL
ALSA: hda - Fix up GPIO for ASUS ROG Ranger
ALSA: firewire-lib: change structure member with proper type
ALSA: firewire-tascam: Fix to handle error from initialization of stream data
ALSA: fireworks: fix asymmetric API call at unit removal
Linus Torvalds [Fri, 6 Jan 2017 23:35:27 +0000 (15:35 -0800)]
Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk fixes from Stephen Boyd:
"One fix for a broken driver on Renesas RZ/A1 SoCs with bootloaders
that don't turn all the clks on and another fix for stm32f4 SoCs where
we have multiple drivers attaching to the same DT node"
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: stm32f4: Use CLK_OF_DECLARE_DRIVER initialization method
clk: renesas: mstp: Support 8-bit registers for r7s72100
Linus Torvalds [Fri, 6 Jan 2017 19:19:03 +0000 (11:19 -0800)]
Merge tag 'vfio-v4.10-rc3' of git://github.com/awilliam/linux-vfio
Pull VFIO fixes from Alex Williamson:
- Add mtty sample driver properly into build system (Alex Williamson)
- Restore type1 mapping performance after mdev (Alex Williamson)
- Fix mdev device race (Alex Williamson)
- Cleanups to the mdev ABI used by vendor drivers (Alex Williamson)
- Build fix for old compilers (Arnd Bergmann)
- Fix sample driver error path (Dan Carpenter)
- Handle pci_iomap() error (Arvind Yadav)
- Fix mdev ioctl return type (Paul Gortmaker)
* tag 'vfio-v4.10-rc3' of git://github.com/awilliam/linux-vfio:
vfio-mdev: fix non-standard ioctl return val causing i386 build fail
vfio-pci: Handle error from pci_iomap
vfio-mdev: fix some error codes in the sample code
vfio-pci: use 32-bit comparisons for register address for gcc-4.5
vfio-mdev: Make mdev_device private and abstract interfaces
vfio-mdev: Make mdev_parent private
vfio-mdev: de-polute the namespace, rename parent_device & parent_ops
vfio-mdev: Fix remove race
vfio/type1: Restore mapping performance with mdev support
vfio-mdev: Fix mtty sample driver building
Linus Torvalds [Fri, 6 Jan 2017 18:53:21 +0000 (10:53 -0800)]
Merge branch 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb fixes from Konrad Rzeszutek Wilk:
"This has one fix to make i915 work when using Xen SWIOTLB, and a
feature from Geert to aid in debugging of devices that can't do DMA
outside the 32-bit address space.
The feature from Geert is on top of v4.10 merge window commit
(specifically you pulling my previous branch), as his changes were
dependent on the Documentation/ movement patches.
I figured it would just easier than me trying than to cherry-pick the
Documentation patches to satisfy git.
The patches have been soaking since 12/20, albeit I updated the last
patch due to linux-next catching an compiler error and adding an
Tested-and-Reported-by tag"
* 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
swiotlb: Export swiotlb_max_segment to users
swiotlb: Add swiotlb=noforce debug option
swiotlb: Convert swiotlb_force from int to enum
x86, swiotlb: Simplify pci_swiotlb_detect_override()
Linus Torvalds [Fri, 6 Jan 2017 18:49:36 +0000 (10:49 -0800)]
Merge tag 'iommu-fixes-v4.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU fixes from Joerg Roedel:
"Three fixes queued up:
- fix an issue with command buffer overflow handling in the AMD IOMMU
driver
- add an additional context entry flush to the Intel VT-d driver to
make sure any old context entry from kdump copying is flushed out
of the cache
- correct the encoding of the PASID table size in the Intel VT-d
driver"
* tag 'iommu-fixes-v4.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
iommu/amd: Fix the left value check of cmd buffer
iommu/vt-d: Fix pasid table size encoding
iommu/vt-d: Flush old iommu caches for kdump when the device gets context mapped
Linus Torvalds [Fri, 6 Jan 2017 18:40:17 +0000 (10:40 -0800)]
Merge tag 'acpi-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI fixes from Rafael Wysocki:
"These fix a device enumeration problem related to _ADR matching and an
IOMMU initialization issue related to the DMAR table missing, remove
an excessive function call from the core ACPI code, update an error
message in the ACPI WDAT watchdog driver and add a way to work around
problems with unhandled GPE notifications.
