From: Paul Durrant <paul.durrant@citrix.com>
Date: Thu, 5 Mar 2015 12:08:08 +0000 (+0000)
Subject: __DbgPrintEnable() cannot be called on paging path
X-Git-Tag: 8.1.0-rc1~48
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=8b60511f41b51d80d373286531b12d24c847b4d9;p=pvdrivers%2Fwin%2Fxenbus.git

__DbgPrintEnable() cannot be called on paging path

The system power up code in XENFILT re-enables DbgPrint hooking.
Unfortunately the undocumented kernel call it uses may require a page-in
and so causes a deadlock when XENVBD is responsible for the page file,
since it depends upon XENFILT to power up.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
---

diff --git a/src/xenfilt/fdo.c b/src/xenfilt/fdo.c
index 4736ac7..1597a15 100644
--- a/src/xenfilt/fdo.c
+++ b/src/xenfilt/fdo.c
@@ -1457,10 +1457,6 @@ FdoSetSystemPowerUp(
           SystemPowerStateName(__FdoGetSystemPowerState(Fdo)),
           SystemPowerStateName(SystemState));
 
-    if (SystemState < PowerSystemHibernate &&
-        __FdoGetSystemPowerState(Fdo) >= PowerSystemHibernate)
-        __DbgPrintEnable();
-
     __FdoSetSystemPowerState(Fdo, SystemState);
 
 done: