Child should wake ups parent from vfork() only after finishing all operations with shared mm. There is no sense to use CLONE_CHILD_CLEARTID together with CLONE_VFORK, but it looks more accurate now. Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> --- kernel/fork.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index 326bb5b..f10ac1d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -728,9 +728,6 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) /* Get rid of any cached register state */ deactivate_mm(tsk, mm); - if (tsk->vfork_done) - complete_vfork_done(tsk); - /* * If we're exiting normally, clear a user-space tid field if * requested. We leave this alone when dying by signal, to leave @@ -759,6 +756,13 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) */ if (mm) sync_mm_rss(mm); + + /* + * All done, finally we can wake up parent and return this mm to him. + * Also kthread_stop() uses this completion for synchronization. + */ + if (tsk->vfork_done) + complete_vfork_done(tsk); } /* -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>