This is a note to let you know that I've just added the patch titled
futex,rt_mutex: Introduce rt_mutex_init_waiter()
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
futex-rt_mutex-introduce-rt_mutex_init_waiter.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Mar 29 07:48:09 AM CEST 2021
From: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Date: Sun, 28 Mar 2021 22:41:33 +0200
Subject: futex,rt_mutex: Introduce rt_mutex_init_waiter()
To: stable@xxxxxxxxxxxxxxx
Cc: Lee Jones <lee.jones@xxxxxxxxxx>, "Luis Claudio R. Goncalves" <lgoncalv@xxxxxxxxxx>, Florian Fainelli <f.fainelli@xxxxxxxxx>
Message-ID: <YGDp/WL8DllYuErc@xxxxxxxxxxxxxxx>
Content-Disposition: inline
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
commit 50809358dd7199aa7ce232f6877dd09ec30ef374 upstream.
Since there's already two copies of this code, introduce a helper now
before adding a third one.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: juri.lelli@xxxxxxx
Cc: bigeasy@xxxxxxxxxxxxx
Cc: xlpang@xxxxxxxxxx
Cc: rostedt@xxxxxxxxxxx
Cc: mathieu.desnoyers@xxxxxxxxxxxx
Cc: jdesfossez@xxxxxxxxxxxx
Cc: dvhart@xxxxxxxxxxxxx
Cc: bristot@xxxxxxxxxx
Link: http://lkml.kernel.org/r/20170322104151.950039479@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/futex.c | 5 +----
kernel/locking/rtmutex.c | 12 +++++++++---
kernel/locking/rtmutex_common.h | 1 +
3 files changed, 11 insertions(+), 7 deletions(-)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -3234,10 +3234,7 @@ static int futex_wait_requeue_pi(u32 __u
* The waiter is allocated on our stack, manipulated by the requeue
* code while we sleep on uaddr.
*/
- debug_rt_mutex_init_waiter(&rt_waiter);
- RB_CLEAR_NODE(&rt_waiter.pi_tree_entry);
- RB_CLEAR_NODE(&rt_waiter.tree_entry);
- rt_waiter.task = NULL;
+ rt_mutex_init_waiter(&rt_waiter);
ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, VERIFY_WRITE);
if (unlikely(ret != 0))
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1176,6 +1176,14 @@ void rt_mutex_adjust_pi(struct task_stru
next_lock, NULL, task);
}
+void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
+{
+ debug_rt_mutex_init_waiter(waiter);
+ RB_CLEAR_NODE(&waiter->pi_tree_entry);
+ RB_CLEAR_NODE(&waiter->tree_entry);
+ waiter->task = NULL;
+}
+
/**
* __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop
* @lock: the rt_mutex to take
@@ -1258,9 +1266,7 @@ rt_mutex_slowlock(struct rt_mutex *lock,
unsigned long flags;
int ret = 0;
- debug_rt_mutex_init_waiter(&waiter);
- RB_CLEAR_NODE(&waiter.pi_tree_entry);
- RB_CLEAR_NODE(&waiter.tree_entry);
+ rt_mutex_init_waiter(&waiter);
/*
* Technically we could use raw_spin_[un]lock_irq() here, but this can
--- a/kernel/locking/rtmutex_common.h
+++ b/kernel/locking/rtmutex_common.h
@@ -103,6 +103,7 @@ extern struct task_struct *rt_mutex_next
extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner);
extern void rt_mutex_proxy_unlock(struct rt_mutex *lock);
+extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter);
extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task);
Patches currently in stable-queue which might be from ben@xxxxxxxxxxxxxxx are
queue-4.9/futex-drop-hb-lock-before-enqueueing-on-the-rtmutex.patch
queue-4.9/futex-rework-futex_lock_pi-to-use-rt_mutex_-_proxy_lock.patch
queue-4.9/futex-avoid-freeing-an-active-timer.patch
queue-4.9/futex-rt_mutex-introduce-rt_mutex_init_waiter.patch
queue-4.9/futex-fix-incorrect-should_fail_futex-handling.patch
queue-4.9/futex-rt_mutex-fix-rt_mutex_cleanup_proxy_lock.patch
queue-4.9/futex-use-smp_store_release-in-mark_wake_futex.patch
queue-4.9/futex-fix-possible-missed-wakeup.patch
queue-4.9/locking-futex-allow-low-level-atomic-operations-to-return-eagain.patch
queue-4.9/futex-prevent-robust-futex-exit-race.patch
queue-4.9/futex-handle-transient-ownerless-rtmutex-state-correctly.patch
queue-4.9/futex-handle-early-deadlock-return-correctly.patch
queue-4.9/arm64-futex-bound-number-of-ldxr-stxr-loops-in-futex_wake_op.patch
