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| author | David Vrabel <david.vrabel@citrix.com> | 2014-07-02 17:25:23 +0100 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2014-07-03 11:02:28 +0100 |
| commit | 1b6478231c6f5f844185acb32045cf195028cfce (patch) | |
| tree | 857d9e129051b69c8207c9785a74849dc03e0158 /drivers/xen | |
| parent | 13cd36a37a06ae0318d23b7e60adf0dac3547238 (diff) | |
| download | linux-1b6478231c6f5f844185acb32045cf195028cfce.tar.bz2 | |
xen/manage: fix potential deadlock when resuming the console
Calling xen_console_resume() in xen_suspend() causes a warning because
it locks irq_mapping_update_lock (a mutex) and this may sleep. If a
userspace process is using the evtchn device then this mutex may be
locked at the point of the stop_machine() call and
xen_console_resume() would then deadlock.
Resuming the console after stop_machine() returns avoids this
deadlock.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: <stable@vger.kernel.org>
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/manage.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index c3667b202f2f..5f1e1f3cd186 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -88,7 +88,6 @@ static int xen_suspend(void *data) if (!si->cancelled) { xen_irq_resume(); - xen_console_resume(); xen_timer_resume(); } @@ -135,6 +134,10 @@ static void do_suspend(void) err = stop_machine(xen_suspend, &si, cpumask_of(0)); + /* Resume console as early as possible. */ + if (!si.cancelled) + xen_console_resume(); + raw_notifier_call_chain(&xen_resume_notifier, 0, NULL); dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |