Merge "Merge android-4.4.180 (71cb827) into msm-4.4"

7 files changed, 64 insertions, 5 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 5b4440d57f89..d484f2869861 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -8,6 +8,7 @@
 #include <linux/init.h>
 #include <linux/notifier.h>
 #include <linux/sched.h>
+#include <linux/sched/smt.h>
 #include <linux/unistd.h>
 #include <linux/cpu.h>
 #include <linux/oom.h>
@@ -206,6 +207,12 @@ void cpu_hotplug_enable(void)
 EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
 #endif	/* CONFIG_HOTPLUG_CPU */
 
+/*
+ * Architectures that need SMT-specific errata handling during SMT hotplug
+ * should override this.
+ */
+void __weak arch_smt_update(void) { }
+
 /* Need to know about CPUs going up/down? */
 int register_cpu_notifier(struct notifier_block *nb)
 {
@@ -445,6 +452,7 @@ out_release:
 	trace_sched_cpu_hotplug(cpu, err, 0);
 	if (!err)
 		cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
+	arch_smt_update();
 	return err;
 }
 
@@ -549,7 +557,7 @@ out_notify:
 out:
 	cpu_hotplug_done();
 	trace_sched_cpu_hotplug(cpu, ret, 1);
-
+	arch_smt_update();
 	return ret;
 }
 
@@ -911,6 +919,19 @@ void init_cpu_isolated(const struct cpumask *src)
 	cpumask_copy(to_cpumask(cpu_isolated_bits), src);
 }
 
+enum cpu_mitigations cpu_mitigations = CPU_MITIGATIONS_AUTO;
+
+static int __init mitigations_parse_cmdline(char *arg)
+{
+	if (!strcmp(arg, "off"))
+		cpu_mitigations = CPU_MITIGATIONS_OFF;
+	else if (!strcmp(arg, "auto"))
+		cpu_mitigations = CPU_MITIGATIONS_AUTO;
+
+	return 0;
+}
+early_param("mitigations", mitigations_parse_cmdline);
+
 static ATOMIC_NOTIFIER_HEAD(idle_notifier);
 
 void idle_notifier_register(struct notifier_block *n)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 36a13b75b48f..d0193c0b2531 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -334,11 +334,10 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
 	desc->affinity_notify = notify;
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 
-	if (!notify && old_notify)
+	if (old_notify) {
 		cancel_work_sync(&old_notify->work);
-
-	if (old_notify)
 		kref_put(&old_notify->kref, old_notify->release);
+	}
 
 	return 0;
 }
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 5e2cd1030702..8303874c2a06 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -228,6 +228,9 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
 
 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
 {
+	if (mode & PTRACE_MODE_SCHED)
+		return false;
+
 	if (mode & PTRACE_MODE_NOAUDIT)
 		return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
 	else
@@ -295,9 +298,16 @@ ok:
 	     !ptrace_has_cap(mm->user_ns, mode)))
 	    return -EPERM;
 
+	if (mode & PTRACE_MODE_SCHED)
+		return 0;
 	return security_ptrace_access_check(task, mode);
 }
 
+bool ptrace_may_access_sched(struct task_struct *task, unsigned int mode)
+{
+	return __ptrace_may_access(task, mode | PTRACE_MODE_SCHED);
+}
+
 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
 {
 	int err;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6b9021b9bc26..56c55e49fe29 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6373,6 +6373,10 @@ static void set_cpu_rq_start_time(void)
 	rq->age_stamp = sched_clock_cpu(cpu);
 }
 
+#ifdef CONFIG_SCHED_SMT
+atomic_t sched_smt_present = ATOMIC_INIT(0);
+#endif
+
 static int sched_cpu_active(struct notifier_block *nfb,
 				      unsigned long action, void *hcpu)
 {
@@ -6389,11 +6393,23 @@ static int sched_cpu_active(struct notifier_block *nfb,
 		 * set_cpu_online(). But it might not yet have marked itself
 		 * as active, which is essential from here on.
 		 */
+#ifdef CONFIG_SCHED_SMT
+		/*
+		 * When going up, increment the number of cores with SMT present.
+		 */
+		if (cpumask_weight(cpu_smt_mask(cpu)) == 2)
+			atomic_inc(&sched_smt_present);
+#endif
 		set_cpu_active(cpu, true);
 		stop_machine_unpark(cpu);
 		return NOTIFY_OK;
 
 	case CPU_DOWN_FAILED:
+#ifdef CONFIG_SCHED_SMT
+		/* Same as for CPU_ONLINE */
+		if (cpumask_weight(cpu_smt_mask(cpu)) == 2)
+			atomic_inc(&sched_smt_present);
+#endif
 		set_cpu_active(cpu, true);
 		return NOTIFY_OK;
 
@@ -6408,7 +6424,15 @@ static int sched_cpu_inactive(struct notifier_block *nfb,
 	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_DOWN_PREPARE:
 		set_cpu_active((long)hcpu, false);
+#ifdef CONFIG_SCHED_SMT
+		/*
+		 * When going down, decrement the number of cores with SMT present.
+		 */
+		if (cpumask_weight(cpu_smt_mask((long)hcpu)) == 2)
+			atomic_dec(&sched_smt_present);
+#endif
 		return NOTIFY_OK;
+
 	default:
 		return NOTIFY_DONE;
 	}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c759c6a3ea20..1eac0642fa86 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1901,6 +1901,10 @@ static u64 numa_get_avg_runtime(struct task_struct *p, u64 *period)
 	if (p->last_task_numa_placement) {
 		delta = runtime - p->last_sum_exec_runtime;
 		*period = now - p->last_task_numa_placement;
+
+		/* Avoid time going backwards, prevent potential divide error: */
+		if (unlikely((s64)*period < 0))
+			*period = 0;
 	} else {
 		delta = p->se.avg.load_sum / p->se.load.weight;
 		*period = LOAD_AVG_MAX;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 8cb8b1c555c8..12883703a021 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2,6 +2,7 @@
 #include <linux/sched.h>
 #include <linux/sched/sysctl.h>
 #include <linux/sched/rt.h>
+#include <linux/sched/smt.h>
 #include <linux/sched/deadline.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 5e091614fe39..1cf2402c6922 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -701,7 +701,7 @@ u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu)
 
 	preempt_disable_notrace();
 	time = rb_time_stamp(buffer);
-	preempt_enable_no_resched_notrace();
+	preempt_enable_notrace();
 
 	return time;
 }