qemu_chr_fe_get_driver() is unsafe, frontends with hotswap support
should not access CharDriver ptr directly as CharDriver might change.
Signed-off-by: Anton Nefedov <anton.nefe...@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
chardev/char.c | 7 +++++++
include/sysemu/char.h | 10 ++++++++++
2 files changed, 17 insertions(+)
diff --git a/chardev/char.c b/chardev/char.c
index ba1a5f5..1eed934 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -484,9 +484,16 @@ static Notifier muxes_realize_notify = {
Chardev *qemu_chr_fe_get_driver(CharBackend *be)
{
+ /* this is unsafe for the users that support chardev hotswap */
+ assert(be->chr_be_change == NULL);
return be->chr;
}
+bool qemu_chr_fe_backend_connected(CharBackend *be)
+{
+ return !!be->chr;
+}
+
static bool qemu_chr_fe_connect(CharBackend *b, Chardev *s, Error **errp)
{
int tag = 0;
diff --git a/include/sysemu/char.h b/include/sysemu/char.h
index 014ebbc..117d628 100644
--- a/include/sysemu/char.h
+++ b/include/sysemu/char.h
@@ -391,10 +391,20 @@ bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error
**errp);
*
* Returns the driver associated with a CharBackend or NULL if no
* associated Chardev.
+ * Note: avoid this function as the driver should never be accessed directly,
+ * especially by the frontends that support chardevice hotswap.
+ * Consider qemu_chr_fe_backend_connected() to check for driver existence
*/
Chardev *qemu_chr_fe_get_driver(CharBackend *be);
/**
+ * @qemu_chr_fe_backend_connected:
+ *
+ * Returns true if there is a chardevice associated with @be.
+ */
+bool qemu_chr_fe_backend_connected(CharBackend *be);
+
+/**
* @qemu_chr_fe_deinit:
*
* Dissociate the CharBackend from the Chardev.
--
2.7.4
