summaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
Diffstat (limited to 'kernel')
-rw-r--r--kernel/irq/manage.c4
-rw-r--r--kernel/livepatch/patch.c8
-rw-r--r--kernel/livepatch/transition.c36
-rw-r--r--kernel/sched/core.c2
-rw-r--r--kernel/sched/fair.c2
-rw-r--r--kernel/time/alarmtimer.c14
-rw-r--r--kernel/time/tick-broadcast.c4
-rw-r--r--kernel/time/tick-internal.h2
8 files changed, 56 insertions, 16 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 070be980c37a..425170d4439b 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1312,8 +1312,10 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
ret = __irq_set_trigger(desc,
new->flags & IRQF_TRIGGER_MASK);
- if (ret)
+ if (ret) {
+ irq_release_resources(desc);
goto out_mask;
+ }
}
desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c
index f8269036bf0b..52c4e907c14b 100644
--- a/kernel/livepatch/patch.c
+++ b/kernel/livepatch/patch.c
@@ -59,7 +59,11 @@ static void notrace klp_ftrace_handler(unsigned long ip,
ops = container_of(fops, struct klp_ops, fops);
- rcu_read_lock();
+ /*
+ * A variant of synchronize_sched() is used to allow patching functions
+ * where RCU is not watching, see klp_synchronize_transition().
+ */
+ preempt_disable_notrace();
func = list_first_or_null_rcu(&ops->func_stack, struct klp_func,
stack_node);
@@ -115,7 +119,7 @@ static void notrace klp_ftrace_handler(unsigned long ip,
klp_arch_set_pc(regs, (unsigned long)func->new_func);
unlock:
- rcu_read_unlock();
+ preempt_enable_notrace();
}
/*
diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
index adc0cc64aa4b..b004a1fb6032 100644
--- a/kernel/livepatch/transition.c
+++ b/kernel/livepatch/transition.c
@@ -49,6 +49,28 @@ static void klp_transition_work_fn(struct work_struct *work)
static DECLARE_DELAYED_WORK(klp_transition_work, klp_transition_work_fn);
/*
+ * This function is just a stub to implement a hard force
+ * of synchronize_sched(). This requires synchronizing
+ * tasks even in userspace and idle.
+ */
+static void klp_sync(struct work_struct *work)
+{
+}
+
+/*
+ * We allow to patch also functions where RCU is not watching,
+ * e.g. before user_exit(). We can not rely on the RCU infrastructure
+ * to do the synchronization. Instead hard force the sched synchronization.
+ *
+ * This approach allows to use RCU functions for manipulating func_stack
+ * safely.
+ */
+static void klp_synchronize_transition(void)
+{
+ schedule_on_each_cpu(klp_sync);
+}
+
+/*
* The transition to the target patch state is complete. Clean up the data
* structures.
*/
@@ -73,7 +95,7 @@ static void klp_complete_transition(void)
* func->transition gets cleared, the handler may choose a
* removed function.
*/
- synchronize_rcu();
+ klp_synchronize_transition();
}
if (klp_transition_patch->immediate)
@@ -92,7 +114,7 @@ static void klp_complete_transition(void)
/* Prevent klp_ftrace_handler() from seeing KLP_UNDEFINED state */
if (klp_target_state == KLP_PATCHED)
- synchronize_rcu();
+ klp_synchronize_transition();
read_lock(&tasklist_lock);
for_each_process_thread(g, task) {
@@ -136,7 +158,11 @@ void klp_cancel_transition(void)
*/
void klp_update_patch_state(struct task_struct *task)
{
- rcu_read_lock();
+ /*
+ * A variant of synchronize_sched() is used to allow patching functions
+ * where RCU is not watching, see klp_synchronize_transition().
