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authorJiri Kosina <jkosina@suse.cz>2017-05-02 11:02:41 +0200
committerJiri Kosina <jkosina@suse.cz>2017-05-02 11:02:41 +0200
commit4d6ca227c768b50b05cf183974b40abe444e9d0c (patch)
treebf953d8e895281053548b9967a2c4b58d641df00 /kernel/exit.c
parent800f3eef8ebc1264e9c135bfa892c8ae41fa4792 (diff)
parentaf22a610bc38508d5ea760507d31be6b6983dfa8 (diff)
Merge branch 'for-4.12/asus' into for-linus
Diffstat (limited to 'kernel/exit.c')
-rw-r--r--kernel/exit.c22
1 files changed, 16 insertions, 6 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 580da79e38ee..516acdb0e0ec 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -6,6 +6,12 @@
#include <linux/mm.h>
#include <linux/slab.h>
+#include <linux/sched/autogroup.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/stat.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/sched/cputime.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/capability.h>
@@ -45,6 +51,7 @@
#include <linux/task_io_accounting_ops.h>
#include <linux/tracehook.h>
#include <linux/fs_struct.h>
+#include <linux/userfaultfd_k.h>
#include <linux/init_task.h>
#include <linux/perf_event.h>
#include <trace/events/sched.h>
@@ -538,7 +545,7 @@ static void exit_mm(void)
__set_current_state(TASK_RUNNING);
down_read(&mm->mmap_sem);
}
- atomic_inc(&mm->mm_count);
+ mmgrab(mm);
BUG_ON(mm != current->active_mm);
/* more a memory barrier than a real lock */
task_lock(current);
@@ -607,15 +614,18 @@ static struct task_struct *find_new_reaper(struct task_struct *father,
return thread;
if (father->signal->has_child_subreaper) {
+ unsigned int ns_level = task_pid(father)->level;
/*
* Find the first ->is_child_subreaper ancestor in our pid_ns.
- * We start from father to ensure we can not look into another
- * namespace, this is safe because all its threads are dead.
+ * We can't check reaper != child_reaper to ensure we do not
+ * cross the namespaces, the exiting parent could be injected
+ * by setns() + fork().
+ * We check pid->level, this is slightly more efficient than
+ * task_active_pid_ns(reaper) != task_active_pid_ns(father).
*/
- for (reaper = father;
- !same_thread_group(reaper, child_reaper);
+ for (reaper = father->real_parent;
+ task_pid(reaper)->level == ns_level;
reaper = reaper->real_parent) {
- /* call_usermodehelper() descendants need this check */
if (reaper == &init_task)
break;
if (!reaper->signal->is_child_subreaper)