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Provide the actual locking functions which make use of the general and
spinlock specific rtmutex code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.826621464@linutronix.de
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A simplified version of the rtmutex slowlock function, which neither handles
signals nor timeouts, and is careful about preserving the state of the
blocked task across the lock operation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.770228446@linutronix.de
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Provide the necessary wrappers around the actual rtmutex based spinlock
implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.712897671@linutronix.de
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RT replaces spinlocks with a simple wrapper around an rtmutex, which turns
spinlocks on RT into 'sleeping' spinlocks. The actual implementation of the
spinlock API differs from a regular rtmutex, as it does neither handle
timeouts nor signals and it is state preserving across the lock operation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.654230709@linutronix.de
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<linux/rbtree_types.h>
We have the following header dependency problem on RT:
- <linux/rtmutex.h> needs the definition of 'struct rb_root_cached'.
- <linux/rbtree.h> includes <linux/kernel.h>, which includes <linux/spinlock.h>
That works nicely for non-RT enabled kernels, but on RT enabled kernels
spinlocks are based on rtmutexes, which creates another circular header
dependency as <linux/spinlocks.h> will require <linux/rtmutex.h>.
Include <linux/rbtree_types.h> instead.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.598003167@linutronix.de
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So we have this header dependency problem on RT:
- <linux/rtmutex.h> needs the definition of 'struct rb_root_cached'.
- <linux/rbtree.h> includes <linux/kernel.h>, which includes <linux/spinlock.h>.
That works nicely for non-RT enabled kernels, but on RT enabled kernels
spinlocks are based on rtmutexes, which creates another circular header
dependency, as <linux/spinlocks.h> will require <linux/rtmutex.h>.
Split out the type definitions and move them into their own header file so
the rtmutex header can include just those.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.542123501@linutronix.de
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The inclusion of printk.h leads to a circular dependency if spinlock_t is
based on rtmutexes on RT enabled kernels.
Include only atomic.h (xchg()) and cache.h (__read_mostly) which is all
what debug_locks.h requires.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.484161136@linutronix.de
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qlcnic_83xx_unlock_flash() is called on all paths after we call
qlcnic_83xx_lock_flash(), except for one error path on failure
of QLCRD32(), which may cause a deadlock. This bug is suggested
by a static analysis tool, please advise.
Fixes: 81d0aeb0a4fff ("qlcnic: flash template based firmware reset recovery")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Link: https://lore.kernel.org/r/20210816131405.24024-1-dinghao.liu@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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rtmutex only needs raw_spinlock_t, but it includes spinlock_types.h, which
is not a problem on an non RT enabled kernel.
RT kernels substitute regular spinlocks with 'sleeping' spinlocks, which
are based on rtmutexes, and therefore must be able to include rtmutex.h.
Include <linux/spinlock_types_raw.h> instead.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.428224188@linutronix.de
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<linux/spinlock_types_raw.h>
Move raw_spinlock into its own file. Prepare for RT 'sleeping spinlocks', to
avoid header recursion, as RT locks require rtmutex.h, which in turn requires
the raw spinlock types.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.371269088@linutronix.de
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Guard the regular sleeping lock specific functionality, which is used for
rtmutex on non-RT enabled kernels and for mutex, rtmutex and semaphores on
RT enabled kernels so the code can be reused for the RT specific
implementation of spinlocks and rwlocks in a different compilation unit.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.311535693@linutronix.de
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Add an rtlock_task pointer to rt_mutex_wake_q, which allows to handle the RT
specific wakeup for spin/rwlock waiters. The pointer is just consuming 4/8
bytes on the stack so it is provided unconditionaly to avoid #ifdeffery all
over the place.
This cannot use a regular wake_q, because a task can have concurrent wakeups which
would make it miss either lock or the regular wakeups, depending on what gets
queued first, unless task struct gains a separate wake_q_node for this, which
would be overkill, because there can only be a single task which gets woken
up in the spin/rw_lock unlock path.
