<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel/locking/rtmutex_api.c, branch v6.12.95</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>locking/rtmutex: Skip remove_waiter() when waiter is not enqueued</title>
<updated>2026-07-04T11:43:26+00:00</updated>
<author>
<name>Davidlohr Bueso</name>
<email>dave@stgolabs.net</email>
</author>
<published>2026-06-16T19:06:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5799f9bd7fee40370b93ab1ddf001cdc7017c14d'/>
<id>5799f9bd7fee40370b93ab1ddf001cdc7017c14d</id>
<content type='text'>
[ Upstream commit 40a25d59e85b3c8709ac2424d44f65610467871e ]

syzbot triggered the following splat in remove_waiter() via
FUTEX_CMP_REQUEUE_PI:

  KASAN: null-ptr-deref in range [0x0000000000000a88-0x0000000000000a8f]
   class_raw_spinlock_constructor
   remove_waiter+0x159/0x1200 kernel/locking/rtmutex.c:1561
   rt_mutex_start_proxy_lock+0x103/0x120
   futex_requeue+0x10e4/0x20d0
   __x64_sys_futex+0x34f/0x4d0

task_blocks_on_rt_mutex() does not arm the waiter upon deadlock detection,
leaving waiter-&gt;task nil, where 3bfdc63936dd ("rtmutex: Use waiter::task instead
of current in remove_waiter()") made this fatal.

Furthermore, rt_mutex_start_proxy_lock() should not be calling into remove_waiter()
upon a successfully grabbing the rtmutex. 1a1fb985f2e2 ("futex: Handle early deadlock
return correctly"), moved the remove_waiter() out of __rt_mutex_start_proxy_lock()
(where 'ret' was only ever 0 or &lt; 0) into the wrapper. Tighten this check to
account for try_to_take_rt_mutex().

Fixes: 3bfdc63936dd ("rtmutex: Use waiter::task instead of current in remove_waiter()")
Reported-by: syzbot+78147abe6c524f183ee9@syzkaller.appspotmail.com
Signed-off-by: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@kernel.org&gt;
Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/all/69f114ac.050a0220.ac8b.0003.GAE@google.com/
Link: https://patch.msgid.link/20260507112913.1019537-1-dave@stgolabs.net
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 40a25d59e85b3c8709ac2424d44f65610467871e ]

syzbot triggered the following splat in remove_waiter() via
FUTEX_CMP_REQUEUE_PI:

  KASAN: null-ptr-deref in range [0x0000000000000a88-0x0000000000000a8f]
   class_raw_spinlock_constructor
   remove_waiter+0x159/0x1200 kernel/locking/rtmutex.c:1561
   rt_mutex_start_proxy_lock+0x103/0x120
   futex_requeue+0x10e4/0x20d0
   __x64_sys_futex+0x34f/0x4d0

task_blocks_on_rt_mutex() does not arm the waiter upon deadlock detection,
leaving waiter-&gt;task nil, where 3bfdc63936dd ("rtmutex: Use waiter::task instead
of current in remove_waiter()") made this fatal.

Furthermore, rt_mutex_start_proxy_lock() should not be calling into remove_waiter()
upon a successfully grabbing the rtmutex. 1a1fb985f2e2 ("futex: Handle early deadlock
return correctly"), moved the remove_waiter() out of __rt_mutex_start_proxy_lock()
(where 'ret' was only ever 0 or &lt; 0) into the wrapper. Tighten this check to
account for try_to_take_rt_mutex().

Fixes: 3bfdc63936dd ("rtmutex: Use waiter::task instead of current in remove_waiter()")
Reported-by: syzbot+78147abe6c524f183ee9@syzkaller.appspotmail.com
Signed-off-by: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@kernel.org&gt;
Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/all/69f114ac.050a0220.ac8b.0003.GAE@google.com/
Link: https://patch.msgid.link/20260507112913.1019537-1-dave@stgolabs.net
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/mutex: Remove wakeups from under mutex::wait_lock</title>
<updated>2026-07-04T11:43:26+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2026-06-16T19:06:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=35bdb300ca7a09ea24410d47cced0295d35ba505'/>
<id>35bdb300ca7a09ea24410d47cced0295d35ba505</id>
<content type='text'>
[ Upstream commit 894d1b3db41cf7e6ae0304429a1747b3c3f390bc ]

In preparation to nest mutex::wait_lock under rq::lock we need
to remove wakeups from under it.

