Messages in this thread Patch in this message | | | Date | Mon, 3 Aug 2015 10:10:01 -0700 | From | tip-bot for Oleg Nesterov <> | Subject | [tip:sched/core] stop_machine: Remove cpu_stop_work' s from list in cpu_stop_park() |
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Commit-ID: d308b9f1e4412bcf583c82c4ca15ef97cb8b0e6f Gitweb: http://git.kernel.org/tip/d308b9f1e4412bcf583c82c4ca15ef97cb8b0e6f Author: Oleg Nesterov <oleg@redhat.com> AuthorDate: Tue, 30 Jun 2015 03:29:58 +0200 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 3 Aug 2015 12:21:28 +0200
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> --- kernel/stop_machine.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 9a70def..12484e5 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); }
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