pidfd: exit: kill the no longer used thread_group_exited()

It was used by pidfd_poll() but now it has no callers.

If it finally finds a modular user we can revert this change, but note
that the comment above this helper and the changelog in 38fd525a4c
("exit: Factor thread_group_exited out of pidfd_poll") are not accurate,
thread_group_exited() won't return true if all other threads have passed
exit_notify() and are zombies, it returns true only when all other threads
are completely gone. Not to mention that it can only work if the task
identified by @pid is a thread-group leader.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20240205174347.GA31461@redhat.com
Reviewed-by: Tycho Andersen <tandersen@netflix.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Oleg Nesterov 2024-02-05 18:43:47 +01:00 committed by Christian Brauner
parent 9ed52108f6
commit e2e8a142fb
2 changed files with 0 additions and 26 deletions

View File

@ -735,8 +735,6 @@ static inline int thread_group_empty(struct task_struct *p)
#define delay_group_leader(p) \
(thread_group_leader(p) && !thread_group_empty(p))
extern bool thread_group_exited(struct pid *pid);
extern struct sighand_struct *__lock_task_sighand(struct task_struct *task,
unsigned long *flags);

View File

@ -1900,30 +1900,6 @@ Efault:
}
#endif
/**
* thread_group_exited - check that a thread group has exited
* @pid: tgid of thread group to be checked.
*
* Test if the thread group represented by tgid has exited (all
* threads are zombies, dead or completely gone).
*
* Return: true if the thread group has exited. false otherwise.
*/
bool thread_group_exited(struct pid *pid)
{
struct task_struct *task;
bool exited;
rcu_read_lock();
task = pid_task(pid, PIDTYPE_PID);
exited = !task ||
(READ_ONCE(task->exit_state) && thread_group_empty(task));
rcu_read_unlock();
return exited;
}
EXPORT_SYMBOL(thread_group_exited);
/*
* This needs to be __function_aligned as GCC implicitly makes any
* implementation of abort() cold and drops alignment specified by