diff options
author | Mark Brown <broonie@kernel.org> | 2018-06-27 14:26:12 +0100 |
---|---|---|
committer | Mark Brown <broonie@kernel.org> | 2018-06-27 14:26:12 +0100 |
commit | 1ce34dea91ae86bb18f493f72292df1bf6f66df7 (patch) | |
tree | a9655fcdd65c2068cc04ffe3562a9c710dfa2145 /kernel | |
parent | b0e4376b34cab1cbbd7ed399a1df787890336837 (diff) | |
parent | a26899e0baa4de07caf97f5e4d7298240e98fd0e (diff) |
Merge tag 'v4.14.52' into linux-linaro-lsk-v4.14lsk-v4.14-18.06
This is the 4.14.52 stable release
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/kthread.c | 7 | ||||
-rw-r--r-- | kernel/locking/rwsem-xadd.c | 19 | ||||
-rw-r--r-- | kernel/locking/rwsem.c | 2 | ||||
-rw-r--r-- | kernel/locking/rwsem.h | 30 | ||||
-rw-r--r-- | kernel/module.c | 5 | ||||
-rw-r--r-- | kernel/sched/core.c | 17 | ||||
-rw-r--r-- | kernel/sched/deadline.c | 4 | ||||
-rw-r--r-- | kernel/sched/rt.c | 2 | ||||
-rw-r--r-- | kernel/sched/sched.h | 5 | ||||
-rw-r--r-- | kernel/signal.c | 17 | ||||
-rw-r--r-- | kernel/stop_machine.c | 19 |
11 files changed, 73 insertions, 54 deletions
diff --git a/kernel/kthread.c b/kernel/kthread.c index 1c19edf82427..1ef8f3a5b072 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -169,12 +169,13 @@ void *kthread_probe_data(struct task_struct *task) static void __kthread_parkme(struct kthread *self) { - __set_current_state(TASK_PARKED); - while (test_bit(KTHREAD_SHOULD_PARK, &self->flags)) { + for (;;) { + set_current_state(TASK_PARKED); + if (!test_bit(KTHREAD_SHOULD_PARK, &self->flags)) + break; if (!test_and_set_bit(KTHREAD_IS_PARKED, &self->flags)) complete(&self->parked); schedule(); - __set_current_state(TASK_PARKED); } clear_bit(KTHREAD_IS_PARKED, &self->flags); __set_current_state(TASK_RUNNING); diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index e795908f3607..a90336779375 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -352,16 +352,15 @@ static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem) struct task_struct *owner; bool ret = true; + BUILD_BUG_ON(!rwsem_has_anonymous_owner(RWSEM_OWNER_UNKNOWN)); + if (need_resched()) return false; rcu_read_lock(); owner = READ_ONCE(sem->owner); - if (!rwsem_owner_is_writer(owner)) { - /* - * Don't spin if the rwsem is readers owned. - */ - ret = !rwsem_owner_is_reader(owner); + if (!owner || !is_rwsem_owner_spinnable(owner)) { + ret = !owner; /* !owner is spinnable */ goto done; } @@ -382,11 +381,11 @@ static noinline bool rwsem_spin_on_owner(struct rw_semaphore *sem) { struct task_struct *owner = READ_ONCE(sem->owner); - if (!rwsem_owner_is_writer(owner)) - goto out; + if (!is_rwsem_owner_spinnable(owner)) + return false; rcu_read_lock(); - while (sem->owner == owner) { + while (owner && (READ_ONCE(sem->owner) == owner)) { /* * Ensure we emit the owner->on_cpu, dereference _after_ * checking sem->owner still matches owner, if that fails, @@ -408,12 +407,12 @@ static noinline bool rwsem_spin_on_owner(struct rw_semaphore *sem) cpu_relax(); } rcu_read_unlock(); -out: + /* * If there is a new owner or the owner is not set, we continue * spinning. */ - return !rwsem_owner_is_reader(READ_ONCE(sem->owner)); + return is_rwsem_owner_spinnable(READ_ONCE(sem->owner)); } static bool rwsem_optimistic_spin(struct rw_semaphore *sem) diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index a6c76a4832b4..22bd01a7dcaa 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -201,5 +201,3 @@ void up_read_non_owner(struct rw_semaphore *sem) EXPORT_SYMBOL(up_read_non_owner); #endif - - diff --git a/kernel/locking/rwsem.h b/kernel/locking/rwsem.h index a883b8f1fdc6..410ee7b9ac2c 100644 --- a/kernel/locking/rwsem.h +++ b/kernel/locking/rwsem.h @@ -1,20 +1,24 @@ /* SPDX-License-Identifier: GPL-2.0 */ /* * The owner field of the rw_semaphore structure will be set to - * RWSEM_READ_OWNED when a reader grabs the lock. A writer will clear + * RWSEM_READER_OWNED when a reader grabs the lock. A writer will clear * the owner field when it unlocks. A reader, on the other hand, will * not touch the owner field when it unlocks. * - * In essence, the owner field now has the following 3 states: + * In essence, the owner field now has the following 4 states: * 1) 0 * - lock is free or the owner hasn't