Hello RT Folks! I'm pleased to announce the 4.14.137-rt65 stable release.
You can get this release via the git tree at: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git branch: v4.14-rt Head SHA1: 99fb7f1893d07e9ff67f78488cda74a2be903213 Or to build 4.14.137-rt65 directly, the following patches should be applied: https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.14.tar.xz https://www.kernel.org/pub/linux/kernel/v4.x/patch-4.14.137.xz https://www.kernel.org/pub/linux/kernel/projects/rt/4.14/patch-4.14.137-rt65.patch.xz You can also build from 4.14.137-rt64 by applying the incremental patch: https://www.kernel.org/pub/linux/kernel/projects/rt/4.14/incr/patch-4.14.137-rt64-rt65.patch.xz Enjoy! Tom Changes from v4.14.137-rt64: --- Corey Minyard (1): sched/completion: Fix a lockup in wait_for_completion() Luis Claudio R. Goncalves (1): mm/zswap: Do not disable preemption in zswap_frontswap_store() Sebastian Andrzej Siewior (13): kthread: add a global worker thread. genirq: Do not invoke the affinity callback via a workqueue on RT genirq: Handle missing work_struct in irq_set_affinity_notifier() locking/rwsem: Rename rwsem_rt.h to rwsem-rt.h locking/lockdep: Don't complain about incorrect name for no validate class arm: imx6: cpuidle: Use raw_spinlock_t rcu: Don't allow to change rcu_normal_after_boot on RT sched/core: Drop a preempt_disable_rt() statement Revert "futex: Ensure lock/unlock symetry versus pi_lock and hash bucket lock" Revert "futex: Fix bug on when a requeued RT task times out" Revert "rtmutex: Handle the various new futex race conditions" Revert "futex: workaround migrate_disable/enable in different context" futex: Make the futex_hash_bucket lock raw Thomas Gleixner (1): futex: Delay deallocation of pi_state Tom Zanussi (2): kthread: Use __RAW_SPIN_LOCK_UNLOCK to initialize kthread_worker lock Linux 4.14.137-rt65 kbuild test robot (1): pci/switchtec: fix stream_open.cocci warnings --- arch/arm/mach-imx/cpuidle-imx6q.c | 10 +- drivers/block/loop.c | 2 +- drivers/pci/switch/switchtec.c | 2 +- drivers/spi/spi-rockchip.c | 1 + include/linux/blk-cgroup.h | 1 + include/linux/interrupt.h | 5 +- include/linux/kthread-cgroup.h | 17 +++ include/linux/kthread.h | 10 +- include/linux/{rwsem_rt.h => rwsem-rt.h} | 0 include/linux/rwsem.h | 2 +- init/main.c | 1 + kernel/futex.c | 232 +++++++++++++------------------ kernel/irq/manage.c | 23 +-- kernel/kthread.c | 13 ++ kernel/locking/lockdep.c | 3 +- kernel/locking/rtmutex.c | 65 +-------- kernel/locking/rtmutex_common.h | 3 - kernel/rcu/update.c | 2 + kernel/sched/completion.c | 2 +- kernel/sched/core.c | 9 +- localversion-rt | 2 +- mm/zswap.c | 12 +- 22 files changed, 179 insertions(+), 238 deletions(-) --- diff --git a/arch/arm/mach-imx/cpuidle-imx6q.c b/arch/arm/mach-imx/cpuidle-imx6q.c index 326e870d7123..d9ac80aa1eb0 100644 --- a/arch/arm/mach-imx/cpuidle-imx6q.c +++ b/arch/arm/mach-imx/cpuidle-imx6q.c @@ -17,22 +17,22 @@ #include "hardware.h" static int num_idle_cpus = 0; -static DEFINE_SPINLOCK(cpuidle_lock); +static DEFINE_RAW_SPINLOCK(cpuidle_lock); static int imx6q_enter_wait(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { - spin_lock(&cpuidle_lock); + raw_spin_lock(&cpuidle_lock); if (++num_idle_cpus == num_online_cpus()) imx6_set_lpm(WAIT_UNCLOCKED); - spin_unlock(&cpuidle_lock); + raw_spin_unlock(&cpuidle_lock); cpu_do_idle(); - spin_lock(&cpuidle_lock); + raw_spin_lock(&cpuidle_lock); if (num_idle_cpus-- == num_online_cpus()) imx6_set_lpm(WAIT_CLOCKED); - spin_unlock(&cpuidle_lock); + raw_spin_unlock(&cpuidle_lock); return index; } diff --git a/drivers/block/loop.c b/drivers/block/loop.c index bd447de4a5b8..2a07dfc9b3ae 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -70,7 +70,7 @@ #include <linux/writeback.h> #include <linux/completion.h> #include <linux/highmem.h> -#include <linux/kthread.h> +#include <linux/kthread-cgroup.h> #include <linux/splice.h> #include <linux/sysfs.h> #include <linux/miscdevice.h> diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c index 69875a196ad8..2b6641c9e868 100644 --- a/drivers/pci/switch/switchtec.c +++ b/drivers/pci/switch/switchtec.c @@ -625,7 +625,7 @@ static int switchtec_dev_open(struct inode *inode, struct file *filp) return PTR_ERR(stuser); filp->private_data = stuser; - nonseekable_open(inode, filp); + stream_open(inode, filp); dev_dbg(&stdev->dev, "%s: %p\n", __func__, stuser); diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index fdcf3076681b..b56619418cea 