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authorVitaly Kuznetsov <vkuznets@redhat.com>2015-08-01 16:08:09 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-08-04 22:28:38 -0700
commitb4370df2b1f5158de028e167974263c5757b34a6 (patch)
tree4a8733a8b1ae446e1b1a3df70f7c180f8bc15ecf /drivers/hv
parentd7646eaa7678fe5adc42247b4bdfbe9d9db8c253 (diff)
downloadop-kernel-dev-b4370df2b1f5158de028e167974263c5757b34a6.zip
op-kernel-dev-b4370df2b1f5158de028e167974263c5757b34a6.tar.gz
Drivers: hv: vmbus: add special crash handler
Full kernel hang is observed when kdump kernel starts after a crash. This hang happens in vmbus_negotiate_version() function on wait_for_completion() as Hyper-V host (Win2012R2 in my testing) never responds to CHANNELMSG_INITIATE_CONTACT as it thinks the connection is already established. We need to perform some mandatory minimalistic cleanup before we start new kernel. Reported-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv')
-rw-r--r--drivers/hv/vmbus_drv.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 31748a2..1ed9b32 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1071,6 +1071,18 @@ static void hv_kexec_handler(void)
hv_cleanup();
};
+static void hv_crash_handler(struct pt_regs *regs)
+{
+ vmbus_initiate_unload();
+ /*
+ * In crash handler we can't schedule synic cleanup for all CPUs,
+ * doing the cleanup for current CPU only. This should be sufficient
+ * for kdump.
+ */
+ hv_synic_cleanup(NULL);
+ hv_cleanup();
+};
+
static int __init hv_acpi_init(void)
{
int ret, t;
@@ -1104,6 +1116,7 @@ static int __init hv_acpi_init(void)
goto cleanup;
hv_setup_kexec_handler(hv_kexec_handler);
+ hv_setup_crash_handler(hv_crash_handler);
return 0;
@@ -1118,6 +1131,7 @@ static void __exit vmbus_exit(void)
int cpu;
hv_remove_kexec_handler();
+ hv_remove_crash_handler();
vmbus_connection.conn_state = DISCONNECTED;
hv_synic_clockevents_cleanup();
vmbus_disconnect();
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