set the field yet * 2) RWSEM_READER_OWNED * - lock is currently or previously owned by readers (lock is free * or not set by owner yet) - * 3) Other non-zero value - * - a writer owns the lock + * 3) RWSEM_ANONYMOUSLY_OWNED bit set with some other bits set as well + * - lock is owned by an anonymous writer, so spinning on the lock + * owner should be disabled. + * 4) Other non-zero value + * - a writer owns the lock and other writers can spin on the lock owner. */ -#define RWSEM_READER_OWNED ((struct task_struct *)1UL) +#define RWSEM_ANONYMOUSLY_OWNED (1UL << 0) +#define RWSEM_READER_OWNED ((struct task_struct *)RWSEM_ANONYMOUSLY_OWNED) #ifdef CONFIG_RWSEM_SPIN_ON_OWNER /* @@ -45,14 +49,22 @@ static inline void rwsem_set_reader_owned(struct rw_semaphore *sem) WRITE_ONCE(sem->owner, RWSEM_READER_OWNED); } -static inline bool rwsem_owner_is_writer(struct task_struct *owner) +/* + * Return true if the a rwsem waiter can spin on the rwsem's owner + * and steal the lock, i.e. the lock is not anonymously owned. + * N.B. !owner is considered spinnable. + */ +static inline bool is_rwsem_owner_spinnable(struct task_struct *owner) { - return owner && owner != RWSEM_READER_OWNED; + return !((unsigned long)owner & RWSEM_ANONYMOUSLY_OWNED); } -static inline bool rwsem_owner_is_reader(struct task_struct *owner) +/* + * Return true if rwsem is owned by an anonymous writer or readers. + */ +static inline bool rwsem_has_anonymous_owner(struct task_struct *owner) { - return owner == RWSEM_READER_OWNED; + return (unsigned long)owner & RWSEM_ANONYMOUSLY_OWNED; } #else static inline void rwsem_set_owner(struct rw_semaphore *sem) diff --git a/kernel/module.c b/kernel/module.c index 690c0651c40f..321b0b1f87e7 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3506,6 +3506,11 @@ static noinline int do_init_module(struct module *mod) * walking this with preempt disabled. In all the failure paths, we * call synchronize_sched(), but we don't want to slow down the success * path, so use actual RCU here. + * Note that module_alloc() on most architectures creates W+X page + * mappings which won't be cleaned up until do_free_init() runs. Any + * code such as mark_rodata_ro() which depends on those mappings to + * be cleaned up needs to sync with the queued work - ie + * rcu_barrier_sched() */ call_rcu_sched(&freeinit->rcu, do_free_init); mutex_unlock(&module_mutex); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 8cf36b30a006..f287dcbe8cb2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3374,23 +3374,8 @@ static void __sched notrace __schedule(bool preempt) void __noreturn do_task_dead(void) { - /* - * The setting of TASK_RUNNING by try_to_wake_up() may be delayed - * when the following two conditions become true. - * - There is race condition of mmap_sem (It is acquired by - * exit_mm()), and - * - SMI occurs before setting TASK_RUNINNG. - * (or hypervisor of virtual machine switches to other guest) - * As a result, we may become TASK_RUNNING after becoming TASK_DEAD - * - * To avoid it, we have to wait for releasing tsk->pi_lock which - * is held by try_to_wake_up() - */ - raw_spin_lock_irq(¤t->pi_lock); - raw_spin_unlock_irq(¤t->pi_lock); - /* Causes final put_task_struct in finish_task_switch(): */ - __set_current_state(TASK_DEAD); + set_special_state(TASK_DEAD); /* Tell freezer to ignore us: */ current->flags |= PF_NOFREEZE; diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 4ae5c1ea90e2..501f17c642ab 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1084,7 +1084,7 @@ extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq); * should be larger than 2^(64 - 20 - 8), which is more than 64 seconds. * So, overflow is not an issue here. */ -u64 grub_reclaim(u64 delta, struct rq *rq, struct sched_dl_entity *dl_se) +static u64 grub_reclaim(u64 delta, struct rq *rq, struct sched_dl_entity *dl_se) { u64 u_inact = rq->dl.this_bw - rq->dl.running_bw; /* Utot - Uact */ u64 u_act; @@ -2655,8 +2655,6 @@ bool dl_cpu_busy(unsigned int cpu) #endif #ifdef CONFIG_SCHED_DEBUG -extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq); - void print_dl_stats(struct seq_file *m, int cpu) { print_dl_rq(m, cpu, &cpu_rq(cpu)->dl); diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 