No functional change for non-RT enabled kernels.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.253614678@linutronix.de
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Prepare for the required state aware handling of waiter wakeups via wake_q
and switch the rtmutex code over to the rtmutex specific wrapper.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.197113263@linutronix.de
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To handle the difference between wakeups for regular sleeping locks (mutex,
rtmutex, rw_semaphore) and the wakeups for 'sleeping' spin/rwlocks on
PREEMPT_RT enabled kernels correctly, it is required to provide a
wake_q_head construct which allows to keep them separate.
Provide a wrapper around wake_q_head and the required helpers, which will be
extended with the state handling later.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.139337655@linutronix.de
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Regular sleeping locks like mutexes, rtmutexes and rw_semaphores are always
entering and leaving a blocking section with task state == TASK_RUNNING.
On a non-RT kernel spinlocks and rwlocks never affect the task state, but
on RT kernels these locks are converted to rtmutex based 'sleeping' locks.
So in case of contention the task goes to block, which requires to carefully
preserve the task state, and restore it after acquiring the lock taking
regular wakeups for the task into account, which happened while the task was
blocked. This state preserving is achieved by having a separate task state
for blocking on a RT spin/rwlock and a saved_state field in task_struct
along with careful handling of these wakeup scenarios in try_to_wake_up().
To avoid conditionals in the rtmutex code, store the wake state which has
to be used for waking a lock waiter in rt_mutex_waiter which allows to
handle the regular and RT spin/rwlocks by handing it to wake_up_state().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.079800739@linutronix.de
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The RT specific R/W semaphore implementation used to restrict the number of
readers to one, because a writer cannot block on multiple readers and
inherit its priority or budget.
The single reader restricting was painful in various ways:
- Performance bottleneck for multi-threaded applications in the page fault
path (mmap sem)
- Progress blocker for drivers which are carefully crafted to avoid the
potential reader/writer deadlock in mainline.
The analysis of the writer code paths shows that properly written RT tasks
should not take them. Syscalls like mmap(), file access which take mmap sem
write locked have unbound latencies, which are completely unrelated to mmap
sem. Other R/W sem users like graphics drivers are not suitable for RT tasks
either.
So there is little risk to hurt RT tasks when the RT rwsem implementation is
done in the following way:
- Allow concurrent readers
- Make writers block until the last reader left the critical section. This
blocking is not subject to priority/budget inheritance.
- Readers blocked on a writer inherit their priority/budget in the normal
way.
There is a drawback with this scheme: R/W semaphores become writer unfair
though the applications which have triggered writer starvation (mostly on
mmap_sem) in the past are not really the typical workloads running on a RT
system. So while it's unlikely to hit writer starvation, it's possible. If
there are unexpected workloads on RT systems triggering it, the problem
has to be revisited.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.016885947@linutronix.de
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On PREEMPT_RT, rw_semaphores and rwlocks are substituted with an rtmutex and
a reader count. The implementation is writer unfair, as it is not feasible
to do priority inheritance on multiple readers, but experience has shown
that real-time workloads are not the typical workloads which are sensitive
to writer starvation.
The inner workings of rw_semaphores and rwlocks on RT are almost identical
except for the task state and signal handling. rw_semaphores are not state
preserving over a contention, they are expected to enter and leave with state
== TASK_RUNNING. rwlocks have a mechanism to preserve the state of the task
at entry and restore it after unblocking taking potential non-lock related
wakeups into account. rw_semaphores can also be subject to signal handling
interrupting a blocked state, while rwlocks ignore signals.
To avoid code duplication, provide a shared implementation which takes the
small difference vs. state and signals into account. The code is included
into the relevant rw_semaphore/rwlock base code and compiled for each use
case separately.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.957920571@linutronix.de
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Provide rt_mutex_base_is_locked(), which will be used for various wrapped
locking primitives for RT.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.899572818@linutronix.de
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Split the inner workings of rt_mutex_slowlock() out into a separate
function, which can be reused by the upcoming RT lock substitutions,
e.g. for rw_semaphores.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.841971086@linutronix.de
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RT builds substitutions for rwsem, mutex, spinlock and rwlock around
rtmutexes. Split the inner working out so each lock substitution can use
them with the appropriate lockdep annotations. This avoids having an extra
unused lockdep map in the wrapped rtmutex.