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -22,6 +22,7 @@ #include <linux/spi/spi.h> #include <linux/pm_runtime.h> #include <linux/scatterlist.h> +#include <linux/interrupt.h> #define DRIVER_NAME "rockchip-spi" diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 8bbc3716507a..a9454ad4de06 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -20,6 +20,7 @@ #include <linux/radix-tree.h> #include <linux/blkdev.h> #include <linux/atomic.h> +#include <linux/kthread-cgroup.h> /* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */ #define BLKG_STAT_CPU_BATCH (INT_MAX / 2) diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 0f25fa19b2d8..233e3c027f53 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -15,7 +15,7 @@ #include <linux/hrtimer.h> #include <linux/kref.h> #include <linux/workqueue.h> -#include <linux/swork.h> +#include <linux/kthread.h> #include <linux/atomic.h> #include <asm/ptrace.h> @@ -230,7 +230,6 @@ extern void resume_device_irqs(void); * struct irq_affinity_notify - context for notification of IRQ affinity changes * @irq: Interrupt to which notification applies * @kref: Reference count, for internal use - * @swork: Swork item, for internal use * @work: Work item, for internal use * @notify: Function to be called on change. This will be * called in process context. @@ -243,7 +242,7 @@ struct irq_affinity_notify { unsigned int irq; struct kref kref; #ifdef CONFIG_PREEMPT_RT_BASE - struct swork_event swork; + struct kthread_work work; #else struct work_struct work; #endif diff --git a/include/linux/kthread-cgroup.h b/include/linux/kthread-cgroup.h new file mode 100644 index 000000000000..53d34bca9d72 --- /dev/null +++ b/include/linux/kthread-cgroup.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_KTHREAD_CGROUP_H +#define _LINUX_KTHREAD_CGROUP_H +#include <linux/kthread.h> +#include <linux/cgroup.h> + +#ifdef CONFIG_BLK_CGROUP +void kthread_associate_blkcg(struct cgroup_subsys_state *css); +struct cgroup_subsys_state *kthread_blkcg(void); +#else +static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { } +static inline struct cgroup_subsys_state *kthread_blkcg(void) +{ + return NULL; +} +#endif +#endif diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 4e0449df82c3..59b85b01fb8b 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -105,7 +105,7 @@ struct kthread_delayed_work { }; #define KTHREAD_WORKER_INIT(worker) { \ - .lock = __SPIN_LOCK_UNLOCKED((worker).lock), \ + .lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \ .work_list = LIST_HEAD_INIT((worker).work_list), \ .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\ } @@ -199,4 +199,12 @@ bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work); void kthread_destroy_worker(struct kthread_worker *worker); +extern struct kthread_worker kthread_global_worker; +void kthread_init_global_worker(void); + +static inline bool kthread_schedule_work(struct kthread_work *work) +{ + return kthread_queue_work(&kthread_global_worker, work); +} + #endif /* _LINUX_KTHREAD_H */ diff --git a/include/linux/rwsem_rt.h b/include/linux/rwsem-rt.h similarity index 100% rename from include/linux/rwsem_rt.h rename to include/linux/rwsem-rt.h diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 513df11a364e..ac0857d60e04 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -21,7 +21,7 @@ #endif #ifdef CONFIG_PREEMPT_RT_FULL -#include <linux/rwsem_rt.h> +#include <linux/rwsem-rt.h> #else /* PREEMPT_RT_FULL */ struct rw_semaphore; diff --git a/init/main.c b/init/main.c index f32aebb5ce54..18c1297b2889 100644 --- a/init/main.c +++ b/init/main.c @@ -1059,6 +1059,7 @@ static noinline void __init kernel_init_freeable(void) smp_prepare_cpus(setup_max_cpus); workqueue_init(); + kthread_init_global_worker(); init_mm_internals(); diff --git a/kernel/futex.c b/kernel/futex.c index ad0abb0e339f..5f1cfa2f02b6 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -240,7 +240,7 @@ struct futex_q { struct plist_node list; struct task_struct *task; - spinlock_t *lock_ptr; + raw_spinlock_t *lock_ptr; union futex_key key; struct futex_pi_state *pi_state; struct rt_mutex_waiter *rt_waiter; @@ -261,7 +261,7 @@ static const struct futex_q futex_q_init = { */ struct futex_hash_bucket { atomic_t waiters; - spinlock_t lock; + raw_spinlock_t lock; struct plist_head chain; } ____cacheline_aligned_in_smp; @@ -822,13 +822,13 @@ static void get_pi_state(struct futex_pi_state *pi_state) * Drops a reference to the pi_state object and frees or caches it * when