Specifics:
- Fix a device enumeration issue leading to incorrect associations
between ACPI device objects and platform device objects
representing physical devices if the given device object has both
_ADR and _HID (Rafael Wysocki).
- Avoid passing NULL to acpi_put_table() during IOMMU initialization
which triggers a (rightful) warning from ACPICA (Rafael Wysocki).
- Drop an excessive call to acpi_dma_deconfigure() from the core code
that binds ACPI device objects to device objects representing
physical devices (Lorenzo Pieralisi).
- Update an error message in the ACPI WDAT watchdog driver to make it
provide more useful information (Mika Westerberg).
- Add a mechanism to work around issues with unhandled GPE
notifications that occur during system initialization and cannot be
prevented by means of sysfs (Lv Zheng)"
* tag 'acpi-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / DMAR: Avoid passing NULL to acpi_put_table()
ACPI / scan: Prefer devices without _HID/_CID for _ADR matching
ACPI / watchdog: Print out error number when device creation fails
ACPI / sysfs: Provide quirk mechanism to prevent GPE flooding
ACPI: Drop misplaced acpi_dma_deconfigure() call from acpi_bind_one()
Linus Torvalds [Fri, 6 Jan 2017 18:37:50 +0000 (10:37 -0800)]
Merge tag 'pm-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These fix a few issues in the intel_pstate driver, a documetation
issue, a false-positive compiler warning in the generic power domains
framework and two problems in the devfreq subsystem. They also update
the MAINTAINERS entry for devfreq and add a new "compatible" string to
the generic cpufreq-dt driver.
Specifics:
- Fix a few intel_pstate driver issues: add missing locking it two
places, avoid exposing a useless debugfs interface and keep the
attribute values in sysfs in sync (Rafael Wysocki).
- Drop confusing kernel-doc references related to power management
and ACPI from the driver API manual (Rafael Wysocki).
- Make a false-positive compiler warning in the generic power domains
framework go away (Augusto Mecking Caringi).
- Fix two initialization issues in the devfreq subsystem and update
the MAINTAINERS entry for it (Chanwoo Choi).
- Add a new "compatible" string for APM X-Gene 2 to the generic DT
cpufreq driver (Hoan Tran)"
* tag 'pm-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: dt: Add support for APM X-Gene 2
PM / devfreq: exynos-bus: Fix the wrong return value
PM / devfreq: Fix the bug of devfreq_add_device when governor is NULL
MAINTAINERS: Add myself as reviewer for DEVFREQ subsystem support
PM / docs: Drop confusing kernel-doc references from infrastructure.rst
PM / domains: Fix 'may be used uninitialized' build warning
cpufreq: intel_pstate: Always keep all limits settings in sync
cpufreq: intel_pstate: Use locking in intel_cpufreq_verify_policy()
cpufreq: intel_pstate: Use locking in intel_pstate_resume()
cpufreq: intel_pstate: Do not expose PID parameters in passive mode
So they can figure out what is the optimal number of pages
that can be contingously stitched together without fear of
bounce buffer.