No functional change.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.784739994@linutronix.de
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Prepare for reusing the inner functions of rtmutex for RT lock
substitutions: introduce kernel/locking/rtmutex_api.c and move
them there.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.726560996@linutronix.de
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Allows the compiler to generate better code depending on the architecture.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.668958502@linutronix.de
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Inlines are type-safe...
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.610830960@linutronix.de
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There are no more users left.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.552218335@linutronix.de
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The only user of rt_mutex_is_locked() is an anti-pattern, remove it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.491442626@linutronix.de
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The RT specific spin/rwlock implementation requires special handling of the
to be woken waiters. Provide a WAKE_Q_HEAD_INITIALIZER(), which can be used by
the rtmutex code to implement an RT aware wake_q derivative.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.429918071@linutronix.de
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RT enabled kernels substitute spin/rwlocks with 'sleeping' variants based
on rtmutexes. Blocking on such a lock is similar to preemption versus:
- I/O scheduling and worker handling, because these functions might block
on another substituted lock, or come from a lock contention within these
functions.
- RCU considers this like a preemption, because the task might be in a read
side critical section.
Add a separate scheduling point for this, and hand a new scheduling mode
argument to __schedule() which allows, along with separate mode masks, to
handle this gracefully from within the scheduler, without proliferating that
to other subsystems like RCU.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.372319055@linutronix.de
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PREEMPT_RT needs to hand a special state into __schedule() when a task
blocks on a 'sleeping' spin/rwlock. This is required to handle
rcu_note_context_switch() correctly without having special casing in the
RCU code. From an RCU point of view the blocking on the sleeping spinlock
is equivalent to preemption, because the task might be in a read side
critical section.
schedule_debug() also has a check which would trigger with the !preempt
case, but that could be handled differently.
To avoid adding another argument and extra checks which cannot be optimized
out by the compiler, the following solution has been chosen:
- Replace the boolean 'preempt' argument with an unsigned integer
'sched_mode' argument and define constants to hand in:
(0 == no preemption, 1 = preemption).
- Add two masks to apply on that mode: one for the debug/rcu invocations,
and one for the actual scheduling decision.
For a non RT kernel these masks are UINT_MAX, i.e. all bits are set,
which allows the compiler to optimize the AND operation out, because it is
not masking out anything. IOW, it's not different from the boolean.
RT enabled kernels will define these masks separately.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.315473019@linutronix.de
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Waiting for spinlocks and rwlocks on non RT enabled kernels is task::state
preserving. Any wakeup which matches the state is valid.
RT enabled kernels substitutes them with 'sleeping' spinlocks. This creates
an issue vs. task::__state.
In order to block on the lock, the task has to overwrite task::__state and a
consecutive wakeup issued by the unlocker sets the state back to
TASK_RUNNING. As a consequence the task loses the state which was set
before the lock acquire and also any regular wakeup targeted at the task
while it is blocked on the lock.
To handle this gracefully, add a 'saved_state' member to task_struct which
is used in the following way:
1) When a task blocks on a 'sleeping' spinlock, the current state is saved
in task::saved_state before it is set to TASK_RTLOCK_WAIT.
2) When the task unblocks and after acquiring the lock, it restores the saved
state.
3) When a regular wakeup happens for a task while it is blocked then the
state change of that wakeup is redirected to operate on task::saved_state.
This is also required when the task state is running because the task
might have been woken up from the lock wait and has not yet restored
the saved state.
To make it complete, provide the necessary helpers to save and restore the
saved state along with the necessary documentation how the RT lock blocking
is supposed to work.
