diff options
| author | Anton Nefedov <anton.nefedov@virtuozzo.com> | 2017-07-06 15:08:51 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-07-14 11:04:33 +0200 |
| commit | 7c44a2a9d178118193febd71cfc6943dd21bdde9 (patch) | |
| tree | 2206791e4494c36a2f70d3a020001910b9a79a9f | |
| parent | 7bb86085e61befc95551055e26645cb23c3f0b86 (diff) | |
char: forbid direct chardevice access for hotswap devices
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.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1499342940-56739-5-git-send-email-anton.nefedov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | chardev/char-fe.c | 7 | ||||
| -rw-r--r-- | include/chardev/char-fe.h | 10 |
2 files changed, 17 insertions, 0 deletions
diff --git a/chardev/char-fe.c b/chardev/char-fe.c index 7054863208..de5ba3c119 100644 --- a/chardev/char-fe.c +++ b/chardev/char-fe.c @@ -179,9 +179,16 @@ void qemu_chr_fe_printf(CharBackend *be, const char *fmt, ...) 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; +} + bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error **errp) { int tag = 0; diff --git a/include/chardev/char-fe.h b/include/chardev/char-fe.h index 9f38060c7e..588abed606 100644 --- a/include/chardev/char-fe.h +++ b/include/chardev/char-fe.h @@ -46,10 +46,20 @@ void qemu_chr_fe_deinit(CharBackend *b, bool del); * * 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_set_handlers: * @b: a CharBackend * @fd_can_read: callback to get the amount of data the frontend may |