From caf3059397fe853808cc5f8f524d9a6580f12abc Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Tue, 14 Feb 2012 11:14:17 +0100
Subject: [PATCH 52/99] Allow nested qemu_bh_poll() after BH deletion
RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1329218101-24213-53-git-send-email-kwolf@redhat.com>
Patchwork-id: 37244
O-Subject: [RHEL-6.3 qemu-kvm PATCH v2 52/96] Allow nested qemu_bh_poll() after BH deletion
Bugzilla: 783950
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
Bugzilla: 783950
Without this, qemu segfaults when a BH handler first deletes its BH and
then calls another function which involves a nested qemu_bh_poll() call.
This can be reproduced by generating an I/O error (e.g. with blkdebug) on
an IDE device and using rerror/werror=stop to stop the VM. When continuing
the VM, qemu segfaults.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
(cherry picked from commit 7887f6201ff3fdc9a142eba14d61c563adb57596)
---
async.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
Signed-off-by: Michal Novotny <minovotn@redhat.com>
---
async.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/async.c b/async.c
index 57ac3a8..fd313df 100644
--- a/async.c
+++ b/async.c
@@ -137,11 +137,12 @@ QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
int qemu_bh_poll(void)
{
- QEMUBH *bh, **bhp;
+ QEMUBH *bh, **bhp, *next;
int ret;
ret = 0;
- for (bh = async_context->first_bh; bh; bh = bh->next) {
+ for (bh = async_context->first_bh; bh; bh = next) {
+ next = bh->next;
if (!bh->deleted && bh->scheduled) {
bh->scheduled = 0;
if (!bh->idle)
--
1.7.7.5