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authorAmadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>2019-05-13 11:18:01 +0200
committerTakashi Iwai <tiwai@suse.de>2019-05-13 14:41:56 +0200
commited180abba7f1fc3cf04ffa27767b1bcc8e8c842a (patch)
tree5e740e02d4fd92f1721d12ef0a7b0012d76b54a8
parent891afcf2462d2cc4ef7caf94215358ca61fa32cb (diff)
downloadlinux-ed180abba7f1fc3cf04ffa27767b1bcc8e8c842a.tar.bz2
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: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--include/sound/hdaudio.h1
-rw-r--r--sound/hda/hdac_device.c7
-rw-r--r--sound/hda/hdac_sysfs.c3
3 files changed, 11 insertions, 0 deletions
diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h
index ca1d9a70d026..5a9315af2d37 100644
--- a/include/sound/hdaudio.h
+++ b/include/sound/hdaudio.h
@@ -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 */
diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c
index 95b073ee4b32..4769f4c03e14 100644
--- a/sound/hda/hdac_device.c
+++ b/sound/hda/hdac_device.c
@@ -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;
}
diff --git a/sound/hda/hdac_sysfs.c b/sound/hda/hdac_sysfs.c
index fb2aa344981e..909d5ef1179c 100644
--- a/sound/hda/hdac_sysfs.c
+++ b/sound/hda/hdac_sysfs.c
@@ -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)
{