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authorIngo Molnar <mingo@kernel.org>2018-05-15 08:10:50 +0200
committerIngo Molnar <mingo@kernel.org>2018-05-15 08:10:50 +0200
commit371b3269082500fc418043742467119ab0d224c6 (patch)
tree02f0e932e356adef8c34420be9a3d0fd5283e803 /kernel
parent8cc05c71ba5f793690bb72aeb404dce65b5d4b52 (diff)
parent67b8d5c7081221efa252e111cd52532ec6d4266f (diff)
downloadlinux-371b3269082500fc418043742467119ab0d224c6.tar.bz2
Merge tag 'v4.17-rc5' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/syscall.c19
-rw-r--r--kernel/compat.c1
-rw-r--r--kernel/events/ring_buffer.c7
-rw-r--r--kernel/kthread.c50
-rw-r--r--kernel/module.c5
-rw-r--r--kernel/sched/autogroup.c7
-rw-r--r--kernel/sched/core.c56
-rw-r--r--kernel/sched/cpufreq_schedutil.c16
-rw-r--r--kernel/sched/fair.c59
-rw-r--r--kernel/signal.c17
-rw-r--r--kernel/stop_machine.c19
-rw-r--r--kernel/time/clocksource.c63
-rw-r--r--kernel/trace/ftrace.c4
-rw-r--r--kernel/trace/trace_events_filter.c3
-rw-r--r--kernel/trace/trace_stack.c2
15 files changed, 164 insertions, 164 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index ebfe9f29dae8..016ef9025827 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -26,6 +26,7 @@
#include <linux/cred.h>
#include <linux/timekeeping.h>
#include <linux/ctype.h>
+#include <linux/nospec.h>
#define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
(map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
@@ -102,12 +103,14 @@ const struct bpf_map_ops bpf_map_offload_ops = {
static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
{
const struct bpf_map_ops *ops;
+ u32 type = attr->map_type;
struct bpf_map *map;
int err;
- if (attr->map_type >= ARRAY_SIZE(bpf_map_types))
+ if (type >= ARRAY_SIZE(bpf_map_types))
return ERR_PTR(-EINVAL);
- ops = bpf_map_types[attr->map_type];
+ type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types));
+ ops = bpf_map_types[type];
if (!ops)
return ERR_PTR(-EINVAL);
@@ -122,7 +125,7 @@ static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
if (IS_ERR(map))
return map;
map->ops = ops;
- map->map_type = attr->map_type;
+ map->map_type = type;
return map;
}
@@ -871,11 +874,17 @@ static const struct bpf_prog_ops * const bpf_prog_types[] = {
static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
{
- if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
+ const struct bpf_prog_ops *ops;
+
+ if (type >= ARRAY_SIZE(bpf_prog_types))
+ return -EINVAL;
+ type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
+ ops = bpf_prog_types[type];
+ if (!ops)
return -EINVAL;
if (!bpf_prog_is_dev_bound(prog->aux))
- prog->aux->ops = bpf_prog_types[type];
+ prog->aux->ops = ops;
else
prog->aux->ops = &bpf_offload_prog_ops;
prog->type = type;
diff --git a/kernel/compat.c b/kernel/compat.c
index 6d21894806b4..92d8c98c0f57 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -34,6 +34,7 @@ int compat_get_timex(struct timex *txc, const struct compat_timex __user *utp)
{
struct compat_timex tx32;
+ memset(txc, 0, sizeof(struct timex));
if (copy_from_user(&tx32, utp, sizeof(struct compat_timex)))
return -EFAULT;
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 6c6b3c48db71..1d8ca9ea9979 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -14,6 +14,7 @@
#include <linux/slab.h>
#include <linux/circ_buf.h>
#include <linux/poll.h>
+#include <linux/nospec.h>
#include "internal.h"
@@ -867,8 +868,10 @@ perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
return NULL;
/* AUX space */
- if (pgoff >= rb->aux_pgoff)
- return virt_to_page(rb->aux_pages[pgoff - rb->aux_pgoff]);
