From: Roger Pau Monne <roger.pau@xxxxxxxxxx> commit 88a479ff6ef8af7f07e11593d58befc644244ff7 upstream. So it can be killed, or else processes can get hung indefinitely waiting for balloon pages. Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20200727091342.52325-3-roger.pau@xxxxxxxxxx Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/xen/balloon.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -570,11 +570,13 @@ static int add_ballooned_pages(int nr_pa if (xen_hotplug_unpopulated) { st = reserve_additional_memory(); if (st != BP_ECANCELED) { + int rc; + mutex_unlock(&balloon_mutex); - wait_event(balloon_wq, + rc = wait_event_interruptible(balloon_wq, !list_empty(&ballooned_pages)); mutex_lock(&balloon_mutex); - return 0; + return rc ? -ENOMEM : 0; } }