Do this by utilizing wake_qs to defer the wakeup until after the
lock is dropped.

[Heavily changed after 55f036ca7e74 ("locking: WW mutex cleanup") and
08295b3b5bee ("locking: Implement an algorithm choice for Wound-Wait
mutexes")]
[jstultz: rebased to mainline, added extra wake_up_q &amp; init
 to avoid hangs, similar to Connor's rework of this patch]

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Juri Lelli &lt;juri.lelli@redhat.com&gt;
Signed-off-by: John Stultz &lt;jstultz@google.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Metin Kaya &lt;metin.kaya@arm.com&gt;
Acked-by: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Tested-by: K Prateek Nayak &lt;kprateek.nayak@amd.com&gt;
Tested-by: Metin Kaya &lt;metin.kaya@arm.com&gt;
Link: https://lore.kernel.org/r/20241009235352.1614323-2-jstultz@google.com
Stable-dep-of: 40a25d59e85b ("locking/rtmutex: Skip remove_waiter() when waiter is not enqueued")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 894d1b3db41cf7e6ae0304429a1747b3c3f390bc ]

In preparation to nest mutex::wait_lock under rq::lock we need
to remove wakeups from under it.

Do this by utilizing wake_qs to defer the wakeup until after the
lock is dropped.

[Heavily changed after 55f036ca7e74 ("locking: WW mutex cleanup") and
08295b3b5bee ("locking: Implement an algorithm choice for Wound-Wait
mutexes")]
[jstultz: rebased to mainline, added extra wake_up_q &amp; init
 to avoid hangs, similar to Connor's rework of this patch]

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Juri Lelli &lt;juri.lelli@redhat.com&gt;
Signed-off-by: John Stultz &lt;jstultz@google.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Metin Kaya &lt;metin.kaya@arm.com&gt;
Acked-by: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Tested-by: K Prateek Nayak &lt;kprateek.nayak@amd.com&gt;
Tested-by: Metin Kaya &lt;metin.kaya@arm.com&gt;
Link: https://lore.kernel.org/r/20241009235352.1614323-2-jstultz@google.com
Stable-dep-of: 40a25d59e85b ("locking/rtmutex: Skip remove_waiter() when waiter is not enqueued")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/rtmutex: Fix task-&gt;pi_waiters integrity</title>
<updated>2023-07-17T11:59:10+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-07-07T14:19:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f7853c34241807bb97673a5e97719123be39a09e'/>
<id>f7853c34241807bb97673a5e97719123be39a09e</id>
<content type='text'>
Henry reported that rt_mutex_adjust_prio_check() has an ordering
problem and puts the lie to the comment in [7]. Sharing the sort key
between lock-&gt;waiters and owner-&gt;pi_waiters *does* create problems,
since unlike what the comment claims, holding [L] is insufficient.

Notably, consider:

	A
      /   \
     M1   M2
     |     |
     B     C

That is, task A owns both M1 and M2, B and C block on them. In this
case a concurrent chain walk (B &amp; C) will modify their resp. sort keys
in [7] while holding M1-&gt;wait_lock and M2-&gt;wait_lock. So holding [L]
is meaningless, they're different Ls.

This then gives rise to a race condition between [7] and [11], where
the requeue of pi_waiters will observe an inconsistent tree order.

	B				C

  (holds M1-&gt;wait_lock,		(holds M2-&gt;wait_lock,
   holds B-&gt;pi_lock)		 holds A-&gt;pi_lock)

  [7]
  waiter_update_prio();
  ...
  [8]
  raw_spin_unlock(B-&gt;pi_lock);
  ...
  [10]
  raw_spin_lock(A-&gt;pi_lock);

				[11]
				rt_mutex_enqueue_pi();
				// observes inconsistent A-&gt;pi_waiters
				// tree order

Fixing this means either extending the range of the owner lock from
[10-13] to [6-13], with the immediate problem that this means [6-8]
hold both blocked and owner locks, or duplicating the sort key.

Since the locking in chain walk is horrible enough without having to
consider pi_lock nesting rules, duplicate the sort key instead.

By giving each tree their own sort key, the above race becomes
harmless, if C sees B at the old location, then B will correct things
(if they need correcting) when it walks up the chain and reaches A.

