0412-char-Disable-write-callback-if-throttled-chardev-is-.patch

   1 From f3551d3640f3436b0e5505fd208cbd7bbfef411f Mon Sep 17 00:00:00 2001
   2 From: Amit Shah <amit.shah@redhat.com>
   3 Date: Fri, 2 Dec 2011 15:42:55 +0530
   4 Subject: [PATCH] char: Disable write callback if throttled chardev is
   5  detached
   6
   7 If a throttled chardev is detached from the frontend device, all future
   8 callbacks should be suppressed.  Not doing this results in a segfault.
   9
  10 Bugzilla: 745758
  11 Upstream: Not applicable, since throttling is a RHEL6-only feature.
  12
  13 Signed-off-by: Amit Shah <amit.shah@redhat.com>
  14 Signed-off-by: Cole Robinson <crobinso@redhat.com>
  15 ---
  16  qemu-char.c | 5 +++++
  17  1 file changed, 5 insertions(+)
  18
  19 diff --git a/qemu-char.c b/qemu-char.c
  20 index bfc94a5..67a6d73 100644
  21 --- a/qemu-char.c
  22 +++ b/qemu-char.c
  23 @@ -223,6 +223,11 @@ void qemu_chr_add_handlers(CharDriverState *s,
  24          ++s->avail_connections;
  25      }
  26      if (!handlers) {
  27 +        if (s->write_blocked) {
  28 +            /* Ensure we disable the callback if we were throttled */
  29 +            s->chr_disable_write_fd_handler(s);
  30 +            /* s->write_blocked is cleared below */
  31 +        }
  32          handlers = &null_handlers;
  33      }
  34      s->chr_can_read = handlers->fd_can_read;
  35 --
  36 1.7.12.1
  37