git: b18b990d8e7b - main - sound: Wrap dsp_clone() and mixer_clone() with bus_topo_lock()

The branch main has been updated by christos:

URL: https://cgit.FreeBSD.org/src/commit/?id=b18b990d8e7b15d25243d85ea22374dfdde8a18b

commit b18b990d8e7b15d25243d85ea22374dfdde8a18b
Author:     Christos Margiolis <christos@FreeBSD.org>
AuthorDate: 2024-04-28 19:40:29 +0000
Commit:     Christos Margiolis <christos@FreeBSD.org>
CommitDate: 2024-04-28 19:48:24 +0000

    sound: Wrap dsp_clone() and mixer_clone() with bus_topo_lock()
    
    Make sure that the softc isn't freed in between the checks.
    
    Sponsored by:   The FreeBSD Foundation
    MFC after;      1 day
    Reviewed by:    markj
    Differential Revision:  https://reviews.freebsd.org/D44991
---
 sys/dev/sound/pcm/dsp.c   | 2 ++
 sys/dev/sound/pcm/mixer.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/sys/dev/sound/pcm/dsp.c b/sys/dev/sound/pcm/dsp.c
index c5bb27530d2b..df1482d6a97a 100644
--- a/sys/dev/sound/pcm/dsp.c
+++ b/sys/dev/sound/pcm/dsp.c
@@ -2085,6 +2085,7 @@ dsp_clone(void *arg, struct ucred *cred, char *name, int namelen,
 	}
 	return;
 found:
+	bus_topo_lock();
 	d = devclass_get_softc(pcm_devclass, snd_unit);
 	/*
 	 * If we only have a single soundcard attached and we detach it right
@@ -2096,6 +2097,7 @@ found:
 		*dev = d->dsp_dev;
 		dev_ref(*dev);
 	}
+	bus_topo_unlock();
 }
 
 static void
diff --git a/sys/dev/sound/pcm/mixer.c b/sys/dev/sound/pcm/mixer.c
index 33a7eb26606d..2f4a6f4d6395 100644
--- a/sys/dev/sound/pcm/mixer.c
+++ b/sys/dev/sound/pcm/mixer.c
@@ -1377,12 +1377,14 @@ mixer_clone(void *arg,
 	if (*dev != NULL)
 		return;
 	if (strcmp(name, "mixer") == 0) {
+		bus_topo_lock();
 		d = devclass_get_softc(pcm_devclass, snd_unit);
 		/* See related comment in dsp_clone(). */
 		if (d != NULL && PCM_REGISTERED(d) && d->mixer_dev != NULL) {
 			*dev = d->mixer_dev;
 			dev_ref(*dev);
 		}
+		bus_topo_unlock();
 	}
 }