+ if (pgoff >= rb->aux_pgoff) {
+ int aux_pgoff = array_index_nospec(pgoff - rb->aux_pgoff, rb->aux_nr_pages);
+ return virt_to_page(rb->aux_pages[aux_pgoff]);
+ }
}
return __perf_mmap_to_page(rb, pgoff);
diff --git a/kernel/kthread.c b/kernel/kthread.c
index cd50e99202b0..2017a39ab490 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -55,7 +55,6 @@ enum KTHREAD_BITS {
KTHREAD_IS_PER_CPU = 0,
KTHREAD_SHOULD_STOP,
KTHREAD_SHOULD_PARK,
- KTHREAD_IS_PARKED,
};
static inline void set_kthread_struct(void *kthread)
@@ -177,14 +176,12 @@ 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)) {
- if (!test_and_set_bit(KTHREAD_IS_PARKED, &self->flags))
- complete(&self->parked);
+ for (;;) {
+ set_current_state(TASK_PARKED);
+ if (!test_bit(KTHREAD_SHOULD_PARK, &self->flags))
+ break;
schedule();
- __set_current_state(TASK_PARKED);
}
- clear_bit(KTHREAD_IS_PARKED, &self->flags);
__set_current_state(TASK_RUNNING);
}
@@ -194,6 +191,11 @@ void kthread_parkme(void)
}
EXPORT_SYMBOL_GPL(kthread_parkme);
+void kthread_park_complete(struct task_struct *k)
+{
+ complete(&to_kthread(k)->parked);
+}
+
static int kthread(void *_create)
{
/* Copy data: it's on kthread's stack */
@@ -450,22 +452,15 @@ void kthread_unpark(struct task_struct *k)
{
struct kthread *kthread = to_kthread(k);
- clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
/*
- * We clear the IS_PARKED bit here as we don't wait
- * until the task has left the park code. So if we'd
- * park before that happens we'd see the IS_PARKED bit
- * which might be about to be cleared.
+ * Newly created kthread was parked when the CPU was offline.
+ * The binding was lost and we need to set it again.
*/
- if (test_and_clear_bit(KTHREAD_IS_PARKED, &kthread->flags)) {
- /*
- * Newly created kthread was parked when the CPU was offline.
- * The binding was lost and we need to set it again.
- */
- if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags))
- __kthread_bind(k, kthread->cpu, TASK_PARKED);
- wake_up_state(k, TASK_PARKED);
- }
+ if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags))
+ __kthread_bind(k, kthread->cpu, TASK_PARKED);
+
+ clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
+ wake_up_state(k, TASK_PARKED);
}
EXPORT_SYMBOL_GPL(kthread_unpark);
@@ -488,12 +483,13 @@ int kthread_park(struct task_struct *k)
if (WARN_ON(k->flags & PF_EXITING))
return -ENOSYS;
- if (!test_bit(KTHREAD_IS_PARKED, &kthread->flags)) {
- set_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
- if (k != current) {
- wake_up_process(k);
- wait_for_completion(&kthread->parked);
- }
+ if (WARN_ON_ONCE(test_bit(KTHREAD_SHOULD_PARK, &kthread->flags)))
+ return -EBUSY;
+
+ set_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
+ if (k != current) {
+ wake_up_process(k);
+ wait_for_completion(&kthread->parked);
}
return 0;
diff --git a/kernel/module.c b/kernel/module.c
index ce8066b88178..c9bea7f2b43e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3517,6 +3517,11 @@ 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/autogroup.c b/kernel/sched/autogroup.c
index 6be6c575b6cd..2d4ff5353ded 100644
--- a/kernel/sched/autogroup.c
+++ b/kernel/sched/autogroup.c
@@ -2,6 +2,7 @@
/*
* Auto-group scheduling implementation:
*/
+#include <linux/nospec.h>
#include "sched.h"
unsigned int __read_mostly sysctl_sched_autogroup_enabled = 1;
@@ -209,7 +210,7 @@ int proc_sched_autogroup_set_nice(struct task_struct *p, int nice)
static unsigned long next = INITIAL_JIFFIES;
struct autogroup *ag;
unsigned long shares;
- int err;
+ int err, idx;
if (nice < MIN_NICE || nice > MAX_NICE)
