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authorPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>2022-09-19 14:10:40 +0200
committerTakashi Iwai <tiwai@suse.de>2022-09-20 08:08:14 +0200
commitac3467ad7f8734a21b65fa1852316a9b1b8c1fad (patch)
tree0a3e95b90048cd5ec7dd71369021b627eb7d600d /sound/hda
parent53f4f6b4e56d5fb6ef95a7e14c10ec244a79b996 (diff)
downloadlinux-ac3467ad7f8734a21b65fa1852316a9b1b8c1fad.tar.gz
ALSA: hda: ext: fix locking in stream_release
The snd_hdac_ext_stream_release() routine uses the bus reg_lock, but releases it before calling snd_hdac_stream_release() where the bus reg_lock is taken again. This creates a timing window where the link stream release could test an invalid 'opened' boolean status and fail to recouple the host and link parts. Fix by exposing a locked version of snd_hdac_stream_release() and use it without releasing the spinlock. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com> Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com> Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Link: https://lore.kernel.org/r/20220919121041.43463-8-pierre-louis.bossart@linux.intel.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/hda')
-rw-r--r--sound/hda/ext/hdac_ext_stream.c2
-rw-r--r--sound/hda/hdac_stream.c19
2 files changed, 17 insertions, 4 deletions
diff --git a/sound/hda/ext/hdac_ext_stream.c b/sound/hda/ext/hdac_ext_stream.c
index 254df9a67bd2b..9a2bc7e803dd6 100644
--- a/sound/hda/ext/hdac_ext_stream.c
+++ b/sound/hda/ext/hdac_ext_stream.c
@@ -384,8 +384,8 @@ void snd_hdac_ext_stream_release(struct hdac_ext_stream *hext_stream, int type)
spin_lock_irq(&bus->reg_lock);
if (hext_stream->decoupled && !hext_stream->link_locked)
snd_hdac_ext_stream_decouple_locked(bus, hext_stream, false);
+ snd_hdac_stream_release_locked(&hext_stream->hstream);
spin_unlock_irq(&bus->reg_lock);
- snd_hdac_stream_release(&hext_stream->hstream);
break;
case HDAC_EXT_STREAM_TYPE_LINK:
diff --git a/sound/hda/hdac_stream.c b/sound/hda/hdac_stream.c
index c056bcc5543d1..1b8be39c38a96 100644
--- a/sound/hda/hdac_stream.c
+++ b/sound/hda/hdac_stream.c
@@ -366,6 +366,21 @@ struct hdac_stream *snd_hdac_stream_assign(struct hdac_bus *bus,
EXPORT_SYMBOL_GPL(snd_hdac_stream_assign);
/**
+ * snd_hdac_stream_release_locked - release the assigned stream
+ * @azx_dev: HD-audio core stream to release
+ *
+ * Release the stream that has been assigned by snd_hdac_stream_assign().
+ * The bus->reg_lock needs to be taken at a higher level
+ */
+void snd_hdac_stream_release_locked(struct hdac_stream *azx_dev)
+{
+ azx_dev->opened = 0;
+ azx_dev->running = 0;
+ azx_dev->substream = NULL;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_stream_release_locked);
+
+/**
* snd_hdac_stream_release - release the assigned stream
* @azx_dev: HD-audio core stream to release
*
@@ -376,9 +391,7 @@ void snd_hdac_stream_release(struct hdac_stream *azx_dev)
struct hdac_bus *bus = azx_dev->bus;
spin_lock_irq(&bus->reg_lock);
- azx_dev->opened = 0;
- azx_dev->running = 0;
- azx_dev->substream = NULL;
+ snd_hdac_stream_release_locked(azx_dev);
spin_unlock_irq(&bus->reg_lock);
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_release);