From 42931bebb2856307dcdc9babc5dd9954b60c8094 Mon Sep 17 00:00:00 2001

From: Amit Shah <amit.shah@redhat.com>

Date: Fri, 2 Dec 2011 15:42:55 +0530

Subject: [PATCH] char: Disable write callback if throttled chardev is detached

If a throttled chardev is detached from the frontend device, all future

callbacks should be suppressed.  Not doing this results in a segfault.

Bugzilla: 745758

Upstream: Not applicable, since throttling is a RHEL6-only feature.

Signed-off-by: Amit Shah <amit.shah@redhat.com>

Signed-off-by: Cole Robinson <crobinso@redhat.com>

---

 qemu-char.c | 5 +++++

 1 file changed, 5 insertions(+)

diff --git a/qemu-char.c b/qemu-char.c

index 53d2c13..fde72ff 100644

--- a/qemu-char.c

+++ b/qemu-char.c

@@ -223,6 +223,11 @@ void qemu_chr_add_handlers(CharDriverState *s,

         ++s->avail_connections;

     }

     if (!handlers) {

+        if (s->write_blocked) {

+            /* Ensure we disable the callback if we were throttled */

+            s->chr_disable_write_fd_handler(s);

+            /* s->write_blocked is cleared below */

+        }

         handlers = &null_handlers;

     }

     s->chr_can_read = handlers->fd_can_read;