1 files changed, 46 insertions, 36 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index c8d0485578be..e69edc74aeeb 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -40,18 +40,24 @@
 #include <linux/cn_proc.h>
 #include <linux/mutex.h>
 #include <linux/futex.h>
-#include <linux/compat.h>
 #include <linux/pipe_fs_i.h>
 #include <linux/audit.h> /* for audit_free() */
 #include <linux/resource.h>
 #include <linux/blkdev.h>
 #include <linux/task_io_accounting_ops.h>
 #include <linux/tracehook.h>
+#include <linux/init_task.h>
+#include <trace/sched.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/pgtable.h>
 #include <asm/mmu_context.h>
+#include "cred-internals.h"
+
+DEFINE_TRACE(sched_process_free);
+DEFINE_TRACE(sched_process_exit);
+DEFINE_TRACE(sched_process_wait);
 
 static void exit_mm(struct task_struct * tsk);
 
@@ -112,8 +118,6 @@ static void __exit_signal(struct task_struct *tsk)
                  * We won't ever get here for the group leader, since it
                  * will have been the last reference on the signal_struct.
                  */
-                sig->utime = cputime_add(sig->utime, task_utime(tsk));
-                sig->stime = cputime_add(sig->stime, task_stime(tsk));
                 sig->gtime = cputime_add(sig->gtime, task_gtime(tsk));
                 sig->min_flt += tsk->min_flt;
                 sig->maj_flt += tsk->maj_flt;
@@ -122,7 +126,6 @@ static void __exit_signal(struct task_struct *tsk)
                 sig->inblock += task_io_get_inblock(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. */
         }
 
@@ -143,13 +146,21 @@ static void __exit_signal(struct task_struct *tsk)
         if (sig) {
                 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);
         }
 }
 
 static void delayed_put_task_struct(struct rcu_head *rhp)
 {
-        put_task_struct(container_of(rhp, struct task_struct, rcu));
+        struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
+
+        trace_sched_process_free(tsk);
+        put_task_struct(tsk);
 }
 
 
@@ -159,7 +170,10 @@ void release_task(struct task_struct * p)
         int zap_leader;
 repeat:
         tracehook_prepare_release_task(p);
-        atomic_dec(&p->user->processes);
+        /* don't need to get the RCU readlock here - the process is dead and
+         * can't be modifying its own credentials */
+        atomic_dec(&__task_cred(p)->user->processes);
+
         proc_flush_task(p);
         write_lock_irq(&tasklist_lock);
         tracehook_finish_release_task(p);
@@ -334,12 +348,12 @@ static void reparent_to_kthreadd(void)
         /* cpus_allowed? */
         /* rt_priority? */
         /* signals? */
-        security_task_reparent_to_init(current);
         memcpy(current->signal->rlim, init_task.signal->rlim,
                sizeof(current->signal->rlim));
-        atomic_inc(&(INIT_USER->__count));
+
+        atomic_inc(&init_cred.usage);
+        commit_creds(&init_cred);
         write_unlock_irq(&tasklist_lock);
-        switch_uid(INIT_USER);
 }
 
 void __set_special_pids(struct pid *pid)
@@ -640,24 +654,23 @@ retry:
 assign_new_owner:
         BUG_ON(c == p);
         get_task_struct(c);
+        read_unlock(&tasklist_lock);
+        down_write(&mm->mmap_sem);
         /*
          * The task_lock protects c->mm from changing.
          * We always want mm->owner->mm == mm
          */
         task_lock(c);
-        /*
-         * Delay read_unlock() till we have the task_lock()
-         * to ensure that c does not slip away underneath us
-         */
-        read_unlock(&tasklist_lock);
         if (c->mm != mm) {
                 task_unlock(c);
+                up_write(&mm->mmap_sem);
                 put_task_struct(c);
                 goto retry;
         }
         cgroup_mm_owner_callbacks(mm->owner, c);
         mm->owner = c;
         task_unlock(c);
+        up_write(&mm->mmap_sem);
         put_task_struct(c);
 }
 #endif /* CONFIG_MM_OWNER */
@@ -1021,8 +1034,6 @@ NORET_TYPE void do_exit(long code)
                  * task into the wait for ever nirwana as well.
                  */
                 tsk->flags |= PF_EXITPIDONE;
-                if (tsk->io_context)
-                        exit_io_context();
                 set_current_state(TASK_UNINTERRUPTIBLE);
                 schedule();
         }
@@ -1051,14 +1062,6 @@ NORET_TYPE void do_exit(long code)
                 exit_itimers(tsk->signal);
         }
         acct_collect(code, group_dead);
-#ifdef CONFIG_FUTEX
-        if (unlikely(tsk->robust_list))
-                exit_robust_list(tsk);
-#ifdef CONFIG_COMPAT
-        if (unlikely(tsk->compat_robust_list))
-                compat_exit_robust_list(tsk);
-#endif
-#endif
         if (group_dead)
                 tty_audit_exit();
         if (unlikely(tsk->audit_context))
@@ -1071,13 +1074,14 @@ NORET_TYPE void do_exit(long code)
 