return -EINVAL;
@@ -227,7 +228,9 @@ int proc_sched_autogroup_set_nice(struct task_struct *p, int nice)
next = HZ / 10 + jiffies;
ag = autogroup_task_get(p);
- shares = scale_load(sched_prio_to_weight[nice + 20]);
+
+ idx = array_index_nospec(nice + 20, 40);
+ shares = scale_load(sched_prio_to_weight[idx]);
down_write(&ag->lock);
err = sched_group_set_shares(ag->tg, shares);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5e10aaeebfcc..092f7c4de903 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7,6 +7,9 @@
*/
#include "sched.h"
+#include <linux/kthread.h>
+#include <linux/nospec.h>
+
#include <asm/switch_to.h>
#include <asm/tlb.h>
@@ -2718,20 +2721,28 @@ static struct rq *finish_task_switch(struct task_struct *prev)
membarrier_mm_sync_core_before_usermode(mm);
mmdrop(mm);
}
- if (unlikely(prev_state == TASK_DEAD)) {
- if (prev->sched_class->task_dead)
- prev->sched_class->task_dead(prev);
+ if (unlikely(prev_state & (TASK_DEAD|TASK_PARKED))) {
+ switch (prev_state) {
+ case TASK_DEAD:
+ if (prev->sched_class->task_dead)
+ prev->sched_class->task_dead(prev);
- /*
- * Remove function-return probe instances associated with this
- * task and put them back on the free list.
- */
- kprobe_flush_task(prev);
+ /*
+ * Remove function-return probe instances associated with this
+ * task and put them back on the free list.
+ */
+ kprobe_flush_task(prev);
+
+ /* Task is done with its stack. */
+ put_task_stack(prev);
- /* Task is done with its stack. */
- put_task_stack(prev);
+ put_task_struct(prev);
+ break;
- put_task_struct(prev);
+ case TASK_PARKED:
+ kthread_park_complete(prev);
+ break;
+ }
}
tick_nohz_task_switch();
@@ -3498,23 +3509,8 @@ 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(&current->pi_lock);
- raw_spin_unlock_irq(&current->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;
@@ -6928,11 +6924,15 @@ static int cpu_weight_nice_write_s64(struct cgroup_subsys_state *css,
struct cftype *cft, s64 nice)
{
unsigned long weight;
+ int idx;
if (nice < MIN_NICE || nice > MAX_NICE)
return -ERANGE;
- weight = sched_prio_to_weight[NICE_TO_PRIO(nice) - MAX_RT_PRIO];
+ idx = NICE_TO_PRIO(nice) - MAX_RT_PRIO;
+ idx = array_index_nospec(idx, 40);
+ weight = sched_prio_to_weight[idx];
+
return sched_group_set_shares(css_tg(css), scale_load(weight));
}
#endif
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index d2c6083304b4..e13df951aca7 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -305,7 +305,8 @@ static void sugov_update_single(struct update_util_data *hook, u64 time,
* Do not reduce the frequency if the CPU has not been idle
* recently, as the reduction is likely to be premature then.
*/
- if (busy && next_f < sg_policy->next_freq) {
+ if (busy && next_f < sg_policy->next_freq &&
+ sg_policy->next_freq != UINT_MAX) {
next_f = sg_policy->next_freq;
/* Reset cached freq as next_freq has changed */
@@ -396,19 +397,6 @@ static void sugov_irq_work(struct irq_work *irq_work)
sg_policy = container_of(irq_work, struct sugov_policy, irq_work);
- /*
- * For RT tasks, the schedutil governor shoots the frequency to maximum.
- * Special care must be taken to ensure that this kthread doesn't result
- * in the same behavior.
- *
- * This is (mostly) guaranteed by the work_in_progress flag. The flag is
- * updated only at the end of the sugov_work() function and before that
- * the schedutil governor rejects all other frequency scaling requests.
- *
- * There is a very rare case though, where the RT thread yields right
- * after the work_in_progress flag is cleared. The effects of that are
- * neglected for now.
