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| author | Oleg Nesterov <oleg@tv-sign.ru> | 2008-03-02 21:44:42 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-03-03 14:53:16 -0800 |
| commit | 05e83df624fe682bb8571cdb2c6d5284a99c3066 (patch) | |
| tree | c55df1d1258f2fae4069aa7954a2c74ba1831192 /kernel | |
| parent | f49ee505b1ecb5960984880740f09aba87f870dc (diff) | |
| download | kernel_samsung_smdk4412-05e83df624fe682bb8571cdb2c6d5284a99c3066.zip kernel_samsung_smdk4412-05e83df624fe682bb8571cdb2c6d5284a99c3066.tar.gz kernel_samsung_smdk4412-05e83df624fe682bb8571cdb2c6d5284a99c3066.tar.bz2 | |
will_become_orphaned_pgrp: partially fix insufficient ->exit_state check
p->exit_state != 0 doesn't mean this process is dead, it may have
sub-threads. Change the code to use "p->exit_state && thread_group_empty(p)"
instead.
Without this patch, ^Z doesn't deliver SIGTSTP to the foreground process
if the main thread has exited.
However, the new check is not perfect either. There is a window when
exit_notify() drops tasklist and before release_task(). Suppose that
the last (non-leader) thread exits. This means that entire group exits,
but thread_group_empty() is not true yet.
As Eric pointed out, is_global_init() is wrong as well, but I did not
dare to do other changes.
Just for the record, has_stopped_jobs() is absolutely wrong too. But we
can't fix it now, we should first fix SIGNAL_STOP_STOPPED issues.
Even with this patch ^Z doesn't play well with the dead main thread.
The task is stopped correctly but do_wait(WSTOPPED) won't see it. This
is another unrelated issue, will be (hopefully) fixed separately.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 11fcce7..41c1eda 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -214,20 +214,19 @@ struct pid *session_of_pgrp(struct pid *pgrp) static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task) { struct task_struct *p; - int ret = 1; do_each_pid_task(pgrp, PIDTYPE_PGID, p) { - if (p == ignored_task - || p->exit_state - || is_global_init(p->real_parent)) + if ((p == ignored_task) || + (p->exit_state && thread_group_empty(p)) || + is_global_init(p->real_parent)) continue; + if (task_pgrp(p->real_parent) != pgrp && - task_session(p->real_parent) == task_session(p)) { - ret = 0; - break; - } + task_session(p->real_parent) == task_session(p)) + return 0; } while_each_pid_task(pgrp, PIDTYPE_PGID, p); - return ret; /* (sighing) "Often!" */ + + return 1; } int is_current_pgrp_orphaned(void) |