Merge branches 'x86/cleanups', 'x86/kexec', 'x86/mce2' and 'linus' into x86/core

kernel/fork.c

@@ -1184,10 +1184,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 #endif
 	clear_all_latency_tracing(p);
 
-	/* Our parent execution domain becomes current domain
-	   These must match for thread signalling to apply */
-	p->parent_exec_id = p->self_exec_id;
-
 	/* ok, now we should be set up.. */
 	p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
 	p->pdeath_signal = 0;
@@ -1225,10 +1221,13 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 		set_task_cpu(p, smp_processor_id());
 
 	/* CLONE_PARENT re-uses the old parent */
-	if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
+	if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
 		p->real_parent = current->real_parent;
-	else
+		p->parent_exec_id = current->parent_exec_id;
+	} else {
 		p->real_parent = current;
+		p->parent_exec_id = current->self_exec_id;
+	}
 
 	spin_lock(&current->sighand->siglock);
 

kernel/module.c

@@ -51,6 +51,7 @@
 #include <linux/tracepoint.h>
 #include <linux/ftrace.h>
 #include <linux/async.h>
+#include <linux/percpu.h>
 
 #if 0
 #define DEBUGP printk
@@ -366,6 +367,34 @@ static struct module *find_module(const char *name)
 }
 
 #ifdef CONFIG_SMP
+
+#ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
+
+static void *percpu_modalloc(unsigned long size, unsigned long align,
+			     const char *name)
+{
+	void *ptr;
+
+	if (align > PAGE_SIZE) {
+		printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
+		       name, align, PAGE_SIZE);
+		align = PAGE_SIZE;
+	}
+
+	ptr = __alloc_reserved_percpu(size, align);
+	if (!ptr)
+		printk(KERN_WARNING
+		       "Could not allocate %lu bytes percpu data\n", size);
+	return ptr;
+}
+
+static void percpu_modfree(void *freeme)
+{
+	free_percpu(freeme);
+}
+
+#else /* ... !CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
+
 /* Number of blocks used and allocated. */
 static unsigned int pcpu_num_used, pcpu_num_allocated;
 /* Size of each block.  -ve means used. */
@@ -480,21 +509,6 @@ static void percpu_modfree(void *freeme)
 	}
 }
 
-static unsigned int find_pcpusec(Elf_Ehdr *hdr,
-				 Elf_Shdr *sechdrs,
-				 const char *secstrings)
-{
-	return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
-}
-
-static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
-{
-	int cpu;
-
-	for_each_possible_cpu(cpu)
-		memcpy(pcpudest + per_cpu_offset(cpu), from, size);
-}
-
 static int percpu_modinit(void)
 {
 	pcpu_num_used = 2;
@@ -513,7 +527,26 @@ static int percpu_modinit(void)
 	return 0;
 }
 __initcall(percpu_modinit);
+
+#endif /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
+
+static unsigned int find_pcpusec(Elf_Ehdr *hdr,
+				 Elf_Shdr *sechdrs,
+				 const char *secstrings)
+{
+	return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
+}
+
+static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		memcpy(pcpudest + per_cpu_offset(cpu), from, size);
+}
+
 #else /* ... !CONFIG_SMP */
+
 static inline void *percpu_modalloc(unsigned long size, unsigned long align,
 				    const char *name)
 {
@@ -535,6 +568,7 @@ static inline void percpu_modcopy(void *pcpudst, const void *src,
 	/* pcpusec should be 0, and size of that section should be 0. */
 	BUG_ON(size != 0);
 }
+
 #endif /* CONFIG_SMP */
 
 #define MODINFO_ATTR(field)	\

kernel/rcuclassic.c

@@ -679,8 +679,8 @@ int rcu_needs_cpu(int cpu)
 void rcu_check_callbacks(int cpu, int user)
 {
 	if (user ||
-	    (idle_cpu(cpu) && !in_softirq() &&
-				hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
+	    (idle_cpu(cpu) && rcu_scheduler_active &&
+	     !in_softirq() && hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
 
 		/*
 		 * Get here if this CPU took its interrupt from user

kernel/rcupdate.c

@@ -44,6 +44,7 @@
 #include <linux/cpu.h>
 #include <linux/mutex.h>
 #include <linux/module.h>
+#include <linux/kernel_stat.h>
 
 enum rcu_barrier {
 	RCU_BARRIER_STD,
@@ -55,6 +56,7 @@ static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
 static atomic_t rcu_barrier_cpu_count;
 static DEFINE_MUTEX(rcu_barrier_mutex);
 static struct completion rcu_barrier_completion;
+int rcu_scheduler_active __read_mostly;
 
