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| author | Christian Brauner <christian@brauner.io> | 2019-07-29 17:48:24 +0200 |
|---|---|---|
| committer | Christian Brauner <christian@brauner.io> | 2019-07-30 19:57:14 +0200 |
| commit | 30b692d3b390c6fe78a5064be0c4bbd44a41be59 (patch) | |
| tree | e50f2c2635beacd11be8b3e8d0c305781425ab27 | |
| parent | 1caf7d50f46bd0388e38e653b146aa81700e8eb8 (diff) | |
| download | linux-30b692d3b390c6fe78a5064be0c4bbd44a41be59.tar.gz linux-30b692d3b390c6fe78a5064be0c4bbd44a41be59.tar.bz2 linux-30b692d3b390c6fe78a5064be0c4bbd44a41be59.zip | |
exit: make setting exit_state consistent
Since commit b191d6491be6 ("pidfd: fix a poll race when setting exit_state")
we unconditionally set exit_state to EXIT_ZOMBIE before calling into
do_notify_parent(). This was done to eliminate a race when querying
exit_state in do_notify_pidfd().
Back then we decided to do the absolute minimal thing to fix this and
not touch the rest of the exit_notify() function where exit_state is
set.
Since this fix has not caused any issues change the setting of
exit_state to EXIT_DEAD in the autoreap case to account for the fact hat
exit_state is set to EXIT_ZOMBIE unconditionally. This fix was planned
but also explicitly requested in [1] and makes the whole code more
consistent.
/* References */
[1]: https://lore.kernel.org/lkml/CAHk-=wigcxGFR2szue4wavJtH5cYTTeNES=toUBVGsmX0rzX+g@mail.gmail.com
Signed-off-by: Christian Brauner <christian@brauner.io>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/exit.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 4436158a6d30..5b4a5dcce8f8 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -734,9 +734,10 @@ static void exit_notify(struct task_struct *tsk, int group_dead) autoreap = true; } - tsk->exit_state = autoreap ? EXIT_DEAD : EXIT_ZOMBIE; - if (tsk->exit_state == EXIT_DEAD) + if (autoreap) { + tsk->exit_state = EXIT_DEAD; list_add(&tsk->ptrace_entry, &dead); + } /* mt-exec, de_thread() is waiting for group leader */ if (unlikely(tsk->signal->notify_count < 0)) |