         if (group_dead)
                 acct_process();
+        trace_sched_process_exit(tsk);
+
         exit_sem(tsk);
         exit_files(tsk);
         exit_fs(tsk);
         check_stack_usage();
         exit_thread();
         cgroup_exit(tsk, 1);
-        exit_keys(tsk);
 
         if (group_dead && tsk->signal->leader)
                 disassociate_ctty(1);
@@ -1122,7 +1126,6 @@ NORET_TYPE void do_exit(long code)
         preempt_disable();
         /* causes final put_task_struct in finish_task_switch(). */
         tsk->state = TASK_DEAD;
-
         schedule();
         BUG();
         /* Avoid "noreturn function does return".  */
@@ -1262,12 +1265,12 @@ static int wait_task_zombie(struct task_struct *p, int options,
         unsigned long state;
         int retval, status, traced;
         pid_t pid = task_pid_vnr(p);
+        uid_t uid = __task_cred(p)->uid;
 
         if (!likely(options & WEXITED))
                 return 0;
 
         if (unlikely(options & WNOWAIT)) {
-                uid_t uid = p->uid;
                 int exit_code = p->exit_code;
                 int why, status;
 
@@ -1299,6 +1302,7 @@ static int wait_task_zombie(struct task_struct *p, int options,
         if (likely(!traced)) {
                 struct signal_struct *psig;
                 struct signal_struct *sig;
+                struct task_cputime cputime;
 
                 /*
                  * The resource counters for the group leader are in its
@@ -1314,20 +1318,23 @@ static int wait_task_zombie(struct task_struct *p, int options,
                  * need to protect the access to p->parent->signal fields,
                  * as other threads in the parent group can be right
                  * here reaping other children at the same time.
+                 *
+                 * We use thread_group_cputime() to get times for the thread
+                 * group, which consolidates times for all threads in the
+                 * group including the group leader.
                  */
+                thread_group_cputime(p, &cputime);
                 spin_lock_irq(&p->parent->sighand->siglock);
                 psig = p->parent->signal;
                 sig = p->signal;
                 psig->cutime =
                         cputime_add(psig->cutime,
-                        cputime_add(p->utime,
-                        cputime_add(sig->utime,
-                                    sig->cutime)));
+                        cputime_add(cputime.utime,
+                                    sig->cutime));
                 psig->cstime =
                         cputime_add(psig->cstime,
-                        cputime_add(p->stime,
-                        cputime_add(sig->stime,
-                                    sig->cstime)));
+                        cputime_add(cputime.stime,
+                                    sig->cstime));
                 psig->cgtime =
                         cputime_add(psig->cgtime,
                         cputime_add(p->gtime,
@@ -1384,7 +1391,7 @@ static int wait_task_zombie(struct task_struct *p, int options,
         if (!retval && infop)
                 retval = put_user(pid, &infop->si_pid);
         if (!retval && infop)
-                retval = put_user(p->uid, &infop->si_uid);
+                retval = put_user(uid, &infop->si_uid);
         if (!retval)
                 retval = pid;
 
@@ -1449,7 +1456,8 @@ static int wait_task_stopped(int ptrace, struct task_struct *p,
         if (!unlikely(options & WNOWAIT))
                 p->exit_code = 0;
 
-        uid = p->uid;
+        /* don't need the RCU readlock here as we're holding a spinlock */
+        uid = __task_cred(p)->uid;
 unlock_sig:
         spin_unlock_irq(&p->sighand->siglock);
         if (!exit_code)
@@ -1523,10 +1531,10 @@ static int wait_task_continued(struct task_struct *p, int options,
         }
         if (!unlikely(options & WNOWAIT))
                 p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
+        uid = __task_cred(p)->uid;
         spin_unlock_irq(&p->sighand->siglock);
 
         pid = task_pid_vnr(p);
-        uid = p->uid;
         get_task_struct(p);
         read_unlock(&tasklist_lock);
 
@@ -1672,6 +1680,8 @@ static long do_wait(enum pid_type type, struct pid *pid, int options,
         struct task_struct *tsk;
         int retval;
 
+        trace_sched_process_wait(pid);
+
         add_wait_queue(&current->signal->wait_chldexit,&wait);
 repeat:
         /*