For non-RT kernels there is no functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.258751046@linutronix.de
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In order to avoid more duplicate implementations for the debug and
non-debug variants of the state change macros, split the debug portion out
and make that conditional on CONFIG_DEBUG_ATOMIC_SLEEP=y.
Suggested-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.200898048@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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RT kernels have an extra quirk for try_to_wake_up() to handle task state
preservation across periods of blocking on a 'sleeping' spin/rwlock.
For this to function correctly and under all circumstances try_to_wake_up()
must be able to identify whether the wakeup is lock related or not and
whether the task is waiting for a lock or not.
The original approach was to use a special wake_flag argument for
try_to_wake_up() and just use TASK_UNINTERRUPTIBLE for the tasks wait state
and the try_to_wake_up() state argument.
This works in principle, but due to the fact that try_to_wake_up() cannot
determine whether the task is waiting for an RT lock wakeup or for a regular
wakeup it's suboptimal.
RT kernels save the original task state when blocking on an RT lock and
restore it when the lock has been acquired. Any non lock related wakeup is
checked against the saved state and if it matches the saved state is set to
running so that the wakeup is not lost when the state is restored.
While the necessary logic for the wake_flag based solution is trivial, the
downside is that any regular wakeup with TASK_UNINTERRUPTIBLE in the state
argument set will wake the task despite the fact that it is still blocked
on the lock. That's not a fatal problem as the lock wait has do deal with
spurious wakeups anyway, but it introduces unnecessary latencies.
Introduce the TASK_RTLOCK_WAIT state bit which will be set when a task
blocks on an RT lock.
The lock wakeup will use wake_up_state(TASK_RTLOCK_WAIT), so both the
waiting state and the wakeup state are distinguishable, which avoids
spurious wakeups and allows better analysis.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.144989915@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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RT kernels have a slightly more complicated handling of wakeups due to
'sleeping' spin/rwlocks. If a task is blocked on such a lock then the
original state of the task is preserved over the blocking period, and
any regular (non lock related) wakeup has to be targeted at the
saved state to ensure that these wakeups are not lost.
Once the task acquires the lock it restores the task state from the saved state.
To avoid cluttering try_to_wake_up() with that logic, split the wakeup
state check out into an inline helper and use it at both places where
task::__state is checked against the state argument of try_to_wake_up().
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.088945085@linutronix.de
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RT mutexes belong to the LD_WAIT_SLEEP class. Make them so.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.031014562@linutronix.de
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If CONFIG_DEBUG_LOCK_ALLOC=y is enabled then local_lock_t has an 'owner'
member which is checked for consistency, but nothing initialized it to
zero explicitly.
The static initializer does so implicit, and the run time allocated per CPU
storage is usually zero initialized as well, but relying on that is not
really good practice.
Fixes: 91710728d172 ("locking: Introduce local_lock()")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211301.969975279@linutronix.de
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For fixing use-after-free during iterating over requests, we grabbed
request's refcount before calling ->fn in commit 2e315dc07df0 ("blk-mq:
grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter").
Turns out this way may cause kernel panic when iterating over one flush
request:
1) old flush request's tag is just released, and this tag is reused by
one new request, but ->rqs[] isn't updated yet
2) the flush request can be re-used for submitting one new flush command,
so blk_rq_init() is called at the same time
3) meantime blk_mq_queue_tag_busy_iter() is called, and old flush request
is retrieved from ->rqs[tag]; when blk_mq_put_rq_ref() is called,
flush_rq->end_io may not be updated yet, so NULL pointer dereference
is triggered in blk_mq_put_rq_ref().
Fix the issue by calling refcount_set(&flush_rq->ref, 1) after
flush_rq->end_io is set. So far the only other caller of blk_rq_init() is
scsi_ioctl_reset() in which the request doesn't enter block IO stack and
the request reference count isn't used, so the change is safe.