We also expose an mechanism for sub-users of SWIOTLB API, such
as Xen-SWIOTLB to set the max segment value. And lastly
if swiotlb=force is set (which mandates we bounce buffer everything)
we set max_segment so at least we can bounce buffer one 4K page
instead of a giant 512KB one for which we may not have space.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reported-and-Tested-by: Juergen Gross <jgross@suse.com>
Merge branches 'pm-domains', 'pm-docs' and 'pm-devfreq'
* pm-domains:
PM / domains: Fix 'may be used uninitialized' build warning
* pm-docs:
PM / docs: Drop confusing kernel-doc references from infrastructure.rst
* pm-devfreq:
PM / devfreq: exynos-bus: Fix the wrong return value
PM / devfreq: Fix the bug of devfreq_add_device when governor is NULL
MAINTAINERS: Add myself as reviewer for DEVFREQ subsystem support
* pm-cpufreq:
cpufreq: dt: Add support for APM X-Gene 2
cpufreq: intel_pstate: Always keep all limits settings in sync
cpufreq: intel_pstate: Use locking in intel_cpufreq_verify_policy()
cpufreq: intel_pstate: Use locking in intel_pstate_resume()
cpufreq: intel_pstate: Do not expose PID parameters in passive mode
Linus Torvalds [Fri, 6 Jan 2017 07:17:41 +0000 (23:17 -0800)]
Merge tag 'platform-drivers-x86-v4.10-3' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86
Pull x86 platform driver fixes from Darren Hart:
"Just two small fixes for platform drivers x86:
- use brightness_set_blocking for LED-setting callbacks on Fujitsu
laptops
- fix surface3_button build errors"
* tag 'platform-drivers-x86-v4.10-3' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86:
platform/x86: fujitsu-laptop: use brightness_set_blocking for LED-setting callbacks
platform/x86: fix surface3_button build errors
Linus Torvalds [Fri, 6 Jan 2017 07:06:06 +0000 (23:06 -0800)]
Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit
Pull audit fixes from Paul Moore:
"Two small fixes relating to audit's use of fsnotify.
The first patch plugs a leak and the second fixes some lock
shenanigans. The patches are small and I banged on this for an
afternoon with our testsuite and didn't see anything odd"
* 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit:
audit: Fix sleep in atomic
fsnotify: Remove fsnotify_duplicate_mark()
Linus Torvalds [Thu, 5 Jan 2017 23:06:02 +0000 (15:06 -0800)]
Merge tag 'drm-intel-fixes-2017-01-05' of git://anongit.freedesktop.org/git/drm-intel
Pull i915 drm fixes from Jani Nikula:
"Here's a bunch of drm/i915 fixes for v4.10-rc3. It includes GVT-g
fixes.
My new year's resolution is to start using signed tags for pulls. If
that feels like a déjà vu, it's ((new year's) resolution), not (new
(year's resolution))"
[ Taking this directly from Jani because Dave Airlie is only partially
connected right now. - Linus ]
* tag 'drm-intel-fixes-2017-01-05' of git://anongit.freedesktop.org/git/drm-intel:
drm/i915: Prevent timeline updates whilst performing reset
drm/i915: Silence allocation failure during sg_trim()
drm/i915: Don't clflush before release phys object
drm/i915: Fix oops in overlay due to frontbuffer tracking
drm/i915: Fix oopses in the overlay code due to i915_gem_active stuff
drm/i915: Initialize overlay->last_flip properly
drm/i915: Move the min_pixclk[] handling to the end of readout
drm/i915: Force VDD off on the new power seqeuencer before starting to use it
drm/i915/gvt: fix typo in cfg_space range check
drm/i915/gvt: fix an issue in emulating cfg space PCI_COMMAND
drm/i915/gvt/kvmgt: trival: code cleanup
drm/i915/gvt/kvmgt: prevent double-release of vgpu
drm/i915/gvt/kvmgt: check returned slot for gfn
drm/i915/gvt/kvmgt: dereference the pointer within lock
drm/i915/gvt: reset the GGTT entry when vGPU created
drm/i915/gvt: fix an error in opregion handling
Alan Stern [Mon, 19 Dec 2016 17:03:41 +0000 (12:03 -0500)]
USB: fix problems with duplicate endpoint addresses
When checking a new device's descriptors, the USB core does not check
for duplicate endpoint addresses. This can cause a problem when the
sysfs files for those endpoints are created; trying to create multiple
files with the same name will provoke a WARNING:
WARNING: CPU: 2 PID: 865 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x8a/0xa0
sysfs: cannot create duplicate filename
'/devices/platform/dummy_hcd.0/usb2/2-1/2-1:64.0/ep_05'
Kernel panic - not syncing: panic_on_warn set ...
