git: a4a473104ec4 - releng/14.1 - sound: Remove nmix variable from mixer_oss_mixerinfo()
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Date: Wed, 22 May 2024 13:23:14 UTC
The branch releng/14.1 has been updated by christos: URL: https://cgit.FreeBSD.org/src/commit/?id=a4a473104ec4a42c66f1b9a09736954ebad43e7e commit a4a473104ec4a42c66f1b9a09736954ebad43e7e Author: Christos Margiolis <christos@FreeBSD.org> AuthorDate: 2024-05-09 19:07:48 +0000 Commit: Christos Margiolis <christos@FreeBSD.org> CommitDate: 2024-05-22 13:20:42 +0000 sound: Remove nmix variable from mixer_oss_mixerinfo() nmix is used to compare against oss_mixerinfo->dev, which is a user-supplied value to select the mixer device (if not -1, in which case we'll select the default one) we want to fetch the information of. It is also used to set oss_mixerinfo->dev in case it is -1. However, nmix is at best redundant, since we have the loop counter already (i), and confusing at worst. For example, suppose a system with 3 mixer devices. We call SNDCTL_MIXERINFO with oss_mixerinfo->dev=1, meaning we want to get information for /dev/mixer1. Suppose /dev/mixer0 detaches while inside the loop, so we'll hit the loop's "continue" case, and nmix won't get incremented (i.e will stay 0 for now). At this point nmix counts 1 device less, so when it reaches 1, we'll be fetching /dev/mixer2's information instead of /dev/mixer1's. This is also true in case the mixer device disappears prior to the call to mixer_oss_mixerinfo(). Simply remove nmix and use the loop counter to both set oss_mixerinfo->dev and check against it in case a non -1 value is supplied. Sponsored by: The FreeBSD Foundation MFC after: 3 days Reviewed by: dev_submerge.ch Differential Revision: https://reviews.freebsd.org/D45135 (cherry picked from commit 2f31a5eb75f1e47b5c49f574e8ce48d2c863e9d3) (cherry picked from commit 8b4e2ba31d1b171f688cb630f1827ec397ecaacb) Approved by: re (cperciva) --- sys/dev/sound/pcm/mixer.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/sys/dev/sound/pcm/mixer.c b/sys/dev/sound/pcm/mixer.c index 0645089ac503..31a633afb380 100644 --- a/sys/dev/sound/pcm/mixer.c +++ b/sys/dev/sound/pcm/mixer.c @@ -1430,7 +1430,7 @@ mixer_oss_mixerinfo(struct cdev *i_dev, oss_mixerinfo *mi) { struct snddev_info *d; struct snd_mixer *m; - int nmix, i; + int i; /* * If probing the device handling the ioctl, make sure it's a mixer @@ -1441,7 +1441,6 @@ mixer_oss_mixerinfo(struct cdev *i_dev, oss_mixerinfo *mi) d = NULL; m = NULL; - nmix = 0; /* * There's a 1:1 relationship between mixers and PCM devices, so @@ -1461,7 +1460,7 @@ mixer_oss_mixerinfo(struct cdev *i_dev, oss_mixerinfo *mi) if (d->mixer_dev != NULL && d->mixer_dev->si_drv1 != NULL && ((mi->dev == -1 && d->mixer_dev == i_dev) || - mi->dev == nmix)) { + mi->dev == i)) { m = d->mixer_dev->si_drv1; mtx_lock(m->lock); @@ -1473,7 +1472,7 @@ mixer_oss_mixerinfo(struct cdev *i_dev, oss_mixerinfo *mi) * sure to unlock when existing. */ bzero((void *)mi, sizeof(*mi)); - mi->dev = nmix; + mi->dev = i; snprintf(mi->id, sizeof(mi->id), "mixer%d", i); strlcpy(mi->name, m->name, sizeof(mi->name)); mi->modify_counter = m->modify_counter; @@ -1537,8 +1536,7 @@ mixer_oss_mixerinfo(struct cdev *i_dev, oss_mixerinfo *mi) mi->legacy_device = i; */ mtx_unlock(m->lock); - } else - ++nmix; + } PCM_UNLOCK(d);