Drivers: hv: vmbus: Properly protect calls to smp_processor_id()
Disable preemption when sampling current processor ID when preemption
is otherwise possible.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index ed9350d..a2d1a96 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -224,11 +224,14 @@
msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released));
- if (channel->target_cpu != smp_processor_id())
+ if (channel->target_cpu != get_cpu()) {
+ put_cpu();
smp_call_function_single(channel->target_cpu,
percpu_channel_deq, channel, true);
- else
+ } else {
percpu_channel_deq(channel);
+ put_cpu();
+ }
if (channel->primary_channel == NULL) {
spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
@@ -294,12 +297,15 @@
spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
if (enq) {
- if (newchannel->target_cpu != smp_processor_id())
+ if (newchannel->target_cpu != get_cpu()) {
+ put_cpu();
smp_call_function_single(newchannel->target_cpu,
percpu_channel_enq,
newchannel, true);
- else
+ } else {
percpu_channel_enq(newchannel);
+ put_cpu();
+ }
}
if (!fnew) {
/*
@@ -314,12 +320,15 @@
list_add_tail(&newchannel->sc_list, &channel->sc_list);
spin_unlock_irqrestore(&channel->sc_lock, flags);
- if (newchannel->target_cpu != smp_processor_id())
+ if (newchannel->target_cpu != get_cpu()) {
+ put_cpu();
smp_call_function_single(newchannel->target_cpu,
percpu_channel_enq,
newchannel, true);
- else
+ } else {
percpu_channel_enq(newchannel);
+ put_cpu();
+ }
newchannel->state = CHANNEL_OPEN_STATE;
if (channel->sc_creation_callback != NULL)
