diff options
author | David Vrabel <david.vrabel@citrix.com> | 2014-07-02 12:25:23 -0400 |
---|---|---|
committer | David Vrabel <david.vrabel@citrix.com> | 2014-07-03 06:02:28 -0400 |
commit | 1b6478231c6f5f844185acb32045cf195028cfce (patch) | |
tree | 857d9e129051b69c8207c9785a74849dc03e0158 /drivers/xen | |
parent | 13cd36a37a06ae0318d23b7e60adf0dac3547238 (diff) |
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) | |||
88 | 88 | ||
89 | if (!si->cancelled) { | 89 | if (!si->cancelled) { |
90 | xen_irq_resume(); | 90 | xen_irq_resume(); |
91 | xen_console_resume(); | ||
92 | xen_timer_resume(); | 91 | xen_timer_resume(); |
93 | } | 92 | } |
94 | 93 | ||
@@ -135,6 +134,10 @@ static void do_suspend(void) | |||
135 | 134 | ||
136 | err = stop_machine(xen_suspend, &si, cpumask_of(0)); | 135 | err = stop_machine(xen_suspend, &si, cpumask_of(0)); |
137 | 136 | ||
137 | /* Resume console as early as possible. */ | ||
138 | if (!si.cancelled) | ||
139 | xen_console_resume(); | ||
140 | |||
138 | raw_notifier_call_chain(&xen_resume_notifier, 0, NULL); | 141 | raw_notifier_call_chain(&xen_resume_notifier, 0, NULL); |
139 | 142 | ||
140 | dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE); | 143 | dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |