From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> When add_memory() fails the following BUG is observed: [ 743.646107] hv_balloon: hot_add memory failed error is -17 [ 743.679973] [ 743.680930] ===================================== [ 743.680930] [ BUG: bad unlock balance detected! ] [ 743.680930] 3.19.0-rc5_bug1131426+ #552 Not tainted [ 743.680930] ------------------------------------- [ 743.680930] kworker/0:2/255 is trying to release lock (&dm_device.ha_region_mutex) at: [ 743.680930] [<ffffffff81aae5fe>] mutex_unlock+0xe/0x10 [ 743.680930] but there are no more locks to release! This happens as we don't acquire ha_region_mutex and hot_add_req() expects us to as it does unconditional mutex_unlock(). Acquire the lock on the error path. The current Linux 4.0 RC3 tree is broken and this patch fixes the problem. Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> --- drivers/hv/hv_balloon.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index c5bb872..f1f17c5 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -652,6 +652,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size, } has->ha_end_pfn -= HA_CHUNK; has->covered_end_pfn -= processed_pfn; + mutex_lock(&dm_device.ha_region_mutex); break; } -- 1.7.4.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
