Dear RT Folks,
I'm pleased to announce the 5.4.54-rt33 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: v5.4-rt Head SHA1: 8b0dbd94090c0b782f374bb645a93517b6b8d887 Or to build 5.4.54-rt33 directly, the following patches should be applied: http://www.kernel.org/pub/linux/kernel/v5.x/linux-5.4.tar.xz http://www.kernel.org/pub/linux/kernel/v5.x/patch-5.4.54.xz http://www.kernel.org/pub/linux/kernel/projects/rt/5.4/patch-5.4.54-rt33.patch.xz You can also build from 5.4.54-rt32 by applying the incremental patch: http://www.kernel.org/pub/linux/kernel/projects/rt/5.4/incr/patch-5.4.54-rt32-rt33.patch.xz Enjoy, -- Steve Changes from v5.4.54-rt32: --- Ahmed S. Darwish (1): net: phy: fixed_phy: Remove unused seqcount Matt Fleming (1): signal: Prevent double-free of user struct Sebastian Andrzej Siewior (3): workqueue: Sync with upstream Bluetooth: Acquire sk_lock.slock without disabling interrupts rwsem: Provide down_read_non_owner() and up_read_non_owner() for -RT Steven Rostedt (VMware) (1): Linux 5.4.54-rt33 ---- drivers/net/phy/fixed_phy.c | 28 +++++++++++----------------- include/linux/swait.h | 14 -------------- kernel/locking/rwsem.c | 8 ++++---- kernel/signal.c | 4 ++-- kernel/workqueue.c | 28 +++++++++++++++++++--------- localversion-rt | 2 +- net/bluetooth/rfcomm/sock.c | 7 ++----- 7 files changed, 39 insertions(+), 52 deletions(-) --------------------------- diff --git a/drivers/net/phy/fixed_phy.c b/drivers/net/phy/fixed_phy.c index 4190f9ed5313..9ed715e9be40 100644 --- a/drivers/net/phy/fixed_phy.c +++ b/drivers/net/phy/fixed_phy.c @@ -19,7 +19,6 @@ #include <linux/slab.h> #include <linux/of.h> #include <linux/gpio/consumer.h> -#include <linux/seqlock.h> #include <linux/idr.h> #include <linux/netdevice.h> #include <linux/linkmode.h> @@ -34,7 +33,6 @@ struct fixed_mdio_bus { struct fixed_phy { int addr; struct phy_device *phydev; - seqcount_t seqcount; struct fixed_phy_status status; bool no_carrier; int (*link_update)(struct net_device *, struct fixed_phy_status *); @@ -80,19 +78,17 @@ static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num) list_for_each_entry(fp, &fmb->phys, node) { if (fp->addr == phy_addr) { struct fixed_phy_status state; - int s; - - do { - s = read_seqcount_begin(&fp->seqcount); - fp->status.link = !fp->no_carrier; - /* Issue callback if user registered it. */ - if (fp->link_update) - fp->link_update(fp->phydev->attached_dev, - &fp->status); - /* Check the GPIO for change in status */ - fixed_phy_update(fp); - state = fp->status; - } while (read_seqcount_retry(&fp->seqcount, s)); + + fp->status.link = !fp->no_carrier; + + /* Issue callback if user registered it. */ + if (fp->link_update) + fp->link_update(fp->phydev->attached_dev, + &fp->status); + + /* Check the GPIO for change in status */ + fixed_phy_update(fp); + state = fp->status; return swphy_read_reg(reg_num, &state); } @@ -150,8 +146,6 @@ static int fixed_phy_add_gpiod(unsigned int irq, int phy_addr, if (!fp) return -ENOMEM; - seqcount_init(&fp->seqcount); - if (irq != PHY_POLL) fmb->mii_bus->irq[phy_addr] = irq; diff --git a/include/linux/swait.h b/include/linux/swait.h index 21ae66cd41d3..f426a0661aa0 100644 --- a/include/linux/swait.h +++ b/include/linux/swait.h @@ -299,18 +299,4 @@ do { \ __ret; \ }) -#define __swait_event_lock_irq(wq, condition, lock, cmd) \ - ___swait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, \ - raw_spin_unlock_irq(&lock); \ - cmd; \ - schedule(); \ - raw_spin_lock_irq(&lock)) - -#define swait_event_lock_irq(wq_head, condition, lock) \ - do { \ - if (condition) \ - break; \ - __swait_event_lock_irq(wq_head, condition, lock, ); \ - } while (0) - #endif /* _LINUX_SWAIT_H */ diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 0d11ba11a32a..0325c721f9b3 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -1616,15 +1616,15 @@ void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest) } EXPORT_SYMBOL(_down_write_nest_lock); -#ifndef CONFIG_PREEMPT_RT void down_read_non_owner(struct rw_semaphore *sem) { might_sleep(); __down_read(sem); +#ifndef CONFIG_PREEMPT_RT __rwsem_set_reader_owned(sem, NULL); +#endif } EXPORT_SYMBOL(down_read_non_owner); -#endif void down_write_nested(struct rw_semaphore *sem, int subclass) { @@ -1649,13 +1649,13 @@ int __sched down_write_killable_nested(struct rw_semaphore *sem, int subclass) } EXPORT_SYMBOL(down_write_killable_nested); -#ifndef CONFIG_PREEMPT_RT void up_read_non_owner(struct rw_semaphore *sem) { +#ifndef CONFIG_PREEMPT_RT DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); +#endif __up_read(sem); } EXPORT_SYMBOL(up_read_non_owner); -#endif #endif diff --git a/kernel/signal.c b/kernel/signal.c index def2e8e37f1f..aa924f0141cf 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -494,8 +494,8 @@ static void sigqueue_free_current(struct sigqueue *q) up = q->user; if (rt_prio(current->normal_prio) && !put_task_cache(current, q)) { - atomic_dec(&up->sigpending); - free_uid(up); + if (atomic_dec_and_test(&up->sigpending)) + free_uid(up); } else __sigqueue_free(q); } diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 26341e8101ee..7c968aea01e1 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -50,7 +50,6 @@ #include <linux/uaccess.h> #include <linux/sched/isolation.h> #include <linux/nmi.h> -#include <linux/swait.h> #include "workqueue_internal.h" @@ -302,7 +301,8 @@ static struct workqueue_attrs *wq_update_unbound_numa_attrs_buf; static DEFINE_MUTEX(wq_pool_mutex); /* protects pools and workqueues list */ static DEFINE_MUTEX(wq_pool_attach_mutex); /* protects worker attach/detach */ static DEFINE_RAW_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */ -static DECLARE_SWAIT_QUEUE_HEAD(wq_manager_wait); /* wait for manager to go away */ +/* wait for manager to go away */ +static struct rcuwait manager_wait = __RCUWAIT_INITIALIZER(manager_wait); static LIST_HEAD(workqueues); /* PR: list of all workqueues */ static bool workqueue_freezing; /* PL: have wqs started freezing? */ @@ -1615,11 +1615,9 @@ EXPORT_SYMBOL_GPL(queue_work_node); void delayed_work_timer_fn(struct timer_list *t) { struct delayed_work *dwork = from_timer(dwork, t, timer); - unsigned long flags; - local_irq_save(flags); + /* should have been called from irqsafe timer with irq already off */ __queue_work(dwork->cpu, dwork->wq, &dwork->work); - local_irq_restore(flags); } EXPORT_SYMBOL(delayed_work_timer_fn); @@ -2147,7 +2145,7 @@ static bool manage_workers(struct worker *worker) pool->manager = NULL; pool->flags &= ~POOL_MANAGER_ACTIVE; - swake_up_one(&wq_manager_wait); + rcuwait_wake_up(&manager_wait); return true; } @@ -3511,6 +3509,18 @@ static void rcu_free_pool(struct rcu_head *rcu) kfree(pool); } +/* This returns with the lock held on success (pool manager is inactive). */ +static bool wq_manager_inactive(struct worker_pool *pool) +{ + raw_spin_lock_irq(&pool->lock); + + if (pool->flags & POOL_MANAGER_ACTIVE) { + raw_spin_unlock_irq(&pool->lock); + return false; + } + return true; +} + /** * put_unbound_pool - put a worker_pool * @pool: worker_pool to put @@ -3546,10 +3556,10 @@ static void put_unbound_pool(struct worker_pool *pool) * Become the manager and destroy all workers. This prevents * @pool's workers from blocking on attach_mutex. We're the last * manager and @pool gets freed with the flag set. + * Because of how wq_manager_inactive() works, we will hold the + * spinlock after a successful wait. */ - raw_spin_lock_irq(&pool->lock); - swait_event_lock_irq(wq_manager_wait, - !(pool->flags & POOL_MANAGER_ACTIVE), pool->lock); + rcuwait_wait_event(&manager_wait, wq_manager_inactive(pool)); pool->flags |= POOL_MANAGER_ACTIVE; while ((worker = first_idle_worker(pool))) diff --git a/localversion-rt b/localversion-rt index ce6a482618d5..e1d836252017 100644 --- a/localversion-rt +++ b/localversion-rt @@ -1 +1 @@ --rt32 +-rt33 diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c index 90bb53aa4bee..2c27aa2acf1c 100644 --- a/net/bluetooth/rfcomm/sock.c +++ b/net/bluetooth/rfcomm/sock.c @@ -64,15 +64,13 @@ static void rfcomm_sk_data_ready(struct rfcomm_dlc *d, struct sk_buff *skb) static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err) { struct sock *sk = d->owner, *parent; - unsigned long flags; if (!sk) return; BT_DBG("dlc %p state %ld err %d", d, d->state, err); - local_irq_save(flags); - bh_lock_sock(sk); + spin_lock_bh(&sk->sk_lock.slock); if (err) sk->sk_err = err; @@ -93,8 +91,7 @@ static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err) sk->sk_state_change(sk); } - bh_unlock_sock(sk); - local_irq_restore(flags); + spin_unlock_bh(&sk->sk_lock.slock); if (parent && sock_flag(sk, SOCK_ZAPPED)) { /* We have to drop DLC lock here, otherwise