the last reference is gone. */ -static void put_pi_state(struct futex_pi_state *pi_state) +static struct futex_pi_state *__put_pi_state(struct futex_pi_state *pi_state) { if (!pi_state) - return; + return NULL; if (!atomic_dec_and_test(&pi_state->refcount)) - return; + return NULL; /* * If pi_state->owner is NULL, the owner is most probably dying @@ -848,9 +848,7 @@ static void put_pi_state(struct futex_pi_state *pi_state) raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); } - if (current->pi_state_cache) { - kfree(pi_state); - } else { + if (!current->pi_state_cache) { /* * pi_state->list is already empty. * clear pi_state->owner. @@ -859,6 +857,30 @@ static void put_pi_state(struct futex_pi_state *pi_state) pi_state->owner = NULL; atomic_set(&pi_state->refcount, 1); current->pi_state_cache = pi_state; + pi_state = NULL; + } + return pi_state; +} + +static void put_pi_state(struct futex_pi_state *pi_state) +{ + kfree(__put_pi_state(pi_state)); +} + +static void put_pi_state_atomic(struct futex_pi_state *pi_state, + struct list_head *to_free) +{ + if (__put_pi_state(pi_state)) + list_add(&pi_state->list, to_free); +} + +static void free_pi_state_list(struct list_head *to_free) +{ + struct futex_pi_state *p, *next; + + list_for_each_entry_safe(p, next, to_free, list) { + list_del(&p->list); + kfree(p); } } @@ -893,6 +915,7 @@ void exit_pi_state_list(struct task_struct *curr) struct futex_pi_state *pi_state; struct futex_hash_bucket *hb; union futex_key key = FUTEX_KEY_INIT; + LIST_HEAD(to_free); if (!futex_cmpxchg_enabled) return; @@ -926,7 +949,7 @@ void exit_pi_state_list(struct task_struct *curr) } raw_spin_unlock_irq(&curr->pi_lock); - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); raw_spin_lock(&curr->pi_lock); /* @@ -936,10 +959,8 @@ void exit_pi_state_list(struct task_struct *curr) if (head->next != next) { /* retain curr->pi_lock for the loop invariant */ raw_spin_unlock(&pi_state->pi_mutex.wait_lock); - raw_spin_unlock_irq(&curr->pi_lock); - spin_unlock(&hb->lock); - raw_spin_lock_irq(&curr->pi_lock); - put_pi_state(pi_state); + raw_spin_unlock(&hb->lock); + put_pi_state_atomic(pi_state, &to_free); continue; } @@ -950,7 +971,7 @@ void exit_pi_state_list(struct task_struct *curr) raw_spin_unlock(&curr->pi_lock); raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); rt_mutex_futex_unlock(&pi_state->pi_mutex); put_pi_state(pi_state); @@ -958,6 +979,8 @@ void exit_pi_state_list(struct task_struct *curr) raw_spin_lock_irq(&curr->pi_lock); } raw_spin_unlock_irq(&curr->pi_lock); + + free_pi_state_list(&to_free); } #endif @@ -1444,7 +1467,7 @@ static void __unqueue_futex(struct futex_q *q) { struct futex_hash_bucket *hb; - if (WARN_ON_SMP(!q->lock_ptr || !spin_is_locked(q->lock_ptr)) + if (WARN_ON_SMP(!q->lock_ptr || !raw_spin_is_locked(q->lock_ptr)) || WARN_ON(plist_node_empty(&q->list))) return; @@ -1572,21 +1595,21 @@ static inline void double_lock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2) { if (hb1 <= hb2) { - spin_lock(&hb1->lock); + raw_spin_lock(&hb1->lock); if (hb1 < hb2) - spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING); + raw_spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING); } else { /* hb1 > hb2 */ - spin_lock(&hb2->lock); - spin_lock_nested(&hb1->lock, SINGLE_DEPTH_NESTING); + raw_spin_lock(&hb2->lock); + raw_spin_lock_nested(&hb1->lock, SINGLE_DEPTH_NESTING); } } static inline void double_unlock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2) { - spin_unlock(&hb1->lock); + raw_spin_unlock(&hb1->lock); if (hb1 != hb2) - spin_unlock(&hb2->lock); + raw_spin_unlock(&hb2->lock); } /* @@ -1614,7 +1637,7 @@ futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset) if (!hb_waiters_pending(hb)) goto out_put_key; - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); plist_for_each_entry_safe(this, next, &hb->chain, list) { if (match_futex (&this->key, &key)) { @@ -1633,7 +1656,7 @@ futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset) } } - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); wake_up_q(&wake_q); out_put_key: put_futex_key(&key); @@ -1940,6 +1963,7 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, struct futex_hash_bucket *hb1, *hb2; struct futex_q *this, *next; DEFINE_WAKE_Q(wake_q); + LIST_HEAD(to_free); if (nr_wake < 0 || nr_requeue < 0) return -EINVAL; @@ -2167,16 +2191,6 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, requeue_pi_wake_futex(this, &key2, hb2); drop_count++; continue; - } else if (ret == -EAGAIN) { - /* - * Waiter was woken by timeout or - * signal and has set pi_blocked_on to - * PI_WAKEUP_INPROGRESS before we - * tried to enqueue it on the rtmutex. - */ - this->pi_state = NULL; - put_pi_state(pi_state); - continue; } else if (ret) { /* * rt_mutex_start_proxy_lock() detected a @@ -2187,7 +2201,7 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, * object. */ this->pi_state = NULL; - put_pi_state(pi_state); + put_pi_state_atomic(pi_state, &to_free); /* * We stop queueing more waiters and let user * space deal with the mess. @@ -2204,7 +2218,7 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, * in futex_proxy_trylock_atomic() or in lookup_pi_state(). We * need to drop it here again. */ - put_pi_state(pi_state); + put_pi_state_atomic(pi_state, &to_free); out_unlock: double_unlock_hb(hb1, hb2); @@ -2225,6 +2239,7 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, out_put_key1: put_futex_key(&key1); out: + free_pi_state_list(&to_free); return ret ? ret : task_count; } @@ -2248,7 +2263,8 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q) q->lock_ptr = &hb->lock; - spin_lock(&hb->lock); /* implies smp_mb(); (A) */ + raw_spin_lock(&hb->lock); + return hb; } @@ -2256,7 +2272,7 @@ static inline void queue_unlock(struct futex_hash_bucket *hb) __releases(&hb->lock) { - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); hb_waiters_dec(hb); } @@ -2295,7 +2311,7 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb) __releases(&hb->lock) { __queue_me(q, hb); - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); } /** @@ -2311,41 +2327,41 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb) */ static int unqueue_me(struct futex_q *q) { - spinlock_t *lock_ptr; + raw_spinlock_t *lock_ptr; int ret = 0; /* In the common case we don't take the spinlock, which is nice. */ retry: /* - * q->lock_ptr can change between this read and the following spin_lock. - * Use READ_ONCE to forbid the compiler from reloading q->lock_ptr and - * optimizing lock_ptr out of the logic below. + * q->lock_ptr can change between this read and the following + * raw_spin_lock. Use READ_ONCE to forbid the compiler from reloading + * q->lock_ptr and optimizing lock_ptr out of the logic below. */ lock_ptr = READ_ONCE(q->lock_ptr); if (lock_ptr != NULL) { - spin_lock(lock_ptr); + raw_spin_lock(lock_ptr); /* * q->lock_ptr can change between reading it and - * spin_lock(), causing us to take the wrong lock. This + * raw_spin_lock(), causing us to take the wrong lock. This * corrects the race condition. * * Reasoning goes like this: if we have the wrong lock, * q->lock_ptr must have changed (maybe several times) - * between reading it and the spin_lock(). It can - * change again after the spin_lock() but only if it was - * already changed before the spin_lock(). It cannot, + * between reading it and the raw_spin_lock(). It can + * change again after the raw_spin_lock() but only if it was + * already changed before the raw_spin_lock(). It cannot, * however, change back to the original value. Therefore * we can detect whether we acquired the correct lock. */ if (unlikely(lock_ptr != q->lock_ptr)) { - spin_unlock(lock_ptr); + raw_spin_unlock(lock_ptr); goto retry; } __unqueue_futex(q); BUG_ON(q->pi_state); - spin_unlock(lock_ptr); + raw_spin_unlock(lock_ptr); ret = 1; } @@ -2361,13 +2377,16 @@ static int unqueue_me(struct futex_q *q) static void unqueue_me_pi(struct futex_q *q) __releases(q->lock_ptr) { + struct futex_pi_state *ps; + __unqueue_futex(q); BUG_ON(!q->pi_state); - put_pi_state(q->pi_state); + ps = __put_pi_state(q->pi_state); q->pi_state = NULL; - spin_unlock(q->lock_ptr); + raw_spin_unlock(q->lock_ptr); + kfree(ps); } static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, @@ -2500,7 +2519,7 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, */ handle_err: raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); - spin_unlock(q->lock_ptr); + raw_spin_unlock(q->lock_ptr); switch (err) { case -EFAULT: @@ -2518,7 +2537,7 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, break; } - spin_lock(q->lock_ptr); + raw_spin_lock(q->lock_ptr); raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); /* @@ -2614,7 +2633,7 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, /* * The task state is guaranteed to be set before another task can * wake it. set_current_state() is implemented using smp_store_mb() and - * queue_me() calls spin_unlock() upon completion, both serializing + * queue_me() calls raw_spin_unlock() upon completion, both serializing * access to the hash list and forcing another memory barrier. */ set_current_state(TASK_INTERRUPTIBLE); @@ -2905,15 +2924,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, * before __rt_mutex_start_proxy_lock() is done. */ raw_spin_lock_irq(&q.pi_state->pi_mutex.wait_lock); - /* - * the migrate_disable() here disables migration in the in_atomic() fast - * path which is enabled again in the following spin_unlock(). We have - * one migrate_disable() pending in the slow-path which is reversed - * after the raw_spin_unlock_irq() where we leave the atomic context. - */ - migrate_disable(); - - spin_unlock(q.lock_ptr); + raw_spin_unlock(q.lock_ptr); /* * __rt_mutex_start_proxy_lock() unconditionally enqueues the @rt_waiter * such that futex_unlock_pi() is guaranteed to observe the waiter when @@ -2921,7 +2932,6 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, */ ret = __rt_mutex_start_proxy_lock(&q.pi_state->pi_mutex, &rt_waiter, current); raw_spin_unlock_irq(&q.pi_state->pi_mutex.wait_lock); - migrate_enable(); if (ret) { if (ret == 1) @@ -2935,7 +2945,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, ret = rt_mutex_wait_proxy_lock(&q.pi_state->pi_mutex, to, &rt_waiter); cleanup: - spin_lock(q.lock_ptr); + raw_spin_lock(q.lock_ptr); /* * If we failed to acquire the lock (deadlock/signal/timeout), we must * first acquire the hb->lock before removing the lock from the @@ -3036,7 +3046,7 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) return ret; hb = hash_futex(&key); - spin_lock(&hb->lock); + raw_spin_lock(&hb->lock); /* * Check waiters first. We do not trust user space values at @@ -3070,21 +3080,11 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) * rt_waiter. Also see the WARN in wake_futex_pi(). */ raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); - /* - * Magic trickery for now to make the RT migrate disable - * logic happy. The following spin_unlock() happens with - * interrupts disabled so the internal migrate_enable() - * won't undo the migrate_disable() which was issued when - * locking hb->lock. - */ - migrate_disable(); - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); /* drops pi_state->pi_mutex.wait_lock */ ret = wake_futex_pi(uaddr, uval, pi_state); - migrate_enable(); - put_pi_state(pi_state); /* @@ -3119,7 +3119,7 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) * owner. */ if ((ret = cmpxchg_futex_value_locked(&curval, uaddr, uval, 0))) { - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); switch (ret) { case -EFAULT: goto pi_faulted; @@ -3139,7 +3139,7 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) ret = (curval == uval) ? 0 : -EAGAIN; out_unlock: - spin_unlock(&hb->lock); + raw_spin_unlock(&hb->lock); out_putkey: put_futex_key(&key); return ret; @@ -3255,7 +3255,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, struct hrtimer_sleeper timeout, *to = NULL; struct futex_pi_state *pi_state = NULL; struct rt_mutex_waiter rt_waiter; - struct futex_hash_bucket *hb, *hb2; + struct futex_hash_bucket *hb; union futex_key key2 = FUTEX_KEY_INIT; struct futex_q q = futex_q_init; int res, ret; @@ -3313,55 +3313,20 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, /* Queue the futex_q, drop the hb lock, wait for wakeup. */ futex_wait_queue_me(hb, &q, to); - /* - * On RT we must avoid races with requeue and trying to block - * on two mutexes (hb->lock and uaddr2's rtmutex) by - * serializing access to pi_blocked_on with pi_lock. - */ - raw_spin_lock_irq(¤t->pi_lock); - if (current->pi_blocked_on) { - /* - * We have been requeued or are in the process of - * being requeued. - */ - raw_spin_unlock_irq(¤t->pi_lock); - } else { - /* - * Setting pi_blocked_on to PI_WAKEUP_INPROGRESS - * prevents a concurrent requeue from moving us to the - * uaddr2 rtmutex. After that we can safely acquire - * (and possibly block on) hb->lock. - */ - current->pi_blocked_on = PI_WAKEUP_INPROGRESS; - raw_spin_unlock_irq(¤t->pi_lock); - - spin_lock(&hb->lock); - - /* - * Clean up pi_blocked_on. We might leak it otherwise - * when we succeeded with the hb->lock in the fast - * path. - */ - raw_spin_lock_irq(¤t->pi_lock); - current->pi_blocked_on = NULL; - raw_spin_unlock_irq(¤t->pi_lock); - - ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to); - spin_unlock(&hb->lock); - if (ret) - goto out_put_keys; - } + raw_spin_lock(&hb->lock); + ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to); + raw_spin_unlock(&hb->lock); + if (ret) + goto out_put_keys; /* - * In order to be here, we have either been requeued, are in - * the process of being requeued, or requeue successfully - * acquired uaddr2 on our behalf. If pi_blocked_on was - * non-null above, we may be racing with a requeue. Do not - * rely on q->lock_ptr to be hb2->lock until after blocking on - * hb->lock or hb2->lock. The futex_requeue dropped our key1 - * reference and incremented our key2 reference count. + * In order for us to be here, we know our q.key == key2, and since + * we took the hb->lock above, we also know that futex_requeue() has + * completed and we no longer have to concern ourselves with a wakeup + * race with the atomic proxy lock acquisition by the requeue code. The + * futex_requeue dropped our key1 reference and incremented our key2 + * reference count. */ - hb2 = hash_futex(&key2); /* Check if the requeue code acquired the second futex for us. */ if (!q.rt_waiter) { @@ -3370,8 +3335,9 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, * did a lock-steal - fix up the PI-state in that case. */ if (q.pi_state && (q.pi_state->owner != current)) { - spin_lock(&hb2->lock); - BUG_ON(&hb2->lock != q.lock_ptr); + struct futex_pi_state *ps_free; + + raw_spin_lock(q.lock_ptr); ret = fixup_pi_state_owner(uaddr2, &q, current); if (ret && rt_mutex_owner(&q.pi_state->pi_mutex) == current) { pi_state = q.pi_state; @@ -3381,8 +3347,9 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, * Drop the reference to the pi state which * the requeue_pi() code acquired for us. */ - put_pi_state(q.pi_state); - spin_unlock(&hb2->lock); + ps_free = __put_pi_state(q.pi_state); + raw_spin_unlock(q.lock_ptr); + kfree(ps_free); } } else { struct rt_mutex *pi_mutex; @@ -3396,8 +3363,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, pi_mutex = &q.pi_state->pi_mutex; ret = rt_mutex_wait_proxy_lock(pi_mutex, to, &rt_waiter); - spin_lock(&hb2->lock); - BUG_ON(&hb2->lock != q.lock_ptr); + raw_spin_lock(q.lock_ptr); if (ret && !rt_mutex_cleanup_proxy_lock(pi_mutex, &rt_waiter)) ret = 0; @@ -3832,7 +3798,7 @@ static int __init futex_init(void) for (i = 0; i < futex_hashsize; i++) { atomic_set(&futex_queues[i].waiters, 0); plist_head_init(&futex_queues[i].chain); - spin_lock_init(&futex_queues[i].lock); + raw_spin_lock_init(&futex_queues[i].lock); } return 0; diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index f9415590661c..071691963f7b 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -228,7 +228,7 @@ int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask, kref_get(&desc->affinity_notify->kref); #ifdef CONFIG_PREEMPT_RT_BASE - swork_queue(&desc->affinity_notify->swork); + kthread_schedule_work(&desc->affinity_notify->work); #else schedule_work(&desc->affinity_notify->work); #endif @@ -293,21 +293,11 @@ static void _irq_affinity_notify(struct irq_affinity_notify *notify) } #ifdef CONFIG_PREEMPT_RT_BASE -static void init_helper_thread(void) -{ - static int init_sworker_once; - - if (init_sworker_once) - return; - if (WARN_ON(swork_get())) - return; - init_sworker_once = 1; -} -static void irq_affinity_notify(struct swork_event *swork) +static void irq_affinity_notify(struct kthread_work *work) { struct irq_affinity_notify *notify = - container_of(swork, struct irq_affinity_notify, swork); + container_of(work, struct irq_affinity_notify, work); _irq_affinity_notify(notify); } @@ -350,8 +340,7 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) notify->irq = irq; kref_init(¬ify->kref); #ifdef CONFIG_PREEMPT_RT_BASE - INIT_SWORK(¬ify->swork, irq_affinity_notify); - init_helper_thread(); + kthread_init_work(¬ify->work, irq_affinity_notify); #else INIT_WORK(¬ify->work, irq_affinity_notify); #endif @@ -363,7 +352,9 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) raw_spin_unlock_irqrestore(&desc->lock, flags); if (old_notify) { -#ifndef CONFIG_PREEMPT_RT_BASE +#ifdef CONFIG_PREEMPT_RT_BASE + kthread_cancel_work_sync(¬ify->work); +#else cancel_work_sync(&old_notify->work); #endif kref_put(&old_notify->kref, old_notify->release); diff --git a/kernel/kthread.c b/kernel/kthread.c index 430fd79cd3fe..44498522e5d5 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -1161,3 +1161,16 @@ void kthread_destroy_worker(struct kthread_worker *worker) kfree(worker); } EXPORT_SYMBOL(kthread_destroy_worker); + +DEFINE_KTHREAD_WORKER(kthread_global_worker); +EXPORT_SYMBOL(kthread_global_worker); + +__init void kthread_init_global_worker(void) +{ + kthread_global_worker.task = kthread_create(kthread_worker_fn, + &kthread_global_worker, + "kswork"); + if (WARN_ON(IS_ERR(kthread_global_worker.task))) + return; + wake_up_process(kthread_global_worker.task); +} diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index e576d234f3ea..f194de27123d 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -719,7 +719,8 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass) * Huh! same key, different name? Did someone trample * on some memory? We're most confused. */ - WARN_ON_ONCE(class->name != lock->name); + WARN_ON_ONCE(class->name != lock->name && + lock->key != &__lockdep_no_validate__); return class; } } diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 1177f2815040..e1497623780b 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -142,12 +142,6 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock) WRITE_ONCE(*p, owner & ~RT_MUTEX_HAS_WAITERS); } -static int rt_mutex_real_waiter(struct rt_mutex_waiter *waiter) -{ - return waiter && waiter != PI_WAKEUP_INPROGRESS && - waiter != PI_REQUEUE_INPROGRESS; -} - /* * We can speed up the acquire/release, if there's no debugging state to be * set up. @@ -421,8 +415,7 @@ int max_lock_depth = 1024; static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p) { - return rt_mutex_real_waiter(p->pi_blocked_on) ? - p->pi_blocked_on->lock : NULL; + return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL; } /* @@ -558,7 +551,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, * reached or the state of the chain has changed while we * dropped the locks. */ - if (!rt_mutex_real_waiter(waiter)) + if (!waiter) goto out_unlock_pi; /* @@ -1341,22 +1334,6 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, return -EDEADLK; raw_spin_lock(&task->pi_lock); - /* - * In the case of futex requeue PI, this will be a proxy - * lock. The task will wake unaware that it is enqueueed on - * this lock. Avoid blocking on two locks and corrupting - * pi_blocked_on via the PI_WAKEUP_INPROGRESS - * flag. futex_wait_requeue_pi() sets this when it wakes up - * before requeue (due to a signal or timeout). Do not enqueue - * the task if PI_WAKEUP_INPROGRESS is set. - */ - if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) { - raw_spin_unlock(&task->pi_lock); - return -EAGAIN; - } - - BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on)); - waiter->task = task; waiter->lock = lock; waiter->prio = task->prio; @@ -1380,7 +1357,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, rt_mutex_enqueue_pi(owner, waiter); rt_mutex_adjust_prio(owner); - if (rt_mutex_real_waiter(owner->pi_blocked_on)) + if (owner->pi_blocked_on) chain_walk = 1; } else if (rt_mutex_cond_detect_deadlock(waiter, chwalk)) { chain_walk = 1; @@ -1480,7 +1457,7 @@ static void remove_waiter(struct rt_mutex *lock, { bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock)); struct task_struct *owner = rt_mutex_owner(lock); - struct rt_mutex *next_lock = NULL; + struct rt_mutex *next_lock; lockdep_assert_held(&lock->wait_lock); @@ -1506,8 +1483,7 @@ static void remove_waiter(struct rt_mutex *lock, rt_mutex_adjust_prio(owner); /* Store the lock on which owner is blocked or NULL */ - if (rt_mutex_real_waiter(owner->pi_blocked_on)) - next_lock = task_blocked_on_lock(owner); + next_lock = task_blocked_on_lock(owner); raw_spin_unlock(&owner->pi_lock); @@ -1543,8 +1519,7 @@ void rt_mutex_adjust_pi(struct task_struct *task) raw_spin_lock_irqsave(&task->pi_lock, flags); waiter = task->pi_blocked_on; - if (!rt_mutex_real_waiter(waiter) || - rt_mutex_waiter_equal(waiter, task_to_waiter(task))) { + if (!waiter || rt_mutex_waiter_equal(waiter, task_to_waiter(task))) { raw_spin_unlock_irqrestore(&task->pi_lock, flags); return; } @@ -2358,34 +2333,6 @@ int __rt_mutex_start_proxy_lock(struct rt_mutex *lock, if (try_to_take_rt_mutex(lock, task, NULL)) return 1; -#ifdef CONFIG_PREEMPT_RT_FULL - /* - * In PREEMPT_RT there's an added race. - * If the task, that we are about to requeue, times out, - * it can set the PI_WAKEUP_INPROGRESS. This tells the requeue - * to skip this task. But right after the task sets - * its pi_blocked_on to PI_WAKEUP_INPROGRESS it can then - * block on the spin_lock(&hb->lock), which in RT is an rtmutex. - * This will replace the PI_WAKEUP_INPROGRESS with the actual - * lock that it blocks on. We *must not* place this task - * on this proxy lock in that case. - * - * To prevent this race, we first take the task's pi_lock - * and check if it has