PulseAudio Marge Bot pushed to branch master at PulseAudio / pulseaudio
Commits: 4bdf4c99 by Takashi Sakamoto at 2022-06-27T22:08:13+03:00 alsa-mixer: avoid assertion at alsa-lib mixer API when element removal PulseAudio v5.99 or later hits assertion at alsa-lib mixer API due to wrong handling of removal event for mixer element. pulseaudio: mixer.c:149: hctl_elem_event_handler: Assertion `bag_empty(bag)' failed. The removal event is defined as '~0U', thus it's not distinguished from the other type of event just by bitwise operator. At the removal event, class implementator for mixer API should detach mixer element from hcontrol element in callback handler since alsa-lib has assertion to check the list of mixer elements for a hcontrol element is empty or not after calling all of handlers. In detail, please refer to MR to alsa-lib: * https://github.com/alsa-project/alsa-lib/pull/244 This commit fixes the above two issues. The issue can be regenerated by `samples/ctl` Python 3 script of alsa-gobject. * https://github.com/alsa-project/alsa-gobject/ It adds some user-defined elements into sound card 0. When terminated by SIGINT signal, it removes the elements. Then PulseAudio dies due to the assertion. Fixes: 1fd8848e64cf ("alsa-util: Add functions for accessing mixer elements through mixer class") Part-of: <https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/merge_requests/728> - - - - - 1 changed file: - src/modules/alsa/alsa-util.c Changes: ===================================== src/modules/alsa/alsa-util.c ===================================== @@ -1654,7 +1654,13 @@ static int mixer_class_event(snd_mixer_class_t *class, unsigned int mask, { int err; const char *name = snd_hctl_elem_get_name(helem); - if (mask & SND_CTL_EVENT_MASK_ADD) { + /* NOTE: The remove event is defined as '~0U`. */ + if (mask == SND_CTL_EVENT_MASK_REMOVE) { + /* NOTE: Unless we remove the pointer to melem from the linked-list at + * private_data of helem, an assertion will be hit in alsa-lib since + * the list is not empty. */ + snd_mixer_elem_detach(melem, helem); + } else if (mask & SND_CTL_EVENT_MASK_ADD) { snd_ctl_elem_iface_t iface = snd_hctl_elem_get_interface(helem); if (iface == SND_CTL_ELEM_IFACE_CARD || iface == SND_CTL_ELEM_IFACE_PCM) { snd_mixer_elem_t *new_melem; View it on GitLab: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/commit/4bdf4c99662f3da0e58d6c04bafff95d84362922 -- View it on GitLab: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/commit/4bdf4c99662f3da0e58d6c04bafff95d84362922 You're receiving this email because of your account on gitlab.freedesktop.org.
