1 files changed, 28 insertions, 15 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index bab34192799..f252784f933 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -973,7 +973,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                                         unsigned long stack_start,
                                         struct pt_regs *regs,
                                         unsigned long stack_size,
-                                        int __user *parent_tidptr,
                                         int __user *child_tidptr,
                                         struct pid *pid)
 {
@@ -1043,11 +1042,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
         p->did_exec = 0;
         delayacct_tsk_init(p);  /* Must remain after dup_task_struct() */
         copy_flags(clone_flags, p);
-        retval = -EFAULT;
-        if (clone_flags & CLONE_PARENT_SETTID)
-                if (put_user(p->pid, parent_tidptr))
-                        goto bad_fork_cleanup_delays_binfmt;
-
         INIT_LIST_HEAD(&p->children);
         INIT_LIST_HEAD(&p->sibling);
         p->vfork_done = NULL;
@@ -1289,11 +1283,22 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                         __ptrace_link(p, current->parent);
 
                 if (thread_group_leader(p)) {
-                        p->signal->tty = current->signal->tty;
-                        p->signal->pgrp = task_pgrp_nr(current);
-                        set_task_session(p, task_session_nr(current));
-                        attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
-                        attach_pid(p, PIDTYPE_SID, task_session(current));
+                        if (clone_flags & CLONE_NEWPID) {
+                                p->nsproxy->pid_ns->child_reaper = p;
+                                p->signal->tty = NULL;
+                                p->signal->pgrp = p->pid;
+                                set_task_session(p, p->pid);
+                                attach_pid(p, PIDTYPE_PGID, pid);
+                                attach_pid(p, PIDTYPE_SID, pid);
+                        } else {
+                                p->signal->tty = current->signal->tty;
+                                p->signal->pgrp = task_pgrp_nr(current);
+                                set_task_session(p, task_session_nr(current));
+                                attach_pid(p, PIDTYPE_PGID,
+                                                task_pgrp(current));
+                                attach_pid(p, PIDTYPE_SID,
+                                                task_session(current));
+                        }
 
                         list_add_tail_rcu(&p->tasks, &init_task.tasks);
                         __get_cpu_var(process_counts)++;
@@ -1339,7 +1344,6 @@ bad_fork_cleanup_policy:
 bad_fork_cleanup_cgroup:
 #endif
         cgroup_exit(p, cgroup_callbacks_done);
-bad_fork_cleanup_delays_binfmt:
         delayacct_tsk_free(p);
         if (p->binfmt)
                 module_put(p->binfmt->module);
@@ -1366,7 +1370,7 @@ struct task_struct * __cpuinit fork_idle(int cpu)
         struct task_struct *task;
         struct pt_regs regs;
 
-        task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL, NULL,
+        task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL,
                                 &init_struct_pid);
         if (!IS_ERR(task))
                 init_idle(task, cpu);
@@ -1414,7 +1418,7 @@ long do_fork(unsigned long clone_flags,
         }
 
         p = copy_process(clone_flags, stack_start, regs, stack_size,
-                        parent_tidptr, child_tidptr, NULL);
+                        child_tidptr, NULL);
         /*
          * Do this prior waking up the new thread - the thread pointer
          * might get invalid after that point, if the thread exits quickly.
@@ -1422,7 +1426,16 @@ long do_fork(unsigned long clone_flags,
         if (!IS_ERR(p)) {
                 struct completion vfork;
 
-                nr = pid_nr(task_pid(p));
+                /*
+                 * this is enough to call pid_nr_ns here, but this if
+                 * improves optimisation of regular fork()
+                 */
+                nr = (clone_flags & CLONE_NEWPID) ?
+                        task_pid_nr_ns(p, current->nsproxy->pid_ns) :
+                                task_pid_vnr(p);
+
+                if (clone_flags & CLONE_PARENT_SETTID)
+                        put_user(nr, parent_tidptr);
 
                 if (clone_flags & CLONE_VFORK) {
                         p->vfork_done = &vfork;