linux-stable.git/kernel/locking, branch linux-5.14.y

lockdep: Let lock_is_held_type() detect recursive read as read

2021-11-17T10:03:58+00:00

[ Upstream commit 2507003a1d10917c9158077bf6030719d02c941e ]

lock_is_held_type(, 1) detects acquired read locks. It only recognized
locks acquired with lock_acquire_shared(). Read locks acquired with
lock_acquire_shared_recursive() are not recognized because a `2' is
stored as the read value.

Rework the check to additionally recognise lock's read value one and two
as a read held lock.

Fixes: e918188611f07 ("locking: More accurate annotations for read_lock()")
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Boqun Feng 
Acked-by: Waiman Long 
Link: https://lkml.kernel.org/r/20210903084001.lblecrvz4esl4mrr@linutronix.de
Signed-off-by: Sasha Levin

locking/rwsem: Disable preemption for spinning region

2021-11-17T10:03:51+00:00

[ Upstream commit 7cdacc5f52d68a9370f182c844b5b3e6cc975cc1 ]

The spinning region rwsem_spin_on_owner() should not be preempted,
however the rwsem_down_write_slowpath() invokes it and don't disable
preemption. Fix it by adding a pair of preempt_disable/enable().

Signed-off-by: Yanfei Xu 
[peterz: Fix CONFIG_RWSEM_SPIN_ON_OWNER=n build]
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Waiman Long 
Link: https://lore.kernel.org/r/20211013134154.1085649-3-yanfei.xu@windriver.com
Signed-off-by: Sasha Levin

locking/lockdep: Avoid RCU-induced noinstr fail

2021-11-17T10:03:44+00:00

[ Upstream commit ce0b9c805dd66d5e49fd53ec5415ae398f4c56e6 ]

vmlinux.o: warning: objtool: look_up_lock_class()+0xc7: call to rcu_read_lock_any_held() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/r/20210624095148.311980536@infradead.org
Signed-off-by: Sasha Levin

locking/rtmutex: Set proper wait context for lockdep

2021-09-18T11:43:52+00:00

[ Upstream commit b41cda03765580caf7723b8c1b672d191c71013f ]

RT mutexes belong to the LD_WAIT_SLEEP class. Make them so.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/r/20210815211302.031014562@linutronix.de
Signed-off-by: Sasha Levin

locking/mutex: Fix HANDOFF condition

2021-09-15T08:02:02+00:00

[ Upstream commit 048661a1f963e9517630f080687d48af79ed784c ]

Yanfei reported that setting HANDOFF should not depend on recomputing
@first, only on @first state. Which would then give:

  if (ww_ctx || !first)
    first = __mutex_waiter_is_first(lock, &waiter);
  if (first)
    __mutex_set_flag(lock, MUTEX_FLAG_HANDOFF);

But because 'ww_ctx || !first' is basically 'always' and the test for
first is relatively cheap, omit that first branch entirely.

Reported-by: Yanfei Xu 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Waiman Long 
Reviewed-by: Yanfei Xu 
Link: https://lore.kernel.org/r/20210630154114.896786297@infradead.org
Signed-off-by: Sasha Levin

locking/rtmutex: Use the correct rtmutex debugging config option

2021-08-10T06:21:52+00:00

It's CONFIG_DEBUG_RT_MUTEXES not CONFIG_DEBUG_RT_MUTEX.

Fixes: f7efc4799f81 ("locking/rtmutex: Inline chainwalk depth check")
Signed-off-by: Zhen Lei 
Signed-off-by: Thomas Gleixner 
Acked-by: Will Deacon 
Acked-by: Boqun Feng 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210731123011.4555-1-thunder.leizhen@huawei.com

Merge tag 'locking-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-07-11T18:06:09+00:00

Pull locking fixes from Ingo Molnar:

 - Fix a Sparc crash

 - Fix a number of objtool warnings

 - Fix /proc/lockdep output on certain configs

 - Restore a kprobes fail-safe

* tag 'locking-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/atomic: sparc: Fix arch_cmpxchg64_local()
  kprobe/static_call: Restore missing static_call_text_reserved()
  static_call: Fix static_call_text_reserved() vs __init
  jump_label: Fix jump_label_text_reserved() vs __init
  locking/lockdep: Fix meaningless /proc/lockdep output of lock classes on !CONFIG_PROVE_LOCKING

locking/lockdep: Fix meaningless /proc/lockdep output of lock classes on !CONFIG_PROVE_LOCKING

2021-07-05T08:44:52+00:00

When enabling CONFIG_LOCK_STAT=y, then CONFIG_LOCKDEP=y is forcedly enabled,
but CONFIG_PROVE_LOCKING is disabled.

We can get output from /proc/lockdep, which currently includes usages of
lock classes. But the usages are meaningless, see the output below:

	/ # cat /proc/lockdep
	all lock classes:
	ffffffff9af63350 ....: cgroup_mutex

	ffffffff9af54eb8 ....: (console_sem).lock

	ffffffff9af54e60 ....: console_lock

	ffffffff9ae74c38 ....: console_owner_lock

	ffffffff9ae74c80 ....: console_owner

	ffffffff9ae66e60 ....: cpu_hotplug_lock

Only one usage context for each lock, this is because each usage is only
changed in mark_lock() that is in the CONFIG_PROVE_LOCKING=y section,
however in the test situation, it's not.

The fix is to move the usages reading and seq_print from the
!CONFIG_PROVE_LOCKING section to its defined section.