Linus Torvalds [Thu, 5 Jan 2017 18:36:56 +0000 (10:36 -0800)]
Merge tag 'pinctrl-v4.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pin control fixes from Linus Walleij:
"Three small pin control fixes for the v4.10 series. Very little to say
about them, just driver fixes.
- one fix to the AMD pinctrl ACPI glue
- fix requests on the Meson driver
- fix bitfield widths on Samsungs Exynos 5433"
* tag 'pinctrl-v4.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: samsung: Fix the width of PINCFG_TYPE_DRV bitfields for Exynos5433
pinctrl: meson: fix gpio request disabling other modes
pinctrl/amd: Set the level based on ACPI tables
Peter Rosin [Thu, 22 Dec 2016 07:43:55 +0000 (08:43 +0100)]
usb: ohci-at91: use descriptor-based gpio APIs correctly
The gpiod_get* function family does not want the -gpio suffix.
Use devm_gpiod_get_index_optional instead of devm_gpiod_get_optional.
The descriptor based APIs handle active high/low automatically.
The vbus-gpios are output, request enable while getting the gpio.
Don't try to get any vbus-gpios for ports outside num-ports.
WTF? Big sigh.
Fixes: 054d4b7b577d ("usb: ohci-at91: Use descriptor-based gpio APIs") Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linus Torvalds [Thu, 5 Jan 2017 18:32:16 +0000 (10:32 -0800)]
Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Arnd Bergmann:
"This is a rather large set of bugfixes, as we just returned from the
Christmas break. Most of these are relatively unimportant fixes for
regressions introduced during the merge window, and about half of the
changes are for mach-omap2.
A couple of patches are just cleanups and dead code removal that I
would not normally have considered for merging after -rc2, but I
decided to take them along with the fixes this time.
Notable fixes include:
- removing the skeleton.dtsi include broke a number of machines, and
we have to put empty /chosen nodes back to be able to pass kernel
command lines as before
- enabling Samsung platforms no longer hardwires CONFIG_HZ to 200, as
it had been for no good reason for a long time"
* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (46 commits)
MAINTAINERS: extend PSCI entry to cover the newly add PSCI checker code
drivers: psci: annotate timer on stack to silence odebug messages
ARM64: defconfig: enable DRM_MESON as module
ARM64: dts: meson-gx: Add Graphic Controller nodes
ARM64: dts: meson-gxl: fix GPIO include
ARM: dts: imx6: Disable "weim" node in the dtsi files
ARM: dts: qcom: apq8064: Add missing scm clock
ARM: davinci: da8xx: Fix sleeping function called from invalid context
ARM: davinci: Make __clk_{enable,disable} functions public
ARM: davinci: da850: don't add emac clock to lookup table twice
ARM: davinci: da850: fix infinite loop in clk_set_rate()
ARM: i.MX: remove map_io callback
ARM: dts: vf610-zii-dev-rev-b: Add missing newline
ARM: dts: imx6qdl-nitrogen6x: remove duplicate iomux entry
ARM: dts: imx31: fix AVIC base address
ARM: dts: am572x-idk: Add gpios property to control PCIE_RESETn
arm64: dts: vexpress: Support GICC_DIR operations
ARM: dts: vexpress: Support GICC_DIR operations
firmware: arm_scpi: fix reading sensor values on pre-1.0 SCPI firmwares
arm64: dts: msm8996: Add required memory carveouts
...
