Merge commit 'v2.6.36' into wip-merge-2.6.36

Conflicts:
	Makefile
	arch/x86/include/asm/unistd_32.h
	arch/x86/kernel/syscall_table_32.S
	kernel/sched.c
	kernel/time/tick-sched.c

Relevant API and functions changes (solved in this commit):
- (API) .enqueue_task() (enqueue_task_litmus),
  dequeue_task() (dequeue_task_litmus),
  [litmus/sched_litmus.c]
- (API) .select_task_rq() (select_task_rq_litmus)
  [litmus/sched_litmus.c]
- (API) sysrq_dump_trace_buffer() and sysrq_handle_kill_rt_tasks()
  [litmus/sched_trace.c]
- struct kfifo internal buffer name changed (buffer -> buf)
  [litmus/sched_trace.c]
- add_wait_queue_exclusive_locked -> __add_wait_queue_tail_exclusive
  [litmus/fmlp.c]
- syscall numbers for both x86_32 and x86_64

1 files changed, 24 insertions, 31 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 256ce8c2ebc8..b9d3bc6c21ec 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -55,17 +55,16 @@
 #include <asm/unistd.h>
 #include <asm/pgtable.h>
 #include <asm/mmu_context.h>
-#include "cred-internals.h"
 
 extern void exit_od_table(struct task_struct *t);
 
 static void exit_mm(struct task_struct * tsk);
 
-static void __unhash_process(struct task_struct *p)
+static void __unhash_process(struct task_struct *p, bool group_dead)
 {
         nr_threads--;
         detach_pid(p, PIDTYPE_PID);
-        if (thread_group_leader(p)) {
+        if (group_dead) {
                 detach_pid(p, PIDTYPE_PGID);
                 detach_pid(p, PIDTYPE_SID);
 
@@ -82,10 +81,9 @@ static void __unhash_process(struct task_struct *p)
 static void __exit_signal(struct task_struct *tsk)
 {
         struct signal_struct *sig = tsk->signal;
+        bool group_dead = thread_group_leader(tsk);
         struct sighand_struct *sighand;
-
-        BUG_ON(!sig);
-        BUG_ON(!atomic_read(&sig->count));
+        struct tty_struct *uninitialized_var(tty);
 
         sighand = rcu_dereference_check(tsk->sighand,
                                         rcu_read_lock_held() ||
@@ -93,14 +91,16 @@ static void __exit_signal(struct task_struct *tsk)
         spin_lock(&sighand->siglock);
 
         posix_cpu_timers_exit(tsk);
-        if (atomic_dec_and_test(&sig->count))
+        if (group_dead) {
                 posix_cpu_timers_exit_group(tsk);
-        else {
+                tty = sig->tty;
+                sig->tty = NULL;
+        } else {
                 /*
                  * If there is any task waiting for the group exit
                  * then notify it:
                  */
-                if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count)
+                if (sig->notify_count > 0 && !--sig->notify_count)
                         wake_up_process(sig->group_exit_task);
 
                 if (tsk == sig->curr_target)
@@ -126,32 +126,24 @@ static void __exit_signal(struct task_struct *tsk)
                 sig->oublock += task_io_get_oublock(tsk);
                 task_io_accounting_add(&sig->ioac, &tsk->ioac);
                 sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
-                sig = NULL; /* Marker for below. */
         }
 
-        __unhash_process(tsk);
+        sig->nr_threads--;
+        __unhash_process(tsk, group_dead);
 
         /*
          * Do this under ->siglock, we can race with another thread
          * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
          */
         flush_sigqueue(&tsk->pending);
-
-        tsk->signal = NULL;
         tsk->sighand = NULL;
         spin_unlock(&sighand->siglock);
 
         __cleanup_sighand(sighand);
         clear_tsk_thread_flag(tsk,TIF_SIGPENDING);
-        if (sig) {
+        if (group_dead) {
                 flush_sigqueue(&sig->shared_pending);
-                taskstats_tgid_free(sig);
-                /*
-                 * Make sure ->signal can't go away under rq->lock,
-                 * see account_group_exec_runtime().
-                 */
-                task_rq_unlock_wait(tsk);
-                __cleanup_signal(sig);
+                tty_kref_put(tty);
         }
 }
 
@@ -781,9 +773,12 @@ static void forget_original_parent(struct task_struct *father)
         struct task_struct *p, *n, *reaper;
         LIST_HEAD(dead_children);
 
-        exit_ptrace(father);
-
         write_lock_irq(&tasklist_lock);
+        /*
+         * Note that exit_ptrace() and find_new_reaper() might
+         * drop tasklist_lock and reacquire it.
+         */
+        exit_ptrace(father);
         reaper = find_new_reaper(father);
 
         list_for_each_entry_safe(p, n, &father->children, sibling) {
@@ -859,12 +854,9 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
 
         tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE;
 
-        /* mt-exec, de_thread() is waiting for us */
-        if (thread_group_leader(tsk) &&
-            tsk->signal->group_exit_task &&
-            tsk->signal->notify_count < 0)
+        /* mt-exec, de_thread() is waiting for group leader */
+        if (unlikely(tsk->signal->notify_count < 0))
                 wake_up_process(tsk->signal->group_exit_task);
-
         write_unlock_irq(&tasklist_lock);
 
         tracehook_report_death(tsk, signal, cookie, group_dead);
@@ -1007,8 +999,10 @@ NORET_TYPE void do_exit(long code)
 
         exit_notify(tsk, group_dead);
 #ifdef CONFIG_NUMA
+        task_lock(tsk);
         mpol_put(tsk->mempolicy);
         tsk->mempolicy = NULL;
+        task_unlock(tsk);
 #endif
 #ifdef CONFIG_FUTEX
         if (unlikely(current->pi_state_cache))
@@ -1396,8 +1390,7 @@ static int wait_task_stopped(struct wait_opts *wo,
         if (!unlikely(wo->wo_flags & WNOWAIT))
                 *p_code = 0;
 
-        /* don't need the RCU readlock here as we're holding a spinlock */
-        uid = __task_cred(p)->uid;
+        uid = task_uid(p);
 unlock_sig:
         spin_unlock_irq(&p->sighand->siglock);
         if (!exit_code)
@@ -1470,7 +1463,7 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
         }
         if (!unlikely(wo->wo_flags & WNOWAIT))
                 p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
-        uid = __task_cred(p)->uid;
+        uid = task_uid(p);
         spin_unlock_irq(&p->sighand->siglock);
 
         pid = task_pid_vnr(p);