On Tue, May 30, 2017 at 6:13 PM Anton Nefedov <anton.nefe...@virtuozzo.com> wrote:
> 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> > Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.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 > > > -- Marc-André Lureau