Also, locks_after list of lock_class is empty when !CONFIG_PROVE_LOCKING,
so do the same thing as what have done for usages of lock classes.

With this patch with !CONFIG_PROVE_LOCKING we can get the results below:

	/ # cat /proc/lockdep
	all lock classes:
	ffffffff85163290: cgroup_mutex
	ffffffff85154dd8: (console_sem).lock
	ffffffff85154d80: console_lock
	ffffffff85074b58: console_owner_lock
	ffffffff85074ba0: console_owner
	ffffffff85066d60: cpu_hotplug_lock

... a class key and the relevant class name each line.

Signed-off-by: Xiongwei Song 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Acked-by: Waiman Long 
Link: https://lore.kernel.org/r/20210629135916.308210-1-sxwjean@me.com

Merge branch 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

2021-07-04T19:58:33+00:00

Pull RCU updates from Paul McKenney:

 - Bitmap parsing support for "all" as an alias for all bits

 - Documentation updates

 - Miscellaneous fixes, including some that overlap into mm and lockdep

 - kvfree_rcu() updates

 - mem_dump_obj() updates, with acks from one of the slab-allocator
   maintainers

 - RCU NOCB CPU updates, including limited deoffloading

 - SRCU updates

 - Tasks-RCU updates

 - Torture-test updates

* 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (78 commits)
  tasks-rcu: Make show_rcu_tasks_gp_kthreads() be static inline
  rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states
  rcu: Add missing __releases() annotation
  rcu: Remove obsolete rcu_read_unlock() deadlock commentary
  rcu: Improve comments describing RCU read-side critical sections
  rcu: Create an unrcu_pointer() to remove __rcu from a pointer
  srcu: Early test SRCU polling start
  rcu: Fix various typos in comments
  rcu/nocb: Unify timers
  rcu/nocb: Prepare for fine-grained deferred wakeup
  rcu/nocb: Only cancel nocb timer if not polling
  rcu/nocb: Delete bypass_timer upon nocb_gp wakeup
  rcu/nocb: Cancel nocb_timer upon nocb_gp wakeup
  rcu/nocb: Allow de-offloading rdp leader
  rcu/nocb: Directly call __wake_nocb_gp() from bypass timer
  rcu: Don't penalize priority boosting when there is nothing to boost
  rcu: Point to documentation of ordering guarantees
  rcu: Make rcu_gp_cleanup() be noinline for tracing
  rcu: Restrict RCU_STRICT_GRACE_PERIOD to at most four CPUs
  rcu: Make show_rcu_gp_kthreads() dump rcu_node structures blocking GP
  ...

Merge tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-06-28T19:14:19+00:00

Pull scheduler udpates from Ingo Molnar:

- Changes to core scheduling facilities:

- Add "Core Scheduling" via CONFIG_SCHED_CORE=y, which enables
coordinated scheduling across SMT siblings. This is a much
requested feature for cloud computing platforms, to allow the
flexible utilization of SMT siblings, without exposing untrusted
domains to information leaks & side channels, plus to ensure more
deterministic computing performance on SMT systems used by
heterogenous workloads.

There are new prctls to set core scheduling groups, which allows
more flexible management of workloads that can share siblings.

- Fix task->state access anti-patterns that may result in missed
wakeups and rename it to ->__state in the process to catch new
abuses.

- Load-balancing changes:

- Tweak newidle_balance for fair-sched, to improve 'memcache'-like
workloads.

- "Age" (decay) average idle time, to better track & improve
workloads such as 'tbench'.

- Fix & improve energy-aware (EAS) balancing logic & metrics.

- Fix & improve the uclamp metrics.

- Fix task migration (taskset) corner case on !CONFIG_CPUSET.

- Fix RT and deadline utilization tracking across policy changes

- Introduce a "burstable" CFS controller via cgroups, which allows
bursty CPU-bound workloads to borrow a bit against their future
quota to improve overall latencies & batching. Can be tweaked via
/sys/fs/cgroup/cpu//cpu.cfs_burst_us.

- Rework assymetric topology/capacity detection & handling.

- Scheduler statistics & tooling:

- Disable delayacct by default, but add a sysctl to enable it at
runtime if tooling needs it. Use static keys and other
optimizations to make it more palatable.

- Use sched_clock() in delayacct, instead of ktime_get_ns().

- Misc cleanups and fixes.

* tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
sched/doc: Update the CPU capacity asymmetry bits
sched/topology: Rework CPU capacity asymmetry detection
sched/core: Introduce SD_ASYM_CPUCAPACITY_FULL sched_domain flag
psi: Fix race between psi_trigger_create/destroy
sched/fair: Introduce the burstable CFS controller
sched/uclamp: Fix uclamp_tg_restrict()
sched/rt: Fix Deadline utilization tracking during policy change
sched/rt: Fix RT utilization tracking during policy change
sched: Change task_struct::state
sched,arch: Remove unused TASK_STATE offsets
sched,timer: Use __set_current_state()
sched: Add get_current_state()
sched,perf,kvm: Fix preemption condition
sched: Introduce task_is_running()
sched: Unbreak wakeups
sched/fair: Age the average idle time
sched/cpufreq: Consider reduced CPU capacity in energy calculation
sched/fair: Take thermal pressure into account while estimating energy
thermal/cpufreq_cooling: Update offline CPUs per-cpu thermal_pressure
sched/fair: Return early from update_tg_cfs_load() if delta == 0
...