- */
kthread_queue_work(&sg_policy->worker, &sg_policy->work);
}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 54dc31e7ab9b..79f574dba096 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1854,7 +1854,6 @@ static int task_numa_migrate(struct task_struct *p)
static void numa_migrate_preferred(struct task_struct *p)
{
unsigned long interval = HZ;
- unsigned long numa_migrate_retry;
/* This task has no NUMA fault statistics yet */
if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults))
@@ -1862,18 +1861,7 @@ static void numa_migrate_preferred(struct task_struct *p)
/* Periodically retry migrating the task to the preferred node */
interval = min(interval, msecs_to_jiffies(p->numa_scan_period) / 16);
- numa_migrate_retry = jiffies + interval;
-
- /*
- * Check that the new retry threshold is after the current one. If
- * the retry is in the future, it implies that wake_affine has
- * temporarily asked NUMA balancing to backoff from placement.
- */
- if (numa_migrate_retry > p->numa_migrate_retry)
- return;
-
- /* Safe to try placing the task on the preferred node */
- p->numa_migrate_retry = numa_migrate_retry;
+ p->numa_migrate_retry = jiffies + interval;
/* Success if task is already running on preferred CPU */
if (task_node(p) == p->numa_preferred_nid)
@@ -5922,48 +5910,6 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
return this_eff_load < prev_eff_load ? this_cpu : nr_cpumask_bits;
}
-#ifdef CONFIG_NUMA_BALANCING
-static void
-update_wa_numa_placement(struct task_struct *p, int prev_cpu, int target)
-{
- unsigned long interval;
-
- if (!static_branch_likely(&sched_numa_balancing))
- return;
-
- /* If balancing has no preference then continue gathering data */
- if (p->numa_preferred_nid == -1)
- return;
-
- /*
- * If the wakeup is not affecting locality then it is neutral from
- * the perspective of NUMA balacing so continue gathering data.
- */
- if (cpu_to_node(prev_cpu) == cpu_to_node(target))
- return;
-
- /*
- * Temporarily prevent NUMA balancing trying to place waker/wakee after
- * wakee has been moved by wake_affine. This will potentially allow
- * related tasks to converge and update their data placement. The
- * 4 * numa_scan_period is to allow the two-pass filter to migrate
- * hot data to the wakers node.
- */
- interval = max(sysctl_numa_balancing_scan_delay,
- p->numa_scan_period << 2);
- p->numa_migrate_retry = jiffies + msecs_to_jiffies(interval);
-
- interval = max(sysctl_numa_balancing_scan_delay,
- current->numa_scan_period << 2);
- current->numa_migrate_retry = jiffies + msecs_to_jiffies(interval);
-}
-#else
-static void
-update_wa_numa_placement(struct task_struct *p, int prev_cpu, int target)
-{
-}
-#endif
-
static int wake_affine(struct sched_domain *sd, struct task_struct *p,
int this_cpu, int prev_cpu, int sync)
{
@@ -5979,7 +5925,6 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p,
if (target == nr_cpumask_bits)
return prev_cpu;
- update_wa_numa_placement(p, prev_cpu, target);
schedstat_inc(sd->ttwu_move_affine);
schedstat_inc(p->se.statistics.nr_wakeups_affine);
return target;
@@ -9847,6 +9792,7 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf)
if (curr_cost > this_rq->max_idle_balance_cost)
this_rq->max_idle_balance_cost = curr_cost;
+out:
/*
* While browsing the domains, we released the rq lock, a task could
* have been enqueued in the meantime. Since we're not going idle,
@@ -9855,7 +9801,6 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf)
if (this_rq->cfs.h_nr_running && !pulled_task)
pulled_task = 1;
-out:
/* Move the next balance forward */
if (time_after(this_rq->next_balance, next_balance))
this_rq->next_balance = next_balance;
diff --git a/kernel/signal.c b/kernel/signal.c
index d4ccea599692..9c33163a6165 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1961,14 +1961,27 @@ 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;
@@ -2176,7 +2189,7 @@ 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(&current->sighand->siglock);
/*
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index c25ba18274fb..f89014a2c238 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;
raw_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);
raw_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:
raw_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:
raw_spin_unlock(&stopper2->lock);
raw_spin_unlock_irq(&stopper1->lock);
@@ -263,6 +269,9 @@ unlock:
cpu_relax();
goto retry;
}
+
+ wake_up_q(&wakeq);
+
return err;
}
/**
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 0e974cface0b..84f37420fcf5 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -119,6 +119,16 @@ static DEFINE_SPINLOCK(watchdog_lock);
static int watchdog_running;
static atomic_t watchdog_reset_pending;
+static void inline clocksource_watchdog_lock(unsigned long *flags)
+{
+ spin_lock_irqsave(&watchdog_lock, *flags);
+}
+
+static void inline clocksource_watchdog_unlock(unsigned long *flags)
+{
+ spin_unlock_irqrestore(&watchdog_lock, *flags);
+}
+
static int clocksource_watchdog_kthread(void *data);
static void __clocksource_change_rating(struct clocksource *cs, int rating);
@@ -142,9 +152,19 @@ static void __clocksource_unstable(struct clocksource *cs)
cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
cs->flags |= CLOCK_SOURCE_UNSTABLE;
+ /*
+ * If the clocksource is registered clocksource_watchdog_kthread() will
+ * re-rate and re-select.