 /*
  * Awaken the corresponding synchronize_rcu() instance now that a
@@ -80,6 +82,10 @@ void wakeme_after_rcu(struct rcu_head  *head)
 void synchronize_rcu(void)
 {
 	struct rcu_synchronize rcu;
+
+	if (rcu_blocking_is_gp())
+		return;
+
 	init_completion(&rcu.completion);
 	/* Will wake me after RCU finished. */
 	call_rcu(&rcu.head, wakeme_after_rcu);
@@ -175,3 +181,9 @@ void __init rcu_init(void)
 	__rcu_init();
 }
 
+void rcu_scheduler_starting(void)
+{
+	WARN_ON(num_online_cpus() != 1);
+	WARN_ON(nr_context_switches() > 0);
+	rcu_scheduler_active = 1;
+}

kernel/rcupreempt.c

@@ -1181,6 +1181,9 @@ void __synchronize_sched(void)
 {
 	struct rcu_synchronize rcu;
 
+	if (num_online_cpus() == 1)
+		return;  /* blocking is gp if only one CPU! */
+
 	init_completion(&rcu.completion);
 	/* Will wake me after RCU finished. */
 	call_rcu_sched(&rcu.head, wakeme_after_rcu);

kernel/rcutree.c

@@ -948,8 +948,8 @@ static void rcu_do_batch(struct rcu_data *rdp)
 void rcu_check_callbacks(int cpu, int user)
 {
 	if (user ||
-	    (idle_cpu(cpu) && !in_softirq() &&
-				hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
+	    (idle_cpu(cpu) && rcu_scheduler_active &&
+	     !in_softirq() && hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
 
 		/*
 		 * Get here if this CPU took its interrupt from user

kernel/sched.c

@@ -223,7 +223,7 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
 {
 	ktime_t now;
 
-	if (rt_bandwidth_enabled() && rt_b->rt_runtime == RUNTIME_INF)
+	if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
 		return;
 
 	if (hrtimer_active(&rt_b->rt_period_timer))
@@ -9219,6 +9219,16 @@ static int sched_rt_global_constraints(void)
 
 	return ret;
 }
+
+int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk)
+{
+	/* Don't accept realtime tasks when there is no way for them to run */
+	if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0)
+		return 0;
+
+	return 1;
+}
+
 #else /* !CONFIG_RT_GROUP_SCHED */
 static int sched_rt_global_constraints(void)
 {
@@ -9312,8 +9322,7 @@ cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
 		      struct task_struct *tsk)
 {
 #ifdef CONFIG_RT_GROUP_SCHED
-	/* Don't accept realtime tasks when there is no way for them to run */
-	if (rt_task(tsk) && cgroup_tg(cgrp)->rt_bandwidth.rt_runtime == 0)
+	if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk))
 		return -EINVAL;
 #else
 	/* We don't support RT-tasks being in separate groups */
@@ -9476,7 +9485,7 @@ cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
 
 static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
 {
-	u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+	u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
 	u64 data;
 
 #ifndef CONFIG_64BIT
@@ -9495,7 +9504,7 @@ static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
 
 static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
 {
-	u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+	u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
 
 #ifndef CONFIG_64BIT
 	/*
@@ -9591,7 +9600,7 @@ static void cpuacct_charge(struct task_struct *tsk, u64 cputime)
 	ca = task_ca(tsk);
 
 	for (; ca; ca = ca->parent) {
-		u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+		u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
 		*cpuusage += cputime;
 	}
 }

kernel/softirq.c

@@ -626,6 +626,7 @@ static int ksoftirqd(void * __bind_cpu)
 			preempt_enable_no_resched();
 			cond_resched();
 			preempt_disable();
+			rcu_qsctr_inc((long)__bind_cpu);
 		}
 		preempt_enable();
 		set_current_state(TASK_INTERRUPTIBLE);

kernel/stop_machine.c

@@ -170,7 +170,7 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
 	 * doesn't hit this CPU until we're ready. */
 	get_cpu();
 	for_each_online_cpu(i) {
-		sm_work = percpu_ptr(stop_machine_work, i);
+		sm_work = per_cpu_ptr(stop_machine_work, i);
 		INIT_WORK(sm_work, stop_cpu);
 		queue_work_on(i, stop_machine_wq, sm_work);
 	}

kernel/sys.c

@@ -559,7 +559,7 @@ error:
 	abort_creds(new);
 	return retval;
 }
-  
+
 /*
  * change the user struct in a credentials set to match the new UID
  */
@@ -571,6 +571,11 @@ static int set_user(struct cred *new)
 	if (!new_user)
 		return -EAGAIN;
 
+	if (!task_can_switch_user(new_user, current)) {
+		free_uid(new_user);
+		return -EINVAL;
+	}
+
 	if (atomic_read(&new_user->processes) >=
 				current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
 			new_user != INIT_USER) {
@@ -631,10 +636,11 @@ SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
 			goto error;
 	}
 