Fixes: fb00aca47440 ("rtmutex: Turn the plist into an rb-tree")
Reported-by: Henry Wu &lt;triangletrap12@gmail.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Henry Wu &lt;triangletrap12@gmail.com&gt;
Link: https://lkml.kernel.org/r/20230707161052.GF2883469%40hirez.programming.kicks-ass.net
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Henry reported that rt_mutex_adjust_prio_check() has an ordering
problem and puts the lie to the comment in [7]. Sharing the sort key
between lock-&gt;waiters and owner-&gt;pi_waiters *does* create problems,
since unlike what the comment claims, holding [L] is insufficient.

Notably, consider:

	A
      /   \
     M1   M2
     |     |
     B     C

That is, task A owns both M1 and M2, B and C block on them. In this
case a concurrent chain walk (B &amp; C) will modify their resp. sort keys
in [7] while holding M1-&gt;wait_lock and M2-&gt;wait_lock. So holding [L]
is meaningless, they're different Ls.

This then gives rise to a race condition between [7] and [11], where
the requeue of pi_waiters will observe an inconsistent tree order.

	B				C

  (holds M1-&gt;wait_lock,		(holds M2-&gt;wait_lock,
   holds B-&gt;pi_lock)		 holds A-&gt;pi_lock)

  [7]
  waiter_update_prio();
  ...
  [8]
  raw_spin_unlock(B-&gt;pi_lock);
  ...
  [10]
  raw_spin_lock(A-&gt;pi_lock);

				[11]
				rt_mutex_enqueue_pi();
				// observes inconsistent A-&gt;pi_waiters
				// tree order

Fixing this means either extending the range of the owner lock from
[10-13] to [6-13], with the immediate problem that this means [6-8]
hold both blocked and owner locks, or duplicating the sort key.

Since the locking in chain walk is horrible enough without having to
consider pi_lock nesting rules, duplicate the sort key instead.

By giving each tree their own sort key, the above race becomes
harmless, if C sees B at the old location, then B will correct things
(if they need correcting) when it walks up the chain and reaches A.

Fixes: fb00aca47440 ("rtmutex: Turn the plist into an rb-tree")
Reported-by: Henry Wu &lt;triangletrap12@gmail.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Henry Wu &lt;triangletrap12@gmail.com&gt;
Link: https://lkml.kernel.org/r/20230707161052.GF2883469%40hirez.programming.kicks-ass.net
</pre>
</div>
</content>
</entry>
<entry>
<title>rtmutex: Add acquire semantics for rtmutex lock acquisition slow path</title>
<updated>2022-12-12T18:55:56+00:00</updated>
<author>
<name>Mel Gorman</name>
<email>mgorman@techsingularity.net</email>
</author>
<published>2022-12-02T10:02:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1c0908d8e441631f5b8ba433523cf39339ee2ba0'/>
<id>1c0908d8e441631f5b8ba433523cf39339ee2ba0</id>
<content type='text'>
Jan Kara reported the following bug triggering on 6.0.5-rt14 running dbench
on XFS on arm64.

 kernel BUG at fs/inode.c:625!
 Internal error: Oops - BUG: 0 [#1] PREEMPT_RT SMP
 CPU: 11 PID: 6611 Comm: dbench Tainted: G            E   6.0.0-rt14-rt+ #1
 pc : clear_inode+0xa0/0xc0
 lr : clear_inode+0x38/0xc0
 Call trace:
  clear_inode+0xa0/0xc0
  evict+0x160/0x180
  iput+0x154/0x240
  do_unlinkat+0x184/0x300
  __arm64_sys_unlinkat+0x48/0xc0
  el0_svc_common.constprop.4+0xe4/0x2c0
  do_el0_svc+0xac/0x100
  el0_svc+0x78/0x200
  el0t_64_sync_handler+0x9c/0xc0
  el0t_64_sync+0x19c/0x1a0

It also affects 6.1-rc7-rt5 and affects a preempt-rt fork of 5.14 so this
is likely a bug that existed forever and only became visible when ARM
support was added to preempt-rt. The same problem does not occur on x86-64
and he also reported that converting sb-&gt;s_inode_wblist_lock to
raw_spinlock_t makes the problem disappear indicating that the RT spinlock
variant is the problem.

Which in turn means that RT mutexes on ARM64 and any other weakly ordered
architecture are affected by this independent of RT.

Will Deacon observed:

  "I'd be more inclined to be suspicious of the slowpath tbh, as we need to
   make sure that we have acquire semantics on all paths where the lock can
   be taken. Looking at the rtmutex code, this really isn't obvious to me
   -- for example, try_to_take_rt_mutex() appears to be able to return via
   the 'takeit' label without acquire semantics and it looks like we might
   be relying on the caller's subsequent _unlock_ of the wait_lock for
   ordering, but that will give us release semantics which aren't correct."