+ */
+ if (list_empty(&cs->list)) {
+ cs->rating = 0;
+ return;
+ }
+
if (cs->mark_unstable)
cs->mark_unstable(cs);
+ /* kick clocksource_watchdog_kthread() */
if (finished_booting)
schedule_work(&watchdog_work);
}
@@ -153,10 +173,8 @@ static void __clocksource_unstable(struct clocksource *cs)
* clocksource_mark_unstable - mark clocksource unstable via watchdog
* @cs: clocksource to be marked unstable
*
- * This function is called instead of clocksource_change_rating from
- * cpu hotplug code to avoid a deadlock between the clocksource mutex
- * and the cpu hotplug mutex. It defers the update of the clocksource
- * to the watchdog thread.
+ * This function is called by the x86 TSC code to mark clocksources as unstable;
+ * it defers demotion and re-selection to a kthread.
*/
void clocksource_mark_unstable(struct clocksource *cs)
{
@@ -164,7 +182,7 @@ void clocksource_mark_unstable(struct clocksource *cs)
spin_lock_irqsave(&watchdog_lock, flags);
if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) {
- if (list_empty(&cs->wd_list))
+ if (!list_empty(&cs->list) && list_empty(&cs->wd_list))
list_add(&cs->wd_list, &watchdog_list);
__clocksource_unstable(cs);
}
@@ -319,9 +337,8 @@ static void clocksource_resume_watchdog(void)
static void clocksource_enqueue_watchdog(struct clocksource *cs)
{
- unsigned long flags;
+ INIT_LIST_HEAD(&cs->wd_list);
- spin_lock_irqsave(&watchdog_lock, flags);
if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
/* cs is a clocksource to be watched. */
list_add(&cs->wd_list, &watchdog_list);
@@ -331,7 +348,6 @@ static void clocksource_enqueue_watchdog(struct clocksource *cs)
if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
}
- spin_unlock_irqrestore(&watchdog_lock, flags);
}
static void clocksource_select_watchdog(bool fallback)
@@ -373,9 +389,6 @@ static void clocksource_select_watchdog(bool fallback)
static void clocksource_dequeue_watchdog(struct clocksource *cs)
{
- unsigned long flags;
-
- spin_lock_irqsave(&watchdog_lock, flags);
if (cs != watchdog) {
if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
/* cs is a watched clocksource. */
@@ -384,21 +397,19 @@ static void clocksource_dequeue_watchdog(struct clocksource *cs)
clocksource_stop_watchdog();
}
}
- spin_unlock_irqrestore(&watchdog_lock, flags);
}
static int __clocksource_watchdog_kthread(void)
{
struct clocksource *cs, *tmp;
unsigned long flags;
- LIST_HEAD(unstable);
int select = 0;
spin_lock_irqsave(&watchdog_lock, flags);
list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
list_del_init(&cs->wd_list);
- list_add(&cs->wd_list, &unstable);
+ __clocksource_change_rating(cs, 0);
select = 1;
}
if (cs->flags & CLOCK_SOURCE_RESELECT) {
@@ -410,11 +421,6 @@ static int __clocksource_watchdog_kthread(void)
clocksource_stop_watchdog();
spin_unlock_irqrestore(&watchdog_lock, flags);
- /* Needs to be done outside of watchdog lock */
- list_for_each_entry_safe(cs, tmp, &unstable, wd_list) {
- list_del_init(&cs->wd_list);
- __clocksource_change_rating(cs, 0);
- }
return select;
}
@@ -447,6 +453,9 @@ static inline int __clocksource_watchdog_kthread(void) { return 0; }
static bool clocksource_is_watchdog(struct clocksource *cs) { return false; }