Linus Torvalds [Thu, 5 Jan 2017 18:29:40 +0000 (10:29 -0800)]
Merge tag 'for-linus-4.10-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes and cleanups from Juergen Gross:
- small fixes for xenbus driver
- one fix for xen dom0 boot on huge system
- small cleanups
* tag 'for-linus-4.10-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
Xen: ARM: Zero reserved fields of xatp before making hypervisor call
xen: events: Replace BUG() with BUG_ON()
xen: remove stale xs_input_avail() from header
xen: return xenstore command failures via response instead of rc
xen: xenbus driver must not accept invalid transaction ids
xen/evtchn: use rb_entry()
xen/setup: Don't relocate p2m over existing one
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: hub: Move hub_port_disable() to fix warning if PM is disabled
If CONFIG_PM=n:
drivers/usb/core/hub.c:107: warning: ‘hub_usb3_port_prepare_disable’ declared inline after being called
drivers/usb/core/hub.c:107: warning: previous declaration of ‘hub_usb3_port_prepare_disable’ was here
To fix this, move hub_port_disable() after
hub_usb3_port_prepare_disable(), and adjust forward declarations.
Jérémy Lefaure [Wed, 4 Jan 2017 00:13:52 +0000 (18:13 -0600)]
usb: musb: blackfin: add bfin_fifo_offset in bfin_ops
The function bfin_fifo_offset is defined but not used:
drivers/usb/musb/blackfin.c:36:12: warning: ‘bfin_fifo_offset’ defined
but not used [-Wunused-function]
static u32 bfin_fifo_offset(u8 epnum)
^~~~~~~~~~~~~~~~
Adding bfin_fifo_offset to bfin_ops fixes this warning and allows musb
core to call this function instead of default_fifo_offset.
Fixes: cc92f6818f6e ("usb: musb: Populate new IO functions for blackfin") Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr> Signed-off-by: Bin Liu <b-liu@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jérémy Lefaure [Wed, 4 Jan 2017 00:13:49 +0000 (18:13 -0600)]
usb: musb: fix compilation warning on unused function
The function musb_run_resume_work is called only when CONFIG_PM is
enabled. So this function should not be defined when CONFIG_PM is
disabled. Otherwise the compiler issues a warning:
drivers/usb/musb/musb_core.c:2057:12: error: ‘musb_run_resume_work’ defined but
not used [-Werror=unused-function]
static int musb_run_resume_work(struct musb *musb)
^~~~~~~~~~~~~~~~~~~~
Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr> Signed-off-by: Bin Liu <b-liu@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During dma teardown for dequque urb, if musb load is high, musb might
generate bogus rx ep interrupt even when the rx fifo is flushed. In such
case any of the follow log messages could happen.
As mentioned in the current inline comment, clearing ep interrupt in the
teardown path avoids the bogus interrupt, so implement clear_ep_rxintr()
callback.
This bug seems to be existing since the initial driver for musb support,
but I only validated the fix back to v4.1, so only cc stable for v4.1+.
cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Bin Liu <b-liu@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bin Liu [Wed, 4 Jan 2017 00:13:46 +0000 (18:13 -0600)]
usb: musb: core: add clear_ep_rxintr() to musb_platform_ops
During dma teardown for dequque urb, if musb load is high, musb might
generate bogus rx ep interrupt even when the rx fifo is flushed. In such
case any of the follow log messages could happen.
Nicholas Piggin [Thu, 5 Jan 2017 10:29:35 +0000 (20:29 +1000)]
kbuild: initramfs fix dependency checking for compressed target
When using initramfs compression, the data file compression suffix
gets quotes pulled in from Kconfig, e.g., initramfs_data.cpio".gz"
which make does not match a target and causes rebuild.
Fix this by filtering out quotes from the Kconfig string.
Fixes: 35e669e1a254 ("initramfs: select builtin initram compression algorithm on KConfig instead of Makefile") Reviewed-by: Francisco Blas Izquierdo Riera (klondike) <klondike@klondike.es> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'usb-serial-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-linus
Johan writes:
USB-serial fixes for v4.10-rc3
These fixes address a number of long-standing issues in various
USB-serial drivers which would lead to crashes should a malicious device
lack the expected endpoints.
Included are also a few related fixes, and a couple of unrelated ones
that were found during my survey (e.g. a memleak and a
sleep-while-atomic).
