1 files changed, 21 insertions, 36 deletions

diff --git a/kernel/sys.c b/kernel/sys.c
index e3c08d4324de..a626116af5db 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -916,8 +916,8 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
 {
         struct task_struct *p;
         struct task_struct *group_leader = current->group_leader;
-        int err = -EINVAL;
-        struct pid_namespace *ns;
+        struct pid *pgrp;
+        int err;
 
         if (!pid)
                 pid = task_pid_vnr(group_leader);
@@ -929,12 +929,10 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
         /* From this point forward we keep holding onto the tasklist lock
          * so that our parent does not change from under us. -DaveM
          */
-        ns = current->nsproxy->pid_ns;
-
         write_lock_irq(&tasklist_lock);
 
         err = -ESRCH;
-        p = find_task_by_pid_ns(pid, ns);
+        p = find_task_by_vpid(pid);
         if (!p)
                 goto out;
 
@@ -942,7 +940,7 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
         if (!thread_group_leader(p))
                 goto out;
 
-        if (p->real_parent->tgid == group_leader->tgid) {
+        if (same_thread_group(p->real_parent, group_leader)) {
                 err = -EPERM;
                 if (task_session(p) != task_session(group_leader))
                         goto out;
@@ -959,10 +957,12 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
         if (p->signal->leader)
                 goto out;
 
+        pgrp = task_pid(p);
         if (pgid != pid) {
                 struct task_struct *g;
 
-                g = find_task_by_pid_type_ns(PIDTYPE_PGID, pgid, ns);
+                pgrp = find_vpid(pgid);
+                g = pid_task(pgrp, PIDTYPE_PGID);
                 if (!g || task_session(g) != task_session(group_leader))
                         goto out;
         }
@@ -971,13 +971,10 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
         if (err)
                 goto out;
 
-        if (task_pgrp_nr_ns(p, ns) != pgid) {
-                struct pid *pid;
-
+        if (task_pgrp(p) != pgrp) {
                 detach_pid(p, PIDTYPE_PGID);
-                pid = find_vpid(pgid);
-                attach_pid(p, PIDTYPE_PGID, pid);
-                set_task_pgrp(p, pid_nr(pid));
+                attach_pid(p, PIDTYPE_PGID, pgrp);
+                set_task_pgrp(p, pid_nr(pgrp));
         }
 
         err = 0;
@@ -994,17 +991,14 @@ asmlinkage long sys_getpgid(pid_t pid)
         else {
                 int retval;
                 struct task_struct *p;
-                struct pid_namespace *ns;
-
-                ns = current->nsproxy->pid_ns;
 
                 read_lock(&tasklist_lock);
-                p = find_task_by_pid_ns(pid, ns);
+                p = find_task_by_vpid(pid);
                 retval = -ESRCH;
                 if (p) {
                         retval = security_task_getpgid(p);
                         if (!retval)
-                                retval = task_pgrp_nr_ns(p, ns);
+                                retval = task_pgrp_vnr(p);
                 }
                 read_unlock(&tasklist_lock);
                 return retval;
@@ -1028,19 +1022,16 @@ asmlinkage long sys_getsid(pid_t pid)
         else {
                 int retval;
                 struct task_struct *p;
-                struct pid_namespace *ns;
-
-                ns = current->nsproxy->pid_ns;
 
-                read_lock(&tasklist_lock);
-                p = find_task_by_pid_ns(pid, ns);
+                rcu_read_lock();
+                p = find_task_by_vpid(pid);
                 retval = -ESRCH;
                 if (p) {
                         retval = security_task_getsid(p);
                         if (!retval)
-                                retval = task_session_nr_ns(p, ns);
+                                retval = task_session_vnr(p);
                 }
-                read_unlock(&tasklist_lock);
+                rcu_read_unlock();
                 return retval;
         }
 }
@@ -1048,35 +1039,29 @@ asmlinkage long sys_getsid(pid_t pid)
 asmlinkage long sys_setsid(void)
 {
         struct task_struct *group_leader = current->group_leader;
-        pid_t session;
+        struct pid *sid = task_pid(group_leader);
+        pid_t session = pid_vnr(sid);
         int err = -EPERM;
 
         write_lock_irq(&tasklist_lock);
-
         /* Fail if I am already a session leader */
         if (group_leader->signal->leader)
                 goto out;
 
-        session = group_leader->pid;
         /* Fail if a process group id already exists that equals the
          * proposed session id.
-         *
-         * Don't check if session id == 1 because kernel threads use this
-         * session id and so the check will always fail and make it so
-         * init cannot successfully call setsid.
          */
-        if (session > 1 && find_task_by_pid_type_ns(PIDTYPE_PGID,
-                                session, &init_pid_ns))
+        if (pid_task(sid, PIDTYPE_PGID))
                 goto out;
 
         group_leader->signal->leader = 1;
-        __set_special_pids(session, session);
+        __set_special_pids(sid);
 
         spin_lock(&group_leader->sighand->siglock);
         group_leader->signal->tty = NULL;
         spin_unlock(&group_leader->sighand->siglock);
 
-        err = task_pgrp_vnr(group_leader);
+        err = session;
 out:
         write_unlock_irq(&tasklist_lock);
         return err;