diff options
| -rw-r--r-- | fs/exec.c | 11 | ||||
| -rw-r--r-- | include/linux/pid.h | 2 | ||||
| -rw-r--r-- | kernel/pid.c | 9 |
3 files changed, 15 insertions, 7 deletions
diff --git a/fs/exec.c b/fs/exec.c index 54135df2a966..b7aa3d6422d6 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -696,23 +696,20 @@ static int de_thread(struct task_struct *tsk) */ /* Become a process group leader with the old leader's pid. - * Note: The old leader also uses thispid until release_task + * The old leader becomes a thread of the this thread group. + * Note: The old leader also uses this pid until release_task * is called. Odd but simple and correct. */ detach_pid(current, PIDTYPE_PID); current->pid = leader->pid; attach_pid(current, PIDTYPE_PID, current->pid); - attach_pid(current, PIDTYPE_PGID, current->signal->pgrp); - attach_pid(current, PIDTYPE_SID, current->signal->session); + transfer_pid(leader, current, PIDTYPE_PGID); + transfer_pid(leader, current, PIDTYPE_SID); list_replace_rcu(&leader->tasks, ¤t->tasks); current->group_leader = current; leader->group_leader = current; - /* Reduce leader to a thread */ - detach_pid(leader, PIDTYPE_PGID); - detach_pid(leader, PIDTYPE_SID); - current->exit_signal = SIGCHLD; BUG_ON(leader->exit_state != EXIT_ZOMBIE); diff --git a/include/linux/pid.h b/include/linux/pid.h index 29960b03bef7..93da7e2d9f30 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -76,6 +76,8 @@ extern int FASTCALL(attach_pid(struct task_struct *task, enum pid_type type, int nr)); extern void FASTCALL(detach_pid(struct task_struct *task, enum pid_type)); +extern void FASTCALL(transfer_pid(struct task_struct *old, + struct task_struct *new, enum pid_type)); /* * look up a PID in the hash table. Must be called with the tasklist_lock diff --git a/kernel/pid.c b/kernel/pid.c index 93e212f20671..6db82b68e2f8 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -252,6 +252,15 @@ void fastcall detach_pid(struct task_struct *task, enum pid_type type) free_pid(pid); } +/* transfer_pid is an optimization of attach_pid(new), detach_pid(old) */ +void fastcall transfer_pid(struct task_struct *old, struct task_struct *new, + enum pid_type type) +{ + new->pids[type].pid = old->pids[type].pid; + hlist_replace_rcu(&old->pids[type].node, &new->pids[type].node); + old->pids[type].pid = NULL; +} + struct task_struct * fastcall pid_task(struct pid *pid, enum pid_type type) { struct task_struct *result = NULL; |