time: Fix accumulation bug triggered by long delay.

[safe/jmp/linux-2.6] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index 3d6f121..17bbf09 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -64,6 +64,7 @@
 #include <linux/magic.h>
 #include <linux/perf_event.h>
 #include <linux/posix-timers.h>
+#include <linux/user-return-notifier.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -85,6 +86,7 @@ int max_threads;              /* tunable limit on nr_threads */
 DEFINE_PER_CPU(unsigned long, process_counts) = 0;
 
 __cacheline_aligned DEFINE_RWLOCK(tasklist_lock);  /* outer */
+EXPORT_SYMBOL_GPL(tasklist_lock);
 
 int nr_processes(void)
 {
@@ -249,6 +251,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
                goto out;
 
        setup_thread_stack(tsk, orig);
+       clear_user_return_notifier(tsk);
        stackend = end_of_stack(tsk);
        *stackend = STACK_END_MAGIC;    /* for overflow detection */
 
@@ -937,9 +940,9 @@ SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
 
 static void rt_mutex_init_task(struct task_struct *p)
 {
-       spin_lock_init(&p->pi_lock);
+       raw_spin_lock_init(&p->pi_lock);
 #ifdef CONFIG_RT_MUTEXES
-       plist_head_init(&p->pi_waiters, &p->pi_lock);
+       plist_head_init_raw(&p->pi_waiters, &p->pi_lock);
        p->pi_blocked_on = NULL;
 #endif
 }
@@ -1125,6 +1128,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 #ifdef CONFIG_DEBUG_MUTEXES
        p->blocked_on = NULL; /* not blocked yet */
 #endif
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+       p->memcg_batch.do_batch = 0;
+       p->memcg_batch.memcg = NULL;
+#endif
 
        p->bts = NULL;
 
@@ -1204,9 +1211,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                p->sas_ss_sp = p->sas_ss_size = 0;
 
        /*
-        * Syscall tracing should be turned off in the child regardless
-        * of CLONE_PTRACE.
+        * Syscall tracing and stepping should be turned off in the
+        * child regardless of CLONE_PTRACE.
         */
+       user_disable_single_step(p);
        clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
 #ifdef TIF_SYSCALL_EMU
        clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
@@ -1234,21 +1242,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        /* Need tasklist lock for parent etc handling! */
        write_lock_irq(&tasklist_lock);
 
-       /*
-        * The task hasn't been attached yet, so its cpus_allowed mask will
-        * not be changed, nor will its assigned CPU.
-        *
-        * The cpus_allowed mask of the parent may have changed after it was
-        * copied first time - so re-copy it here, then check the child's CPU
-        * to ensure it is on a valid CPU (and if not, just force it back to
-        * parent's CPU). This avoids alot of nasty races.
-        */
-       p->cpus_allowed = current->cpus_allowed;
-       p->rt.nr_cpus_allowed = current->rt.nr_cpus_allowed;
-       if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) ||
-                       !cpu_online(task_cpu(p))))
-               set_task_cpu(p, smp_processor_id());
-
        /* CLONE_PARENT re-uses the old parent */
        if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
                p->real_parent = current->real_parent;
@@ -1284,7 +1277,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        }
 
        if (likely(p->pid)) {
-               list_add_tail(&p->sibling, &p->real_parent->children);
                tracehook_finish_clone(p, clone_flags, trace);
 
                if (thread_group_leader(p)) {
@@ -1296,6 +1288,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                        p->signal->tty = tty_kref_get(current->signal->tty);
                        attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
                        attach_pid(p, PIDTYPE_SID, task_session(current));
+                       list_add_tail(&p->sibling, &p->real_parent->children);
                        list_add_tail_rcu(&p->tasks, &init_task.tasks);
                        __get_cpu_var(process_counts)++;
                }
@@ -1315,7 +1308,8 @@ bad_fork_free_pid:
        if (pid != &init_struct_pid)
                free_pid(pid);
 bad_fork_cleanup_io:
-       put_io_context(p->io_context);
+       if (p->io_context)
+               exit_io_context(p);
 bad_fork_cleanup_namespaces:
        exit_task_namespaces(p);
 bad_fork_cleanup_mm: