The patch titled
coredump: zap_threads() must skip kernel threads
has been added to the -mm tree. Its filename is
coredump-zap_threads-must-skip-kernel-threads.patch
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See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: coredump: zap_threads() must skip kernel threads
From: Oleg Nesterov <oleg@xxxxxxxxxx>
The main loop in zap_threads() must skip kthreads which may use the same
mm. Otherwise we "kill" this thread erroneously (for example, it can not
fork or exec after that), and the coredumping task stucks in the
TASK_UNINTERRUPTIBLE state forever because of the wrong ->core_waiters
count.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff -puN fs/exec.c~coredump-zap_threads-must-skip-kernel-threads fs/exec.c
--- a/fs/exec.c~coredump-zap_threads-must-skip-kernel-threads
+++ a/fs/exec.c
@@ -1543,11 +1543,12 @@ static inline int zap_threads(struct tas
for_each_process(g) {
if (g == tsk->group_leader)
continue;
-
+ if (g->flags & PF_KTHREAD)
+ continue;
p = g;
do {
if (p->mm) {
- if (p->mm == mm) {
+ if (unlikely(p->mm == mm)) {
/*
* p->sighand can't disappear, but
* may be changed by de_thread()
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
vt-fix-vc_resize-locking.patch
introduce-pf_kthread-flag.patch
kill-pf_borrowed_mm-in-favour-of-pf_kthread.patch
coredump-zap_threads-must-skip-kernel-threads.patch
uml-activate_mm-remove-the-dead-pf_borrowed_mm-check.patch
posix-timers-timer_delete-remove-the-bogus-it_process-=-null-check.patch
posix-timers-release_posix_timer-kill-the-bogus-put_task_struct-it_process.patch
signals-collect_signal-remove-the-unneeded-sigismember-check.patch
signals-collect_signal-simplify-the-still_pending-logic.patch
signals-change-collect_signal-to-return-void.patch
__exit_signal-dont-take-rcu-lock.patch
signals-dequeue_signal-dont-check-signal_group_exit-when-setting-signal_stop_dequeued.patch
signals-do_signal_stop-kill-the-signal_unkillable-check.patch
coredump-zap_threads-comments-use-while_each_thread.patch
distinct-tgid-tid-i-o-statistics.patch
--
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