A compiler warning revealed an error-handling issue in the new f81534
driver which is also fixed.
ACPI / DMAR: Avoid passing NULL to acpi_put_table()
Linus reported that commit 174cc7187e6f "ACPICA: Tables: Back port
acpi_get_table_with_size() and early_acpi_os_unmap_memory() from
Linux kernel" added a new warning on his desktop system:
ACPI Warning: Table ffffffff9fe6c0a0, Validation count is zero before decrement
which turns out to come from the acpi_put_table() in
detect_intel_iommu().
This happens if the DMAR table is not present in which case NULL is
passed to acpi_put_table() which doesn't check against that and
attempts to handle it regardless.
For this reason, check the pointer passed to acpi_put_table()
before invoking it.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Fixes: 6b11d1d67713 ("ACPI / osl: Remove acpi_get_table_with_size()/early_acpi_os_unmap_memory() users") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
James Hogan [Tue, 3 Jan 2017 17:43:00 +0000 (17:43 +0000)]
KVM: MIPS: Don't clobber CP0_Status.UX
On 64-bit kernels, MIPS KVM will clear CP0_Status.UX to prevent the
guest (running in user mode) from accessing the 64-bit memory segments.
However the previous value of CP0_Status.UX is never restored when
exiting from the guest.
If the user process uses 64-bit addressing (the n64 ABI) this can result
in address error exceptions from the kernel if it needs to deliver a
signal before returning to user mode, as the kernel will need to write a
sigframe to high user addresses on the user stack which are disallowed
by CP0_Status.UX=0.
This is fixed by explicitly setting SX and UX again when exiting from
the guest, and explicitly clearing those bits when returning to the
guest. Having the SX and UX bits set when handling guest exits (rather
than only when exiting to userland) will be helpful when we support VZ,
since we shouldn't need to directly read or write guest memory, so it
will be valid for cache management IPIs to access host user addresses.
Michal Marek [Tue, 3 Jan 2017 12:49:42 +0000 (13:49 +0100)]
asm-prototypes: Clear any CPP defines before declaring the functions
The asm-prototypes.h file is used to provide dummy function declarations
for genksyms, when processing asm files with EXPORT_SYMBOL. Make sure
that any architecture defines get out of our way. x86 currently has an
issue with memcpy on 64bit with CONFIG_KMEMCHECK=y and with
memset/__memset on 32bit:
$ cat init/test.c
#include <asm/asm-prototypes.h>
$ make -s init/test.o
In file included from ./arch/x86/include/asm/string.h:4:0,
from ./include/linux/string.h:18,
from ./include/linux/bitmap.h:8,
from ./include/linux/cpumask.h:11,
from ./arch/x86/include/asm/cpumask.h:4,
from ./arch/x86/include/asm/msr.h:10,
from ./arch/x86/include/asm/processor.h:20,
from ./arch/x86/include/asm/cpufeature.h:4,
from ./arch/x86/include/asm/thread_info.h:52,
from ./include/linux/thread_info.h:25,
from ./arch/x86/include/asm/preempt.h:6,
from ./include/linux/preempt.h:59,
from ./include/linux/spinlock.h:50,
from ./include/linux/seqlock.h:35,
from ./include/linux/time.h:5,
from ./include/uapi/linux/timex.h:56,
from ./include/linux/timex.h:56,
from ./include/linux/sched.h:19,
from ./include/linux/uaccess.h:4,
from ./arch/x86/include/asm/asm-prototypes.h:2,
from init/test.c:1:
./arch/x86/include/asm/string_64.h:52:47: error: expected declaration specifiers or ‘...’ before ‘(’ token
#define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
./include/asm-generic/asm-prototypes.h:6:14: note: in expansion of macro ‘memcpy’
extern void *memcpy(void *, const void *, __kernel_size_t);
^
...
During real build, this manifests itself by genksyms segfaulting.
