From 2115b5617adf2eecca49e78f3810f359ddc5c396 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Thu, 28 Aug 2014 18:29:53 -0700 Subject: 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 Tested-by: Sitsofe Wheeler Signed-off-by: Greg Kroah-Hartman --- drivers/hv/channel_mgmt.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) (limited to 'drivers/hv/channel_mgmt.c') diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index ed9350d42764..a2d1a9612c86 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -224,11 +224,14 @@ static void vmbus_process_rescind_offer(struct work_struct *work) 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 @@ static void vmbus_process_offer(struct work_struct *work) 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 @@ static void vmbus_process_offer(struct work_struct *work) 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) -- cgit v1.2.3