updated its pi_blocked_on. If it has, - * we assume that it woke up and we return -EAGAIN. - * Otherwise, we set the task's pi_blocked_on to - * PI_REQUEUE_INPROGRESS, so that if the task is waking up - * it will know that we are in the process of requeuing it. - */ - raw_spin_lock(&task->pi_lock); - if (task->pi_blocked_on) { - raw_spin_unlock(&task->pi_lock); - return -EAGAIN; - } - task->pi_blocked_on = PI_REQUEUE_INPROGRESS; - raw_spin_unlock(&task->pi_lock); -#endif - /* We enforce deadlock detection for futexes */ ret = task_blocks_on_rt_mutex(lock, waiter, task, RT_MUTEX_FULL_CHAINWALK); diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h index 2a157c78e18c..2f6662d052d6 100644 --- a/kernel/locking/rtmutex_common.h +++ b/kernel/locking/rtmutex_common.h @@ -131,9 +131,6 @@ enum rtmutex_chainwalk { /* * PI-futex support (proxy locking functions, etc.): */ -#define PI_WAKEUP_INPROGRESS ((struct rt_mutex_waiter *) 1) -#define PI_REQUEUE_INPROGRESS ((struct rt_mutex_waiter *) 2) - extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock); extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock, struct task_struct *proxy_owner); diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 2006a09680aa..307592810f6b 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -67,7 +67,9 @@ module_param(rcu_expedited, int, 0); extern int rcu_normal; /* from sysctl */ module_param(rcu_normal, int, 0); static int rcu_normal_after_boot = IS_ENABLED(CONFIG_PREEMPT_RT_FULL); +#ifndef CONFIG_PREEMPT_RT_FULL module_param(rcu_normal_after_boot, int, 0); +#endif #endif /* #ifndef CONFIG_TINY_RCU */ #ifdef CONFIG_DEBUG_LOCK_ALLOC diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c index 0fe2982e46a0..ac6d5efcd6ff 100644 --- a/kernel/sched/completion.c +++ b/kernel/sched/completion.c @@ -80,12 +80,12 @@ do_wait_for_common(struct completion *x, if (!x->done) { DECLARE_SWAITQUEUE(wait); - __prepare_to_swait(&x->wait, &wait); do { if (signal_pending_state(state, current)) { timeout = -ERESTARTSYS; break; } + __prepare_to_swait(&x->wait, &wait); __set_current_state(state); raw_spin_unlock_irq(&x->wait.lock); timeout = action(timeout); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 7d2cc0715114..17da1c1aba56 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -583,14 +583,11 @@ void resched_cpu(int cpu) */ int get_nohz_timer_target(void) { - int i, cpu; + int i, cpu = smp_processor_id(); struct sched_domain *sd; - preempt_disable_rt(); - cpu = smp_processor_id(); - if (!idle_cpu(cpu) && is_housekeeping_cpu(cpu)) - goto preempt_en_rt; + return cpu; rcu_read_lock(); for_each_domain(cpu, sd) { @@ -609,8 +606,6 @@ int get_nohz_timer_target(void) cpu = housekeeping_any_cpu(); unlock: rcu_read_unlock(); -preempt_en_rt: - preempt_enable_rt(); return cpu; } diff --git a/localversion-rt b/localversion-rt index 10474042df49..e2eb19782d4c 100644 --- a/localversion-rt +++ b/localversion-rt @@ -1 +1 @@ --rt64 +-rt65 diff --git a/mm/zswap.c b/mm/zswap.c index ebb0bc88c5f7..a2b4e14f851c 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -27,6 +27,7 @@ #include <linux/highmem.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/locallock.h> #include <linux/types.h> #include <linux/atomic.h> #include <linux/frontswap.h> @@ -953,6 +954,8 @@ static int zswap_shrink(void) return ret; } +/* protect zswap_dstmem from concurrency */ +static DEFINE_LOCAL_IRQ_LOCK(zswap_dstmem_lock); /********************************* * frontswap hooks **********************************/ @@ -1016,12 +1019,11 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, } /* compress */ - dst = get_cpu_var(zswap_dstmem); - tfm = *get_cpu_ptr(entry->pool->tfm); + dst = get_locked_var(zswap_dstmem_lock, zswap_dstmem); + tfm = *this_cpu_ptr(entry->pool->tfm); src = kmap_atomic(page); ret = crypto_comp_compress(tfm, src, PAGE_SIZE, dst, &dlen); kunmap_atomic(src); - put_cpu_ptr(entry->pool->tfm); if (ret) { ret = -EINVAL; goto put_dstmem; @@ -1045,7 +1047,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, buf = (u8 *)(zhdr + 1); memcpy(buf, dst, dlen); zpool_unmap_handle(entry->pool->zpool, handle); - put_cpu_var(zswap_dstmem); + put_locked_var(zswap_dstmem_lock, zswap_dstmem); /* populate entry */ entry->offset = offset; @@ -1072,7 +1074,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, return 0; put_dstmem: - put_cpu_var(zswap_dstmem); + put_locked_var(zswap_dstmem_lock, zswap_dstmem); zswap_pool_put(entry->pool); freepage: zswap_entry_cache_free(entry);