Fixes: 334bb7738764 ("x86/kbuild: enable modversions for symbols exported from asm") Reported-and-tested-by: Borislav Petkov <bp@alien8.de> Cc: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Michal Marek <mmarek@suse.com>
Revert "ALSA: firewire-lib: change structure member with proper type"
This reverts commit 6b7e95d1336b9eb0d4c6db190ce756480496bd13. This commit
is based on a concern about value of the given parameter. It's expected
to be ORed value with some enumeration-constants, thus often it can not be
one of the enumeration-constants. I understood that this is out of
specification and causes implementation-dependent issues.
In C language specification, enumerated type can be interpreted as an
integer type, in which all of enumeration-constants in corresponding
enumerator-list can be stored. Implementations can select one of char,
signed int and unsigned int as its type, and this selection is
implementation-dependent.
In GCC, a signed integer is selected when at least one of
enumeration-constants has negative value, else an unsigned integer is
selected. This behaviour can be switched by -fshort-enums to short type.
Anyway, the type can be decided after scanning all of
enumeration-constants.
Totally, there's no rules to constrain the value of enumerated type to
be one of enumeration-constants. In short, in enumerated type, decision
of actual type for the type is the most important and
enumeration-constants are just used for the decision, thus it's permitted
to have an integer value in a range of enumeration-constants. In our case,
actual type for the type is currently deterministic to be either char or
unsigned int. Under GCC, it's unsigned int.
ALSA: usb-audio: test EP_FLAG_RUNNING at urb completion
Testing EP_FLAG_RUNNING in snd_complete_urb() before running the completion
logic allows us to save a few cpu cycles by returning early, skipping the
pending urb in case the stream was stopped; the stop logic handles the urb
and sets the completion callbacks to NULL.
ALSA: usb-audio: Fix irq/process data synchronization
Commit 16200948d83 ("ALSA: usb-audio: Fix race at stopping the stream") was
incomplete causing another more severe kernel panic, so it got reverted.
This fixes both the original problem and its fallout kernel race/crash.
The original fix is to move the endpoint member NULL clearing logic inside
wait_clear_urbs() so the irq triggering the urb completion doesn't call
retire_capture/playback_urb() after the NULL clearing and generate a panic.
However this creates a new race between snd_usb_endpoint_start()'s call
to wait_clear_urbs() and the irq urb completion handler which again calls
retire_capture/playback_urb() leading to a new NULL dereference.
We keep the EP deactivation code in snd_usb_endpoint_start() because
removing it will break the EP reference counting (see [1] [2] for info),
however we don't need the "can_sleep" mechanism anymore because a new
function was introduced (snd_usb_endpoint_sync_pending_stop()) which
synchronizes pending stops and gets called inside the pcm prepare callback.
It also makes sense to remove can_sleep because it was also removed from
deactivate_urbs() signature in [3] so we benefit from more simplification.
Linus Torvalds [Thu, 5 Jan 2017 02:33:35 +0000 (18:33 -0800)]
Merge tag 'xfs-for-linus-4.10-rc3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Darrick Wong:
- fixes for crashes and double-cleanup errors
- XFS maintainership handover
- fix to prevent absurdly large block reservations
- fix broken sysfs getter/setters
* tag 'xfs-for-linus-4.10-rc3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: fix max_retries _show and _store functions
xfs: update MAINTAINERS
xfs: fix crash and data corruption due to removal of busy COW extents
xfs: use the actual AG length when reserving blocks
xfs: fix double-cleanup when CUI recovery fails
1) stmmac_drv_probe() can race with stmmac_open() because we register
the netdevice too early. Fix from Florian Fainelli.
2) UFO handling in __ip6_append_data() and ip6_finish_output() use
different tests for deciding whether a frame will be fragmented or
not, put them in sync. Fix from Zheng Li.
3) The rtnetlink getstats handlers need to validate that the netlink
request is large enough, fix from Mathias Krause.
4) Use after free in mlx4 driver, from Jack Morgenstein.
