Merge 'Linux v3.0' into Litmus

Some notes:
* Litmus^RT scheduling class is the topmost scheduling class
  (above stop_sched_class).
* scheduler_ipi() function (e.g., in smp_reschedule_interrupt())
  may increase IPI latencies.
* Added path into schedule() to quickly re-evaluate scheduling
  decision without becoming preemptive again. This used to be
  a standard path before the removal of BKL.

Conflicts:
	Makefile
	arch/arm/kernel/calls.S
	arch/arm/kernel/smp.c
	arch/x86/include/asm/unistd_32.h
	arch/x86/kernel/smp.c
	arch/x86/kernel/syscall_table_32.S
	include/linux/hrtimer.h
	kernel/printk.c
	kernel/sched.c
	kernel/sched_fair.c

1 files changed, 8 insertions, 2 deletions

diff --git a/kernel/pid.c b/kernel/pid.c
index d55c6fb8d087..57a8346a270e 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -217,11 +217,14 @@ static int alloc_pidmap(struct pid_namespace *pid_ns)
         return -1;
 }
 
-int next_pidmap(struct pid_namespace *pid_ns, int last)
+int next_pidmap(struct pid_namespace *pid_ns, unsigned int last)
 {
         int offset;
         struct pidmap *map, *end;
 
+        if (last >= PID_MAX_LIMIT)
+                return -1;
+
         offset = (last + 1) & BITS_PER_PAGE_MASK;
         map = &pid_ns->pidmap[(last + 1)/BITS_PER_PAGE];
         end = &pid_ns->pidmap[PIDMAP_ENTRIES];
@@ -401,7 +404,7 @@ struct task_struct *pid_task(struct pid *pid, enum pid_type type)
         struct task_struct *result = NULL;
         if (pid) {
                 struct hlist_node *first;
-                first = rcu_dereference_check(pid->tasks[type].first,
+                first = rcu_dereference_check(hlist_first_rcu(&pid->tasks[type]),
                                               rcu_read_lock_held() ||
                                               lockdep_tasklist_lock_is_held());
                 if (first)
@@ -416,6 +419,7 @@ EXPORT_SYMBOL(pid_task);
  */
 struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns)
 {
+        rcu_lockdep_assert(rcu_read_lock_held());
         return pid_task(find_pid_ns(nr, ns), PIDTYPE_PID);
 }
 
@@ -434,6 +438,7 @@ struct pid *get_task_pid(struct task_struct *task, enum pid_type type)
         rcu_read_unlock();
         return pid;
 }
+EXPORT_SYMBOL_GPL(get_task_pid);
 
 struct task_struct *get_pid_task(struct pid *pid, enum pid_type type)
 {
@@ -445,6 +450,7 @@ struct task_struct *get_pid_task(struct pid *pid, enum pid_type type)
         rcu_read_unlock();
         return result;
 }
+EXPORT_SYMBOL_GPL(get_pid_task);
 
 struct pid *find_get_pid(pid_t nr)
 {