-	retval = -EAGAIN;
-	if (new->uid != old->uid && set_user(new) < 0)
-		goto error;
-
+	if (new->uid != old->uid) {
+		retval = set_user(new);
+		if (retval < 0)
+			goto error;
+	}
 	if (ruid != (uid_t) -1 ||
 	    (euid != (uid_t) -1 && euid != old->uid))
 		new->suid = new->euid;
@@ -680,9 +686,10 @@ SYSCALL_DEFINE1(setuid, uid_t, uid)
 	retval = -EPERM;
 	if (capable(CAP_SETUID)) {
 		new->suid = new->uid = uid;
-		if (uid != old->uid && set_user(new) < 0) {
-			retval = -EAGAIN;
-			goto error;
+		if (uid != old->uid) {
+			retval = set_user(new);
+			if (retval < 0)
+				goto error;
 		}
 	} else if (uid != old->uid && uid != new->suid) {
 		goto error;
@@ -734,11 +741,13 @@ SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
 			goto error;
 	}
 
-	retval = -EAGAIN;
 	if (ruid != (uid_t) -1) {
 		new->uid = ruid;
-		if (ruid != old->uid && set_user(new) < 0)
-			goto error;
+		if (ruid != old->uid) {
+			retval = set_user(new);
+			if (retval < 0)
+				goto error;
+		}
 	}
 	if (euid != (uid_t) -1)
 		new->euid = euid;

kernel/tsacct.c

@@ -122,8 +122,10 @@ void acct_update_integrals(struct task_struct *tsk)
 	if (likely(tsk->mm)) {
 		cputime_t time, dtime;
 		struct timeval value;
+		unsigned long flags;
 		u64 delta;
 
+		local_irq_save(flags);
 		time = tsk->stime + tsk->utime;
 		dtime = cputime_sub(time, tsk->acct_timexpd);
 		jiffies_to_timeval(cputime_to_jiffies(dtime), &value);
@@ -131,10 +133,12 @@ void acct_update_integrals(struct task_struct *tsk)
 		delta = delta * USEC_PER_SEC + value.tv_usec;
 
 		if (delta == 0)
-			return;
+			goto out;
 		tsk->acct_timexpd = time;
 		tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm);
 		tsk->acct_vm_mem1 += delta * tsk->mm->total_vm;
+	out:
+		local_irq_restore(flags);
 	}
 }
 

kernel/user.c

@@ -286,14 +286,12 @@ int __init uids_sysfs_init(void)
 /* work function to remove sysfs directory for a user and free up
  * corresponding structures.
  */
-static void remove_user_sysfs_dir(struct work_struct *w)
+static void cleanup_user_struct(struct work_struct *w)
 {
 	struct user_struct *up = container_of(w, struct user_struct, work);
 	unsigned long flags;
 	int remove_user = 0;
 
-	if (up->user_ns != &init_user_ns)
-		return;
 	/* Make uid_hash_remove() + sysfs_remove_file() + kobject_del()
 	 * atomic.
 	 */
@@ -312,9 +310,11 @@ static void remove_user_sysfs_dir(struct work_struct *w)
 	if (!remove_user)
 		goto done;
 
-	kobject_uevent(&up->kobj, KOBJ_REMOVE);
-	kobject_del(&up->kobj);
-	kobject_put(&up->kobj);
+	if (up->user_ns == &init_user_ns) {
+		kobject_uevent(&up->kobj, KOBJ_REMOVE);
+		kobject_del(&up->kobj);
+		kobject_put(&up->kobj);
+	}
 
 	sched_destroy_user(up);
 	key_put(up->uid_keyring);
@@ -335,7 +335,7 @@ static void free_user(struct user_struct *up, unsigned long flags)
 	atomic_inc(&up->__count);
 	spin_unlock_irqrestore(&uidhash_lock, flags);
 
-	INIT_WORK(&up->work, remove_user_sysfs_dir);
+	INIT_WORK(&up->work, cleanup_user_struct);
 	schedule_work(&up->work);
 }
 
@@ -362,6 +362,24 @@ static void free_user(struct user_struct *up, unsigned long flags)
 
 #endif
 
+#if defined(CONFIG_RT_GROUP_SCHED) && defined(CONFIG_USER_SCHED)
+/*
+ * We need to check if a setuid can take place. This function should be called
+ * before successfully completing the setuid.
+ */
+int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
+{
+
+	return sched_rt_can_attach(up->tg, tsk);
+
+}
+#else
+int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
+{
+	return 1;
+}
+#endif
+
 /*
  * Locate the user_struct for the passed UID.  If found, take a ref on it.  The
  * caller must undo that ref with free_uid().