git: fab137d23462 - stable/14 - sound: Add missing CHN_[UN]LOCKs in sndstat

The branch stable/14 has been updated by christos:

URL: https://cgit.FreeBSD.org/src/commit/?id=fab137d2346252f210417e9dee0ca190d5cbe198

commit fab137d2346252f210417e9dee0ca190d5cbe198
Author:     Christos Margiolis <christos@FreeBSD.org>
AuthorDate: 2024-07-06 18:23:22 +0000
Commit:     Christos Margiolis <christos@FreeBSD.org>
CommitDate: 2024-07-10 16:48:13 +0000

    sound: Add missing CHN_[UN]LOCKs in sndstat
    
    In sndstat_build_sound4_nvlist(), if we have INVARIANTS or
    SND_DIAGNOSTIC enabled, we will hit a lock assertion panic when we call
    CHN_GETVOLUME(). Also lock the channel in the sndstat_prepare_pcm() loop
    for good measure.
    
    Fixes:          bbca3a75bb41 ("sound: Include sound(4) channel information in sndstat nvlist")
    Sponsored by:   The FreeBSD Foundation
    MFC after:      2 days
    Reviewed by:    dev_submerge.ch
    Differential Revision:  https://reviews.freebsd.org/D45898
    
    (cherry picked from commit e850bd36dfda98608432d2459800627d16119fec)
---
 sys/dev/sound/pcm/sndstat.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sys/dev/sound/pcm/sndstat.c b/sys/dev/sound/pcm/sndstat.c
index 5b770810d19b..753531f3694e 100644
--- a/sys/dev/sound/pcm/sndstat.c
+++ b/sys/dev/sound/pcm/sndstat.c
@@ -456,6 +456,8 @@ sndstat_build_sound4_nvlist(struct snddev_info *d, nvlist_t **dip)
 			goto done;
 		}
 
+		CHN_LOCK(c);
+
 		nvlist_add_string(cdi, SNDST_DSPS_SOUND4_CHAN_NAME, c->name);
 		nvlist_add_string(cdi, SNDST_DSPS_SOUND4_CHAN_PARENTCHAN,
 		    c->parentchannel != NULL ? c->parentchannel->name : "");
@@ -537,6 +539,8 @@ sndstat_build_sound4_nvlist(struct snddev_info *d, nvlist_t **dip)
 		sbuf_printf(&sb, "%s]",
 		    (c->direction == PCMDIR_REC) ? "userland" : "hardware");
 
+		CHN_UNLOCK(c);
+
 		sbuf_finish(&sb);
 		nvlist_add_string(cdi, SNDST_DSPS_SOUND4_CHAN_FEEDERCHAIN,
 		    sbuf_data(&sb));
@@ -1230,6 +1234,8 @@ sndstat_prepare_pcm(struct sbuf *s, device_t dev, int verbose)
 		KASSERT(c->bufhard != NULL && c->bufsoft != NULL,
 		    ("hosed pcm channel setup"));
 
+		CHN_LOCK(c);
+
 		sbuf_printf(s, "\n\t");
 
 		sbuf_printf(s, "%s[%s]: ",
@@ -1321,6 +1327,8 @@ sndstat_prepare_pcm(struct sbuf *s, device_t dev, int verbose)
 		}
 		sbuf_printf(s, "{%s}",
 		    (c->direction == PCMDIR_REC) ? "userland" : "hardware");
+
+		CHN_UNLOCK(c);
 	}
 
 	return (0);