Fixes: 2e315dc07df0 ("blk-mq: grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter")
Reported-by: "Blank-Burian, Markus, Dr." <blankburian@uni-muenster.de>
Tested-by: "Blank-Burian, Markus, Dr." <blankburian@uni-muenster.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20210811142624.618598-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Inside blk_mq_queue_tag_busy_iter() we already grabbed request's
refcount before calling ->fn(), so needn't to grab it one more time
in blk_mq_check_expired().
Meantime remove extra request expire check in blk_mq_check_expired().
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20210811155202.629575-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Ilan's change to move locking around accidentally lost the
wiphy_lock() during some porting, add it back.
Fixes: 45daaa131841 ("mac80211: Properly WARN on HW scan before restart")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20210817121210.47bdb177064f.Ib1ef79440cd27f318c028ddfc0c642406917f512@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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There's no need to print a message on every change in battery percentage
on regular log levels.
Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Prepared by checking the datasheets of max17042, max17047/50
and max170455 for differences in register maps.
Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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This register is same as in MAX17047 and MAX17050, so there's no need
for custom casing it.
Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Add the rockchip serial flash controller (SFC) driver.
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Signed-off-by: Jon Lin <jon.lin@rock-chips.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Chris Morgan <macromorgan@hotmail.com>
Link: https://lore.kernel.org/r/20210812134546.31340-3-jon.lin@rock-chips.com
Signed-off-by: Mark Brown <broonie@kernel.org>
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Add bindings for the Rockchip serial flash controller. New device
specific parameter of rockchip,sfc-no-dma included in documentation.
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Signed-off-by: Jon Lin <jon.lin@rock-chips.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Link: https://lore.kernel.org/r/20210812134546.31340-2-jon.lin@rock-chips.com
Signed-off-by: Mark Brown <broonie@kernel.org>
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Commit a02e8964eaf92 ("virtio-net: ethtool configurable LRO")
maps LRO to virtio guest offloading features and allows the
administrator to enable and disable those features via ethtool.
This leads to several issues:
- For a device that doesn't support control guest offloads, the "LRO"
can't be disabled triggering WARN in dev_disable_lro() when turning
off LRO or when enabling forwarding bridging etc.
- For a device that supports control guest offloads, the guest
offloads are disabled in cases of bridging, forwarding etc slowing
down the traffic.
Fix this by using NETIF_F_GRO_HW instead. Though the spec does not
guarantee packets to be re-segmented as the original ones,
we can add that to the spec, possibly with a flag for devices to
differentiate between GRO and LRO.
Further, we never advertised LRO historically before a02e8964eaf92
("virtio-net: ethtool configurable LRO") and so bridged/forwarded
configs effectively always relied on virtio receive offloads behaving
like GRO - thus even if this breaks any configs it is at least not
a regression.
Fixes: a02e8964eaf92 ("virtio-net: ethtool configurable LRO")
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reported-by: Ivan <ivan@prestigetransportation.com>
Tested-by: Ivan <ivan@prestigetransportation.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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ASUS B23E requires the same workaround like other machines with
VT1802, otherwise it looses the codec power on a few nodes and the
sound kept silence.
Fixes: a0645daf1610 ("ALSA: HDA: Early Forbid of runtime PM")
Link: https://lore.kernel.org/r/ac2232f142efcd67fe6ac38897f704f7176bd200.camel@gmail.com
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210817052432.14751-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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During system shutdown codecs may be still active, and resetting the
controller->codec HW link in this state - based on the bug reporter's
tests - leads to the shutdown sequence to get stuck. This happens at
least on the reporter's KBL system with an ALC662 codec.
For now fix the issue by skipping the link reset step.
Fixes: 472e18f63c42 ("ALSA: hda: Release controller display power during shutdown/reboot")
References: https://bugzilla.kernel.org/show_bug.cgi?id=214045
References: https://gitlab.freedesktop.org/drm/intel/-/issues/3618#note_1024665
Reported-and-tested-by: youling257@gmail.com
Cc: youling257@gmail.com
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://lore.kernel.org/r/20210816174259.2759103-1-imre.deak@intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fix from Herbert Xu:
"This contains a fix for a potential boot failure due to a missing
Kconfig dependency for people upgrading with the DRBG enabled"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: drbg - select SHA512
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To fix the "reverse-NAT" for replies.
