diff options
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/fs/exec.c b/fs/exec.c index 950ebd43cdc..3234a0c32d5 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -561,7 +561,7 @@ static int exec_mmap(struct mm_struct *mm) arch_pick_mmap_layout(mm); if (old_mm) { up_read(&old_mm->mmap_sem); - if (active_mm != old_mm) BUG(); + BUG_ON(active_mm != old_mm); mmput(old_mm); return 0; } @@ -678,6 +678,18 @@ static int de_thread(struct task_struct *tsk) while (leader->exit_state != EXIT_ZOMBIE) yield(); + /* + * The only record we have of the real-time age of a + * process, regardless of execs it's done, is start_time. + * All the past CPU time is accumulated in signal_struct + * from sister threads now dead. But in this non-leader + * exec, nothing survives from the original leader thread, + * whose birth marks the true age of this process now. + * When we take on its identity by switching to its PID, we + * also take its birthdate (always earlier than our own). + */ + current->start_time = leader->start_time; + spin_lock(&leader->proc_lock); spin_lock(¤t->proc_lock); proc_dentry1 = proc_pid_unhash(current); @@ -723,7 +735,12 @@ static int de_thread(struct task_struct *tsk) current->parent = current->real_parent = leader->real_parent; leader->parent = leader->real_parent = child_reaper; current->group_leader = current; - leader->group_leader = leader; + leader->group_leader = current; + + /* Reduce leader to a thread */ + detach_pid(leader, PIDTYPE_PGID); + detach_pid(leader, PIDTYPE_SID); + list_del_init(&leader->tasks); add_parent(current); add_parent(leader); |