diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2014-04-07 15:38:43 -0700 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2019-05-02 18:19:01 +0200 |
| commit | 7ee48c4c48b6d7f9104f1e34dc5904c88602e397 (patch) | |
| tree | decaad78933481895e09adf3e85a02a2e75cb3b5 /kernel/exit.c | |
| parent | c14af65738418131be1e18f9b2a1d0f1e90110e0 (diff) | |
wait: use EXIT_TRACE only if thread_group_leader(zombie)
wait_task_zombie() always uses EXIT_TRACE/ptrace_unlink() if
ptrace_reparented(). This is suboptimal and a bit confusing: we do not
need do_notify_parent(p) if !thread_group_leader(p) and in this case we
also do not need ptrace_unlink(), we can rely on ptrace_release_task().
Change wait_task_zombie() to check thread_group_leader() along with
ptrace_reparented() and simplify the final p->exit_state transition.
Change-Id: I4e5f79e0b8900b0b167f82c596ce5ad235745be6
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Michal Schmidt <mschmidt@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 279865af0..1ccf4e746 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1078,7 +1078,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) /* * Move the task's state to DEAD/TRACE, only one thread can do this. */ - state = traced ? EXIT_TRACE : EXIT_DEAD; + state = traced && thread_group_leader(p) ? EXIT_TRACE : EXIT_DEAD; if (cmpxchg(&p->exit_state, EXIT_ZOMBIE, state) != EXIT_ZOMBIE) return 0; /* @@ -1178,18 +1178,15 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) if (!retval) retval = pid; - if (traced) { + if (state == EXIT_TRACE) { write_lock_irq(&tasklist_lock); /* We dropped tasklist, ptracer could die and untrace */ ptrace_unlink(p); - /* - * If this is not a sub-thread, notify the parent. - * If parent wants a zombie, don't release it now. - */ - state = EXIT_DEAD; - if (thread_group_leader(p) && - !do_notify_parent(p, p->exit_signal)) - state = EXIT_ZOMBIE; + + /* If parent wants a zombie, don't release it now */ + state = EXIT_ZOMBIE; + if (do_notify_parent(p, p->exit_signal)) + state = EXIT_DEAD; p->exit_state = state; write_unlock_irq(&tasklist_lock); } |