diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup.c | 7 | ||||
| -rw-r--r-- | kernel/fork.c | 3 | ||||
| -rw-r--r-- | kernel/kthread.c | 7 | ||||
| -rw-r--r-- | kernel/sched/wait.c | 7 | ||||
| -rw-r--r-- | kernel/smpboot.c | 27 | ||||
| -rw-r--r-- | kernel/sys_ni.c | 1 | ||||
| -rw-r--r-- | kernel/user_namespace.c | 1 | ||||
| -rw-r--r-- | kernel/watchdog.c | 189 |
8 files changed, 143 insertions, 99 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index f3f5cd5e2c0d..a8538e443784 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1342,7 +1342,7 @@ static int cgroup_show_options(struct seq_file *seq, if (root != &cgrp_dfl_root) for_each_subsys(ss, ssid) if (root->subsys_mask & (1 << ssid)) - seq_printf(seq, ",%s", ss->legacy_name); + seq_show_option(seq, ss->name, NULL); if (root->flags & CGRP_ROOT_NOPREFIX) seq_puts(seq, ",noprefix"); if (root->flags & CGRP_ROOT_XATTR) @@ -1350,13 +1350,14 @@ static int cgroup_show_options(struct seq_file *seq, spin_lock(&release_agent_path_lock); if (strlen(root->release_agent_path)) - seq_printf(seq, ",release_agent=%s", root->release_agent_path); + seq_show_option(seq, "release_agent", + root->release_agent_path); spin_unlock(&release_agent_path_lock); if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags)) seq_puts(seq, ",clone_children"); if (strlen(root->name)) - seq_printf(seq, ",name=%s", root->name); + seq_show_option(seq, "name", root->name); return 0; } diff --git a/kernel/fork.c b/kernel/fork.c index 03aa2e6de7a4..7d5f0f118a63 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -454,8 +454,9 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) tmp->vm_mm = mm; if (anon_vma_fork(tmp, mpnt)) goto fail_nomem_anon_vma_fork; - tmp->vm_flags &= ~VM_LOCKED; + tmp->vm_flags &= ~(VM_LOCKED|VM_UFFD_MISSING|VM_UFFD_WP); tmp->vm_next = tmp->vm_prev = NULL; + tmp->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; file = tmp->vm_file; if (file) { struct inode *inode = file_inode(file); diff --git a/kernel/kthread.c b/kernel/kthread.c index 490924cc9e7c..9ff173dca1ae 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -248,15 +248,16 @@ static void create_kthread(struct kthread_create_info *create) * kthread_create_on_node - create a kthread. * @threadfn: the function to run until signal_pending(current). * @data: data ptr for @threadfn. - * @node: memory node number. + * @node: task and thread structures for the thread are allocated on this node * @namefmt: printf-style name for the thread. * * Description: This helper function creates and names a kernel * thread. The thread will be stopped: use wake_up_process() to start - * it. See also kthread_run(). + * it. See also kthread_run(). The new thread has SCHED_NORMAL policy and + * is affine to all CPUs. * * If thread is going to be bound on a particular cpu, give its node - * in @node, to get NUMA affinity for kthread stack, or else give -1. + * in @node, to get NUMA affinity for kthread stack, or else give NUMA_NO_NODE. * When woken, the thread will run @threadfn() with @data as its * argument. @threadfn() can either call do_exit() directly if it is a * standalone thread for which no one will call kthread_stop(), or diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c index 052e02672d12..272d9322bc5d 100644 --- a/kernel/sched/wait.c +++ b/kernel/sched/wait.c @@ -106,9 +106,10 @@ void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr) } EXPORT_SYMBOL_GPL(__wake_up_locked); -void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) +void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, int nr, + void *key) { - __wake_up_common(q, mode, 1, 0, key); + __wake_up_common(q, mode, nr, 0, key); } EXPORT_SYMBOL_GPL(__wake_up_locked_key); @@ -283,7 +284,7 @@ void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, if (!list_empty(&wait->task_list)) list_del_init(&wait->task_list); else if (waitqueue_active(q)) - __wake_up_locked_key(q, mode, key); + __wake_up_locked_key(q, mode, 1, key); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL(abort_exclusive_wait); diff --git a/kernel/smpboot.c b/kernel/smpboot.c index 7c434c39f02a..a818cbc73e14 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -113,7 +113,8 @@ static int smpboot_thread_fn(void *data) if (kthread_should_stop()) { __set_current_state(TASK_RUNNING); preempt_enable(); - if (ht->cleanup) + /* cleanup must mirror setup */ + if (ht->cleanup && td->status != HP_THREAD_NONE) ht->cleanup(td->cpu, cpu_online(td->cpu)); kfree(td); return 0; @@ -259,15 +260,6 @@ static void smpboot_destroy_threads(struct smp_hotplug_thread *ht) { unsigned int cpu; - /* Unpark any threads that were voluntarily parked. */ - for_each_cpu_not(cpu, ht->cpumask) { - if (cpu_online(cpu)) { - struct task_struct *tsk = *per_cpu_ptr(ht->store, cpu); - if (tsk) - kthread_unpark(tsk); - } - } - /* We need to destroy also the parked threads of offline cpus */ for_each_possible_cpu(cpu) { struct task_struct *tsk = *per_cpu_ptr(ht->store, cpu); @@ -281,19 +273,22 @@ static void smpboot_destroy_threads(struct smp_hotplug_thread *ht) } /** - * smpboot_register_percpu_thread - Register a per_cpu thread related to hotplug + * smpboot_register_percpu_thread_cpumask - Register a per_cpu thread related + * to hotplug * @plug_thread: Hotplug thread descriptor + * @cpumask: The cpumask where threads run * * Creates and starts the threads on all online cpus. */ -int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread) +int smpboot_register_percpu_thread_cpumask(struct smp_hotplug_thread *plug_thread, + const struct cpumask *cpumask) { unsigned int cpu; int ret = 0; if (!alloc_cpumask_var(&plug_thread->cpumask, GFP_KERNEL)) return -ENOMEM; - cpumask_copy(plug_thread->cpumask, cpu_possible_mask); + cpumask_copy(plug_thread->cpumask, cpumask); get_online_cpus(); mutex_lock(&smpboot_threads_lock); @@ -301,9 +296,11 @@ int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread) ret = __smpboot_create_thread(plug_thread, cpu); if (ret) { smpboot_destroy_threads(plug_thread); + free_cpumask_var(plug_thread->cpumask); goto out; } - smpboot_unpark_thread(plug_thread, cpu); + if (cpumask_test_cpu(cpu, cpumask)) + smpboot_unpark_thread(plug_thread, cpu); } list_add(&plug_thread->list, &hotplug_threads); out: @@ -311,7 +308,7 @@ out: put_online_cpus(); return ret; } -EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread); +EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread_cpumask); /** * smpboot_unregister_percpu_thread - Unregister a per_cpu thread related to hotplug diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index ca7d84f438f1..03c3875d9958 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -219,6 +219,7 @@ cond_syscall(compat_sys_timerfd_gettime); cond_syscall(sys_eventfd); cond_syscall(sys_eventfd2); cond_syscall(sys_memfd_create); +cond_syscall(sys_userfaultfd); /* performance counters: */ cond_syscall(sys_perf_event_open); diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index f65a0a06a8c0..88fefa68c516 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -39,6 +39,7 @@ static void set_cred_user_ns(struct cred *cred, struct user_namespace *user_ns) cred->cap_inheritable = CAP_EMPTY_SET; cred->cap_permitted = CAP_FULL_SET; cred->cap_effective = CAP_FULL_SET; + cred->cap_ambient = CAP_EMPTY_SET; cred->cap_bset = CAP_FULL_SET; #ifdef CONFIG_KEYS key_put(cred->request_key_auth); diff --git a/kernel/watchdog.c b/kernel/watchdog.c index a6ffa43f2993..64ed1c37bd1f 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -24,6 +24,7 @@ #include <asm/irq_regs.h> #include <linux/kvm_para.h> #include <linux/perf_event.h> +#include <linux/kthread.h> /* * The run state of the lockup detectors is controlled by the content of the @@ -66,7 +67,26 @@ unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask); #define for_each_watchdog_cpu(cpu) \ for_each_cpu_and((cpu), cpu_online_mask, &watchdog_cpumask) +/* + * The 'watchdog_running' variable is set to 1 when the watchdog threads + * are registered/started and is set to 0 when the watchdog threads are + * unregistered/stopped, so it is an indicator whether the threads exist. + */ static int __read_mostly watchdog_running; +/* + * If a subsystem has a need to deactivate the watchdog temporarily, it + * can use the suspend/resume interface to achieve this. The content of + * the 'watchdog_suspended' variable reflects this state. Existing threads + * are parked/unparked by the lockup_detector_{suspend|resume} functions + * (see comment blocks pertaining to those functions for further details). + * + * 'watchdog_suspended' also prevents threads from being registered/started + * or unregistered/stopped via parameters in /proc/sys/kernel, so the state + * of 'watchdog_running' cannot change while the watchdog is deactivated + * temporarily (see related code in 'proc' handlers). + */ +static int __read_mostly watchdog_suspended; + static u64 __read_mostly sample_period; static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts); @@ -613,46 +633,9 @@ static void watchdog_nmi_disable(unsigned int cpu) } } -void watchdog_nmi_enable_all(void) -{ - int cpu; - - mutex_lock(&watchdog_proc_mutex); - - if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED)) - goto unlock; - - get_online_cpus(); - for_each_watchdog_cpu(cpu) - watchdog_nmi_enable(cpu); - put_online_cpus(); - -unlock: - mutex_unlock(&watchdog_proc_mutex); -} - -void watchdog_nmi_disable_all(void) -{ - int cpu; - - mutex_lock(&watchdog_proc_mutex); - - if (!watchdog_running) - goto unlock; - - get_online_cpus(); - for_each_watchdog_cpu(cpu) - watchdog_nmi_disable(cpu); - put_online_cpus(); - -unlock: - mutex_unlock(&watchdog_proc_mutex); -} #else static int watchdog_nmi_enable(unsigned int cpu) { return 0; } static void watchdog_nmi_disable(unsigned int cpu) { return; } -void watchdog_nmi_enable_all(void) {} -void watchdog_nmi_disable_all(void) {} #endif /* CONFIG_HARDLOCKUP_DETECTOR */ static struct smp_hotplug_thread watchdog_threads = { @@ -666,46 +649,89 @@ static struct smp_hotplug_thread watchdog_threads = { .unpark = watchdog_enable, }; -static void restart_watchdog_hrtimer(void *info) +/* + * park all watchdog threads that are specified in 'watchdog_cpumask' + */ +static int watchdog_park_threads(void) { - struct hrtimer *hrtimer = raw_cpu_ptr(&watchdog_hrtimer); - int ret; + int cpu, ret = 0; + get_online_cpus(); + for_each_watchdog_cpu(cpu) { + ret = kthread_park(per_cpu(softlockup_watchdog, cpu)); + if (ret) + break; + } + if (ret) { + for_each_watchdog_cpu(cpu) + kthread_unpark(per_cpu(softlockup_watchdog, cpu)); + } + put_online_cpus(); + + return ret; +} + +/* + * unpark all watchdog threads that are specified in 'watchdog_cpumask' + */ +static void watchdog_unpark_threads(void) +{ + int cpu; + + get_online_cpus(); + for_each_watchdog_cpu(cpu) + kthread_unpark(per_cpu(softlockup_watchdog, cpu)); + put_online_cpus(); +} + +/* + * Suspend the hard and soft lockup detector by parking the watchdog threads. + */ +int lockup_detector_suspend(void) +{ + int ret = 0; + + mutex_lock(&watchdog_proc_mutex); /* - * No need to cancel and restart hrtimer if it is currently executing - * because it will reprogram itself with the new period now. - * We should never see it unqueued here because we are running per-cpu - * with interrupts disabled. + * Multiple suspend requests can be active in parallel (counted by + * the 'watchdog_suspended' variable). If the watchdog threads are + * running, the first caller takes care that they will be parked. + * The state of 'watchdog_running' cannot change while a suspend + * request is active (see related code in 'proc' handlers). */ - ret = hrtimer_try_to_cancel(hrtimer); - if (ret == 1) - hrtimer_start(hrtimer, ns_to_ktime(sample_period), - HRTIMER_MODE_REL_PINNED); + if (watchdog_running && !watchdog_suspended) + ret = watchdog_park_threads(); + + if (ret == 0) + watchdog_suspended++; + + mutex_unlock(&watchdog_proc_mutex); + + return ret; } -static void update_watchdog(int cpu) +/* + * Resume the hard and soft lockup detector by unparking the watchdog threads. + */ +void lockup_detector_resume(void) { + mutex_lock(&watchdog_proc_mutex); + + watchdog_suspended--; /* - * Make sure that perf event counter will adopt to a new - * sampling period. Updating the sampling period directly would - * be much nicer but we do not have an API for that now so - * let's use a big hammer. - * Hrtimer will adopt the new period on the next tick but this - * might be late already so we have to restart the timer as well. + * The watchdog threads are unparked if they were previously running + * and if there is no more active suspend request. */ - watchdog_nmi_disable(cpu); - smp_call_function_single(cpu, restart_watchdog_hrtimer, NULL, 1); - watchdog_nmi_enable(cpu); + if (watchdog_running && !watchdog_suspended) + watchdog_unpark_threads(); + + mutex_unlock(&watchdog_proc_mutex); } static void update_watchdog_all_cpus(void) { - int cpu; - - get_online_cpus(); - for_each_watchdog_cpu(cpu) - update_watchdog(cpu); - put_online_cpus(); + watchdog_park_threads(); + watchdog_unpark_threads(); } static int watchdog_enable_all_cpus(void) @@ -713,15 +739,12 @@ static int watchdog_enable_all_cpus(void) int err = 0; if (!watchdog_running) { - err = smpboot_register_percpu_thread(&watchdog_threads); + err = smpboot_register_percpu_thread_cpumask(&watchdog_threads, + &watchdog_cpumask); if (err) pr_err("Failed to create watchdog threads, disabled\n"); - else { - if (smpboot_update_cpumask_percpu_thread( - &watchdog_threads, &watchdog_cpumask)) - pr_err("Failed to set cpumask for watchdog threads\n"); + else watchdog_running = 1; - } } else { /* * Enable/disable the lockup detectors or @@ -787,6 +810,12 @@ static int proc_watchdog_common(int which, struct ctl_table *table, int write, mutex_lock(&watchdog_proc_mutex); + if (watchdog_suspended) { + /* no parameter changes allowed while watchdog is suspended */ + err = -EAGAIN; + goto out; + } + /* * If the parameter is being read return the state of the corresponding * bit(s) in 'watchdog_enabled', else update 'watchdog_enabled' and the @@ -872,6 +901,12 @@ int proc_watchdog_thresh(struct ctl_table *table, int write, mutex_lock(&watchdog_proc_mutex); + if (watchdog_suspended) { + /* no parameter changes allowed while watchdog is suspended */ + err = -EAGAIN; + goto out; + } + old = ACCESS_ONCE(watchdog_thresh); err = proc_dointvec_minmax(table, write, buffer, lenp, ppos); @@ -903,6 +938,13 @@ int proc_watchdog_cpumask(struct ctl_table *table, int write, int err; mutex_lock(&watchdog_proc_mutex); + + if (watchdog_suspended) { + /* no parameter changes allowed while watchdog is suspended */ + err = -EAGAIN; + goto out; + } + err = proc_do_large_bitmap(table, write, buffer, lenp, ppos); if (!err && write) { /* Remove impossible cpus to keep sysctl output cleaner. */ @@ -920,6 +962,7 @@ int proc_watchdog_cpumask(struct ctl_table *table, int write, pr_err("cpumask update failed\n"); } } +out: mutex_unlock(&watchdog_proc_mutex); return err; } @@ -932,10 +975,8 @@ void __init lockup_detector_init(void) #ifdef CONFIG_NO_HZ_FULL if (tick_nohz_full_enabled()) { - if (!cpumask_empty(tick_nohz_full_mask)) - pr_info("Disabling watchdog on nohz_full cores by default\n"); - cpumask_andnot(&watchdog_cpumask, cpu_possible_mask, - tick_nohz_full_mask); + pr_info("Disabling watchdog on nohz_full cores by default\n"); + cpumask_copy(&watchdog_cpumask, housekeeping_mask); } else cpumask_copy(&watchdog_cpumask, cpu_possible_mask); #else |