113eaeb6c0f8..bba2217652ff 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2689,8 +2689,6 @@ int sched_rr_handler(struct ctl_table *table, int write, } #ifdef CONFIG_SCHED_DEBUG -extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); - void print_rt_stats(struct seq_file *m, int cpu) { rt_rq_iter_t iter; diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 307c35d33660..b29376169f3f 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1969,8 +1969,9 @@ extern bool sched_debug_enabled; extern void print_cfs_stats(struct seq_file *m, int cpu); extern void print_rt_stats(struct seq_file *m, int cpu); extern void print_dl_stats(struct seq_file *m, int cpu); -extern void -print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); +extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); +extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); +extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq); #ifdef CONFIG_NUMA_BALANCING extern void show_numa_stats(struct task_struct *p, struct seq_file *m); diff --git a/kernel/signal.c b/kernel/signal.c index 6895f6bb98a7..4439ba9dc5d9 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1828,14 +1828,27 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) return; } + set_special_state(TASK_TRACED); + /* * We're committing to trapping. TRACED should be visible before * TRAPPING is cleared; otherwise, the tracer might fail do_wait(). * Also, transition to TRACED and updates to ->jobctl should be * atomic with respect to siglock and should be done after the arch * hook as siglock is released and regrabbed across it. + * + * TRACER TRACEE + * + * ptrace_attach() + * [L] wait_on_bit(JOBCTL_TRAPPING) [S] set_special_state(TRACED) + * do_wait() + * set_current_state() smp_wmb(); + * ptrace_do_wait() + * wait_task_stopped() + * task_stopped_code() + * [L] task_is_traced() [S] task_clear_jobctl_trapping(); */ - set_current_state(TASK_TRACED); + smp_wmb(); current->last_siginfo = info; current->exit_code = exit_code; @@ -2043,7 +2056,7 @@ static bool do_signal_stop(int signr) if (task_participate_group_stop(current)) notify = CLD_STOPPED; - __set_current_state(TASK_STOPPED); + set_special_state(TASK_STOPPED); spin_unlock_irq(¤t->sighand->siglock); /* diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index b7591261652d..64c0291b579c 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -21,6 +21,7 @@ #include <linux/smpboot.h> #include <linux/atomic.h> #include <linux/nmi.h> +#include <linux/sched/wake_q.h> /* * Structure to determine completion condition and record errors. May @@ -65,27 +66,31 @@ static void cpu_stop_signal_done(struct cpu_stop_done *done) } static void __cpu_stop_queue_work(struct cpu_stopper *stopper, - struct cpu_stop_work *work) + struct cpu_stop_work *work, + struct wake_q_head *wakeq) { list_add_tail(&work->list, &stopper->works); - wake_up_process(stopper->thread); + wake_q_add(wakeq, stopper->thread); } /* queue @work to @stopper. if offline, @work is completed immediately */ static bool cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work) { struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); + DEFINE_WAKE_Q(wakeq); unsigned long flags; bool enabled; spin_lock_irqsave(&stopper->lock, flags); enabled = stopper->enabled; if (enabled) - __cpu_stop_queue_work(stopper, work); + __cpu_stop_queue_work(stopper, work, &wakeq); else if (work->done) cpu_stop_signal_done(work->done); spin_unlock_irqrestore(&stopper->lock, flags); + wake_up_q(&wakeq); + return enabled; } @@ -229,6 +234,7 @@ static int cpu_stop_queue_two_works(int cpu1, struct cpu_stop_work *work1, { struct cpu_stopper *stopper1 = per_cpu_ptr(&cpu_stopper, cpu1); struct cpu_stopper *stopper2 = per_cpu_ptr(&cpu_stopper, cpu2); + DEFINE_WAKE_Q(wakeq); int err; retry: spin_lock_irq(&stopper1->lock); @@ -252,8 +258,8 @@ retry: goto unlock; err = 0; - __cpu_stop_queue_work(stopper1, work1); - __cpu_stop_queue_work(stopper2, work2); + __cpu_stop_queue_work(stopper1, work1, &wakeq); + __cpu_stop_queue_work(stopper2, work2, &wakeq); unlock: spin_unlock(&stopper2->lock); spin_unlock_irq(&stopper1->lock); @@ -263,6 +269,9 @@ unlock: cpu_relax(); goto retry; } + + wake_up_q(&wakeq); + return err; } /** |