void clocksource_mark_unstable(struct clocksource *cs) { }
+static void inline clocksource_watchdog_lock(unsigned long *flags) { }
+static void inline clocksource_watchdog_unlock(unsigned long *flags) { }
+
#endif /* CONFIG_CLOCKSOURCE_WATCHDOG */
/**
@@ -779,14 +788,19 @@ EXPORT_SYMBOL_GPL(__clocksource_update_freq_scale);
*/
int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
{
+ unsigned long flags;
/* Initialize mult/shift and max_idle_ns */
__clocksource_update_freq_scale(cs, scale, freq);
/* Add clocksource to the clocksource list */
mutex_lock(&clocksource_mutex);
+
+ clocksource_watchdog_lock(&flags);
clocksource_enqueue(cs);
clocksource_enqueue_watchdog(cs);
+ clocksource_watchdog_unlock(&flags);
+
clocksource_select();
clocksource_select_watchdog(false);
mutex_unlock(&clocksource_mutex);
@@ -808,8 +822,13 @@ static void __clocksource_change_rating(struct clocksource *cs, int rating)
*/
void clocksource_change_rating(struct clocksource *cs, int rating)
{
+ unsigned long flags;
+
mutex_lock(&clocksource_mutex);
+ clocksource_watchdog_lock(&flags);
__clocksource_change_rating(cs, rating);
+ clocksource_watchdog_unlock(&flags);
+
clocksource_select();
clocksource_select_watchdog(false);
mutex_unlock(&clocksource_mutex);
@@ -821,6 +840,8 @@ EXPORT_SYMBOL(clocksource_change_rating);
*/
static int clocksource_unbind(struct clocksource *cs)
{
+ unsigned long flags;
+
if (clocksource_is_watchdog(cs)) {
/* Select and try to install a replacement watchdog. */
clocksource_select_watchdog(true);
@@ -834,8 +855,12 @@ static int clocksource_unbind(struct clocksource *cs)
if (curr_clocksource == cs)
return -EBUSY;
}
+
+ clocksource_watchdog_lock(&flags);
clocksource_dequeue_watchdog(cs);
list_del_init(&cs->list);
+ clocksource_watchdog_unlock(&flags);
+
return 0;
}
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 16bbf062018f..8d83bcf9ef69 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5514,10 +5514,10 @@ static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
ftrace_create_filter_files(&global_ops, d_tracer);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- trace_create_file("set_graph_function", 0444, d_tracer,
+ trace_create_file("set_graph_function", 0644, d_tracer,
NULL,
&ftrace_graph_fops);
- trace_create_file("set_graph_notrace", 0444, d_tracer,
+ trace_create_file("set_graph_notrace", 0644, d_tracer,
NULL,
&ftrace_graph_notrace_fops);
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 1f951b3df60c..7d306b74230f 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -762,6 +762,9 @@ static int regex_match_full(char *str, struct regex *r, int len)
static int regex_match_front(char *str, struct regex *r, int len)
{
+ if (len < r->len)
+ return 0;
+
if (strncmp(str, r->pattern, r->len) == 0)
return 1;
return 0;
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 3c7bfc4bf5e9..4237eba4ef20 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -472,7 +472,7 @@ static __init int stack_trace_init(void)
NULL, &stack_trace_fops);
#ifdef CONFIG_DYNAMIC_FTRACE
- trace_create_file("stack_trace_filter", 0444, d_tracer,
+ trace_create_file("stack_trace_filter", 0644, d_tracer,
&trace_ops, &stack_trace_filter_fops);
#endif