5) Fix setting of garbage UID value in sockets during setattr() calls,
from Eric Biggers.
6) Packet drop_monitor doesn't format the netlink messages properly
such that nlmsg_next fails to work, fix from Reiter Wolfgang.
7) Fix handling of wildcard addresses in l2tp lookups, from Guillaume
Nault.
8) __skb_flow_dissect() can crash on pptp packets, from Ian Kumlien.
9) IGMP code doesn't reset group query timers properly, from Michal
Tesar.
10) Fix overzealous MAIN/LOCAL route table combining in ipv4, from
Alexander Duyck.
11) vxlan offload check needs to be more strict in be2net driver, from
Sabrina Dubroca.
12) Moving l3mdev to packet hooks lost RX stat counters unintentionally,
fix from David Ahern.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (52 commits)
sh_eth: enable RX descriptor word 0 shift on SH7734
sfc: don't report RX hash keys to ethtool when RSS wasn't enabled
dpaa_eth: Initialize CGR structure before init
dpaa_eth: cleanup after init_phy() failure
net: systemport: Pad packet before inserting TSB
net: systemport: Utilize skb_put_padto()
LiquidIO VF: s/select/imply/ for PTP_1588_CLOCK
libcxgb: fix error check for ip6_route_output()
net: usb: asix_devices: add .reset_resume for USB PM
net: vrf: Add missing Rx counters
drop_monitor: consider inserted data in genlmsg_end
benet: stricter vxlan offloading check in be_features_check
ipv4: Do not allow MAIN to be alias for new LOCAL w/ custom rules
net: macb: Updated resource allocation function calls to new version of API.
net: stmmac: dwmac-oxnas: use generic pm implementation
net: stmmac: dwmac-oxnas: fix fixed-link-phydev leaks
net: stmmac: dwmac-oxnas: fix of-node leak
Documentation/networking: fix typo in mpls-sysctl
igmp: Make igmp group member RFC 3376 compliant
flow_dissector: Update pptp handling to avoid null pointer deref.
...
Sergei Shtylyov [Wed, 4 Jan 2017 20:10:23 +0000 (23:10 +0300)]
sh_eth: enable RX descriptor word 0 shift on SH7734
The RX descriptor word 0 on SH7734 has the RFS[9:0] field in bits 16-25
(bits 0-15 usually used for that are occupied by the packet checksum).
Thus we need to set the 'shift_rd0' field in the SH7734 SoC data...
Fixes: f0e81fecd4f8 ("net: sh_eth: Add support SH7734") Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Takashi Iwai [Wed, 4 Jan 2017 20:38:16 +0000 (21:38 +0100)]
ALSA: hda - Apply asus-mode8 fixup to ASUS X71SL
Although the old quirk table showed ASUS X71SL with ALC663 codec being
compatible with asus-mode3 fixup, the bugzilla reporter explained that
asus-model8 fits better for the dual headphone controls. So be it.
Paul Gortmaker [Wed, 4 Jan 2017 20:08:15 +0000 (15:08 -0500)]
vfio-mdev: fix non-standard ioctl return val causing i386 build fail
What appears to be a copy and paste error from the line above gets
the ioctl a ssize_t return value instead of the traditional "int".
The associated sample code used "long" which meant it would compile
for x86-64 but not i386, with the latter failing as follows:
CC [M] samples/vfio-mdev/mtty.o
samples/vfio-mdev/mtty.c:1418:20: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
.ioctl = mtty_ioctl,
^
samples/vfio-mdev/mtty.c:1418:20: note: (near initialization for ‘mdev_fops.ioctl’)
cc1: some warnings being treated as errors
Since in this case, vfio is working with struct file_operations; as such:
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
...and so here we just standardize on long vs. the normal int that user
space typically sees and documents as per "man ioctl" and similar.
Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.") Cc: Kirti Wankhede <kwankhede@nvidia.com> Cc: Neo Jia <cjia@nvidia.com> Cc: kvm@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
projects / linux.git / log