From c18d5d57fc782121020e11af6a48d1d669aaa4d2 Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Wed, 26 Sep 2012 16:23:24 +0100 Subject: Fix potential deadlock when agent is closed If the qemuAgentClose method is called from a place which holds the domain lock, it is theoretically possible to get a deadlock in the agent destroy callback. This has not been observed, but the equivalent code in the QEMU monitor destroy callback has seen a deadlock. Remove the redundant locking while unrefing the object and the bogus assignment Signed-off-by: Daniel P. Berrange --- src/qemu/qemu_process.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index f67495f34..f30493877 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -128,7 +128,8 @@ qemuProcessHandleAgentEOF(qemuAgentPtr agent, virDomainObjLock(vm); priv = vm->privateData; - priv->agent = NULL; + if (priv->agent == agent) + priv->agent = NULL; virDomainObjUnlock(vm); qemuDriverUnlock(driver); @@ -166,16 +167,9 @@ qemuProcessHandleAgentError(qemuAgentPtr agent ATTRIBUTE_UNUSED, static void qemuProcessHandleAgentDestroy(qemuAgentPtr agent, virDomainObjPtr vm) { - qemuDomainObjPrivatePtr priv; - VIR_DEBUG("Received destroy agent=%p vm=%p", agent, vm); - virDomainObjLock(vm); - priv = vm->privateData; - if (priv->agent == agent) - priv->agent = NULL; - if (virObjectUnref(vm)) - virDomainObjUnlock(vm); + virObjectUnref(vm); } -- cgit v1.2.3-65-gdbad