Commit ed180abb authored by Amadeusz Sławiński's avatar Amadeusz Sławiński Committed by Takashi Iwai
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ALSA: hda: Fix race between creating and refreshing sysfs entries 

hda_widget_sysfs_reinit() can free underlying codec->widgets structure
on which widget_tree_create() operates. Add locking to prevent such
issues from happening.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110382


Signed-off-by: default avatarAmadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 891afcf2

include/sound/hdaudio.h

+1 −0
Original line number Diff line number Diff line
@@ -81,6 +81,7 @@ struct hdac_device { 
	atomic_t in_pm;		/* suspend/resume being performed */



	/* sysfs */

	struct mutex widget_lock;

	struct hdac_widget_tree *widgets;



	/* regmap */

sound/hda/hdac_device.c

+7 −0
Original line number Diff line number Diff line
@@ -55,6 +55,7 @@ int snd_hdac_device_init(struct hdac_device *codec, struct hdac_bus *bus, 
	codec->bus = bus;

	codec->addr = addr;

	codec->type = HDA_DEV_CORE;

	mutex_init(&codec->widget_lock);

	pm_runtime_set_active(&codec->dev);

	pm_runtime_get_noresume(&codec->dev);

	atomic_set(&codec->in_pm, 0);
@@ -141,7 +142,9 @@ int snd_hdac_device_register(struct hdac_device *codec) 
	err = device_add(&codec->dev);

	if (err < 0)

		return err;

	mutex_lock(&codec->widget_lock);

	err = hda_widget_sysfs_init(codec);

	mutex_unlock(&codec->widget_lock);

	if (err < 0) {

		device_del(&codec->dev);

		return err;
@@ -158,7 +161,9 @@ EXPORT_SYMBOL_GPL(snd_hdac_device_register); 
void snd_hdac_device_unregister(struct hdac_device *codec)

{

	if (device_is_registered(&codec->dev)) {

		mutex_lock(&codec->widget_lock);

		hda_widget_sysfs_exit(codec);

		mutex_unlock(&codec->widget_lock);

		device_del(&codec->dev);

		snd_hdac_bus_remove_device(codec->bus, codec);

	}
@@ -404,7 +409,9 @@ int snd_hdac_refresh_widgets(struct hdac_device *codec, bool sysfs) 
	}



	if (sysfs) {

		mutex_lock(&codec->widget_lock);

		err = hda_widget_sysfs_reinit(codec, start_nid, nums);

		mutex_unlock(&codec->widget_lock);

		if (err < 0)

			return err;

	}

sound/hda/hdac_sysfs.c

+3 −0
Original line number Diff line number Diff line
@@ -395,6 +395,7 @@ static int widget_tree_create(struct hdac_device *codec) 
	return 0;

}



/* call with codec->widget_lock held */

int hda_widget_sysfs_init(struct hdac_device *codec)

{

	int err;
@@ -411,11 +412,13 @@ int hda_widget_sysfs_init(struct hdac_device *codec) 
	return 0;

}



/* call with codec->widget_lock held */

void hda_widget_sysfs_exit(struct hdac_device *codec)

{

	widget_tree_free(codec);

}



/* call with codec->widget_lock held */

int hda_widget_sysfs_reinit(struct hdac_device *codec,

			    hda_nid_t start_nid, int num_nodes)

{

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