When a packet is sent over a VRF, the POST_ROUTING hooks are called
twice: Once from the VRF interface, and once from the "actual"
interface the packet will be sent from:
1) First SNAT: l3mdev_l3_out() -> vrf_l3_out() -> .. -> vrf_output_direct()
This causes the POST_ROUTING hooks to run.
2) Second SNAT: 'ip_output()' calls POST_ROUTING hooks again.
Similarly for replies, first ip_rcv() calls PRE_ROUTING hooks, and
second vrf_l3_rcv() calls them again.
As an example, consider the following SNAT rule:
> iptables -t nat -A POSTROUTING -p udp -m udp --dport 53 -j SNAT --to-source 2.2.2.2 -o vrf_1
In this case sending over a VRF will create 2 conntrack entries.
The first is from the VRF interface, which performs the IP SNAT.
The second will run the SNAT, but since the "expected reply" will remain
the same, conntrack randomizes the source port of the packet:
e..g With a socket bound to 1.1.1.1:10000, sending to 3.3.3.3:53, the conntrack
rules are:
udp 17 29 src=2.2.2.2 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 [UNREPLIED] src=3.3.3.3 dst=2.2.2.2 sport=53 dport=61033 packets=0 bytes=0 mark=0 use=1
udp 17 29 src=1.1.1.1 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 [UNREPLIED] src=3.3.3.3 dst=2.2.2.2 sport=53 dport=10000 packets=0 bytes=0 mark=0 use=1
i.e. First SNAT IP from 1.1.1.1 --> 2.2.2.2, and second the src port is
SNAT-ed from 10000 --> 61033.
But when a reply is sent (3.3.3.3:53 -> 2.2.2.2:61033) only the later
conntrack entry is matched:
udp 17 29 src=2.2.2.2 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 src=3.3.3.3 dst=2.2.2.2 sport=53 dport=61033 packets=1 bytes=49 mark=0 use=1
udp 17 28 src=1.1.1.1 dst=3.3.3.3 sport=10000 dport=53 packets=1 bytes=68 [UNREPLIED] src=3.3.3.3 dst=2.2.2.2 sport=53 dport=10000 packets=0 bytes=0 mark=0 use=1
And a "port 61033 unreachable" ICMP packet is sent back.
The issue is that when PRE_ROUTING hooks are called from vrf_l3_rcv(),
the skb already has a conntrack flow attached to it, which means
nf_conntrack_in() will not resolve the flow again.
This means only the dest port is "reverse-NATed" (61033 -> 10000) but
the dest IP remains 2.2.2.2, and since the socket is bound to 1.1.1.1 it's
not received.
This can be verified by logging the 4-tuple of the packet in '__udp4_lib_rcv()'.
The fix is then to reset the flow when skb is received on a VRF, to let
conntrack resolve the flow again (which now will hit the earlier flow).
