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authorOleg Nesterov <oleg@redhat.com>2015-06-30 03:29:58 +0200
committerIngo Molnar <mingo@kernel.org>2015-08-03 12:21:28 +0200
commitd308b9f1e4412bcf583c82c4ca15ef97cb8b0e6f (patch)
tree0cc6e212c9ae62ad62ed3845629287d91f98a398
parentstop_machine: Use 'cpu_stop_fn_t' where possible (diff)
downloadlinux-d308b9f1e4412bcf583c82c4ca15ef97cb8b0e6f.tar.xz
linux-d308b9f1e4412bcf583c82c4ca15ef97cb8b0e6f.zip
stop_machine: Remove cpu_stop_work's from list in cpu_stop_park()
cpu_stop_park() does cpu_stop_signal_done() but leaves the work on stopper->works. The owner of this work can free/reuse this memory right after that and corrupt the list, so if this CPU becomes online again cpu_stopper_thread() will crash. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Cc: der.herr@hofr.at Cc: paulmck@linux.vnet.ibm.com Cc: riel@redhat.com Cc: viro@ZenIV.linux.org.uk Link: http://lkml.kernel.org/r/20150630012958.GA23944@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--kernel/stop_machine.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 9a70defe9f1f..12484e5d5c88 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -462,13 +462,15 @@ static void cpu_stop_create(unsigned int cpu)
static void cpu_stop_park(unsigned int cpu)
{
struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
- struct cpu_stop_work *work;
+ struct cpu_stop_work *work, *tmp;
unsigned long flags;
/* drain remaining works */
spin_lock_irqsave(&stopper->lock, flags);
- list_for_each_entry(work, &stopper->works, list)
+ list_for_each_entry_safe(work, tmp, &stopper->works, list) {
+ list_del_init(&work->list);
cpu_stop_signal_done(work->done, false);
+ }
stopper->enabled = false;
spin_unlock_irqrestore(&stopper->lock, flags);
}