+ */
+ preempt_disable_notrace();
/*
* This test_and_clear_tsk_thread_flag() call also serves as a read
@@ -153,7 +179,7 @@ void klp_update_patch_state(struct task_struct *task)
if (test_and_clear_tsk_thread_flag(task, TIF_PATCH_PENDING))
task->patch_state = READ_ONCE(klp_target_state);
- rcu_read_unlock();
+ preempt_enable_notrace();
}
/*
@@ -539,7 +565,7 @@ void klp_reverse_transition(void)
clear_tsk_thread_flag(idle_task(cpu), TIF_PATCH_PENDING);
/* Let any remaining calls to klp_update_patch_state() complete */
- synchronize_rcu();
+ klp_synchronize_transition();
klp_start_transition();
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 803c3bc274c4..326d4f88e2b1 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5605,7 +5605,7 @@ void idle_task_exit(void)
BUG_ON(cpu_online(smp_processor_id()));
if (mm != &init_mm) {
- switch_mm_irqs_off(mm, &init_mm, current);
+ switch_mm(mm, &init_mm, current);
finish_arch_post_lock_switch();
}
mmdrop(mm);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d71109321841..c77e4b1d51c0 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3563,7 +3563,7 @@ static inline void check_schedstat_required(void)
trace_sched_stat_runtime_enabled()) {
printk_deferred_once("Scheduler tracepoints stat_sleep, stat_iowait, "
"stat_blocked and stat_runtime require the "
- "kernel parameter schedstats=enabled or "
+ "kernel parameter schedstats=enable or "
"kernel.sched_schedstats=1\n");
}
#endif
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 5cb5b0008d97..ee2f4202d82a 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -387,7 +387,7 @@ void alarm_start_relative(struct alarm *alarm, ktime_t start)
{
struct alarm_base *base = &alarm_bases[alarm->type];
- start = ktime_add(start, base->gettime());
+ start = ktime_add_safe(start, base->gettime());
alarm_start(alarm, start);
}
EXPORT_SYMBOL_GPL(alarm_start_relative);
@@ -475,7 +475,7 @@ u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
overrun++;
}
- alarm->node.expires = ktime_add(alarm->node.expires, interval);
+ alarm->node.expires = ktime_add_safe(alarm->node.expires, interval);
return overrun;
}
EXPORT_SYMBOL_GPL(alarm_forward);
@@ -660,13 +660,21 @@ static int alarm_timer_set(struct k_itimer *timr, int flags,
/* start the timer */
timr->it.alarm.interval = timespec64_to_ktime(new_setting->it_interval);
+
+ /*
+ * Rate limit to the tick as a hot fix to prevent DOS. Will be
+ * mopped up later.
+ */
+ if (timr->it.alarm.interval < TICK_NSEC)
+ timr->it.alarm.interval = TICK_NSEC;
+
exp = timespec64_to_ktime(new_setting->it_value);
/* Convert (if necessary) to absolute time */
if (flags != TIMER_ABSTIME) {
ktime_t now;
now = alarm_bases[timr->it.alarm.alarmtimer.type].gettime();
- exp = ktime_add(now, exp);
+ exp = ktime_add_safe(now, exp);
}
alarm_start(&timr->it.alarm.alarmtimer, exp);
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 987e496bb51a..b398c2ea69b2 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -37,9 +37,11 @@ static int tick_broadcast_forced;
static __cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(tick_broadcast_lock);
#ifdef CONFIG_TICK_ONESHOT
+static void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
static void tick_broadcast_clear_oneshot(int cpu);
static void tick_resume_broadcast_oneshot(struct clock_event_device *bc);
#else
+static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { BUG(); }
static inline void tick_broadcast_clear_oneshot(int cpu) { }
static inline void tick_resume_broadcast_oneshot(struct clock_event_device *bc) { }
#endif
@@ -867,7 +869,7 @@ static void tick_broadcast_init_next_event(struct cpumask *mask,
/**
* tick_broadcast_setup_oneshot - setup the broadcast device
*/
-void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
+static void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
{
int cpu = smp_processor_id();
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index f738251000fe..be0ac01f2e12 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -126,7 +126,6 @@ static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
/* Functions related to oneshot broadcasting */
#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
-extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
extern void tick_broadcast_switch_to_oneshot(void);
extern void tick_shutdown_broadcast_oneshot(unsigned int cpu);
extern int tick_broadcast_oneshot_active(void);
@@ -134,7 +133,6 @@ extern void tick_check_oneshot_broadcast_this_cpu(void);
bool tick_broadcast_oneshot_available(void);
extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
#else /* !(BROADCAST && ONESHOT): */
-static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { BUG(); }
static inline void tick_broadcast_switch_to_oneshot(void) { }
static inline void tick_shutdown_broadcast_oneshot(unsigned int cpu) { }
static inline int tick_broadcast_oneshot_active(void) { return 0; }