Sebastian Andrzej Siewior prototyped a fix that does work based on that
comment but it was a little bit overkill and added some fences that should
not be necessary.

The lock owner is updated with an IRQ-safe raw spinlock held, but the
spin_unlock does not provide acquire semantics which are needed when
acquiring a mutex.

Adds the necessary acquire semantics for lock owner updates in the slow path
acquisition and the waiter bit logic.

It successfully completed 10 iterations of the dbench workload while the
vanilla kernel fails on the first iteration.

[ bigeasy@linutronix.de: Initial prototype fix ]

Fixes: 700318d1d7b38 ("locking/rtmutex: Use acquire/release semantics")
Fixes: 23f78d4a03c5 ("[PATCH] pi-futex: rt mutex core")
Reported-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221202100223.6mevpbl7i6x5udfd@techsingularity.net
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Jan Kara reported the following bug triggering on 6.0.5-rt14 running dbench
on XFS on arm64.

 kernel BUG at fs/inode.c:625!
 Internal error: Oops - BUG: 0 [#1] PREEMPT_RT SMP
 CPU: 11 PID: 6611 Comm: dbench Tainted: G            E   6.0.0-rt14-rt+ #1
 pc : clear_inode+0xa0/0xc0
 lr : clear_inode+0x38/0xc0
 Call trace:
  clear_inode+0xa0/0xc0
  evict+0x160/0x180
  iput+0x154/0x240
  do_unlinkat+0x184/0x300
  __arm64_sys_unlinkat+0x48/0xc0
  el0_svc_common.constprop.4+0xe4/0x2c0
  do_el0_svc+0xac/0x100
  el0_svc+0x78/0x200
  el0t_64_sync_handler+0x9c/0xc0
  el0t_64_sync+0x19c/0x1a0

It also affects 6.1-rc7-rt5 and affects a preempt-rt fork of 5.14 so this
is likely a bug that existed forever and only became visible when ARM
support was added to preempt-rt. The same problem does not occur on x86-64
and he also reported that converting sb-&gt;s_inode_wblist_lock to
raw_spinlock_t makes the problem disappear indicating that the RT spinlock
variant is the problem.

Which in turn means that RT mutexes on ARM64 and any other weakly ordered
architecture are affected by this independent of RT.

Will Deacon observed:

  "I'd be more inclined to be suspicious of the slowpath tbh, as we need to
   make sure that we have acquire semantics on all paths where the lock can
   be taken. Looking at the rtmutex code, this really isn't obvious to me
   -- for example, try_to_take_rt_mutex() appears to be able to return via
   the 'takeit' label without acquire semantics and it looks like we might
   be relying on the caller's subsequent _unlock_ of the wait_lock for
   ordering, but that will give us release semantics which aren't correct."

Sebastian Andrzej Siewior prototyped a fix that does work based on that
comment but it was a little bit overkill and added some fences that should
not be necessary.

The lock owner is updated with an IRQ-safe raw spinlock held, but the
spin_unlock does not provide acquire semantics which are needed when
acquiring a mutex.

Adds the necessary acquire semantics for lock owner updates in the slow path
acquisition and the waiter bit logic.

It successfully completed 10 iterations of the dbench workload while the
vanilla kernel fails on the first iteration.

[ bigeasy@linutronix.de: Initial prototype fix ]

Fixes: 700318d1d7b38 ("locking/rtmutex: Use acquire/release semantics")
Fixes: 23f78d4a03c5 ("[PATCH] pi-futex: rt mutex core")
Reported-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221202100223.6mevpbl7i6x5udfd@techsingularity.net
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/rtmutex: Add rt_mutex_lock_nest_lock() and rt_mutex_lock_killable().</title>
<updated>2021-12-04T09:56:23+00:00</updated>
<author>
<name>Sebastian Andrzej Siewior</name>
<email>bigeasy@linutronix.de</email>
</author>
<published>2021-11-29T17:46:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a3642021923b26d86bb27d88c826494827612c06'/>
<id>a3642021923b26d86bb27d88c826494827612c06</id>
<content type='text'>
The locking selftest for ww-mutex expects to operate directly on the
base-mutex which becomes a rtmutex on PREEMPT_RT.

