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authorVitaly Kuznetsov <vkuznets@redhat.com>2016-02-26 15:13:16 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-03-01 16:57:20 -0800
commit75ff3a8a9168df750b5bd0589e897a6c0517a9f1 (patch)
tree8fd74ea7038aee9503e31dda1281010aa16a9713
parent7be3e169444d2c625f15a0b6639252b98d1f226a (diff)
downloadlinux-75ff3a8a9168df750b5bd0589e897a6c0517a9f1.tar.bz2
Drivers: hv: vmbus: avoid wait_for_completion() on crash
wait_for_completion() may sleep, it enables interrupts and this is something we really want to avoid on crashes because interrupt handlers can cause other crashes. Switch to the recently introduced vmbus_wait_for_unload() doing busy wait instead. Reported-by: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Radim Kr.má<rkrcmar@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/hv/channel_mgmt.c4
-rw-r--r--drivers/hv/connection.c2
-rw-r--r--drivers/hv/hyperv_vmbus.h2
-rw-r--r--drivers/hv/vmbus_drv.c4
4 files changed, 6 insertions, 6 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index b40f429aaa13..f70e35278b94 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -641,7 +641,7 @@ static void vmbus_unload_response(struct vmbus_channel_message_header *hdr)
complete(&vmbus_connection.unload_event);
}
-void vmbus_initiate_unload(void)
+void vmbus_initiate_unload(bool crash)
{
struct vmbus_channel_message_header hdr;
@@ -658,7 +658,7 @@ void vmbus_initiate_unload(void)
* vmbus_initiate_unload() is also called on crash and the crash can be
* happening in an interrupt context, where scheduling is impossible.
*/
- if (!in_interrupt())
+ if (!crash)
wait_for_completion(&vmbus_connection.unload_event);
else
vmbus_wait_for_unload();
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index fa86b2cb28b8..3b6dc0017269 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -236,7 +236,7 @@ void vmbus_disconnect(void)
/*
* First send the unload request to the host.
*/
- vmbus_initiate_unload();
+ vmbus_initiate_unload(false);
if (vmbus_connection.work_queue) {
drain_workqueue(vmbus_connection.work_queue);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index b9ea7f59036b..b0299da9c2db 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -663,7 +663,7 @@ void hv_vss_onchannelcallback(void *);
int hv_fcopy_init(struct hv_util_service *);
void hv_fcopy_deinit(void);
void hv_fcopy_onchannelcallback(void *);
-void vmbus_initiate_unload(void);
+void vmbus_initiate_unload(bool crash);
static inline void hv_poll_channel(struct vmbus_channel *channel,
void (*cb)(void *))
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 30ea8ad902e2..c8f1671944d5 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1291,7 +1291,7 @@ static void hv_kexec_handler(void)
int cpu;
hv_synic_clockevents_cleanup();
- vmbus_initiate_unload();
+ vmbus_initiate_unload(false);
for_each_online_cpu(cpu)
smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
hv_cleanup();
@@ -1299,7 +1299,7 @@ static void hv_kexec_handler(void)
static void hv_crash_handler(struct pt_regs *regs)
{
- vmbus_initiate_unload();
+ vmbus_initiate_unload(true);
/*
* In crash handler we can't schedule synic cleanup for all CPUs,
* doing the cleanup for current CPU only. This should be sufficient