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From: Dan Carpenter <dan.carpenter@oracle.com>
To: bigeasy@linutronix.de
Cc: linux-perf-users@vger.kernel.org
Subject: [bug report] irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support.
Date: Wed, 19 Jan 2022 16:37:29 +0300	[thread overview]
Message-ID: <20220119133729.GA14183@kili> (raw)

Hello Sebastian Andrzej Siewior,

The patch 810979682ccc: "irq_work: Allow irq_work_sync() to sleep if
irq_work() no IRQ support." from Oct 6, 2021, leads to the following
Smatch static checker warning:

	kernel/events/core.c:4955 _free_event()
	warn: sleeping in atomic context

There are two potential call trees where preemption is disabled.

perf_remove_from_context() <- disables preempt
__perf_event_exit_context() <- disables preempt
-> __perf_remove_from_context()
   -> perf_group_detach()
      -> perf_put_aux_event()
         -> put_event()
            -> _free_event()

_free_event() calls irq_work_sync() which can now sleep.

regards,
dan carpenter


             reply	other threads:[~2022-01-19 13:37 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-19 13:37 Dan Carpenter [this message]
2022-01-26 12:11 ` [bug report] irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support Sebastian Andrzej Siewior
2022-01-26 13:24   ` Dan Carpenter

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