diff options
author | Amit Shah <amit.shah@redhat.com> | 2013-08-28 15:24:05 +0530 |
---|---|---|
committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2013-12-02 21:18:10 -0600 |
commit | 8501da4b93959ccbae4d04a673d0f1c5b72b1a4b (patch) | |
tree | 684e2326b4f6de51e6b15f4b14b517b8a5a1970d | |
parent | aeefaaac83a38a563a0511d6012abea5c49a3165 (diff) | |
download | qemu-8501da4b93959ccbae4d04a673d0f1c5b72b1a4b.tar.gz |
char: remove watch callback on chardev detach from frontend
If a frontend device releases the chardev (via unplug), the chr handlers
are set to NULL via qdev's exit callbacks invoking
qemu_chr_add_handlers(). If the chardev had a pending operation, a
callback will be invoked, which will try to access data in the
just-released frontend, causing a segfault.
Ensure the callbacks are disabled when frontends release chardevs.
This was seen when a virtio-serial port was unplugged when heavy
guest->host IO was in progress (causing a callback to be registered).
In the window in which the throttling was active, unplugging ports
caused a qemu segfault.
https://bugzilla.redhat.com/show_bug.cgi?id=985205
CC: <qemu-stable@nongnu.org>
Reported-by: Sibiao Luo <sluo@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
(cherry picked from commit 386a5a1e0057e220f79c48fe3689e3dfb17f1b09)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
-rw-r--r-- | qemu-char.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/qemu-char.c b/qemu-char.c index fa005174dd..fc1c23d2c3 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -193,6 +193,8 @@ void qemu_chr_fe_printf(CharDriverState *s, const char *fmt, ...) va_end(ap); } +static void remove_fd_in_watch(CharDriverState *chr); + void qemu_chr_add_handlers(CharDriverState *s, IOCanReadHandler *fd_can_read, IOReadHandler *fd_read, @@ -203,6 +205,7 @@ void qemu_chr_add_handlers(CharDriverState *s, if (!opaque && !fd_can_read && !fd_read && !fd_event) { fe_open = 0; + remove_fd_in_watch(s); } else { fe_open = 1; } |