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| author | Oleg Nesterov <oleg@redhat.com> | 2009-06-18 16:49:11 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-19 16:46:06 -0700 |
| commit | befca96779b0259ac8fad0183e748a62935c39cb (patch) | |
| tree | ab4962e27ce10abc932de4c7a4c1c29fac2988cf /kernel | |
| parent | e6229bec25be4ba00f31dd26e25721cc96c22262 (diff) | |
| download | op-kernel-dev-befca96779b0259ac8fad0183e748a62935c39cb.zip op-kernel-dev-befca96779b0259ac8fad0183e748a62935c39cb.tar.gz | |
ptrace: wait_task_zombie: do not account traced sub-threads
The bug is ancient.
If we trace the sub-thread of our natural child and this sub-thread exits,
we update parent->signal->cxxx fields. But we should not do this until
the whole thread-group exits, otherwise we account this thread (and all
other live threads) twice.
Add the task_detached() check. No need to check thread_group_empty(),
wait_consider_task()->delay_group_leader() already did this.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Vitaly Mayatskikh <vmayatsk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 13ae640..628d41f 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1197,8 +1197,11 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) } traced = ptrace_reparented(p); - - if (likely(!traced)) { + /* + * It can be ptraced but not reparented, check + * !task_detached() to filter out sub-threads. + */ + if (likely(!traced) && likely(!task_detached(p))) { struct signal_struct *psig; struct signal_struct *sig; |