To reproduce: (Without the fix "Got pkt_to_nat_port" will not be printed by
running 'bash ./repro'):
$ cat run_in_A1.py
import logging
logging.getLogger("scapy.runtime").setLevel(logging.ERROR)
from scapy.all import *
import argparse
def get_packet_to_send(udp_dst_port, msg_name):
return Ether(src='11:22:33:44:55:66', dst=iface_mac)/ \
IP(src='3.3.3.3', dst='2.2.2.2')/ \
UDP(sport=53, dport=udp_dst_port)/ \
Raw(f'{msg_name}\x0012345678901234567890')
parser = argparse.ArgumentParser()
parser.add_argument('-iface_mac', dest="iface_mac", type=str, required=True,
help="From run_in_A3.py")
parser.add_argument('-socket_port', dest="socket_port", type=str,
required=True, help="From run_in_A3.py")
parser.add_argument('-v1_mac', dest="v1_mac", type=str, required=True,
help="From script")
args, _ = parser.parse_known_args()
iface_mac = args.iface_mac
socket_port = int(args.socket_port)
v1_mac = args.v1_mac
print(f'Source port before NAT: {socket_port}')
while True:
pkts = sniff(iface='_v0', store=True, count=1, timeout=10)
if 0 == len(pkts):
print('Something failed, rerun the script :(', flush=True)
break
pkt = pkts[0]
if not pkt.haslayer('UDP'):
continue
pkt_sport = pkt.getlayer('UDP').sport
print(f'Source port after NAT: {pkt_sport}', flush=True)
pkt_to_send = get_packet_to_send(pkt_sport, 'pkt_to_nat_port')
sendp(pkt_to_send, '_v0', verbose=False) # Will not be received
pkt_to_send = get_packet_to_send(socket_port, 'pkt_to_socket_port')
sendp(pkt_to_send, '_v0', verbose=False)
break
$ cat run_in_A2.py
import socket
import netifaces
print(f"{netifaces.ifaddresses('e00000')[netifaces.AF_LINK][0]['addr']}",
flush=True)
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_BINDTODEVICE,
str('vrf_1' + '\0').encode('utf-8'))
s.connect(('3.3.3.3', 53))
print(f'{s. getsockname()[1]}', flush=True)
s.settimeout(5)
while True:
try:
# Periodically send in order to keep the conntrack entry alive.
s.send(b'a'*40)
resp = s.recvfrom(1024)
msg_name = resp[0].decode('utf-8').split('\0')[0]
print(f"Got {msg_name}", flush=True)
except Exception as e:
pass
$ cat repro.sh
ip netns del A1 2> /dev/null
ip netns del A2 2> /dev/null
ip netns add A1
ip netns add A2
ip -n A1 link add _v0 type veth peer name _v1 netns A2
ip -n A1 link set _v0 up
ip -n A2 link add e00000 type bond
ip -n A2 link add lo0 type dummy
ip -n A2 link add vrf_1 type vrf table 10001
ip -n A2 link set vrf_1 up
ip -n A2 link set e00000 master vrf_1
ip -n A2 addr add 1.1.1.1/24 dev e00000
ip -n A2 link set e00000 up
ip -n A2 link set _v1 master e00000
ip -n A2 link set _v1 up
ip -n A2 link set lo0 up
ip -n A2 addr add 2.2.2.2/32 dev lo0
ip -n A2 neigh add 1.1.1.10 lladdr 77:77:77:77:77:77 dev e00000
ip -n A2 route add 3.3.3.3/32 via 1.1.1.10 dev e00000 table 10001
ip netns exec A2 iptables -t nat -A POSTROUTING -p udp -m udp --dport 53 -j \
SNAT --to-source 2.2.2.2 -o vrf_1
sleep 5
ip netns exec A2 python3 run_in_A2.py > x &
XPID=$!
sleep 5
IFACE_MAC=`sed -n 1p x`
SOCKET_PORT=`sed -n 2p x`
V1_MAC=`ip -n A2 link show _v1 | sed -n 2p | awk '{print $2'}`
ip netns exec A1 python3 run_in_A1.py -iface_mac ${IFACE_MAC} -socket_port \
${SOCKET_PORT} -v1_mac ${SOCKET_PORT}
sleep 5
kill -9 $XPID
wait $XPID 2> /dev/null
ip netns del A1
ip netns del A2
tail x -n 2
rm x
set +x
Fixes: 73e20b761acf ("net: vrf: Add support for PREROUTING rules on vrf device")
Signed-off-by: Lahav Schlesinger <lschlesinger@drivenets.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20210815120002.2787653-1-lschlesinger@drivenets.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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With the patch to separate the gpio driver from the pinctrl driver, now
the pinctrl-rockchip can drop the gpio related codes now.
Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
Link: https://lore.kernel.org/r/20210816012146.1119289-1-jay.xu@rock-chips.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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