Add a rtmutex based implementation of mutex_lock_nest_lock() and
mutex_lock_killable() named rt_mutex_lock_nest_lock() abd
rt_mutex_lock_killable().

Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20211129174654.668506-5-bigeasy@linutronix.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The locking selftest for ww-mutex expects to operate directly on the
base-mutex which becomes a rtmutex on PREEMPT_RT.

Add a rtmutex based implementation of mutex_lock_nest_lock() and
mutex_lock_killable() named rt_mutex_lock_nest_lock() abd
rt_mutex_lock_killable().

Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20211129174654.668506-5-bigeasy@linutronix.de
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/rtmutex: Prevent lockdep false positive with PI futexes</title>
<updated>2021-08-17T17:06:02+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2021-08-15T21:29:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=51711e825a6d1b2fe7ca46bb06d08c25d97656ee'/>
<id>51711e825a6d1b2fe7ca46bb06d08c25d97656ee</id>
<content type='text'>
On PREEMPT_RT the futex hashbucket spinlock becomes 'sleeping' and rtmutex
based. That causes a lockdep false positive because some of the futex
functions invoke spin_unlock(&amp;hb-&gt;lock) with the wait_lock of the rtmutex
associated to the pi_futex held.  spin_unlock() in turn takes wait_lock of
the rtmutex on which the spinlock is based which makes lockdep notice a
lock recursion.

Give the futex/rtmutex wait_lock a separate key.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210815211305.750701219@linutronix.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On PREEMPT_RT the futex hashbucket spinlock becomes 'sleeping' and rtmutex
based. That causes a lockdep false positive because some of the futex
functions invoke spin_unlock(&amp;hb-&gt;lock) with the wait_lock of the rtmutex
associated to the pi_futex held.  spin_unlock() in turn takes wait_lock of
the rtmutex on which the spinlock is based which makes lockdep notice a
lock recursion.

Give the futex/rtmutex wait_lock a separate key.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210815211305.750701219@linutronix.de
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/rtmutex: Add mutex variant for RT</title>
<updated>2021-08-17T17:05:29+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2021-08-15T21:29:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bb630f9f7a7d43869e4e7f5e4c002207396aea59'/>
<id>bb630f9f7a7d43869e4e7f5e4c002207396aea59</id>
<content type='text'>
Add the necessary defines, helpers and API functions for replacing struct mutex on
a PREEMPT_RT enabled kernel with an rtmutex based variant.

No functional change when CONFIG_PREEMPT_RT=n

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210815211305.081517417@linutronix.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add the necessary defines, helpers and API functions for replacing struct mutex on
a PREEMPT_RT enabled kernel with an rtmutex based variant.

No functional change when CONFIG_PREEMPT_RT=n

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210815211305.081517417@linutronix.de
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/rtmutex: Extend the rtmutex core to support ww_mutex</title>
<updated>2021-08-17T17:05:23+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2021-08-15T21:28:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=add461325ec5bc39aa619a1bfcde7245e5f31ac7'/>
<id>add461325ec5bc39aa619a1bfcde7245e5f31ac7</id>
<content type='text'>
Add a ww acquire context pointer to the waiter and various functions and
add the ww_mutex related invocations to the proper spots in the locking
code, similar to the mutex based variant.

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210815211304.966139174@linutronix.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add a ww acquire context pointer to the waiter and various functions and
add the ww_mutex related invocations to the proper spots in the locking
code, similar to the mutex based variant.

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210815211304.966139174@linutronix.de
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/rtmutex: Guard regular sleeping locks specific functions</title>
<updated>2021-08-17T15:23:27+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2021-08-15T21:28:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e17ba59b7e8e1f67e36d8fcc46daa13370efcf11'/>
<id>e17ba59b7e8e1f67e36d8fcc46daa13370efcf11</id>
<content type='text'>
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 &lt;tglx@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210815211303.311535693@linutronix.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;tglx@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210815211303.311535693@linutronix.de
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/rtmutex: Use rt_mutex_wake_q_head</title>
<updated>2021-08-17T15:20:14+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2021-08-15T21:28:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7980aa397cc0968ea3ffee7a985c31c92ad84f81'/>
<id>7980aa397cc0968ea3ffee7a985c31c92ad84f81</id>
<content type='text'>
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 &lt;tglx@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210815211303.197113263@linutronix.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;tglx@linutronix.de&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210815211303.197113263@linutronix.de
</pre>
</div>
</content>
</entry>
</feed>
